Texas, USA 2010 - International Herbage Seed Group

More documents

Recommendations

Info

The relationship between whole-plant N concentration and N uptake with the NIR band andNDVI was examined across sites using a non-linear procedure in SAS (SAS, 2002). A high Nreference approach (Blackmer and Schepers, 1995) was also examined by determining therelative NIR or NDVI values for each treatment using the mean NIR or NDVI values from thehighest N rate treatment.Results and Discussion:To examine the spectral measurements across site-years the Hyslop 2009 dataset was removeddue to its unusually high whole-plant N concentrations and small N uptake values that resultedfrom poor plant growth in the spring. At the remaining three sites, differences in whole-plant Nconcentration across site-years could be accounted for using a high N fertilizer referenceapproach (Fig. 1a). In addition, the linear plateau model determined a critical whole-plant Nconcentration value of 36 g kg -1 . This critical value is higher than that determined by the tissuetesting analysis (data not shown) and previous studies (Young et al., 1998 and Rowarth et al.,1998). However, the difference among critical values is not likely to be the largest problem withimplementation of this approach. The need to use a high N fertilizer reference strip is likely tobe a much greater obstacle to grower adoption.1.11.0If N Concentration < 36.2 thenRelative NIR = 0.8945 - 0.0106*(36.2 - N Concentration)If N Concentration > 36.2 thenRelative NIR = 0.8945A1.00.8If N Uptake < 143.6 thenNDVI = 0.5751 - 0.0036*(143.6 - N Uptake)If N Uptake > 143.6 thenNDVI = 0.5751BRelative NIR0.90.80.7r 2 = 0.46NDVI0.60.4r 2 = 0.610.60.50 10 20 30 40 50 60Whole-Plant N Concentration (g kg -1 )2007 Hyslop2008 Hyslop2008 Macphearson0.22007 Hyslop2008 Hyslop2008 Macphearson0.00 50 100 150 200 250 300N Uptake (kg N ha -1 )Figure 1. Relationship between nitrogen (N) uptake and relative near infrared (NIR) values (A) or thenormalized difference vegetation index (NDVI; B) at three sites in 2007 and 2008.Unlike the results for whole-plant N concentration, NDVI was able to account for differences inN uptake across site-years without the use of a high N fertilizer reference (Fig 1b). Thisenhances the appeal of using spectral measurements or sensor readings and may increase groweradoption of such techniques. In addition, the critical value determined by the linear plateaumodel is 144 kg N ha -1 . This is similar to the critical N uptake value of 158 kg N ha -1 determinedby the analysis of the tissue tests (data not shown). Thus, both the plant tissue samples andspectral measurements are providing the same information in regards to N uptake.57
Conclusion:Perhaps our most important finding was a strong relationship between NDVI and N uptakeacross site-years (Fig. 1b). This relationship does not depend on the use of a high N referenceand also has a critical value very close to that determined by the analysis of the tissue tests (datanot shown).Our results are very promising and indicate that spectral measurements from aerial images candirectly replace sampling for in-season assessment of N status of perennial ryegrass. This couldhave a major impact in improving the management of N fertilizer in perennial ryegrass grown forseed. Future research should focus on developing and validating a robust model for predictingspring N fertilizer rate as well as examining the many commercial sensor platforms available forproducers.References:Blackmer, T.M. and J.S. Schepers. 1994. Techniques for monitoring crop nitrogen status incorn. Commun. Soil Sci. Plant Anal. 25(9&10):1791-1800.ERDAS. 2006. ERDAS Imagine v. 9.1. Leica Geosystems Geospatial Imaging LLC. Norcross,GA.Flowers, M. R. Weisz, and R. Heiniger. 2001. Remote sensing of winter wheat tiller density forearly nitrogen application decisions. Agron. J. 93:783-789.Gates, D.M., H.J. Keegan, J.C. Schleter, and V.R. Weidner. 1965. Spectral properties of plants.Appl. Optics. 4:11-20.Hart, J.M., M.E. Mellbye, T.B. Silberstein, N.W. Christensen, and W.C. Young III. 2006.Evaluation of the N mineralization test to refine spring nitrogen rate for western Oregon grassseed production. In: W.C. Young III (ed), 2006 <strong>Seed</strong> Production Research at Oregon StateUniversity USDA-ARS Cooperating, Department of Crop and Soil Science Ext/CrS 126, 4/07,Corvallis, OR.Knipling, E.B. 1970. Physical and physiological basis for the reflectance of visible and nearinfraredradiation from vegetation. Remote Sens. Environ. 1:155-159.Rowarth, J.S., B. Boelt, J.G. Hampton, A.H. Marshall, M.P. Rolston, G. Sicard, T.B. Silberstein,J.R. Sedcole, and W.C. Young III. 1998. The relationship between applied nitrogen, nitrogenconcentration in herbage and seed yield in perennial ryegrass (Lolium perenne L.). I. Cv.Grasslands Nui at five sites around the globe. J. of Applied <strong>Seed</strong> Production. 16:105-114.SAS Institute. 2002. SAS version 9.1. SAS Inst., Cary NC.58
Page 1 and 2:
Proceedings of the 7th Internationa
Page 3 and 4:
Table of ContentsORAL PRESENTATIONS
Page 5 and 6:
Seed yield components and yield per
Page 7 and 8:
International Herbage Seed Conferen
Page 9 and 10:
16:15 - 16:30 Reliability of salini
Page 11 and 12:
Hotel expense is covered for night
Page 13 and 14:
40,000 were slaves (McDonald, 2007)
Page 15 and 16:
Fig. 1. Texas AgriLife Research and
Page 17 and 18: $7 billion for cattle, $3 billion f
Page 19 and 20: principle and encourages both AgriL
Page 21 and 22: eceived by growers, the above perce
Page 23 and 24: seed conditioning plants are locate
Page 25 and 26: Table 4.Hectares of open-field burn
Page 27 and 28: system, a seed crop is produced fro
Page 29 and 30: Fig. 1. Land resource areas of Texa
Page 31 and 32: y land owners. Seed yields are low
Page 33 and 34: The influence of planting density o
Page 35 and 36: Simple correlation and regression a
Page 37 and 38: Variation in seed shattering in a g
Page 39 and 40: Seed retention (SR) was calculated
Page 41 and 42: mm160120Precipitation8040020Km h -1
Page 43 and 44: Young, B. A. (1986). A Source of Re
Page 45 and 46: Several methods are commonly used f
Page 47 and 48: 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: Thus, similar to tissue tests, remo
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 and 100: Figure 2. Establishment of five ove
Page 101 and 102: The seed vigour testing was perform
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
Page 151 and 152:
The pot experiments did not reveale
Page 153 and 154:
CharacterWeed abundance1 A few plan
Page 155 and 156:
Jensen, P. K. (2010) Longevity of s
Page 157 and 158:
Effects of intraspecific competitio
Page 159 and 160:
flowering, Gangi accumulated a high
Page 161 and 162:
The seed yield of Gangi was, on ave
Page 163 and 164:
Seed yield components and yield per
Page 165 and 166:
ResultsVariation among populations
Page 167 and 168:
Table 2. Means of total seeds per p
Page 169 and 170:
Ryle, G. J. (1970). Partition of As
Page 171 and 172:
Control of Apion trifolii in red cl
Page 173 and 174:
Number of seeds /inflorescencesimil
Page 175 and 176:
population. However, in spite of th
Page 177 and 178:
Corvallis where they were debearded
Page 179 and 180:
Table 1. Effect of Palisade growth
Page 181 and 182:
Variations on potential and harvest
Page 183 and 184:
Determination of optimum desiccatio
Page 185 and 186:
Relative seed yield (%)Flowers/m225
Page 187 and 188:
Harvesting too soon after peak flow
Page 189 and 190:
Annual ryegrass seed production in
Page 191 and 192:
seed yield, kg/haExtractable Al, mg
Page 193 and 194:
ReferencesHaby, V.A. (1995). Soil m
Page 195 and 196:
Kentucky bluegrass (Poa pratensis L
Page 197 and 198:
urn residue management (Fig. 1 and
Page 199 and 200:
Comparing herbicide selectivity in
Page 201 and 202:
Development of new tetraploid Chlor
Page 203 and 204:
Following 4 (or 5) cycles of select
Page 205 and 206:
Loch, D.S., Rethman, N.F.G. & van N
Page 207 and 208:
KBGcocksfootHykorLofatimothymeadowf
Page 209 and 210:
Figure 2 Relative seed yield (%) se
Page 211 and 212:
and GA 4 . In consequence this inac
Page 213 and 214:
Table 1 The effect of trinexapac-et
Page 215 and 216:
Silberstein, T.B., Young, W.C. III,
Page 217 and 218:
inflorescece number and seed yield
Page 219 and 220:
Germination of Lolium multiflorum g
Page 221 and 222:
Effect of sowing density on seed yi
Page 223 and 224:
y-products of this grass seed crop
Page 225 and 226:
Table 2. Effect of PGR on seed yiel
Page 227 and 228:
Further culm length measurements ga
Page 229 and 230:
chlorophyllometer. Measurements wer
Page 231 and 232:
Table 2. Photosynthesis rate of fla
Page 233 and 234:
Organization of grass seed research
Page 235 and 236:
Path Coefficient and Ridge Regressi
Page 237 and 238:
through y4 (0.133). Increasing y 1
Page 239 and 240:
Newell G.J., Lee B. (1981)Ridge reg
Page 241 and 242:
Relative humidity, seed moisture co
Page 243 and 244:
Ergovaline contents in grasses from
Page 245 and 246:
11.8 % (Central East) to 40.0% (Nor
Page 247 and 248:
ReferencesBony, S. & Delatour, P. (
Page 249 and 250:
Long-term Evaluation of Annual Ryeg
Page 251 and 252:
seed yield. All systems of establis
Page 253 and 254:
Preliminary results after four year
Page 255 and 256:
Casals, Marie-LaureFNAMSImpasse du
Page 257 and 258:
Mao, PeishengForage Seed LabChina A
Page 259 and 260:
Vanasche, DavidVanasche Farm36130 N
show all

Texas, USA 2010 - International Herbage Seed Group

Create successful ePaper yourself

Delete template?

Save as template?