Yield and quality of canola seed as affected by stage of maturity at swathing

Abstract

. 2007. Yield and quality of canola seed as affected by stage of maturity at swathing. Can. J. Plant Sci. 87: 13-26. Swathing is an important canola (Brassica napus L.) harvest operation in western Canada. The determination of the optimum timing for this operation is worth considering, as premature swathing may lead to reduced seed yield and quality. Seed yield and quality of three canola cultivars (44A89, AC Excel and Ebony), as affected by two seeding dates and several harvest times (six or eight swathing times and one direct combined treatment) was investigated on a Black Chernozem silty loam soil at Melfort, Saskatchewan, Canada, during 1998, 2000and 2001. Seed yield, weight, protein content (oil-free meal basis) and oil content generally increased with seed development and swathing time. Early seeding was more conducive to achieving higher seed yield, especially in good growing conditions, and resulted in heavier mature seeds with higher oil content. Seed oil composition also changed during seed development. The proportion of oleic (C18:1) and linolenic (C18:3) acids increased, while that of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0), linoleic (C18:2) and arachidic (C20:0) acids decreased. The levels of the long chain fatty acids eicosenoic (C20:1) and erucic (C22:1) acids were unaffected. However, the overall amount of fatty acids synthesized (mg 100 seeds -1 ) increased as seeds matured. Swathing was advantageous over direct combining in preventing weather-induced shattering. . En général, le rendement grainier, le poids, la teneur en protéines (tourteau délipidé) et celle en huile s'améliorent avec le degré de maturité de la graine et le moment où a lieu l'andainage. Des semis hâtifs favorisent un meilleur rendement grainier, surtout quand les conditions de croissance sont propices à cette culture, et donnent des graines plus lourdes et plus riches en huile à maturité. La composition de l'huile évolue également avec le développement de la graine. Ainsi, la proportion des acides oléique (C18:1) et linolénique (C18:3) augmente tandis que celle des acides myristique (C14:0), palmitique (C16:0), palmitoléique (C16:1), stéarique (C18:0), linoléique (C18:2) et arachidique (C20:0) diminue. La concentration des acides gras à chaîne longue comme les acides éicosénoïques (C20:1) et érucique (C22:1) n'est cependant pas affectée. La quantité globale d'acides gras synthétisés (mg par centaine de semences) augmente néanmoins avec la maturité des graines. L'andainage s'avère plus utile que la récolte directe pour prévenir l'égrenage prématuré attribuable aux intempéries.

Pod Shattering: A Homologous Series of Variation Underlying Domestication and an Avenue for Crop Improvement

“…In canola, precipitation was the limiting factor in crop yield, and dry conditions were shown to reduce yield [126]. Strong winds can also have negative effects on yield, because it causes canola pods to shatter, further reducing the yield [126].…”

“…Whereas direct cutting is used to harvest spring crops, swathing is preferred for winter crops, because it minimizes seed loss due to uneven ripening, which is commonly observed in winter crops [125]. Direct cutting is advantageous during rainy and windy seasons, whereas, swathing is preferred in harsh winter conditions, as it protects the crops from frost [126]. Harvest time is also important, as harvesting at the optimum stage of seed development results in higher yield in both winter and spring crops [125,127], and swathing before the crop reaches maturity reduces yield [126].…”

“…Strong winds can also have negative effects on yield, because it causes canola pods to shatter, further reducing the yield [126]. In soybean, high temperatures and low humidity have been reported to increase yield loss due to pod shattering [131,132].…”

“…Direct cutting is advantageous during rainy and windy seasons, whereas, swathing is preferred in harsh winter conditions, as it protects the crops from frost [126]. Harvest time is also important, as harvesting at the optimum stage of seed development results in higher yield in both winter and spring crops [125,127], and swathing before the crop reaches maturity reduces yield [126]. Delayed harvest was found to have adverse effects on yield in other crops including wheat [119], soybean [128], lentil [129], and chickpea [130].…”

“…Delayed harvest was found to have adverse effects on yield in other crops including wheat [119], soybean [128], lentil [129], and chickpea [130]. In addition to harvest time, seeding time also affected crop yield in Brassica, where early seeding gave higher yields [126].…”