measurement methods of soil, water, plant and fruit, in berry ... - NJF

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Conclusion For scientists wanting to calculate total nutrient uptake only the leaf analysis can give the answer. If the object of research is root-uptake, root breathing, ion antagonism a.s.o. the sap method gives a more direct result. For long cultures with little maintenance, such as forestry, short time variations are of less interest and leaf analysis is the best choice. For practical growers and advisors working with intensely maintained crops the Sap analysis is the best tool.
PRELIMINARY RESULTS WITH AWETA ACOUSTIC FIRMNESS SENSOR Marianne Bertelsen Department of Horticulture Research Centre Aarslev Danish Institute of Agricultural Sciences Marianne.Bertelsen@agrsci.dk The grading company Aweta is currently developing a firmness sensor (AFS) that employs sounds as a tool to measure firmness. A probe gently taps the fruit and the ensuing sound is picked up by a microphone and transformed into a firmness-value. The firmness value is weight specific and the fruit is weighed simultaneously with the sound recording. The University of Gent has developed the mathematics behind the sound to firmness conversion, but no details were available with the purchase of the AFS. The AFS measurement is nondestructive, enabling consecutive measurements of the same fruit during storage. The AFS is currently being tested at different research Institutes, but ultimately it is the goal of the company to equip commercial graders with the AFS. At Research Centre Aarslev we have tested the AFS as part of our standard fruit quality evaluation program. The equipment is easy to handle and large quantities of fruit can be handled in a short time. Fruit weight is determined with a 1-2 g uncertainty, which suffices for most purposes. The AFS-value of individual fruits have been found to decline in response to softening of the fruit under shelf life conditions. For a number of apple varieties and for the 'Clara Frijs' pear we found no correlation between the AFS-value and fruit firmness measured on the peeled fruit using a penetrometer. Despite the lack of correlation, the newest version of the AFS-program includes a conversion feature between AFS and penetrometer values. Fruit size appear to affect the AFS value, small fruits exhibit lower AFS-values than large fruits. In one case, pear fruits were found to be firmer after 5 days of shelf life than they were straight out of cold storage.
Page 1 and 2: NJF SEMINAR NO 333 MEASUREMENT METH
Page 3 and 4: COMPARISON OF SOIL-N AND LEAF-N AND
Page 5 and 6: Figure 1. Graphical presentation of
Page 7 and 8: The total uncertainty in the result
Page 9: Leaf analysis shows all nutrients a
Page 13 and 14: picking fruits when the changes in
Page 15 and 16: FIRMNESS IN PLUMS - COMPARISONS OF
Page 17 and 18: (Rosaceae). It has firm fruits that
Page 19 and 20: References FISCHER, M. AND AMADÒ,
Page 21 and 22: SIZE AND WATER CONTENT OF SPUR BUDS
Page 23 and 24: EVALUATION OF THREE METHODS TO ASSE
Page 25 and 26: lagring, och fruktträdens närings
Page 27: historia. Han menade också att en

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