Test-weight and weathering of spring wheat

Late maturity often causes substantial losses in yield and quality of chickpea (Cicer arietinum L.) in the short growing season in western Canada. This study determined optimum harvest management practices to minimize losses due to late maturity. Kabuli chickpea was grown in southwestern Saskatchewan from 2002 to 2004, and seed and straw were harvested with various harvest management practices. Seed yield in 2004 was higher compared with 2002 and 2003, but the 2004 seed samples had a high percentage of shrivelled and green seeds. Seed yield, weight per seed and harvest index (HI) were highest when the crop was directly combined at natural maturity either before or after a killing (-5°C) frost. On average, swathing at early or late maturity stages decreased seed yield, weight per seed and HI significantly compared with direct combine practices. Seeds from the swathing treatments had high percentages of green and shrivelled seeds with high levels of fungal colonization. Both seed and straw from swathing had the poorest feeding quality measured as neutral detergent fibre, acid detergent fibre, and organic matter content and digestibility. Desiccation of chickpea plants with Reglone or low dosages of glyphosate when 80% of pods had turned colour did not advance plant maturity, nor did they affect seed yield or HI compared with direct combine practices. It is concluded that in the short growing season in western Canada, harvest of chickpea at natural maturity either prior to or after a killing frost may optimize the seed yield and quality. Regardless of harvest practices, the quality of both seed and straw in chickpea may be suitable as salvage feed materials for beef livestock. Key words: Cicer arietinum, desiccation, direct-combine, maturity, glyphosate stress, swath, salvage feed

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confidence: 99%

Optimizing harvest schemes to improve yield and feeding quality in chickpea

Gan¹,

Iwaasa²,

Fernandez³

et al. 2008

“…Part of this goal has been achieved through development of screening techniques for sprouting resistance (McCaig and DePauw 1992) and high test weight (Gan et al 2000). However, our understanding of the environmental effects, genetic variation, and potential screening techniques for resistance to colour changes associated with kernel bleaching and loss of vitreousness are minimal.…”

mentioning

confidence: 99%

“…Swanson (1941) was among the first to recognize that the test weight loss results from irreversible swelling of the grain due to moisture absorption, which on drying decreases the packing efficiency. The impact of weathering on the test weight loss of Canadian spring wheat cultivars was discussed in an earlier publication (Gan et al 2000).…”

mentioning

confidence: 99%

Kernel colour changes associated with field weathering of spring wheat.

McCaig¹,

Gan²,

Clarke³

et al. 2006

Self Cite

. Kernel colour changes associated with field weathering of spring wheat. Can. J. Plant Sci. 86: 371-377. The Canadian wheat-grading system is based on visual assessment to estimate end-use quality, both for assignment to classes and to grades within classes. Extensive training and experience are required to accurately interpret visual indicators of quality. Therefore, breeding programs are attempting to develop instrumental techniques to objectively measure visual characteristics of potential new cultivars. The objective of this research was to examine colour changes associated with field weathering of wheat cultivars from the Canada Western Red Spring, Canada Western Amber Durum, and Canada Prairie Spring Red and White classes of wheat, as measured with a portable colorimeter. The class means exhibited colour differences, although the large variability within classes suggests that, used in isolation, colour measurements would not be a satisfactory means of identifying the class of individual samples. Weathering caused an increase in L* (lightness), a decrease in a* (redness), and a slight increase in b* (yellowness), and the effects were similar for all classes. Severe weathering caused loss of vitreousness in addition to bleaching, and the colour measurements reflect the integrated colour changes associated with both effects. Within each class, although there were cultivar differences for colour, the cultivars responded similarly to weathering, suggesting that breeders should simply select lines which exhibit intense, desirable colour prior to weathering. Les obtenteurs s'efforcent donc de mettre au point des techniques instrumentales qui les aideront à quantifier objectivement les paramètres visuels des nouveaux cultivars éventuels. La présente étude avait pour but d'établir les variations de couleur associées à l'altération sur pied de variétés appartenant aux différentes classes de blé (blé roux de printemps de l'Ouest canadien, blé dur ambré de l'Ouest canadien, blé roux de printemps des Prairies et blé blanc) au moyen d'un colorimètre portatif. La couleur moyenne des différentes classes varie effectivement, mais la forte variabilité au sein de chaque classe laisse supposer qu'employés séparément, les relevés colorimétriques ne permettraient pas d'identifier de manière satisfaisante la classe des échantillons. L'altération sur pied entraîne une hausse de L* (luminosité), une baisse de a* (rouge) et une légère hausse de b* (jaune) dans toutes les classes. Une grave altération pourrait entraîner la perte de la vitrosité et le blanchiment du grain, de sorte que les valeurs reflèteraient le changement de couleur général associé à ces deux conséquences. Bien qu'ils présentent des différences de couleur, les cultivars de chaque classe réagissent de la même façon à l'altération sur pied, signe que les obtenteurs devraient se contenter de sélectionner les lignées ayant la couleur souhaitée la plus vive avant l'altération sur pied.

“…Rainfall just prior to harvest reduces test weight of wheat (Swanson 1943;Czarnecki and Evans 1986), which leads to reduction of commercial grades and economic loss to wheat producers (Gan et al 2000). Gan et al (2000) concluded from a study of durum and common wheat cultivars that the best strategy to deal with rainfallinduced test weight loss would be to select for high test weight in the absence of weather damage, which would contribute to high test weight following weathering.…”

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confidence: 99%

“…Gan et al (2000) concluded from a study of durum and common wheat cultivars that the best strategy to deal with rainfallinduced test weight loss would be to select for high test weight in the absence of weather damage, which would contribute to high test weight following weathering.…”

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confidence: 99%

Inheritance of test weight and kernel weight in eight durum wheat crosses

Clarke¹,

Clarke²,

Pozniak³

et al. 2009

. Inheritance of test weight and kernel weight in eight durum wheat crosses. Can. J. Plant Sci. 89: 1047Á1057. High test weight and uniform kernel size are important grading factors for durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] because both are associated with semolina yield. The objective of this research was to determine the inheritance and heritability of test and kernel weights to facilitate development of selection strategies. Eight durum populations were grown in replicated, multi-location, multi-year field trials. Test weight and kernel weights were determined on all plots after harvest. Both traits were affected by genotype and to a lesser extent by year or location. Genotype environmental interactions were generally minor. Trial means for test weight ranged from 72.7 to 81.0 kg hL (1 and from 31.5 to 50.9 mg for kernel weight. All populations showed bidirectional transgressive segregation for both traits, and the estimated number of effective factors controlling them ranged from 4 to 23, indicating quantitative inheritance. With the exception of one population, heritability of test weight ranged from 0.80 to 0.92 and of kernel weight from 0.83 to 0.93. Both traits generally showed positive phenotypic and genotypic correlations with plant height. Also, mean test weight and kernel weight were higher for the gibberellic acid-sensitive (tall) than for the insensitive (semidwarf) group within populations segregating for gibberellic acid response. ], car tous deux sont lie´s au rendement en semoule. L'e´tude devait e´tablir l'he´re´dite´et l'he´ritabilite´de ces deux facteurs en vue de faciliter l'e´laboration de strate´gies de se´lection. À cette fin, les auteurs ont cultive´huit populations de ble´dur en pleine terre ap lusieurs sites et pendant plusieurs anne´es, avec re´plication. Ils ont mesure´le poids spe´cifique et le poids de l'amande dans toutes les parcelles apre`s la re´colte. Les deux caracte`res sont affecte´s par le ge´notype et dans une moindre mesure par le lieu ou l'anne´e. Les interactions entre le ge´notype et l'environnement sont ge´ne´ralement minimes. Le poids spe´cifique moyen e´tabli lors des essais variait de 72,7 a`81,0 kg par hL tandis que le poids moyen de l'amande fluctuait de 31,5 a`50,9 mg. Les populations pre´sentaient toutes une se´gre´gation transgressive bidirectionnelle pour ces caracte`res. On estime que 4 a2 3 facteurs efficaces les commandent, signe d'une he´re´dite´quantitative. Sauf pour une population, l'he´ritabilite´du poids spe´cifique varie de 0,80 a`0,92 tandis que celle du poids de l'amande fluctue de 0,83 a`0,93. Les deux caracte`res pre´sentent ge´ne´ralement des corre´lations phe´notypiques et ge´notypiques positives avec la taille du plant. D'autre part, chez les populations ou`il y a se´gre´gation de la re´action a`l'acide gibbe´rellique, le poids spe´cifique et le poids de l'amande moyens e´taient plus e´leve´s chez les varie´te´s sensibles a`l'acide gibbe´rellique (cultivars de haute taille) que chez celles qui ne le sont pas (semi-nain...