Test weight

Abstract: Continued genetic improvement in the ahility of hybrid corn (Zea mays L.) to withstand high plant density stress requires agronomists to periodically reassess optimal plant density and row width. Furthermore, the optimal plant density level and row width for corn grain yield may vary with location, primarily latitude, in the Corn Belt. This study was conducted to evaluate corn grain yield, harvest moisture, test weight, and stalk lodging with modern corn hybrids, as affected by row width and plant density in the northern Corn Belt. At six locations in 1998 and 1999, four hybrids differing in relative maturity, ear type, plant height, and leaf orientation were planted at row widths of 76, 56, and 38 cm and five plant density levels ranging from 56 000 to 90 000 plants ha -1 . Plots were arranged randomly in a split-split plot configuration. Results show that corn grain yield increased 2 and 4% and harvest moisture decreased by a factor of 2.1% when row width was narrowed from 76 cm to 56 cm and 38 cm, respectively. The highest plant density evaluated, 90 000 plants ha -1 , had the highest grain yield. Grain moisture decreased and grain test weight increases slightly as plant density increased. A hybrid × row width interaction was not observed indicating that hybrids that yield well in conventional 76-cm row systems will also yield well in narrow row systems.

Abstract: Crown rot of wheat and barley in the Pacific Northwest is caused by a complex of Fusarium pseudograminearum, F. culmorum, F. avenaceum, Bipolaris sorokiniana, and Microdochium nivale. Yield-loss estimates were made by evaluating yield components on tillers collected from commercial fields and sorted by disease severity classes, and by comparing yields for field plots inoculated with F. pseudograminearum with yields in naturally infested soil. Increasing crown rot severity caused an increase in grain protein content and reduction in grain yield, kernels per head, kernel weight, test weight, tiller height, and straw weight. Crown rot reduced winter wheat yield as much as 1,550 kg/ha (35%, $219/ha) in commercial fields, with a 13-field mean of 9.5% ($51/ha). Inoculation reduced yields as much as 2,630 kg/ha (61%, $372/ha) over that caused by the native pathogen flora. Rain-induced crusting of the soil surface greatly amplified preemergence damping-off caused by F. pseudograminearum. Crown rot caused the greatest losses during seasons of lowest precipitation but also damaged crops under wet conditions. Aboveground symptoms were not always apparent under conditions of moderate infection and yield constraint. Damage from crown rot in the Pacific Northwest is more widespread and damaging than previously recognized.

Abstract: age improves both milling yield and energy density for livestock. Genotypeandenvironmentaremajordeterminantsofplantpheno- Improvement of agronomic traits has been the pritype. Economically important quantitative traits include agronomic mary objective of oat breeders for many years. Breeders characteristics and grain composition. This study examined relationhave also measured and selected for certain grain physiships among agronomic traits and grain composition as influenced by cal traits such as test weight, kernel weight, and groat genotype and environment. Thirty-three oat (Avena sativa L.) geno

Abstract: Genotypes of cereal grains, including winter barley (n = 21), maize (n = 27), oats (n = 14), winter rye (n = 22), winter triticale (n = 21) and winter wheat (n = 29), were assayed for their chemical composition and physical characteristics as part of the collaborative research project referred to as GrainUp. Genotypes of one grain species were grown on the same site, except maize. In general, concentrations of proximate nutrients were not largely different from feed tables. The coefficient of variation (CV) for the ether extract concentration of maize was high because the data pool comprised speciality maize bred for its high oil content. A subset of 8 barley, 20 rye, 20 triticale and 20 wheat samples was analysed to differ significantly in several carbohydrate fractions. Gross energy concentration of cereal grains could be predicted from proximate nutrient concentration with good accuracy. The mean lysine concentration of protein was the highest in oats (4.2 g/16 g N) and the lowest in wheat (2.7 g/16 g N). Significant differences were also detected in the concentrations of macro elements as well as iron, manganese, zinc and copper. Concentrations of arsenic, cadmium and lead were below the limit of detection. The concentration of lower inositol phosphates was low, but some inositol pentaphosphates were detected in all grains. In barley, relatively high inositol tetraphosphate concentration also was found. Intrinsic phytase activity was the highest in rye, followed by triticale, wheat, barley and maize, and it was not detectable in oats. Substantial differences were seen in the thousand seed weight, test weight, falling number and extract viscoelasticity characteristics. The study is a comprehensive overview of the composition of different cereal grain genotypes when grown on the same location. The relevance of the variation in composition for digestibility in different animal species will be subject of other communications.