measurement methods of soil, water, plant and fruit, in berry ... - NJF
measurement methods of soil, water, plant and fruit, in berry ... - NJF
measurement methods of soil, water, plant and fruit, in berry ... - NJF
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<strong>NJF</strong> SEMINAR NO 333<br />
MEASUREMENT METHODS OF SOIL, WATER, PLANT AND<br />
FRUIT, IN BERRY AND FRUIT GROWING<br />
29 – 30 November 2001<br />
The Swedish University <strong>of</strong> Agricultural Sciences, Alnarp, Sweden<br />
BACKGROUND AND OBJECTIVES:<br />
Work<strong>in</strong>g group: Fruit<br />
Optimal content <strong>of</strong> <strong>soil</strong>, <strong>plant</strong> <strong>and</strong> <strong>fruit</strong> constituents, as well as <strong>water</strong> content <strong>of</strong> <strong>soil</strong> is basic<br />
for <strong>fruit</strong> <strong>and</strong> <strong>berry</strong> grow<strong>in</strong>g to get optimal growth, high yield <strong>and</strong> quality. To <strong>in</strong>dicate amount<br />
<strong>of</strong> these constituents by sampl<strong>in</strong>g <strong>and</strong> analys<strong>in</strong>g <strong>soil</strong> <strong>and</strong> <strong>plant</strong> products, several <strong>methods</strong> <strong>and</strong><br />
equipment are used <strong>in</strong> various countries. Also, the results are <strong>of</strong>ten used <strong>in</strong> different ways <strong>and</strong><br />
guidel<strong>in</strong>es by advisors. Thus, it would be excellent if we could f<strong>in</strong>d more uniform sampl<strong>in</strong>g<br />
<strong>methods</strong>, better evaluation <strong>of</strong> results <strong>and</strong> uniform guidel<strong>in</strong>es.<br />
On the other h<strong>and</strong>, several questions about <strong>fruit</strong> <strong>and</strong> <strong>berry</strong> production <strong>and</strong> storage should be<br />
answered accord<strong>in</strong>g to Nordic countries conditions:<br />
How to activate warn<strong>in</strong>g systems to prevent <strong>in</strong>sects <strong>and</strong> fungi attack, by means <strong>of</strong> right use <strong>of</strong><br />
meteorological data?<br />
How to determ<strong>in</strong>e <strong>and</strong> describe optimal quality for storage?<br />
Which k<strong>in</strong>ds <strong>of</strong> <strong>methods</strong> are usable to evaluate w<strong>in</strong>ter hard<strong>in</strong>ess <strong>and</strong> bud quality <strong>in</strong> the cold<br />
Nordic climate that stress the <strong>plant</strong> <strong>and</strong> deteriorate tree <strong>and</strong> bud?<br />
The mean objective <strong>of</strong> the sem<strong>in</strong>ar is to br<strong>in</strong>g together scientists, advisors <strong>and</strong> other persons<br />
work<strong>in</strong>g with <strong>fruit</strong>s <strong>and</strong> berries to discuss problems with <strong>methods</strong> for sampl<strong>in</strong>g <strong>and</strong> analysis,<br />
equipment <strong>and</strong> evaluation <strong>of</strong> the results.<br />
Content:<br />
Nils-Arthur Ericsson. Comparison <strong>of</strong> <strong>soil</strong>-N <strong>and</strong> leaf-N <strong>and</strong> use <strong>of</strong> the hydro N-tester.<br />
Lis Sørensen. Monitor <strong>and</strong> evaluate fertigation with “FertiReg” <strong>in</strong> <strong>fruit</strong> <strong>and</strong> <strong>berry</strong> experiments.<br />
Thomas Olsson. Sampl<strong>in</strong>g, analysis <strong>and</strong> <strong>in</strong>terpretation <strong>of</strong> nutrients levels <strong>in</strong> Apples<br />
Ingemar Månsson. Leaf- or sap analysis? A comparison <strong>of</strong> strong <strong>and</strong> weak po<strong>in</strong>ts.<br />
Marianne Bertelsen. Prelim<strong>in</strong>ary results with Aweta Acoustic Firmness Sensor.<br />
Ibrahim Tahir. Estimation <strong>of</strong> optimum harvest date for apples by more practical method.<br />
Lars Sekse, Ursula Wermund, Sigrid Flatl<strong>and</strong> <strong>and</strong> Eiv<strong>in</strong>d Vangdal. Firmness <strong>in</strong> plumscomparisons<br />
<strong>of</strong> three different test<strong>in</strong>g <strong>methods</strong>.<br />
Kimmo Rumpunen.Protocol for screen<strong>in</strong>g <strong>of</strong> pect<strong>in</strong>s <strong>in</strong> <strong>fruit</strong>s <strong>of</strong> Japanese qu<strong>in</strong>ce<br />
(Chaenomeles japonica).<br />
Christer Tornéus. Meteorological data for warn<strong>in</strong>g systems <strong>and</strong> <strong>fruit</strong> storage.
Ivar Dencker <strong>and</strong> Bjarne Hjelmsted Pedersen. Size <strong>and</strong> <strong>water</strong> content <strong>of</strong> spur buds <strong>in</strong> ‘Lap<strong>in</strong>s’<br />
sweet cherry on 27 different rootstocks. Poster.<br />
Ivar Dencker <strong>and</strong> Torben Toldam Andersen. A methodology for studies <strong>of</strong> dormancy <strong>and</strong><br />
<strong>water</strong> content <strong>of</strong> floral buds <strong>in</strong> sour cherry cv. Stevnsbær. Poster.<br />
Leena L<strong>in</strong>dén, Pauli<strong>in</strong>a Palonen, <strong>and</strong> Timo Hytönen. Evaluation <strong>of</strong> Three Methods to Assess<br />
W<strong>in</strong>terhard<strong>in</strong>ess <strong>of</strong> Straw<strong>berry</strong> Genotypes. Poster.<br />
In memoriam, Nils-Arthur Ericsson.
COMPARISON OF SOIL-N AND LEAF-N AND USE OF THE<br />
HYDRO N-TESTER<br />
Nils-Arthur Ericsson<br />
SLU, Division <strong>of</strong> Top Fruit Grow<strong>in</strong>g<br />
P.O. Box 97, SE-277 21 KIVIK<br />
New grow<strong>in</strong>g systems with precise nutrition via fertigation allow us to regulate the <strong>in</strong>put <strong>of</strong><br />
nutrients to <strong>soil</strong> <strong>and</strong> leaves for optimum shoot <strong>and</strong> <strong>fruit</strong> growth. This can be done both <strong>in</strong><br />
accordance to amount <strong>of</strong> nutrients <strong>and</strong> <strong>in</strong> accordance to different times dur<strong>in</strong>g the season. It is<br />
also obvious that leakage <strong>of</strong> nutrients can be prevented by precise fertigation. This however<br />
needs a rapid estimation <strong>of</strong> the nutrient content <strong>in</strong> leaves. New forms <strong>of</strong> rapid analysis must<br />
be used.<br />
Formerly leaf content <strong>of</strong> m<strong>in</strong>erals was determ<strong>in</strong>ed by dry-matter analysis. The leaves were<br />
sampled <strong>in</strong> august. The results were relatively rough <strong>and</strong> could not be used <strong>in</strong> the orchard<br />
before next year. To day we have other <strong>methods</strong>. Plant Sap analyses is one <strong>of</strong> them. It gives<br />
the content <strong>in</strong> <strong>plant</strong> sap <strong>in</strong> one or two days. Another form <strong>of</strong> estimat<strong>in</strong>g nitrogen <strong>in</strong> leaves is to<br />
estimate the chlorophyll content <strong>in</strong> one way or another.<br />
Optimum shoot <strong>and</strong> <strong>fruit</strong> growth is depend<strong>in</strong>g on maximum transformation <strong>of</strong> sunlight <strong>in</strong>to<br />
available energy. The “bio-catalyst” for this reaction is chlorophyll. Optimum <strong>plant</strong> growth is<br />
therefore related to optimum chlorophyll content <strong>in</strong> leaves. The leaf chlorophyll content can<br />
be measured by ord<strong>in</strong>ary laboratory technique – extraction <strong>and</strong> us<strong>in</strong>g spectrophotometer. The<br />
chlorophyll content can however also be estimated momentarily by The Hydro N-Tester.<br />
This <strong>in</strong>strument measures the light transmittances <strong>of</strong> the leaf at 650 nm <strong>and</strong> 960 nm<br />
wavelength, red <strong>and</strong> near <strong>in</strong>frared chlorophyll absorption.<br />
Results from a trial with fertigation with different amounts <strong>of</strong> nitrogen to apple trees,<br />
cv. Amorosa <strong>and</strong> comparison between <strong>soil</strong>-N <strong>and</strong> leaf-N estimated by different analytical<br />
<strong>methods</strong> are presented at my presentation <strong>in</strong> the sem<strong>in</strong>ar.
MONITOR AND EVALUATE FERTIGATION WITH<br />
“FERTIREG” IN FRUIT AND BERRY EXPERIMENTS<br />
Lis Sørensen<br />
Department <strong>of</strong> Horticulture<br />
Danish Institute <strong>of</strong> Agricultural Sciences<br />
DK-5792 Aarslev, Denmark<br />
Lis.Sorensen@agrsci.dk<br />
Introduction<br />
Fertigation <strong>in</strong> <strong>fruit</strong> <strong>and</strong> <strong>berry</strong> experiments needs to be monitored <strong>and</strong> evaluated repeatedly to<br />
control that the planned strategy is achieved. An Excel spreadsheet, “FertiReg” (Fertigation<br />
Registration), was therefore developed to improve monitor<strong>in</strong>g <strong>and</strong> evaluation <strong>of</strong> fertigation <strong>in</strong><br />
<strong>fruit</strong> <strong>and</strong> <strong>berry</strong> experiments.<br />
Facilities <strong>in</strong> FertiReg<br />
FertiReg is developed for fertigation with Dosatrons. The program <strong>in</strong>cludes sheets that allow<br />
calculations <strong>of</strong> various fertigation factors. Nutrient concentration <strong>in</strong> the stock solution can be<br />
calculated as well as the sett<strong>in</strong>g <strong>of</strong> Dosatrons <strong>and</strong> irrigation time. This is based on expected<br />
number <strong>of</strong> days with irrigation comb<strong>in</strong>ed with <strong>water</strong> <strong>and</strong> nutrient dem<strong>and</strong> <strong>of</strong> the <strong>plant</strong>. Only<br />
<strong>water</strong> gauge read<strong>in</strong>gs are entered <strong>in</strong>to FertiReg dur<strong>in</strong>g the fertigation period. All other<br />
<strong>in</strong>formation can be entered prior to the grow<strong>in</strong>g season. Tables <strong>and</strong> graphs <strong>of</strong> <strong>water</strong> <strong>and</strong><br />
nutrient supply on weekly <strong>and</strong> monthly basis are automatically generated (figure 1). A direct<br />
comparison between the planned <strong>and</strong> achieved fertigation strategy is presented. When<br />
experimental lots are to receive equal amounts <strong>of</strong> <strong>water</strong>, deviations from this can be<br />
monitored on a weekly basis. Tables with <strong>water</strong> <strong>and</strong> nutrient supply can be used when<br />
report<strong>in</strong>g experimental conditions after completion <strong>of</strong> the experiment.<br />
Results <strong>and</strong> conclusion<br />
The first season us<strong>in</strong>g FertiReg was 2001. Improved control <strong>of</strong> the fertigation was achieved<br />
dur<strong>in</strong>g the grow<strong>in</strong>g season. Time was saved as nutrient <strong>and</strong> <strong>water</strong> supply was already<br />
computed for use <strong>in</strong> e.g. lectures or reports. More facilities, e.g. <strong>soil</strong> <strong>water</strong> content, may be<br />
<strong>in</strong>cluded <strong>in</strong> the future. FertiReg can also be used <strong>in</strong> commercial <strong>fruit</strong> production <strong>and</strong> has been<br />
<strong>in</strong>troduced to Danish growers.<br />
Supplied kg N/ha<br />
20.0<br />
18.0<br />
16.0<br />
14.0<br />
12.0<br />
10.0<br />
8.0<br />
6.0<br />
4.0<br />
2.0<br />
0.0<br />
10 15 20 25 30 35 40 45<br />
Week<br />
StrategyA<br />
StrategyB
Figure 1. Graphical presentation <strong>of</strong> weekly nitrogen supply for two fertigation strategies. The graph is<br />
automatically up-dated dur<strong>in</strong>g the grow<strong>in</strong>g season. A maximum <strong>of</strong> six fertilisation treatments can be<br />
h<strong>and</strong>led <strong>in</strong> each file.
SAMPLING, ANALYSIS AND INTERPRETATION<br />
OF NUTRIENTS LEVELS IN APPLES<br />
Thomas Olsson<br />
AnalyCen Nordic AB<br />
Box 9024<br />
291 09 KRISTIANSTAD<br />
email thomas.olsson@analycen.se<br />
Background<br />
Knowledge <strong>of</strong> the nutrient status <strong>in</strong> apples dur<strong>in</strong>g different grow<strong>in</strong>g stages is <strong>of</strong> great<br />
importance s<strong>in</strong>ce it might answer questions regard<strong>in</strong>g malnutrition, fertilisation strategy<br />
sensory quality aspects <strong>and</strong> storability. S<strong>in</strong>ce the f<strong>in</strong>al amount <strong>of</strong> analysed sample is very<br />
small (few grams) much care must be taken on sampl<strong>in</strong>g <strong>and</strong> further subsampl<strong>in</strong>g.<br />
What parameters causes variation?<br />
Representative samples from a given field with one variety must <strong>in</strong>clude variations such as<br />
topography, <strong>soil</strong> chemistry, sunlight as well as <strong>water</strong> exposure. All these parameters will<br />
effect nutrient uptake <strong>and</strong> hence effect analytical results. Another approach is to sample<br />
different subfields with uniform conditions <strong>and</strong> analyse separately, unfortunately at higher<br />
analytical costs. If a field is very heterogeneous regard<strong>in</strong>g <strong>soil</strong> chemistry (ie different <strong>soil</strong><br />
types) this approach is how ever recommended.<br />
Number <strong>of</strong> <strong>in</strong>dividuals.<br />
The number <strong>of</strong> <strong>in</strong>dividuals is a compromise between statistical variations <strong>of</strong> nutrient content<br />
between <strong>in</strong>dividual apples <strong>and</strong> practical h<strong>and</strong>l<strong>in</strong>g <strong>of</strong> the samples regard<strong>in</strong>g transport <strong>and</strong><br />
analytical costs. At earlier grow<strong>in</strong>g stages (<strong>fruit</strong>lets) nutrient variation <strong>in</strong> <strong>in</strong>dividuals vary<br />
more than at more matured stages <strong>and</strong> hence greater number <strong>of</strong> <strong>in</strong>dividuals should be<br />
analysed. A commonly accepted role <strong>of</strong> thumb is 40 <strong>in</strong>dividuals for <strong>fruit</strong>lets <strong>and</strong> 20<br />
<strong>in</strong>dividuals for <strong>fruit</strong>s.<br />
Subsampl<strong>in</strong>g<br />
At the laboratory the sample has to be subsampled <strong>in</strong>to a smaller portion <strong>in</strong> order to be able to<br />
h<strong>and</strong>le it <strong>in</strong> the analytical equipment. From each <strong>in</strong>dividual two opposite slides will be taken<br />
<strong>and</strong> put <strong>in</strong> a blender. The slides will then be thoroughly mixed to homogeneous slurry. For<br />
apples with low <strong>water</strong> content <strong>water</strong> has to be added dur<strong>in</strong>g mix<strong>in</strong>g. The sample is then ready<br />
for further analysis.<br />
Digestion<br />
When analys<strong>in</strong>g for total content <strong>of</strong> nutrients organic matter has to be removed without any<br />
loss <strong>of</strong> nutrients. Different <strong>methods</strong> are used <strong>in</strong>volv<strong>in</strong>g dry ash<strong>in</strong>g, acid digestion, microwave<br />
supported acid digestion. We are us<strong>in</strong>g closed vessels microwave supported acid digestion.<br />
The method gives short digestion times <strong>and</strong> losses can be avoided. The amount <strong>of</strong> samples<br />
actually analysed is from 3 – 20 grams depend<strong>in</strong>g on method used.<br />
Measurement<br />
The f<strong>in</strong>al detection <strong>and</strong> quantification <strong>of</strong> the nutrients are carried out with means <strong>of</strong> ICP-<br />
OES, ICP-MS <strong>and</strong> for nitrogen automatic distillation.<br />
Uncerta<strong>in</strong>ty
The total uncerta<strong>in</strong>ty <strong>in</strong> the results is a comb<strong>in</strong>ation <strong>of</strong> the “errors” aris<strong>in</strong>g <strong>in</strong> the different<br />
steps <strong>in</strong>volved. Studies on how much the different steps is effect<strong>in</strong>g total error have been<br />
performed on different sample types but to my knowledge not specifically on apples.
LEAF- OR SAP ANALYSIS ?<br />
A comparison <strong>of</strong> strong <strong>and</strong> weak po<strong>in</strong>ts<br />
Ingemar Månsson,<br />
LMI AB, Sweden.<br />
Abstract<br />
Leaf analysis is compared with Sap analysis on general pr<strong>in</strong>ciples. The second half <strong>of</strong> the<br />
article is a subjective evaluation <strong>of</strong> strong <strong>and</strong> weak po<strong>in</strong>ts based on 55 years <strong>of</strong> experience.<br />
Background<br />
In all <strong>plant</strong>s nutrients are present <strong>in</strong> 2 forms. Partly as dissolved <strong>in</strong>organic salts, these are raw<br />
material necessary for further growth. Partly as organic products such as prote<strong>in</strong>s, chlorophyll<br />
<strong>and</strong> enzymes.<br />
The conventional leaf-analysis measures everyth<strong>in</strong>g <strong>in</strong> the sample, both raw material <strong>and</strong><br />
f<strong>in</strong>ished products. Results are given / kg dry matter.<br />
Sap analysis measures only the raw material <strong>and</strong> results are given as mg/l.<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
0<br />
Leaf analysis<br />
% or mg/l, does it matter?<br />
Plant material conta<strong>in</strong>s vary<strong>in</strong>g amounts <strong>of</strong> sugar, starch <strong>and</strong> cellulose. These carbohydrates<br />
do not conta<strong>in</strong> <strong>plant</strong> nutrients, but they affect the weight <strong>of</strong> the dry sample.<br />
The practical effect <strong>of</strong> this is that leaf analysis will show lower nutrient levels as<br />
carbohydrates <strong>in</strong>crease. Normally carbohydrate content <strong>in</strong>creases with age, why<br />
optimumlevels <strong>of</strong> nutrients will change drastically dur<strong>in</strong>g the year. This effect is so strong that<br />
it is necessary to strict regulate what parts are to be sampled, also the developementstage has<br />
to be <strong>in</strong>cluded <strong>in</strong> order to evaluate the result. To get reliable references <strong>in</strong>volves a lot <strong>of</strong><br />
analysis <strong>and</strong> work. Specific references for different varieties might be necessary.<br />
Sap analysis is not affected by above variations. Differences <strong>in</strong> reference values between<br />
varieties are rare.<br />
Total content or raw material ?<br />
OPTIMUM VALUES<br />
Sap analysis<br />
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
Leaf analysis shows all nutrients accumulated dur<strong>in</strong>g the lifetime <strong>of</strong> the leafs. In order to<br />
m<strong>in</strong>imise 'history' <strong>and</strong> show the present nutrient situation, the 5:th leaf from the top is <strong>of</strong>ten<br />
chosen as base for the analysis. If a deficiency limits growth it takes time for the leaf analysis<br />
to <strong>in</strong>dicate the reason. Either the leaf has to <strong>in</strong>crease weight, or the limit<strong>in</strong>g nutrient has to be<br />
translocated to other parts <strong>of</strong> the <strong>plant</strong>. Both processes are slow. Excess is shown faster as no<br />
growth is necessary.<br />
Sap analysis measures only <strong>in</strong>organic nutrients. Both deficiencies <strong>and</strong> excesses are shown by<br />
the analysis with<strong>in</strong> days after some change <strong>in</strong> uptake. The changes can be big as levels can<br />
vary between 0 <strong>and</strong> decades above optimum level. For correct evaluation <strong>of</strong> a sample, greater<br />
attention must be directed to the relation between elements.<br />
The <strong>methods</strong> are completely different. Experiences from one method cannot be applied to the<br />
other without caution.<br />
Matchstart<br />
To answer the question <strong>in</strong> the headl<strong>in</strong>e a comparison will be made on some important po<strong>in</strong>ts.<br />
Sampl<strong>in</strong>g<br />
Both <strong>methods</strong> have dem<strong>and</strong>s on what parts has to be sampled. This is more critical for<br />
leafanalysis, where also developementstage has to be identified.<br />
Sap samples should be taken at full turgor <strong>and</strong> without dew or ra<strong>in</strong> on the leafs. This limits<br />
sampl<strong>in</strong>g to suitable weather. After sampl<strong>in</strong>g Sap-samples must be protected aga<strong>in</strong>st<br />
evaporation <strong>and</strong> arrive at the lab with<strong>in</strong> days.<br />
It is easier to take <strong>and</strong> transport a leaf-sample why leaf analysis w<strong>in</strong>s, 1-0.<br />
Time <strong>of</strong> analysis<br />
Sap analysis takes less work <strong>in</strong> the lab <strong>and</strong> thus is normally faster.<br />
Sap analysis w<strong>in</strong>s, 1-1.<br />
References<br />
Worldwide most references are for leafanalysis. On this po<strong>in</strong>t there is no contest.<br />
Leaf analysis w<strong>in</strong>s, 2-1.<br />
Interpretation<br />
In spite <strong>of</strong> the advantage <strong>in</strong> available references for leaf analysis the <strong>in</strong>terpretation <strong>of</strong> sap<br />
analysis is less likely to be wrong.<br />
The sap method is 'error' tolerant as variatons for many elements is big, a small analytical<br />
error does not affect the <strong>in</strong>terpretation.<br />
For a disturbed culture that does not follow 'normal' development, references for leafanalysis<br />
can be directly mislead<strong>in</strong>g.<br />
For iron most scientists agree that leaf-analysis <strong>of</strong>ten show a <strong>in</strong>vers correlation to a visible<br />
deficiensy, whereas sap has a positive correlation.<br />
Sap w<strong>in</strong>s 2-2.<br />
Harvest<br />
As sap shows a more current nutrient status the odds <strong>in</strong>creases that a treatment has positive<br />
effect on the harvest. For a practical grower this is the most important po<strong>in</strong>t.<br />
Sap w<strong>in</strong>s 2-3.<br />
Analysis price<br />
As Sap takes less work <strong>in</strong> the lab the price should be lower.<br />
Sap w<strong>in</strong>s 2-4.
Conclusion<br />
For scientists want<strong>in</strong>g to calculate total nutrient uptake only the leaf analysis can give the<br />
answer.<br />
If the object <strong>of</strong> research is root-uptake, root breath<strong>in</strong>g, ion antagonism a.s.o. the sap method<br />
gives a more direct result.<br />
For long cultures with little ma<strong>in</strong>tenance, such as forestry, short time variations are <strong>of</strong> less<br />
<strong>in</strong>terest <strong>and</strong> leaf analysis is the best choice.<br />
For practical growers <strong>and</strong> advisors work<strong>in</strong>g with <strong>in</strong>tensely ma<strong>in</strong>ta<strong>in</strong>ed crops the Sap analysis<br />
is the best tool.
PRELIMINARY RESULTS WITH AWETA ACOUSTIC<br />
FIRMNESS SENSOR<br />
Marianne Bertelsen<br />
Department <strong>of</strong> Horticulture<br />
Research Centre Aarslev<br />
Danish Institute <strong>of</strong> Agricultural Sciences<br />
Marianne.Bertelsen@agrsci.dk<br />
The grad<strong>in</strong>g company Aweta is currently develop<strong>in</strong>g a firmness sensor (AFS) that employs<br />
sounds as a tool to measure firmness. A probe gently taps the <strong>fruit</strong> <strong>and</strong> the ensu<strong>in</strong>g sound is<br />
picked up by a microphone <strong>and</strong> transformed <strong>in</strong>to a firmness-value. The firmness value is<br />
weight specific <strong>and</strong> the <strong>fruit</strong> is weighed simultaneously with the sound record<strong>in</strong>g. The<br />
University <strong>of</strong> Gent has developed the mathematics beh<strong>in</strong>d the sound to firmness conversion,<br />
but no details were available with the purchase <strong>of</strong> the AFS. The AFS <strong>measurement</strong> is nondestructive,<br />
enabl<strong>in</strong>g consecutive <strong>measurement</strong>s <strong>of</strong> the same <strong>fruit</strong> dur<strong>in</strong>g storage. The AFS is<br />
currently be<strong>in</strong>g tested at different research Institutes, but ultimately it is the goal <strong>of</strong> the<br />
company to equip commercial graders with the AFS.<br />
At Research Centre Aarslev we have tested the AFS as part <strong>of</strong> our st<strong>and</strong>ard <strong>fruit</strong> quality<br />
evaluation program. The equipment is easy to h<strong>and</strong>le <strong>and</strong> large quantities <strong>of</strong> <strong>fruit</strong> can be<br />
h<strong>and</strong>led <strong>in</strong> a short time. Fruit weight is determ<strong>in</strong>ed with a 1-2 g uncerta<strong>in</strong>ty, which suffices for<br />
most purposes. The AFS-value <strong>of</strong> <strong>in</strong>dividual <strong>fruit</strong>s have been found to decl<strong>in</strong>e <strong>in</strong> response to<br />
s<strong>of</strong>ten<strong>in</strong>g <strong>of</strong> the <strong>fruit</strong> under shelf life conditions. For a number <strong>of</strong> apple varieties <strong>and</strong> for the<br />
'Clara Frijs' pear we found no correlation between the AFS-value <strong>and</strong> <strong>fruit</strong> firmness measured<br />
on the peeled <strong>fruit</strong> us<strong>in</strong>g a penetrometer. Despite the lack <strong>of</strong> correlation, the newest version <strong>of</strong><br />
the AFS-program <strong>in</strong>cludes a conversion feature between AFS <strong>and</strong> penetrometer values.<br />
Fruit size appear to affect the AFS value, small <strong>fruit</strong>s exhibit lower AFS-values than large<br />
<strong>fruit</strong>s.<br />
In one case, pear <strong>fruit</strong>s were found to be firmer after 5 days <strong>of</strong> shelf life than they were<br />
straight out <strong>of</strong> cold storage.
ESTIMATION OF OPTIMUM HARVEST DATE FOR APPLES<br />
BY MORE PRACTICAL METHOD<br />
Ibrahim Tahir<br />
SLU, Section <strong>of</strong> Top Fruit Production-Kivik<br />
Box 97, 277 21 Kivik-Sweden<br />
ibrahim.tahir@hvf.slu.se<br />
Pick<strong>in</strong>g <strong>fruit</strong>s <strong>in</strong> optimum date, is the best way to carry out high quality <strong>and</strong> m<strong>in</strong>imum losses<br />
dur<strong>in</strong>g storage. However the determ<strong>in</strong>ation <strong>of</strong> this date is cultivar <strong>and</strong> production-area depend,<br />
<strong>and</strong> this situation causes many difficulties at the choos<strong>in</strong>g <strong>of</strong> the accurate ripen<strong>in</strong>g <strong>in</strong>dex.<br />
Various maturity <strong>in</strong>dexes have been used to estimate the last save harvest date for long- term<br />
storage. Many <strong>in</strong>vestigations showed that ethylene production <strong>and</strong> / or respiration rate were<br />
most useful. Accord<strong>in</strong>g to these results, the long <strong>of</strong> safety period can not be shorter than one<br />
week <strong>and</strong> no longer than four weeks. ( Faragher & Brochier 1981, Liu 1978). Whereas<br />
<strong>measurement</strong> <strong>of</strong> ethylene production is not practical for the growers, many other <strong>in</strong>dexes were<br />
used such as : days from full bloom, flesh firmness, soluble solids concentration, starch test,<br />
acidity, color, sk<strong>in</strong> wax <strong>and</strong> ease <strong>of</strong> separation from spurs. The purpose <strong>of</strong> this work is to<br />
exam<strong>in</strong>e the accuracy <strong>of</strong> three practical ripen<strong>in</strong>g <strong>in</strong>dices ( firmness, solid soluble<br />
concentration <strong>and</strong> starch content ) by correlation with storage results <strong>and</strong> ethylene production.<br />
Material <strong>and</strong> <strong>methods</strong><br />
Fifteen trees / cultivar ( Aroma, Cox´s Orange Pipp<strong>in</strong> <strong>and</strong> Ingrid Marie) were mentioned<br />
r<strong>and</strong>omly <strong>in</strong> Kiviks orchard dur<strong>in</strong>g the seasons 1993 – 1997. Fruits were picked ( 12<br />
<strong>fruit</strong>s/tree) early <strong>in</strong> the morn<strong>in</strong>g twice a week, dur<strong>in</strong>g the period between end <strong>of</strong> August <strong>and</strong><br />
end <strong>of</strong> October. At all <strong>of</strong> pick<strong>in</strong>g times, a lot <strong>of</strong> 30 <strong>fruit</strong>s were analyzed <strong>and</strong> 150 <strong>fruit</strong>s hold on<br />
2-3C , 90% RH. After 15 weeks <strong>of</strong> storage, <strong>fruit</strong>s were removed, quality parameters, fungal<br />
decay, <strong>and</strong> disorders controlled.<br />
Analyses:<br />
Flesh firmness by Penetrometer.<br />
Solid soluble concentration by refrectometer.<br />
Ethylene production by gas chromatography.<br />
Ground <strong>and</strong> superficial color by M<strong>in</strong>olta Chromameter CR 200.<br />
Starch content by Iod<strong>in</strong>e –test.<br />
Acidity by titration.<br />
All data were subjected to analysis <strong>of</strong> variance, us<strong>in</strong>g the Micros<strong>of</strong>t Excel 5 spreadsheet.<br />
Results & Discussion<br />
Dur<strong>in</strong>g the five seasons, the flesh firmness <strong>and</strong> starch content <strong>of</strong> the three cultivars <strong>fruit</strong>s<br />
decreased with maturation as well as solid soluble concentration <strong>in</strong>creased. Our results<br />
showed that there was a period <strong>of</strong> <strong>fruit</strong> development, dist<strong>in</strong>guished by very slow changes <strong>in</strong><br />
these ripen<strong>in</strong>g parameters. This period that was 2- 4 weeks long, <strong>in</strong>tervened two<br />
other development’s phases when the changes <strong>in</strong> the same parameters took place <strong>in</strong> higher<br />
rates.<br />
To control our conclusion <strong>in</strong> correlation with storage results, we found that <strong>fruit</strong>s which<br />
picked dur<strong>in</strong>g these weeks had better storability than other <strong>fruit</strong>s. ( Table 1 – 3 ) However,<br />
slow change <strong>in</strong> the three parameters was not always a good <strong>in</strong>dex to predict storability, s<strong>in</strong>ce<br />
we found <strong>fruit</strong>s with slow change that had bad storability <strong>and</strong> also <strong>fruit</strong>s with faster changes<br />
which had good storability. Due to this problem we shortened the period <strong>and</strong> found that
pick<strong>in</strong>g <strong>fruit</strong>s when the changes <strong>in</strong> these three parameters together took place very slowly,<br />
was the best <strong>in</strong>dex <strong>of</strong> optimum harvest date.<br />
Any <strong>in</strong>creas<strong>in</strong>g <strong>in</strong> the change rate could be a useful <strong>in</strong>dicator to estimate the end <strong>of</strong> safety<br />
harvest period.<br />
On the other h<strong>and</strong>, <strong>in</strong>creas<strong>in</strong>g <strong>of</strong> ethylene production started two weeks later. ( Fig 1-3 )<br />
Pick<strong>in</strong>g <strong>fruit</strong>s <strong>in</strong> this period ( climacteric or post climacteric po<strong>in</strong>t ) <strong>in</strong>creased damaged <strong>fruit</strong>s<br />
by 12,5% ( about 20 000 SEK/ ha ). Also, pick<strong>in</strong>g <strong>fruit</strong>s two weeks earlier caused loss that<br />
reached more than 12 000 SEK/ ha.<br />
F<strong>in</strong>ally, this suggested method, which need more study, can be a primary useful <strong>in</strong>dex for the<br />
grower to safe their yield.<br />
Fig 1. Controll<strong>in</strong>g accuracy <strong>of</strong> harvest date <strong>in</strong>dexes <strong>in</strong> Aroma apples<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
35<br />
30<br />
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3<br />
Decay IEC<br />
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3<br />
Decay IEC<br />
Fig 2. Controll<strong>in</strong>g accuracy <strong>of</strong> harvest date <strong>in</strong>dexes <strong>in</strong> Cox´s Orange Pipp<strong>in</strong> apples
25<br />
20<br />
15<br />
10<br />
5<br />
0<br />
1 2 3 1 2 3 1 2 3 1 2 3 1 2 3<br />
Decay IEC<br />
3. Controll<strong>in</strong>g accuracy <strong>of</strong> harvest date <strong>in</strong>dexes <strong>in</strong> Ingrid Marie apples.<br />
1 = Two weeks earlier 2 = optimum harvest period 3 = Two weeks later
FIRMNESS IN PLUMS – COMPARISONS OF THREE<br />
DIFFERENT TESTING METHODS<br />
Lars Sekse¹, Ursula Wermund², Sigrid Flatl<strong>and</strong>¹ <strong>and</strong> Eiv<strong>in</strong>d Vangdal¹<br />
¹Planteforsk, Ullensvang Research Centre,<br />
N-5781 L<strong>of</strong>thus, Norway<br />
e-mail: lars.Sekse@<strong>plant</strong>eforsk.no<br />
²Imperial College at Wye, University <strong>of</strong> London, Wye,<br />
Ashford, Kent TN25 5AH, UK<br />
Firmness is an important quality factor <strong>in</strong> plums, <strong>of</strong>ten related to taste <strong>and</strong> shelf life. Different<br />
<strong>methods</strong> can be used to measure firmness <strong>in</strong> stone <strong>fruit</strong>s. At Ullensvang Research Centre three<br />
different <strong>in</strong>strumental <strong>methods</strong> to measure firmness were tested dur<strong>in</strong>g the 2001-season, <strong>and</strong><br />
compared to a method judg<strong>in</strong>g firmness press<strong>in</strong>g the <strong>fruit</strong>s between two f<strong>in</strong>gers.<br />
The Dur<strong>of</strong>el ® is a manual Shore-type non-destructive penetrometer that has a plunger <strong>of</strong><br />
diameter 0.25 cm² connected to a sensor measur<strong>in</strong>g the superficial contraction <strong>of</strong> the <strong>fruit</strong><br />
surface.<br />
The PNR10 ® penetrometer has a needle with a sphaeric end with diameter 0.50 mm <strong>and</strong> a<br />
total weight <strong>of</strong> 115 g. The needle is placed <strong>in</strong> vertical position tangentially to the <strong>fruit</strong> surface<br />
<strong>and</strong> is then allowed to penetrate <strong>in</strong>to the <strong>fruit</strong> surface for 15 seconds, driven by its total<br />
weight. The distance measured represents a measure <strong>of</strong> the firmness <strong>of</strong> the <strong>fruit</strong> surface.<br />
Fruit firmness <strong>in</strong> stone <strong>fruit</strong>s can also me measured us<strong>in</strong>g the f<strong>in</strong>gers to gently squeese the<br />
<strong>fruit</strong>, giv<strong>in</strong>g scores for firmness on a scale rat<strong>in</strong>g from e. g. 1-5, where 1 is regarded very<br />
hard, 3 medium <strong>and</strong> 5 very s<strong>of</strong>t.<br />
Fruit firmness <strong>of</strong> ‘Victoria’ plums were measured first with the Dur<strong>of</strong>el ® <strong>in</strong>strument on the<br />
two opposite “cheeks” <strong>of</strong> the <strong>fruit</strong>s. Firmness <strong>of</strong> the same <strong>fruit</strong>s were then measured on<br />
approximately the same location on the <strong>fruit</strong> surface by PNR10 ® . The same <strong>fruit</strong>s were then<br />
tested for firmness by “the two f<strong>in</strong>gers” method.<br />
Comparisons by regression analyses showed that <strong>in</strong>dividual <strong>fruit</strong>s had approximately the same<br />
firmness on each <strong>of</strong> the two cheeks, measured with both Dur<strong>of</strong>el ® <strong>and</strong> PNR10 ® .<br />
When compar<strong>in</strong>g Dur<strong>of</strong>el ® with “the two f<strong>in</strong>gers” method, the results were highly significant<br />
as well, but gave lower value <strong>of</strong> the square <strong>of</strong> the correlation coefficient (R²). Even lower was<br />
the straight l<strong>in</strong>e regression between the results <strong>of</strong> the two f<strong>in</strong>ger method <strong>and</strong> the means <strong>of</strong> the<br />
paired PMR10 ® <strong>measurement</strong>s, but still highly significant.<br />
When compar<strong>in</strong>g the results from the two penetrometers, a clearcut curvature <strong>in</strong> the<br />
regression plot was observed, the straight l<strong>in</strong>e fitt<strong>in</strong>g was high <strong>and</strong> significant, but the<br />
observed results fitted much better to a quadratic regression model account<strong>in</strong>g for the l<strong>in</strong>e<br />
curvature, <strong>and</strong> even better to a model <strong>in</strong>corporat<strong>in</strong>g the logaritmic values <strong>of</strong> the PMR10 ®<br />
<strong>measurement</strong>s.<br />
The results <strong>in</strong>dicate that <strong>fruit</strong> firmness <strong>in</strong> plums measured by the two penetrometers correlates<br />
more or less well with “the two f<strong>in</strong>gers” method, while compar<strong>in</strong>g the two penetrometers<br />
showed that convert<strong>in</strong>g results from one type <strong>of</strong> <strong>measurement</strong> to another can not similarly be<br />
made on the basis <strong>of</strong> straight l<strong>in</strong>e regression fitness.
PROTOCOL FOR SCREENING OF PECTINS IN FRUITS OF<br />
JAPANESE QUINCE (CHAENOMELES JAPONICA)<br />
Kimmo Rumpunen<br />
Balsgård - Department <strong>of</strong> Horticultural Plant Breed<strong>in</strong>g, Swedish University <strong>of</strong><br />
Agricultural Sciences, Fjälkestadsvägen 123-1, 291 94 Kristianstad, Sweden.<br />
Tel.: +46-44-75533; fax: +46-44-75530.<br />
E-mail address: kimmo.rumpunen@hvf.slu.se (K. Rumpunen)<br />
Abstract<br />
An important component <strong>of</strong> <strong>fruit</strong> dietary fibre is pect<strong>in</strong>s, which have well documented health<br />
benefits <strong>and</strong> <strong>in</strong>dustrial applications. Estimat<strong>in</strong>g content <strong>of</strong> pect<strong>in</strong>s <strong>in</strong> <strong>plant</strong> material is,<br />
however, difficult because <strong>of</strong> their complex composition <strong>and</strong> because <strong>of</strong> their association with<br />
other cell wall materials. In this paper a comb<strong>in</strong>ed enzymatic <strong>and</strong> HPLC method is presented,<br />
that recently was validated for analysis <strong>of</strong> galacturonic acid (GalA) <strong>in</strong> alcohol-<strong>in</strong>soluble solids<br />
(AIS), <strong>and</strong> <strong>in</strong> pect<strong>in</strong>s, extracted from <strong>fruit</strong>s <strong>of</strong> Japanese qu<strong>in</strong>ce (Chaenomeles japonica). The<br />
enzymatic/HPLC method proved to be useful as a simple <strong>and</strong> efficient screen<strong>in</strong>g method s<strong>in</strong>ce<br />
a very high correlation was obta<strong>in</strong> between GalA estimates <strong>of</strong> the <strong>fruit</strong> <strong>and</strong> the AIS content <strong>of</strong><br />
acid extracted pect<strong>in</strong>s <strong>in</strong> Japanese qu<strong>in</strong>ce.<br />
Keywords: Alcohol-<strong>in</strong>soluble solids; Galacturonic acid; Pect<strong>in</strong>s; Screen<strong>in</strong>g method; Uronic<br />
acids<br />
Introduction<br />
Pect<strong>in</strong>s are widely used <strong>in</strong> various foods as gell<strong>in</strong>g or thicken<strong>in</strong>g agents, <strong>and</strong> are at present<br />
commercially extracted by hot dilute acid, ma<strong>in</strong>ly from citrus <strong>fruit</strong>s. Pect<strong>in</strong>s are considered as<br />
valuable components <strong>of</strong> dietary fibres s<strong>in</strong>ce they are able to reduce blood plasma cholesterol<br />
levels <strong>and</strong> provide other health benefits to humans (Sungsoo Cho <strong>and</strong> Dreher 2001). Fresh<br />
<strong>fruit</strong>s are a valuable source <strong>of</strong> pect<strong>in</strong>s. The content <strong>of</strong> pect<strong>in</strong>s <strong>in</strong> <strong>fruit</strong>s is therefore important,<br />
<strong>and</strong> should be considered also <strong>in</strong> <strong>plant</strong> breed<strong>in</strong>g.<br />
In breed<strong>in</strong>g, efficient screen<strong>in</strong>g <strong>methods</strong> are needed to enable analysis <strong>of</strong> large number <strong>of</strong><br />
genotypes. Quantitative extraction <strong>of</strong> pect<strong>in</strong>s <strong>in</strong> <strong>plant</strong> material is, however, difficult because<br />
<strong>of</strong> their complicated chemical nature <strong>and</strong> because <strong>of</strong> their association with other cell wall<br />
materials. The extraction method as such affects the yield <strong>and</strong> composition <strong>of</strong> pect<strong>in</strong>s <strong>and</strong><br />
therefore also presents problems <strong>and</strong> may <strong>in</strong>duce artefacts. In those pect<strong>in</strong>s, which are<br />
composed ma<strong>in</strong>ly <strong>of</strong> GalA polymers, e.g. apple pect<strong>in</strong>s (Voragen et al. 1995), analysis <strong>of</strong> the<br />
GalA monomers may be a method to estimate the total amount <strong>of</strong> pect<strong>in</strong>s present <strong>in</strong> the<br />
sample. Furthermore, the content <strong>of</strong> GalA appears to be more stable dur<strong>in</strong>g <strong>fruit</strong> ripen<strong>in</strong>g than<br />
the content <strong>of</strong> extractable pect<strong>in</strong>s (e.g. <strong>in</strong> apple, Fischer <strong>and</strong> Amadò 1994). GalA is usually<br />
analysed colorimetrically after acid hydrolysis (Thibault 1979). The colorimetric method can<br />
only be used for analysis <strong>of</strong> purified samples, which make it less efficient as a screen<strong>in</strong>g<br />
method <strong>in</strong> <strong>plant</strong> breed<strong>in</strong>g, <strong>and</strong> therefore enzymatic <strong>methods</strong> have been advocated.<br />
In this paper a comb<strong>in</strong>ed enzymatic <strong>and</strong> HPLC method is described. The method has<br />
recently been validated for analysis <strong>of</strong> galacturonic acid (GalA) <strong>in</strong> alcohol-<strong>in</strong>soluble<br />
solids (AIS), <strong>and</strong> <strong>in</strong> pect<strong>in</strong>s, extracted from <strong>fruit</strong>s <strong>of</strong> Japanese qu<strong>in</strong>ce (Chaenomeles<br />
japonica) <strong>and</strong> for screen<strong>in</strong>g <strong>of</strong> pect<strong>in</strong>s (Rumpunen et al. 2002). Japanese qu<strong>in</strong>ce is<br />
presently studied <strong>and</strong> developed as a commercial crop <strong>in</strong> a jo<strong>in</strong>t north-European <strong>plant</strong><br />
breed<strong>in</strong>g program. Japanese qu<strong>in</strong>ce is a dwarf shrub belong<strong>in</strong>g to Maloideae
(Rosaceae). It has firm <strong>fruit</strong>s that are rich <strong>in</strong> aroma, juice <strong>and</strong> dietary fibres (Rumpunen<br />
et al. 1998, Thomas et al. 2000).<br />
Protocol<br />
A protocol for the comb<strong>in</strong>ed enzymatic <strong>and</strong> HPLC analysis <strong>of</strong> GalA <strong>in</strong> alcohol-<strong>in</strong>soluble<br />
solids (AIS), pect<strong>in</strong>s <strong>and</strong> <strong>fruit</strong> flesh (as published <strong>in</strong> Rumpunen et al. 2002):<br />
Sample preparation<br />
Pick a representative number <strong>of</strong> <strong>fruit</strong>s, 3-5 may be sufficient. Remove seeds from the fresh<br />
<strong>fruit</strong>s, cut the <strong>fruit</strong>s <strong>in</strong> pieces (appr. 2 cm), mix <strong>and</strong> freeze the sample. Homogenize the sample<br />
while still frozen (e.g. by a Büchi mixer B-400), <strong>and</strong> keep the sample at -20°C until analysis.<br />
Enzymatic degradation<br />
Put triplicates (or duplicates) <strong>of</strong> 2 g <strong>of</strong> homogenized samples <strong>in</strong> test tubes with 5 mL <strong>of</strong> a 2%<br />
solution (<strong>in</strong> distilled <strong>water</strong>) <strong>of</strong> Rapidase ® Press (Gist-brocades 1998) for enzymatic<br />
degradation. For AIS 40 mg, <strong>and</strong> for pect<strong>in</strong> 20 mg, is used <strong>in</strong> duplicates, <strong>and</strong> 2.5 mL <strong>of</strong> the<br />
enzyme solution is added. Shake the test tubes <strong>and</strong> <strong>in</strong>cubate for 3 h at 48°C <strong>in</strong> a <strong>water</strong> bath.<br />
Transfer the slurry to a 200 mL E-flask, <strong>and</strong> make up with 0.0125 M H2SO4. Let st<strong>and</strong> for 10<br />
m<strong>in</strong> <strong>and</strong> filter approximately 2 mL <strong>of</strong> the clear fraction through a 0.45 m Acrodisc particle<br />
filter (GELMAN). Collect the filtered sample directly <strong>in</strong> an HPLC vial.<br />
HPLC assay <strong>of</strong> galacturonic acid<br />
For separation <strong>of</strong> organic acids use an Am<strong>in</strong>ex HPX-87H column, 300 x 7.8 mm (Bio-Rad), a<br />
30 x 4.6 mm guard column (Cation H cartridge, Bio-Rad), <strong>and</strong> a UV-detector (210 nm). Keep<br />
the column temperature at 60°C <strong>and</strong> use 0.0125 M sulphuric acid as mobile phase at an<br />
isocratic flow <strong>of</strong> 0.6 mL per m<strong>in</strong>ute. Identify GalA by compar<strong>in</strong>g retention times with a<br />
st<strong>and</strong>ard. Inject external st<strong>and</strong>ards before <strong>and</strong> after each set <strong>of</strong> 10 samples. Express the GalA<br />
content as anhydrogalacturonic acid (us<strong>in</strong>g the polymeric factor 0.907).<br />
Discussion<br />
The comb<strong>in</strong>ed enzymatic <strong>and</strong> HPLC method has been validated for analysis <strong>of</strong> galacturonic<br />
acid <strong>in</strong> AIS <strong>and</strong> pect<strong>in</strong>s extracted from AIS <strong>of</strong> Japanese qu<strong>in</strong>ce <strong>fruit</strong>s (Rumpunen et al. 2002).<br />
The results <strong>of</strong> the validation <strong>and</strong> its conclusions are here reproduced <strong>and</strong> discussed.<br />
The content <strong>of</strong> alcohol-<strong>in</strong>soluble solids (AIS, roughly correspond<strong>in</strong>g to the content <strong>of</strong> dietary<br />
fibres) was <strong>in</strong> average 30 g/100 g dry weight (3.5 g/100 g fresh weight) <strong>in</strong> <strong>fruit</strong>s <strong>of</strong> Japanese<br />
qu<strong>in</strong>ce. This is similar to previously reported data (Thomas et al. 2000), but much higher than<br />
<strong>in</strong> apple (12.6 g/100 g dry weight or 2 g/100 g fresh weight, Renard et al. 1991; Massiot et al.<br />
1994).<br />
UA <strong>and</strong> GalA <strong>in</strong> AIS<br />
The enzymatic/HPLC <strong>and</strong> colorimetric <strong>methods</strong> appeared to produce directly comparable<br />
estimates <strong>of</strong> UA/GalA <strong>in</strong> AIS s<strong>in</strong>ce no significant difference was detected between the<br />
<strong>methods</strong>, <strong>and</strong> there was no significant <strong>in</strong>teraction between genotype <strong>and</strong> method. AIS <strong>of</strong> the<br />
Japanese qu<strong>in</strong>ce <strong>fruit</strong>s conta<strong>in</strong>ed 20.4% UA, estimated colorimetrically, <strong>and</strong> 20.0% GalA,<br />
estimated by the comb<strong>in</strong>ed enzymatic/HPLC method. However, s<strong>in</strong>ce UA <strong>in</strong> AIS also conta<strong>in</strong><br />
a small amount <strong>of</strong> glucuronic acid (less than 5% <strong>of</strong> total UA, Thomas et al. 2000), <strong>and</strong> the<br />
enzymatic degradation may not be complete (Massiot <strong>and</strong> Renard 1997), slightly higher<br />
estimates were expected from the colorimetric method. The reason that no significant<br />
difference was obta<strong>in</strong>ed between the <strong>methods</strong> could be that the pre-hydrolysis <strong>of</strong> AIS may<br />
have resulted <strong>in</strong> slight degradation <strong>of</strong> the GalA (decarboxylation).
Pect<strong>in</strong>s <strong>in</strong> AIS<br />
The AIS conta<strong>in</strong>ed <strong>in</strong> average 26 g/100 g dry weight acid extractable pect<strong>in</strong>s, correspond<strong>in</strong>g<br />
to a content <strong>in</strong> the <strong>fruit</strong> <strong>of</strong> 0.9 g pect<strong>in</strong>s/100 g fresh weight or 11 g pect<strong>in</strong>s/100 g dry weight.<br />
The range noticed among the genotypes (23.0–30.4 g/100 g dry weight) is large <strong>and</strong> should<br />
make it possible to improve yield through selection <strong>of</strong> genotypes with high content <strong>of</strong> pectic<br />
substances.<br />
UA <strong>and</strong> GalA <strong>in</strong> pect<strong>in</strong>s<br />
There was a significant difference between the <strong>methods</strong> for UA/GalA estimates <strong>in</strong> pect<strong>in</strong>s but<br />
no significant <strong>in</strong>teraction between genotype <strong>and</strong> method. Thus anyone <strong>of</strong> the two <strong>methods</strong><br />
could be used to estimate uronic acids <strong>in</strong> pect<strong>in</strong>s.<br />
In pect<strong>in</strong>s, the content <strong>of</strong> UA was <strong>in</strong> average 63% dw, <strong>and</strong> the content <strong>of</strong> GalA 57% dw. The<br />
reason for the higher estimates obta<strong>in</strong>ed by the colorimetric method (about 10%) may be that<br />
the used enzymes were not able to completely degrade the pect<strong>in</strong>s (Massiot <strong>and</strong> Renard<br />
1997).<br />
GalA <strong>in</strong> <strong>fruit</strong>s<br />
The comb<strong>in</strong>ed enzymatic/HPLC method revealed significant differences between genotypes<br />
<strong>in</strong> content <strong>of</strong> GalA when homogenized frozen <strong>fruit</strong> samples were analysed. The rank<strong>in</strong>g <strong>of</strong> the<br />
genotypes was consistent regardless <strong>of</strong> whether fresh weight or dry weight estimates were<br />
used. Furthermore, the rank<strong>in</strong>g <strong>of</strong> genotypes was also consistent with the rank<strong>in</strong>g <strong>of</strong><br />
genotypes based on content <strong>of</strong> acid extractable pect<strong>in</strong>s.<br />
Correlations<br />
Between content <strong>of</strong> GalA <strong>in</strong> <strong>fruit</strong>s estimated by the comb<strong>in</strong>ed enzymatic/HPLC method, <strong>and</strong><br />
content <strong>of</strong> acid extracted pect<strong>in</strong>s, a high correlation (R=0.89) was obta<strong>in</strong>ed based on dry<br />
weight. Between estimates based on fresh weight an even higher correlation was obta<strong>in</strong>ed<br />
(R=0.93). UA were not assayed colorimetrically <strong>in</strong> fresh <strong>fruit</strong> samples because <strong>of</strong> the presence<br />
<strong>of</strong> <strong>in</strong>terfer<strong>in</strong>g compounds which exclude the colorimetric approach. By contrast, the comb<strong>in</strong>ed<br />
enzymatic/HPLC method is most useful for this purpose. At the same time other important<br />
organic acids like malic <strong>and</strong> succ<strong>in</strong>ic acids can be analysed with this method, thus enabl<strong>in</strong>g<br />
detection <strong>of</strong> multiple compounds <strong>and</strong> reduc<strong>in</strong>g screen<strong>in</strong>g costs.<br />
Selection <strong>of</strong> a proper column for HPLC separation is most important. The Am<strong>in</strong>ex HPX-87H<br />
column produces highly reproducible results, can be used for years with limited ma<strong>in</strong>tenance<br />
<strong>and</strong> provides good separation for a range <strong>of</strong> compounds. However, the Am<strong>in</strong>ex HPX-87H<br />
column has one drawback: citric acid elutes close with GalA, which may cause problem if this<br />
compound is present <strong>in</strong> detectable amount. This problem could be avoided by use <strong>of</strong> another<br />
analytical column.<br />
It would be <strong>in</strong>terest<strong>in</strong>g to validate the comparatively easy <strong>and</strong> fast enzymatic/HPLC method<br />
for analysis <strong>of</strong> other raw materials, e.g. apple. In case <strong>of</strong> apples, there is no reason why the<br />
comb<strong>in</strong>ed enzymatic <strong>and</strong> HPLC method shouldn’t work, s<strong>in</strong>ce it has been shown that pect<strong>in</strong>s<br />
<strong>in</strong> Japanese qu<strong>in</strong>ce are very similar to pect<strong>in</strong>s <strong>in</strong> apples.<br />
Acknowledgements<br />
I thank Dr Maud Thomas, Dr Jean-Francois Thibault <strong>and</strong> Nancy Badilas, INRA, Nantes, who<br />
made the validation <strong>of</strong> the comb<strong>in</strong>ed enzymatic <strong>and</strong> HPLC method possible, <strong>in</strong> a <strong>fruit</strong>ful cooperation.<br />
The cited study was carried out with f<strong>in</strong>ancial support from the Commission <strong>of</strong> the<br />
European Communities, Agriculture <strong>and</strong> Fisheries (FAIR) specific RTD programme, CT 97-<br />
3894, ’Japanese qu<strong>in</strong>ce (Chaenomeles japonica) - a new European <strong>fruit</strong> crop for production <strong>of</strong><br />
juice, flavour <strong>and</strong> fibre’. It does not necessarily reflect its views <strong>and</strong> <strong>in</strong> no way anticipates the<br />
Commission’s future policy <strong>in</strong> this area.
References<br />
FISCHER, M. AND AMADÒ, R. Changes <strong>in</strong> the pectic substances <strong>of</strong> apples dur<strong>in</strong>g<br />
development <strong>and</strong> postharvest ripen<strong>in</strong>g. Part 1: Analysis <strong>of</strong> the alcohol-<strong>in</strong>soluble residue.<br />
Carbohydrate Polymers, 25, 161–166 (1994)<br />
GIST-BROCADES. Rapidase ® Press. Product sheet, 1998/04/29 (1998)<br />
MASSIOT, P. AND RENARD, C. M. G. C. Composition, physiochemical properties <strong>and</strong><br />
enzymatic degradation <strong>of</strong> fibres prepared from different tissues <strong>of</strong> apple. Lebensmittel-<br />
Wissenschaft und -Technologie, 30, 800-806 (1997)<br />
MASSIOT, P., BARON, A. AND DRILLEAU, J. F. Characterisation <strong>and</strong> enzymatic<br />
hydrolysis <strong>of</strong> cell-wall polysaccharides from different tissue zones <strong>of</strong> apple. Carbohydrate<br />
Polymers, 25, 145–154 (1994)<br />
RENARD, C. M. G. C. AND THIBAULT, J. -F. Composition <strong>and</strong> physico-chemical<br />
properties <strong>of</strong> apple fibres from fresh <strong>fruit</strong>s <strong>and</strong> <strong>in</strong>dustrial products. Lebensmittel-Wissenschaft<br />
und -Technologie, 24, 523–527 (1991)<br />
RUMPUNEN, K., KVIKLYS, D., KAUFMANE, E. AND GARKAVA, L. Breed<strong>in</strong>g<br />
Chaenomeles - a new aromatic <strong>fruit</strong> crop. Acta Horticulturae, 484, 211–216 (1998)<br />
RUMPUNEN, K., THOMAS, M., BADILAS, N. AND THIBAULT. J.-F. Validation <strong>of</strong> a<br />
comb<strong>in</strong>ed enzymatic <strong>and</strong> HPLC method for screen<strong>in</strong>g <strong>of</strong> pect<strong>in</strong>s <strong>in</strong> <strong>fruit</strong>s <strong>of</strong> Japanese qu<strong>in</strong>ce<br />
(Chaenomeles japonica). Lebensmittel-Wissenschaft und –Technologie, (2002, <strong>in</strong> press).<br />
SUNGSOO CHO, S. AND DREHER M.L. H<strong>and</strong>book <strong>of</strong> dietary fibre. Marcel Dekker, Inc.,<br />
New York (2001)<br />
THIBAULT, J.-F. Automatisation du dosage des substances pectiques par la methode au<br />
méta-hydroxydiphényl. Lebensmittel-Wissenschaft und -Technologie, 12, 247–251 (1979)<br />
THOMAS, M., CRÉPEAU, M. J. C., RUMPUNEN, K. AND THIBAULT, J.-F. Dietary fibre<br />
<strong>and</strong> cell-wall polysaccharides <strong>in</strong> the <strong>fruit</strong>s <strong>of</strong> Japanese qu<strong>in</strong>ce (Chaenomeles japonica).<br />
Lebensmittel-Wissenschaft und -Technologie, 33, 124–131 (2000)<br />
VORAGEN, A. G. J., PILNIK, W., THIBAULT, J.-F., AXELOS, M. A. V. AND RENARD,<br />
C. M. G. C. Pect<strong>in</strong>s. In: Stephen, A. M, Food Polysaccharides <strong>and</strong> their applications. New<br />
York: Marcel Dekker, pp. 287–339 (1995)
METEOROLOGICAL DATA FOR WARNING SYSTEMS AND<br />
FRUIT STORAGE<br />
Christer Tornéus<br />
Swedish Board <strong>of</strong> Agriculture<br />
christer.tornéus@sjv.se<br />
Summary<br />
Weather data, as a basis for estimat<strong>in</strong>g various biological developments, has become an<br />
important resource <strong>in</strong> our efforts to produce food with more environmental-friendly <strong>methods</strong>.<br />
Several s<strong>of</strong>t wares deal with <strong>plant</strong> diseases <strong>and</strong> pests or are used as decision support tools for<br />
<strong>plant</strong> nutrition management. Some s<strong>of</strong>t wares for weather data presentation <strong>and</strong> disease<br />
prediction are mentioned.<br />
A management system consists <strong>of</strong> three parts; a model based on biological research, a<br />
collect<strong>in</strong>g system for weather data <strong>and</strong> s<strong>of</strong>tware for comb<strong>in</strong><strong>in</strong>g those <strong>in</strong>to a user-friendly<br />
<strong>in</strong>terface.<br />
Ma<strong>in</strong>ly three different types <strong>of</strong> weather stations are used <strong>in</strong> Sweden; Metos, Adcon <strong>and</strong><br />
Campbell. Some discrim<strong>in</strong>at<strong>in</strong>g features are presented. They are used either as st<strong>and</strong>-alone<br />
<strong>in</strong>struments or <strong>in</strong> smaller networks. At least one <strong>of</strong> the systems has options that make it<br />
suitable for storage room monitor<strong>in</strong>g. Weather data can also be obta<strong>in</strong>ed from SMHI<br />
(Swedish Meteorological <strong>and</strong> Hydrological Institute). Whether the sensors should be placed <strong>in</strong><br />
or near the crop, or accord<strong>in</strong>g to the rules for “normal” stations used by public <strong>in</strong>stitutes like<br />
SMHI, is another important issue. A project (Lantmet) is go<strong>in</strong>g on with the ma<strong>in</strong> object to<br />
gather weather data <strong>in</strong> one place <strong>and</strong> make it accessible on the Internet.<br />
Other items discussed <strong>in</strong> this lecture are weak po<strong>in</strong>ts <strong>in</strong> the field part, especially leaf wetness<br />
sensors <strong>and</strong> relative air humidity sensors. Some systems calculate the leaf wetness periods <strong>and</strong><br />
there are two types <strong>of</strong> sensors used, with two different ways <strong>of</strong> present<strong>in</strong>g the leaf wetness<br />
status. The importance <strong>of</strong> high quality system ma<strong>in</strong>tenance <strong>and</strong> a validation system for the<br />
database is also emphasized.
SIZE AND WATER CONTENT OF SPUR BUDS IN ‘LAPINS’<br />
SWEET CHERRY ON 27 DIFFERENT ROOTSTOCKS<br />
Ivar Dencker<br />
KVL, Department <strong>of</strong> Agr. Sci., 2630 Tåstrup, Danmark<br />
Bjarne Hjelmsted Pedersen<br />
DJF, Kirst<strong>in</strong>ebjergvej 10, 5792 Årslev, Danmark<br />
Dur<strong>in</strong>g the last decades many rootstocks have been tested <strong>in</strong> sweet cherry (Prunus avium),<br />
<strong>and</strong> the search for a dwarf<strong>in</strong>g rootstock with good compatibility cont<strong>in</strong>ues <strong>in</strong> rootstock trials<br />
<strong>in</strong> most parts <strong>of</strong> the world. Traditionally, rootstocks are evaluated <strong>in</strong> long-term trials by their<br />
yield efficiency, but it is also known that the rootstock affects both <strong>fruit</strong> set <strong>and</strong> frost<br />
hard<strong>in</strong>ess <strong>of</strong> cherry trees. Fruit set ability is related to floral bud size <strong>in</strong> several tree <strong>fruit</strong><br />
species, <strong>and</strong> the frost hard<strong>in</strong>ess <strong>of</strong> cherry buds depends on their <strong>water</strong> content dur<strong>in</strong>g the<br />
freez<strong>in</strong>g period. The present <strong>in</strong>vestigation was carried out to test the rootstock effect on bud<br />
size <strong>and</strong> bud <strong>water</strong> content <strong>in</strong> 3-year-old sweet cherry cv. Lap<strong>in</strong>s on 27 different rootstocks.<br />
The buds were sampled <strong>in</strong> November 2000 after complete leaf abscission but before the first<br />
night frost. Only lateral buds from spurs shorter than 2 cm were <strong>in</strong>cluded. The spurs were<br />
situated on 2-year-old wood <strong>and</strong> had at least three floral buds. Buds were broken <strong>of</strong>f, put <strong>in</strong>to<br />
sealed plastic tubes, placed directly on ice <strong>and</strong> brought to the lab for fresh <strong>and</strong> dry matter<br />
determ<strong>in</strong>ation.<br />
The average bud size was significantly affected by rootstock <strong>and</strong> ranged between 15 <strong>and</strong> 25<br />
mg dry matter. Many <strong>of</strong> the rootstocks from the Giessen breed<strong>in</strong>g program had very large<br />
buds, the n<strong>in</strong>e rootstocks with the largest buds all be<strong>in</strong>g Gisela selections. Especially, the<br />
Giessen hybrids <strong>of</strong> Prunus canescens turned out to have large buds on the spurs. The two<br />
Czech rootstocks P-HL-A <strong>and</strong> P-HL-B both had very small buds. There was not any clear<br />
relationship between known rootstock vigor <strong>and</strong> bud size. Bud <strong>water</strong> content ranged between<br />
114 <strong>and</strong> 137 (measured as percentage <strong>of</strong> dry matter) <strong>and</strong> was affected by rootstock as well.<br />
The six rootstocks with the highest <strong>water</strong> content were all dwarf<strong>in</strong>g or semi-dwarf<strong>in</strong>g.<br />
Especially Piku 4.20, P-HL-B <strong>and</strong> the Weiroot selections 53 <strong>and</strong> 158 had high <strong>water</strong> contents<br />
<strong>in</strong> the buds, <strong>and</strong> those four could all be separated from 17 rootstocks with a <strong>water</strong> content<br />
below 121 percent. The usability <strong>and</strong> importance <strong>of</strong> early test<strong>in</strong>g <strong>methods</strong> <strong>in</strong> rootstock trials <strong>in</strong><br />
sweet cherry are discussed.
A METHODOLOGY FOR STUDIES OF DORMANCY AND<br />
WATER CONTENT OF FLORAL BUDS IN SOUR CHERRY<br />
CV. STEVNSBÆR<br />
Ivar Dencker, KVL, Agrovej 10, 2630 Taastrup, Danmark<br />
Torben Toldam Andersen, KVL, Agrovej 10, 2630 Taastrup, Danmark<br />
The sour cherry ’Stevnsbær’ suffers severely from bud damages dur<strong>in</strong>g w<strong>in</strong>ter <strong>in</strong> both<br />
Denmark <strong>and</strong> Sweden. The floral mortality may exceed 90 percent on annual shoots. It is now<br />
known that this bud damage can occur already <strong>in</strong> December, be<strong>in</strong>g caused by night frosts <strong>of</strong><br />
only –6 to –9 0 C <strong>in</strong> both year 1999 <strong>and</strong> 2000. It is also known that there is a strong negative<br />
relationship between the <strong>water</strong> content <strong>of</strong> the flower bud <strong>and</strong> the actual frost hard<strong>in</strong>ess. This<br />
experiment was carried out to study the <strong>water</strong> content <strong>and</strong> dormancy <strong>of</strong> flower buds <strong>in</strong><br />
‘Stevnsbær’ dur<strong>in</strong>g autumn <strong>and</strong> early w<strong>in</strong>ter year 2000-2001. In the period August-January,<br />
lateral flower buds were sampled from the base <strong>and</strong> tip <strong>of</strong> annual shoots <strong>of</strong> trees from<br />
different irrigation <strong>and</strong> fertilizer treatments. The buds were put <strong>in</strong>to sealed plastic tubes,<br />
placed on ice <strong>and</strong> immediately brought to the lab for fresh <strong>and</strong> dry matter determ<strong>in</strong>ations.<br />
Furthermore, <strong>in</strong> September-January shoot pieces from the same dates <strong>and</strong> trees as above were<br />
forced for six days at +20 0 C <strong>in</strong> a climate chamber, whereafter the buds were broken <strong>of</strong>f <strong>and</strong><br />
weighed as <strong>in</strong> the field sampl<strong>in</strong>gs. Dur<strong>in</strong>g autumn a major decrease <strong>in</strong> the <strong>water</strong> content <strong>of</strong><br />
flower buds was recorded <strong>in</strong> all treatments. Lateral buds near the shoot tip had a markedly<br />
higher <strong>water</strong> content than buds at the shoot base, <strong>and</strong> this difference persisted throughout the<br />
sampl<strong>in</strong>g period. The forc<strong>in</strong>g <strong>of</strong> buds under optimized grow<strong>in</strong>g conditions showed that buds<br />
rema<strong>in</strong>ed dormant only until the middle <strong>of</strong> November. From late November <strong>and</strong> throughout<br />
the rest <strong>of</strong> the sampl<strong>in</strong>g period forced buds turned green <strong>and</strong> swelled dist<strong>in</strong>ctly, <strong>and</strong><br />
simultaneously such forced buds had a sharp <strong>in</strong>crease <strong>in</strong> <strong>water</strong> content. Bud dormancy was<br />
gone <strong>in</strong> late November <strong>in</strong> all treatments. The lack <strong>of</strong> bud dormancy <strong>in</strong> December may expla<strong>in</strong><br />
the comprehensive bud damages occurr<strong>in</strong>g <strong>in</strong> Stevnsbær: A warm period <strong>in</strong> the beg<strong>in</strong>n<strong>in</strong>g <strong>of</strong><br />
December (as <strong>in</strong> year 2000) may force the buds, <strong>in</strong>creas<strong>in</strong>g their <strong>water</strong> content <strong>and</strong><br />
subsequently a sudden but not very severe freeze (as <strong>in</strong> year 2000) would cause frost<br />
damages. The usability <strong>of</strong> <strong>water</strong> content <strong>measurement</strong>s <strong>in</strong> floral buds to predict frost hard<strong>in</strong>ess<br />
is discussed.<br />
Poster
EVALUATION OF THREE METHODS TO ASSESS<br />
WINTERHARDINESS OF STRAWBERRY GENOTYPES<br />
Leena L<strong>in</strong>dén, Pauli<strong>in</strong>a Palonen, <strong>and</strong> Timo Hytönen<br />
Department <strong>of</strong> Applied Biology, Horticulture, P.O. Box 27,<br />
FIN – 00014 University <strong>of</strong> Hels<strong>in</strong>ki, F<strong>in</strong>l<strong>and</strong><br />
In northern regions, w<strong>in</strong>ter <strong>in</strong>jury is a frequent problem <strong>in</strong> straw<strong>berry</strong> (Fragaria x ananassa<br />
Duch.) production. Controlled freez<strong>in</strong>g tests provide an option for screen<strong>in</strong>g <strong>of</strong> w<strong>in</strong>ter<br />
survival potential <strong>in</strong> different genotypes. In this study, w<strong>in</strong>terhard<strong>in</strong>ess <strong>of</strong> straw<strong>berry</strong><br />
genotypes was evaluated by three low-temperature procedures: an artificial harden<strong>in</strong>gdeharden<strong>in</strong>g-reharden<strong>in</strong>g<br />
program accompanied by freez<strong>in</strong>g tests, prolonged freez<strong>in</strong>g test, <strong>and</strong><br />
cold hard<strong>in</strong>ess <strong>measurement</strong> <strong>of</strong> field-grown <strong>plant</strong>s. Rooted runner cutt<strong>in</strong>gs <strong>of</strong> five Junebear<strong>in</strong>g<br />
straw<strong>berry</strong> cultivars <strong>and</strong> three new selections were tested <strong>in</strong> the course <strong>of</strong> two years.<br />
Relative w<strong>in</strong>terhard<strong>in</strong>ess <strong>of</strong> the genotypes could not be predicted by the harden<strong>in</strong>gdeharden<strong>in</strong>g-reharden<strong>in</strong>g<br />
program employed <strong>in</strong> the present study. Prolonged freez<strong>in</strong>g at –6 ºC<br />
yielded promis<strong>in</strong>g results, whereas storage at –4 ºC <strong>and</strong> –8 ºC failed <strong>in</strong> discrim<strong>in</strong>ation<br />
between genotypes. Field-grown <strong>plant</strong>s were sampled for cold hard<strong>in</strong>ess <strong>measurement</strong>s <strong>in</strong><br />
January, March, <strong>and</strong> April. The genotypes were best differentiated <strong>in</strong> January, at a fully<br />
acclimated state. The results <strong>in</strong>dicate that straw<strong>berry</strong> w<strong>in</strong>terhard<strong>in</strong>ess can be evaluated by<br />
test<strong>in</strong>g differences <strong>in</strong> the ability to survive lengthy exposure to sub-lethal low temperatures, or<br />
by apply<strong>in</strong>g conventional freez<strong>in</strong>g tests to measure cold hard<strong>in</strong>ess <strong>in</strong> different genotypes after<br />
field acclimation.
In Memoriam<br />
Nils-Arthur Ericsson<br />
Med Nils-Arthur Ericsson bortgick den 10 december 2001 en av märkesmännen <strong>in</strong>om svensk<br />
fruktforskn<strong>in</strong>g. Inom sitt fackområde som forskare, lärare, rådgivare och författare åtnjöt han<br />
ett välförtjänt anseende som en av de förnämsta.<br />
För kollegor, som såg honom aktiv <strong>in</strong> i det sista, bl a som organisatör av mötet för nordiska<br />
fruktforskare den 28 november 2001 och det efterfölj<strong>and</strong>e <strong>NJF</strong>-sem<strong>in</strong>ariet "Measurement<br />
<strong>methods</strong> <strong>of</strong> <strong>soil</strong>, <strong>water</strong>, <strong>plant</strong> <strong>and</strong> <strong>fruit</strong>, <strong>in</strong> <strong>berry</strong> <strong>and</strong> <strong>fruit</strong> grow<strong>in</strong>g" den 29-30 november 2001,<br />
kom budskapet om hans bortgång chockartat och oväntat.<br />
Det är svårt att tänka sig att en man som med sådan kraft, energi och glädje drivit<br />
försöksverksamheten i Kivik <strong>in</strong>te längre f<strong>in</strong>ns hos oss. Lika svårt är det att förstå att ett<br />
livsslut ska komma så oväntat. Våra varmaste tankar går till de närmast anhöriga, till hustrun<br />
Kerst<strong>in</strong> och dottern Helén med familj.<br />
Nils-Arthur föddes den 24 april 1934 på familjegården Grytt<strong>in</strong>ge 14 utanför Svalöv.<br />
Föräldrarna var lantbrukare Eric Nilsson och hans hustru Agda. Fadern gick bort när han var<br />
endast fyra år gammal och brodern två, varefter modern ensam drev gården vidare. Att på den<br />
tiden vara både ensamstående mor och egen företagare kan <strong>in</strong>te ha varit lätt. Det vittnar om<br />
stor styrka och envishet, egenskaper som också Nils-Arthur besatt.<br />
Efter studentexamen i Eslöv följde studier vid Lantmannaskolan i Svalöv och<br />
lantbrukshögskolan i Ultuna. Under åren på högskolan komb<strong>in</strong>erade han studierna med en<br />
assistenttjänst på dess lantbrukskemiska <strong>in</strong>stitution. Redan då stod hans håg till kem<strong>in</strong>. Senare<br />
i livet skulle han nyttja dessa kunskaper i forskn<strong>in</strong>gsprojekt kr<strong>in</strong>g fruktens kvalitet och
lagr<strong>in</strong>g, och fruktträdens när<strong>in</strong>gsupptagn<strong>in</strong>g. Under studietiden i Ultuna hjälpte han också<br />
flitigt modern hemma på gården i Skåne.<br />
Det bör också nämnas några ord om Nils-Arthurs militära engagemang. Han genomgick<br />
kadettskolan i L<strong>in</strong>köp<strong>in</strong>g och avancerade därefter till kapten i reserven. Ännu upp i<br />
sextioårsåldern deltog han aktivt i luftvärnets årliga och veckolånga fältövn<strong>in</strong>gar.<br />
Under Ultuna-tiden lärde Nils-Arthur känna s<strong>in</strong> bliv<strong>and</strong>e hustru Kerst<strong>in</strong>. De gifte sig 1963 och<br />
tog året därpå gemensamt över driften av familjegården i Grytt<strong>in</strong>ge. Efter ett antal år som<br />
lantbrukare återvände Nils-Arthur till lantbrukshögskolan, denna gång till Alnarp.<br />
Inkörsporten var en tillfällig anställn<strong>in</strong>g hos universitetslektor Lennart Gröné, som <strong>in</strong>nebar<br />
medverkan i ett projekt rör<strong>and</strong>e skörd och torkn<strong>in</strong>g av lök.<br />
När anställn<strong>in</strong>gen hos lektor Gröné upphörde fanns en vakans vid <strong>in</strong>stitution för frukt- och<br />
bärodl<strong>in</strong>g. I och med att Nils-Arthur erbjöds denna tjänst var hans livsbana utstakad.<br />
Pr<strong>of</strong>essor Fredrik Nilsson, som blev hans mentor och lär<strong>of</strong>ader, ledde honom genast <strong>in</strong> på<br />
området fruktkvalitet och lagr<strong>in</strong>g. Två år senare, vid 36 års ålder, framlade Nils-Arthur s<strong>in</strong><br />
licentiatavh<strong>and</strong>l<strong>in</strong>g på detta tema. Det var under dessa första Alnarps-år som Viktor<br />
Trajkovski lärde känna Nils-Arthur. Gemensam mentor och gemensamma forskarstudier lade<br />
grunden till en varm och livslång vänskap.<br />
Efter licentiatexamen följde 15 år som försöksledare i Alnarp. Under ledn<strong>in</strong>g av pr<strong>of</strong>essor<br />
Ingevald Fernqvist fortsatte Nils-Arthur nu s<strong>in</strong>a kvalitets- och lagr<strong>in</strong>gsstudier parallellt med<br />
de odl<strong>in</strong>gstekniska fältförsöken. Detta breda verksamhetsfält <strong>in</strong>om fruktodl<strong>in</strong>gens alla<br />
områden, i praktik såväl som teori, gav honom en unik och bred kunskap <strong>in</strong>om fackområdet.<br />
Avh<strong>and</strong>l<strong>in</strong>gen "Skördetidpunktens <strong>in</strong>verkan på avkastn<strong>in</strong>g, frukttillväxt och kvalitet hos tre<br />
äpplesorter" försvarades 1982. Nils-Arthur promoverades till agronomie doktor av pr<strong>of</strong>essor<br />
Ingevald Fernqvist, som då var promotor. Tre år efter examen fick han ett sexårigt<br />
förordn<strong>and</strong>e som forskarassistent <strong>in</strong>om ämnet frukt- och bärproduktion. Under denna period<br />
blev han ävenledes kompetensförklarad till pr<strong>of</strong>essuren i ämnet trädgårdsproduktlära vid<br />
Sveriges lantbruksuniversitet (SLU), <strong>in</strong>stitutionen för trädgårdsvetenskap.<br />
Under 1980-talet kom Nils-Arthur också att bli mer och mer engagerad i utbildn<strong>in</strong>gen.<br />
Bl a skrev han ett uppskattat kompendium om produktegenskaper och produktbeh<strong>and</strong>l<strong>in</strong>g hos<br />
frukter och bär. Det var i det sammanhanget som undertecknad Inger Hjalmarsson, i egenskap<br />
av undervisn<strong>in</strong>gsassistent, lärde känna honom närmare. Han ställde alltid upp närhelst hans<br />
gedigna kunskaper efterfrågades i samb<strong>and</strong> med föreläsn<strong>in</strong>gar, sem<strong>in</strong>arier, övn<strong>in</strong>gar,<br />
fältv<strong>and</strong>r<strong>in</strong>gar eller studiebesök. Att arbeta tillsammans med Nils-Arthur var alltid<br />
<strong>in</strong>spirer<strong>and</strong>e och roligt.<br />
Många är de årskurser hortonom- och trädgårds<strong>in</strong>genjörsstuder<strong>and</strong>e som m<strong>in</strong>ns hans<br />
lärargärn<strong>in</strong>g. Som exempel kan nämnas hans uppskattade <strong>in</strong>satser som baskursh<strong>and</strong>ledare i<br />
Glorias fruktodl<strong>in</strong>g. Ännu vid 67 års ålder deltog han i dessa övn<strong>in</strong>gar liksom i föreläsn<strong>in</strong>gar<br />
på frukt- och bärkurserna. Under sistlidna höst försåg han också i sedvanlig ordn<strong>in</strong>g<br />
kursansvariga med frukter till pomologiundervisn<strong>in</strong>gen. Frukterna plockade han själv från<br />
kylarna i Kivik och lade i papperspåsar på vilka han skrev respektive sorts namn. Han hjälpte<br />
också arrangörer av fruktutställn<strong>in</strong>gar med fruktprov. Hans hjälpsamhet och vilja att skapa<br />
"good will" för svensk frukt är omvittnad.<br />
I samb<strong>and</strong> med att Stiftelsen Kiviks försöksstation bildades 1990 utsågs Nils-Arthur att vara<br />
dess verkställ<strong>and</strong>e tjänsteman. Han blev även verksamhets- och vetenskaplig ledare för den
tillämpade forskn<strong>in</strong>gen vid Kivik, en position som han upprätthöll fram till s<strong>in</strong> bortgång.<br />
Kivik kom att bli Nils-Arthurs "hjärtebarn".<br />
Kiviks försöksstation tillkom i slutet av 1960-talet genom <strong>in</strong>itiativ av bl a nu bortgångne dir.<br />
Nils Wikström, vars odl<strong>in</strong>g blev grunden för stationen. Till en början <strong>in</strong>gick den<br />
organisatoriskt i dåvar<strong>and</strong>e södra trädgårdsförsöksdistriktet, men överfördes 1989 till<br />
<strong>in</strong>stitutionen för trädgårdsvetenskap i Alnarp. Redan vid stationens tillkomst var ett av<br />
huvudmålen att kunna provodla lov<strong>and</strong>e Balsgård-sorter i större skala. Sålunda föll det sig<br />
naturligt att stationen 1994 <strong>in</strong>lemmades i <strong>in</strong>stitutionen för hortikulturell<br />
växtförädl<strong>in</strong>g/Balsgård under benämn<strong>in</strong>gen avdeln<strong>in</strong>gen för fruktproduktion i Kivik.<br />
Under Nils-Arthurs ledarskap utvecklades Kiviks försöksverksamhet betydligt. Stor tonvikt<br />
lades vid försök <strong>in</strong>riktade på att m<strong>in</strong>ska användn<strong>in</strong>gen av bekämpn<strong>in</strong>gsmedel. Olika<br />
odl<strong>in</strong>gssystem och fruktsorter testades för såväl IP- som ekologisk odl<strong>in</strong>g. Nils-Arthur<br />
planerade fältförsöken i nära samverkan med fruktodlarna. Jämsides med detta arbete fortsatte<br />
hans forskn<strong>in</strong>g rör<strong>and</strong>e fruktens skörd, lagr<strong>in</strong>g och kvalitet. Han var med om att utarbeta<br />
jodstärkelsetestet till att bli en rut<strong>in</strong>åtgärd för odlarna i deras strävan att bestämma rätt<br />
skördetidpunkt, och tillsammans med Ibrahim Tahir genomförde han för svenskt<br />
vidkomm<strong>and</strong>e banbryt<strong>and</strong>e försök med värmebeh<strong>and</strong>l<strong>in</strong>g av frukt i syfte att förlänga<br />
hållbarheten.<br />
Ibrahim Tahir, hade en ungersk doktorsexamen i bagaget när han kom till Sverige 1992.<br />
Han ville gärna träffa en likas<strong>in</strong>nad forskare och fick rådet att kontakta Nils-Arthur. I ett brev<br />
till denne skrev han "Eftersom jag <strong>in</strong>te kan förstå varför Gud avvisade vår förfader,<br />
Adam från Paradiset bara för att han åt ett äpple, bestämde jag mig för att engagera mig i<br />
äpplenas produktionslära. Idag har jag doktorsexamen <strong>in</strong>om det området utan att varken ha<br />
hittat något svar på m<strong>in</strong> ursprungliga fråga eller ha något jobb". Några dagar senare svarade<br />
Nils-Arthur: "Kom till Malmö så kan vi diskutera båda frågorna".<br />
Ibrahim berättar vidare: "Ända sedan vårt första möte, den 1 september 1992 tills hans<br />
överrask<strong>and</strong>e avsked nu i december, var Nils-Arthur för mig en nära vän, storebror och bästa<br />
rådgivare. Hans lojalitet, uppriktighet, livlighet och vänlighet gjorde så att jag lärde känna<br />
svenskarna och Sverige.<br />
En annan sak som jag också har lärt mig är att en m<strong>in</strong>ut av livet är oerhört värdefullt och får<br />
<strong>in</strong>te slösas. Och en forskare är <strong>in</strong>gen forskare fullt ut om han <strong>in</strong>te även jobbar på fältet. Jag<br />
lärde mig dessutom att tro på ordspråket: De odlade så vi åt, och vi odlar för de kan äta. Hans<br />
avsked har lämnat fruktansvärd sorg och enorm tomhet <strong>in</strong>om mig."<br />
Nils-Arthur var som forskare en synnerligen utåtriktad person. Med stor omsorg välkomnades<br />
alla som ville lära känna hans älskade Kivik. Under årens lopp passerade många besökare -<br />
forskarkollegor från när och fjärran, odlare, studenter, utländska praktikanter, nämnder av<br />
olika slag, SLUs ledn<strong>in</strong>g såväl som departementsråd och -sekreterare. Han såg till att alla fick<br />
en ordentlig genomgång av verksamheten och helst också en kopp kaffe och en god kaka<br />
därtill. Guidn<strong>in</strong>g och server<strong>in</strong>g ombesörjde han själv på bästa sätt.<br />
Det tynger oss att veta att Nils-Arthur gick bort i en tid när framtiden för avdeln<strong>in</strong>gen för<br />
fruktproduktion i Kivik är mer osäker än någons<strong>in</strong>. Han hade förberett kallelse till möte med<br />
rådgiv<strong>and</strong>e gruppen för Stiftelsen Kiviks försöksstation den 5 december 2001, men mötet<br />
måste <strong>in</strong>ställas p g a hans sjukdom. Nils-Arthur hävdade bestämt att en flyttn<strong>in</strong>g av<br />
verksamheten rent fysiskt till Balsgård skulle ta lång tid (10-12 år) och därtill bli en dyrbar
historia. Han menade också att en snabb avveckl<strong>in</strong>g av Kivik skulle <strong>in</strong>nebära slöseri med<br />
samhällets och skattebetalarnas, <strong>in</strong>klusive fruktodlarnas, pengar. Hans högsta önskan var att<br />
fruktodlarna skulle ge sitt stöd - såväl ekonomiskt som moraliskt - till den framtida<br />
verksamheten.<br />
Nils-Arthur lade själv ned ett mycket stort arbete för att säkra Kiviks framtid, <strong>in</strong>te m<strong>in</strong>st<br />
arbetade han ideellt. På fritiden satt han hemma framför datorn - skrev och räknade. Hans<br />
produktion av försöksrapporter och artiklar är imponer<strong>and</strong>e, och vittnar om såväl god<br />
författartalang som stor flit. Vid tiden för s<strong>in</strong> bortgång arbetade han med ett kompendium om<br />
fruktträdens när<strong>in</strong>gsupptagn<strong>in</strong>g och gödsl<strong>in</strong>g på uppdrag från Statens jordbruksverk.<br />
Nils-Arthurs <strong>in</strong>tresse för människor ledde också till <strong>and</strong>ra engagemang. Både <strong>in</strong>om politiken<br />
och svenska kyrkan <strong>in</strong>nehade han förtroendeposter på hemorten. Sålunda <strong>in</strong>gick han sedan<br />
1979 i kommunfullmäktige för centern i Eslövs kommun, och var under ett tiotal år<br />
omväxl<strong>and</strong>e ordför<strong>and</strong>e och vice ordför<strong>and</strong>e i skolstyrelsen. Fr o m 1995 tillhörde han kultur-<br />
och fritidsnämnden.<br />
På s<strong>in</strong> lediga tid, den lilla han unnade sig, njöt han helst av tillvaron tillsammans med<br />
familjen. Gärna i sommarstugan i Brönnestad, där han lekte och odlade upp trädgårdsl<strong>and</strong>et<br />
tillsammans med barnbarnen Anders och Calle. Såsom var<strong>and</strong>e en glad och god skån<strong>in</strong>g var<br />
han också matlagn<strong>in</strong>gs<strong>in</strong>tresserad. Ett av m<strong>in</strong>nena är att bästa marmeladen kokas på 'Re<strong>in</strong>e<br />
Claude Bålnäs'.<br />
Nils-Arthur Ericsson skall i tacksamt m<strong>in</strong>ne bevaras som en livligt <strong>in</strong>tresserad, vidsynt,<br />
mångsidig och synnerligen kunskapsrik fackman. Men han efterlämnar <strong>in</strong>te bara m<strong>in</strong>net av en<br />
skicklig och framgångsrik trädgårdsman, han var också en helgjuten karaktär, en verklig<br />
hedersman i stort som i smått.<br />
Vi är tacksamma för den tid som han funnits bl<strong>and</strong> oss. Till hans m<strong>in</strong>ne har i samråd med<br />
familjen <strong>in</strong>itierats en fond.<br />
Nils-Arthur Ericssons Pomologiska M<strong>in</strong>nesfond<br />
Fondens ändamål är att främja pomologisk kunskap <strong>in</strong>om de områden som låg Nils-Arthur<br />
varmt om hjärtat. Häribl<strong>and</strong> säkr<strong>and</strong>e av det pomologiskt historiska material som genom hans<br />
försorg räddats till eftervärlden. Vidare ska fonden främja kunskap om fruktens kvalitet och<br />
lagr<strong>in</strong>g jämte fruktträdens när<strong>in</strong>gsbehov. Nordiskt samarbete <strong>in</strong>om fruktforskn<strong>in</strong>gen ska också<br />
vara prioriterat.<br />
Alla som vill hedra Nils-Arthurs m<strong>in</strong>ne med ett bidrag till fonden har möjlighet att sätta <strong>in</strong><br />
detta på Bankgironummer: 5361-4350 (N-A Ericssons Pomologiska M<strong>in</strong>nesfond).<br />
Alnarp, Balsgård och Kivik i januari 2002<br />
Inger Hjalmarsson<br />
Ibrahim Tahir<br />
Viktor Trajkovski