Texas, USA 2010 - International Herbage Seed Group

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Evaluation of vigour tests for determination of seed storage potential in redclover (Trifolium pratensis L.) and timothy (Phleum pretense L.)L.T. HavstadBioforsk, The Norwegian Institute of Agricultural and Environmental Research, Arable Crop DivisionLandvik, N-4886 Grimstad, Norway. E-mail: lars.havstad@bioforsk.noAbstractThree different seed vigour tests, Accelerated ageing (AA), Germination index (GI) andPolyetylenglycol (PEG), were evaluated with regard to ranking six reference seed lots of timothycv. Grindstad and red clover cv. Lea according to their physiological potential for storage. Theseed reference lots, which all had germination percentages between 70-100%, had sustaineddifferent degrees of ageing before examination. In timothy, both the AA-test and the GI-testmanaged well to separate the low-vigour seed lots, having a poor storage potential, from thehigh-vigour seed lots with better storage longevity. The clearest separation was obtained usingthe GI-test, either as complete test (six out of six seed lots was significantly separated) or as asimplified test (five out of six seed lots was significantly separated). The germination index ofthe two tests was based on counting of germinating seeds either on a daily basis for ten days orafter counting on day 3 and day 5, respectively. Also the AA-test managed to separate five out ofsix seed lots of timothy after optimal treatment for 56 h at 45 o C. In red clover, the AA-test gavethe clearest separation between seed lots. At optimal conditions for 24 h at 43-45 o C, as many asfive of the six red clover seed lots could significantly be separated from each other. Also thePEG-test discriminated well between reference seed lots of both species, but was considered asmore labour-intensive than the two other vigour tests. The recommended seed vigour test fortimothy (simplified GI-test) and red clover (AA-test for 24 h at 43-45 o C) has later been adoptedfor use in practical seed testing routines at the Norwegian National seed laboratory.IntroductionIn the early 2000s Norwegian seed companies had to discard large amount of forage seed,especially of timothy, due to germination losses on storage. In order to minimize losses,methods for ranking seed lots with regard to storage longevity were highly requested by the seedcompanies. Seed vigour tests have earlier been found as good predicators for seed longevity instorage (Wang & Hampton 1991). The maximum seed vigour occurs at physiological maturity,after which vigour decline during ageing on plant and during storage.The aim of the present project was to evaluate three different seed vigour tests, Acceleratedageing (AA), Germination index (GI) and Polyetylenglycol (PEG), with regard to ranking seedlots of timothy (Phleum pretense L.) and red clover (Trifolium pratense L.) according to theirphysiological potential for storage.Materials and methodsSeed reference set89
The seed vigour testing was performed at the seed laboratory at Bioforsk Øst Landvik in 2007.The original seed material used for vigour testing was supplied from commercial production oftimothy cv. Grindstad and red clover cv. Lea. From the original seed lot, seed samples wereartificially aged under humid conditions (about 100% RH in airtight plastic containers) at fourdifferent temperatures (35, 38, 41 and 44 o C) for various incubation periods. After ageing,germination capacity was determined according to ISTA (2008) but with one replicate of 100seed per treatment. In both species, only seed aged at the highest temperature (44 o C) obtained asevere loss of germination capacity during the 82 h incubation period (Figure 1a and 1b). Thus,five samples of both species with different physiological age, incubated for various lengths atthis temperature, was selected as a seed reference set for later use in the seed vigour testingprogramme. The initial germination capacity of the selected reference seed lots (B-F) wasbetween 70-100% as shown in Figure 1 and 2. In addition, seed from the original seed lot (A:untreated seed, 97 % germination in both species) was selected as a reference (i.e. six referencelots in total for each species). According to the different degrees of physiological ageing,reference seed lot F was „oldest‟ (low storage potential) and seed lot A „youngest‟ (high storagepotential).Figure 1. Germination capacity (%) of the selected reference seed lots (marked with greycircles) of a) timothy cv. Grindstad and b) red clover cv. Lea after being aged at differenttemperature and incubation length.Germination index testThe germination index test was carried out as a standard germination test (ISTA 2008) wherefour replicates of 100 seeds of the six reference seed lots of each species were laid out on theJacobsen germination apparatus, but with a more frequent counting regime. The day/nighttemperature was regulated to 25 / 20 o C and 20 / 20 o C for timothy and red clover, respectively.The first registration of emerging seedlings was performed after 2 and 3 days in red clover andtimothy, respectively. New seedlings were then daily counted for 7 days before a last countingafter 10 days completed the registration program. Seed was registered as germinated when thelength of the emerging seedling (timothy) or the total length of radicle and seedling (red clover)was 2 mm or longer. The germination index (GI) was calculated based on the following formula:GI = (number of new seedlings after day n 1 / n 1 ) + (number of new seedlings after day n 2 / n 2 ) +……………. + (number of new seedlings after day n i / n i ).PEG-test90
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Proceedings of the 7th Internationa
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Table of ContentsORAL PRESENTATIONS
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Seed yield components and yield per
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International Herbage Seed Conferen
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16:15 - 16:30 Reliability of salini
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Hotel expense is covered for night
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40,000 were slaves (McDonald, 2007)
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Fig. 1. Texas AgriLife Research and
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$7 billion for cattle, $3 billion f
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principle and encourages both AgriL
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eceived by growers, the above perce
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seed conditioning plants are locate
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Table 4.Hectares of open-field burn
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system, a seed crop is produced fro
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Fig. 1. Land resource areas of Texa
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y land owners. Seed yields are low
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The influence of planting density o
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Simple correlation and regression a
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Variation in seed shattering in a g
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Seed retention (SR) was calculated
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mm160120Precipitation8040020Km h -1
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Young, B. A. (1986). A Source of Re
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Several methods are commonly used f
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Table 3. Effect of the length of ha
Page 49 and 50: Alfalfa seed production in semi-hum
Page 51 and 52: Rather near the meteorological stat
Page 53 and 54: ReferencesBolaños-Aguilar E.D., Hu
Page 55 and 56: ased bioenergy conversion plants wa
Page 57 and 58: Table 1. Average distances required
Page 59 and 60: Figure 1. Optimized locations for 1
Page 61 and 62: Perennial ryegrass (Lolium perenne
Page 63 and 64: Relative Seed Yieldsingle composite
Page 65 and 66: Flowers, M.D.; Hart, J.M.; Young II
Page 67 and 68: Thus, similar to tissue tests, remo
Page 69 and 70: Conclusion:Perhaps our most importa
Page 71 and 72: Modelling critical NDVI curves in p
Page 73 and 74: The five spectral reflectance measu
Page 75 and 76: Harvest loss in ryegrass seed crops
Page 77 and 78: Larger than expected harvest losses
Page 79 and 80: Rolston, P.; Trethewey, J.; McCloy,
Page 81 and 82: Optical sensors have the potential
Page 83 and 84: Figure 2. Seed yield response to ap
Page 85 and 86: Flowers, M. D., Hart, J.M., Young I
Page 87 and 88: In 2010, France has launched the fo
Page 89 and 90: Yield (% maximum)ConclusionThe resu
Page 91 and 92: Plant N uptakeN unavailableSoil nit
Page 93 and 94: Stresses associated with germinatio
Page 95 and 96: correspond to electrical conductivi
Page 97 and 98: applied later in the fall was more
Page 99: Figure 2. Establishment of five ove
Page 103 and 104: Table 1. Germination index (GI) for
Page 105 and 106: Reliability of salinity screening L
Page 107 and 108: AcknowledgmentThis research was sup
Page 109 and 110: Table 2. Greenhouse salinity screen
Page 111 and 112: The seeds were collected from the A
Page 113 and 114: increases germination to its potent
Page 115 and 116: Light, lodging and flag leaves-what
Page 117 and 118: Relative seed yieldSeed yield (kg/h
Page 119 and 120: Hampton, J.G.; Clemence, T.G.A.; He
Page 121 and 122: The seed set is of major importance
Page 123 and 124: In grass species with poor seed ret
Page 125 and 126: support system to optimize fungicid
Page 127 and 128: weather stations in grass seed fiel
Page 129 and 130: ust resistance loci in Lolium peren
Page 131 and 132: Seed yield variation in a red clove
Page 133 and 134: 100Seed yield plant -1 (g)806040200
Page 135 and 136: Marden, J. H. 1984. Remote percepti
Page 137 and 138: Crimson clover seed production in t
Page 139 and 140: Piper, C.V. 1935. Forage plants and
Page 141 and 142: deal of investigation into the caus
Page 143 and 144: genes and subsequent ability to pro
Page 145 and 146: Gatenby, W.A., S.C. Munday-Finch, A
Page 147 and 148: Control of Vulpia myuros in red fes
Page 149 and 150: The strip design provides an opport
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The pot experiments did not reveale
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CharacterWeed abundance1 A few plan
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Jensen, P. K. (2010) Longevity of s
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Effects of intraspecific competitio
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flowering, Gangi accumulated a high
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The seed yield of Gangi was, on ave
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Seed yield components and yield per
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ResultsVariation among populations
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Table 2. Means of total seeds per p
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Ryle, G. J. (1970). Partition of As
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Control of Apion trifolii in red cl
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Number of seeds /inflorescencesimil
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population. However, in spite of th
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Corvallis where they were debearded
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Table 1. Effect of Palisade growth
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Variations on potential and harvest
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Determination of optimum desiccatio
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Relative seed yield (%)Flowers/m225
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Harvesting too soon after peak flow
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Annual ryegrass seed production in
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seed yield, kg/haExtractable Al, mg
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ReferencesHaby, V.A. (1995). Soil m
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Kentucky bluegrass (Poa pratensis L
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urn residue management (Fig. 1 and
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Comparing herbicide selectivity in
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Development of new tetraploid Chlor
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Following 4 (or 5) cycles of select
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Loch, D.S., Rethman, N.F.G. & van N
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KBGcocksfootHykorLofatimothymeadowf
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Figure 2 Relative seed yield (%) se
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and GA 4 . In consequence this inac
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Table 1 The effect of trinexapac-et
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Silberstein, T.B., Young, W.C. III,
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inflorescece number and seed yield
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Germination of Lolium multiflorum g
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Effect of sowing density on seed yi
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y-products of this grass seed crop
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Table 2. Effect of PGR on seed yiel
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Further culm length measurements ga
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chlorophyllometer. Measurements wer
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Table 2. Photosynthesis rate of fla
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Organization of grass seed research
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Path Coefficient and Ridge Regressi
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through y4 (0.133). Increasing y 1
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Newell G.J., Lee B. (1981)Ridge reg
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Relative humidity, seed moisture co
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Ergovaline contents in grasses from
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11.8 % (Central East) to 40.0% (Nor
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ReferencesBony, S. & Delatour, P. (
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Long-term Evaluation of Annual Ryeg
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seed yield. All systems of establis
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Preliminary results after four year
Page 255 and 256:
Casals, Marie-LaureFNAMSImpasse du
Page 257 and 258:
Mao, PeishengForage Seed LabChina A
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Vanasche, DavidVanasche Farm36130 N
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Texas, USA 2010 - International Herbage Seed Group

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