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An experiment was conducted for two years to determine the effect of seeding rate, and nitrogen fertility on the yield and quality of hard red spring wheat (Triticum aestivum L.) in Quebec. The experiment was conducted on a Ste-Rosalie series soil (humic gleysol), in the St-Hyacinthe region, 50 km east of Montreal. The design of the experiment was a split-plot design. The treatments in the main plots were the plant densities while the nitrogen treatments (rate of nitrogen, number and timing of the applications and formulation of fertilizer nitrogen) were applied to the sub-plots. Nitrogen had a significant effect on yields in 1987, but not in 1986. Maximum yield was 6838 kg ha$ sp{-1}$ in 1986 and 3807 kg ha$ sp{-1}$ in 1987. Protein concentration was increased by higher nitrogen rates in both years. The yield and protein concentration were affected by low precipitation in 1987. Applying the nitrogen later in the season increased the protein concentration in both seasons. It also decreased yield in 1987, but this was caused by lack of water in late June and July 1987. Formulation of nitrogen fertilizer did not have an effect on yield and protein content of the crop.

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No description available.

Graduation date: 1994

Graduation date: 1991

The effect of level and timing of nitrogen (N) fertilizer application on grain yield (YLD), grain protein (GPC), and breadmaking ability of four hard red spring wheat cultivars and on soil residual nitrate was investigated. Nitrogen fertility caused an increase in YLD, lodging, several yield components, GPC, and breadmaking quality and caused a reduction in N harvest index and grain ash, and N use efficiency (NUE) resulting in an increase in soil residual NO$ sb3$-N. Split N application reduced lodging, tillers and spikes m$ sp{-2}$ and caused an increase in grain weight, GPC, loaf volume and NUE. Grain yield increases were largely due to increases in the grain spike$ sp{-1}$ and tillers n$ sp{-2}$. Absolute protein content was found to be critical in determining GPC. Cultivars showed plastic responses to N. Despite its high YLD and flour yield, Hege 155-85 may be risky to produce because of its high dependence on N. Mineralization of N occurred during winter. Marked differences existed between the sites.

Wheat improvement most often has been accompanied by a narrowing germplasm base, as newer cultivars have been derived from intercrosses between elite germplasm. However, there is a concern that narrow germplasm may restrict breeding improvement for important traits such as resistances to new biotic and abiotic stresses. In addition to germplasm base, the wheat kernel is a major component of wheat grain yield and an important factor for milling characteristics. Focusing on wheat kernel characteristics might be a key element to improve wheat genotypes for agronomic and quality traits. With the intention to broaden the wheat germplasm, and to explore the associations between kernel traits and agronomic as well as quality traits, a two-year study was initiated in 2009 to examine the influence of the kernel traits on the agronomic and quality attributes of a 160 Recombinant Inbred Lines (RIL) population developed from an adapted (ND 705) and a non-adapted genotype (PI 414566). The experiment was conducted at Prosper and Carrington, North Dakota, during 2009 and 2010. The RIL population had a better performance at Carrington than Prosper due to favorable climatic conditions at this location, in 2009 and 2010. The results in this study showed that kernel traits had a high correlation among them and they exhibited continuous variations suggesting a polygenic inheritance. Grain yield, kernel volume weight (KVW), and flour extraction were highly correlated with kernel width, length/width ratio, weight, and area. Eight RIL yielded better than the adapted parent ND 705 and two of the RIL along with three checks were significantly superior for gram yield compared with the other genotypes across all environments. Although the non-adapted parent has a facultative grown habit, several RIL required fewer days to flower compared to the adapted parent. Two RIL had better flour extraction compared to the other genotypes included in this study. These results indicated that kernel traits can play a significant role in improving agronomic and quality traits. Higher values for grain yield, KVW, and flour extraction were significantly associated with spheroid or round shape (short and plump), large, and heavy kernels. The high agronomic and quality attributes showed by some RIL demonstrated that the use of a non-adapted parent can broaden the genetic variability while increasing the genetic gain for certain traits. Also, breeders should pay attention to kernel size and shape during the parental selection for the development of populations with improved agronomic and quality traits.

No description available.

Winter wheat is commonly grown in dryland cropping systems in the Pacific Northwest region of semi-arid eastern Oregon. For agronomic, economic, and environmental reasons, it is important to understand the long-term sustainability of such dryland systems. The objective of this study was to evaluate the long-term effects of tillage, nitrogen (N), soil depth, and the influence of precipitation on wheat yields in dry land cropping systems of eastern Oregon. Data were taken from the Tillage/Fertility or "Balenger" experiment, which was established in 1940 by a Soil Conservation employee, and is one of the oldest replicated research experiments in the western United States. The experiment consisted of a winter wheat-summer fallow rotation arranged in a randomized block design with three replications. The main plot consisted of three primary tillage treatments (moldboard plow, offset disk, and subsurface sweep) and subplots consisted of six nitrogen treatments that changed over time and most recently ranged from 0 to 180 kg ha�����. Soil depth of individual plots ranged from 1.2- to 3.0-m. The study was divided into four main time periods (1940-1951, 1952-1961, 1962-1987, and 1988-1997) within which experimental treatments were consistently maintained. The moldboard plow tillage treatment significantly increased yields by more than 300 kg ha����� over the subsurface sweep tillage treatment in all four time periods. Yields with the moldboard plow system were significantly higher than with the offset disk system in time periods 3 and 4. The same trend was evident for mean yield in time periods 1 and 2, but differences were not statistically significant. In time periods 1, 2, and 3, mean yields were higher with the offset disk tillage treatment than the subsurface sweep tillage system, although the differences were not statistically significant. In time period 4, mean yield was higher for the subsurface sweep system than the offset disk treatment, but differences were not statistically significantly. The optimum amount of N for winter wheat differed from year to year, within, and between experiment periods. This was apparently in response to rainfall patterns and improved management factors, specifically more N responsive semi-dwarf varieties. For time period 1, the maximum fertilizer rate was 11.2 kg N ha�����, which tended to produce higher mean grain yields than an application rate of than 0 kg N ha�����, regardless of the quantity or distribution of precipitation. For time period 2, the maximum fertilizer rate was 33.7 kg N ha�����, which produced significantly higher grain yields than an application rate of than 0 kg N ha�����, regardless of the quantity or distribution of precipitation. For time period 3 (1962-1987), which had below-normal annual and growing season precipitation, yield increased with the addition of 45 kg N ha�����. For time period 4 (1988- 1997), which had above-normal annual and growing season precipitation, yield increased with the addition of 90 kg N ha�����. Yield increases at greater rates of N were insignificant. For time periods 3 and 4, maximum mean yield was obtained at an application rate of 135 kg N ha�����. The response of wheat yield to N during dry years was greater for deep (> 2.8 m) soils than for shallow soils. In addition to amount, rainfall distribution during the winter (October to March) and growing (April to June) season significantly affected yield. Results demonstrate the importance of rainfall and nitrogen to winter wheat production in eastern Oregon, and that the most environmentally sound tillage systems are not necessarily the most profitable from farmers' point of view. / Graduation date: 2000