Winter cereal survival in Saskatchewan

Non-Peer Reviewe

Nitrogen and phosphorus requirements of winter wheat

Non-Peer Reviewe

Recent improvements in winter wheat production potential

Non-Peer ReviewedThe Crop Development Centre (CDC) winter wheat breeding program at the University of Saskatchewan has released eight highly adapted winter wheat cultivars in the 1990's. As a group, they represent the first semidwarf, rust resistant winter wheat cultivars with superior winter hardiness that have been developed in western Canada, or, for that matter, the world. Their short, strong straw allows for the use of higher nitrogen fertilizer rates thereby providing the farmer with the opportunity to achieve both a much higher grain protein concentration and greatly increased grain yield. When combined with the management package that the CDC winter wheat program has developed, they have allowed farmers in higher moisture areas to increase their yield targets from 45 to 50 bu/acre to 60 to 90 bu/acre while maintaining or improving grain protein concentration. As a result, they have been widely accepted by farmers and, according to Canadian Wheat Board surveys, accounted for more than 95 percent of the western Canadian winter wheat acreage in 1999 and 2000. The improved rust resistance, lodging resistance, and high yield potential of recent CDC cultivar releases makes them highly adapted to the rust hazard area of the prairies. Winter wheat is also of particular interest to farmers in this area because it avoids most of the of problems they have been experiencing with Fusarium Head Blight, Orange Blossom Wheat Midge, herbicide resistant weeds, and seeding delays due to excess spring moisture. In addition to the traditional Canadian Wheat Board markets, the expansion in livestock production across western Canada has increased demand for high-energy low fibre feed grains such as wheat. This has become an important alternate market for winter wheat and demand for this purpose and in other niche markets is expected to continue to grow in the future. Improved cultivar performance, effective extension programs, experienced growers, and new opportunities have resulted nearly a four fold increase in winter wheat production (bushels harvested) in western Canada in the last six years

Winter wheat production in western Canada – opportunities and obstacles

Non-Peer ReviewedNo-till seeding into standing stubble from a previous crop has proven to be a successful method of overwintering wheat on the Canadian prairies. Snow trapped by the standing stubble essentially eliminates the risk of winterkill if cultivars with a high level of winter hardiness are grown using recommended management practices. When combined with recent plant breeding improvements, the major limitations due to winter survival, lodging, crop residue management, and rust susceptibility are now no longer barriers to winter wheat production on the Canadian prairies. In recent years, winter wheat production has grown to become western Canada’s third largest wheat class. Average commercial yields of 149, 125, and 118 percent of spring wheat in Manitoba, Saskatchewan, and Alberta, respectively, in the twelve year period from 1999 to 2010 has demonstrated its high grain yield potential. The 10 to 15 percent yield increase of recently released Canada Western General Purpose class cultivars indicates that opportunities exist for continued advances in production potential. No-till winter wheat embraces the philosophies of conservation farming by providing the opportunity for a) reducing the rate of soil degradation, b) efficient crop moisture utilization, c) avoidance of seeding problems on late, wet springs, d) reduced tillage, e) increased competition with summer annual weeds resulting in reduced pesticide use and selection pressure for herbicide resistance, f) early harvest, g) less disturbance to wildlife, especially waterfowl and upland game birds. A high commercial grain yield also provides the opportunity enormous increases in production potential while employing a production system that fits into the objectives of sustainable agriculture. In light of current concerns with changing weather patterns, diminishing world wheat reserves and an ever increasing number of mouths to feed, one would assume that winter wheat production in western Canada would be widely embraced. However, marketing obstacles, which have a direct influence on farmers’ net returns, remain to be overcome before this potential will be fully realized

Use of grain protein concentration as an indicator of N deficiency in spring and winter wheat

Non-Peer ReviewedAvailable soil N and a cultivars genetic potential are the primary factors determining grain protein concentration (GPC). Several studies have suggested that the close relationship between GPC and the amount of available soil N may allow GPC to be used as a post harvest indicator of growing season soil N deficiencies. The objective of this study was to determine if GPC was a practical indicator of crop N deficiencies in a wide range of wheat cultivars grown under the variable environmental conditions of western Canada. Wheat cultivars and lines representing quality types and GPC ranging from low protein soft white through Canada Prairie Spring and hard red winter to high protein hard red spring were grown in a total of 16 N fertilizer trials on dryland at Saskatoon, Clair and Yorkton and partial irrigation at Saskatoon from 1992 to 1998. Two methods were used to determine GPC at maximum grain yield and 90 and 80 percent of maximum grain yield. Both genotype and environment influenced the upper limit of yield when N was not limiting. While variation amongst cultivars tended to be smaller within market classes, it was large enough to suggest that the critical GPC-grain yield responses must be know for each cultivar before GPC can be used as a practical post-harvest indicator of N sufficiency. Growing season weather conditions also had a large influence on GPC-grain yield relationships and as the potential grain yield of a cultivar was reduced by environmental limitations the GPC at the point of maximum grain yield increased. Similar GPC-grain yield relationships were found at 90 and 80 percent of maximum grain yield. These observations indicate that GPC may be a useful post-harvest indicator of N deficiencies for crops that are under high N stress but caution must be used when employing GPC to develop management systems that optimize N fertilizer use

Response of winter wheat and rye to nitrogen fertilization

Non-Peer Reviewe

No-till seeded winter wheat: influence of date of nitrogen application on the seasonal pattern of crop growth and water use

Non-Peer ReviewedAn experiment was carried out to determine the influence of fertilizer N timing on the early season crop development and water use (ET) of no-till seeded winter wheat (Triticum aestivum L.). Ammonium nitrate N was surface broadcast either as early as possible (early), split between 2/3 early and 1/3 at the beginning of stem elongation (split), and 3 weeks after early (late), at rates of 0, 67, 134, and 202 kg N ha-1. Early and split-N application increased the early season plant development over Iate-N as recorded by tiller number and leaf area production. The development and maintenance of a larger leaf area with N fertilization in 1987 resulted in increased grain yields. However, high evaporative demand prior to anthesis in 1988 resulted in the 'collapse' of early season leaf and tiller responses. A positive correlation (r=0.82*) was recorded between leaf stomatal conductance (gl) and leaf relative water content, illustrating the importance of tissue water content in maintaining high photosynthetic activity. While added N increased pre-anthesis gl over the unfertilized check, the opposite response was recorded during the post-anthesis grain filling period. Increasing fertilizer N rate increased seasonal ET at 2 of the 8 trials by increasing post-anthesis ET over the unfertilized check. High pre-anthesis evaporative demand reduced season long ET to 159 mm in 1988, 59 % of the 218 mm recorded in 1987. Soil water contributed 16 % of total ET in 1987 and 30 % in 1988. The bulk of this soil water was taken up pre-anthesis, with 98 % of post-anthesis ET coming from rainfall

Web ware for cultivar grain yield evaluation and selection

Non-Peer ReviewedThe variable weather conditions and climatic zones in western Canada often lead to differences in regional adaptation of cultivars that must be identified so that cropping risks can be reduced and returns maximized. Regional testing programs have been developed to provide a database for the determination of average grain yields for target areas, but in recent years the number of new cultivar releases has increased dramatically and the available resources for regional testing has been reduced. Attempts to deal with these problems have lead to web based systems that allow visitors to make head-to-head comparisons among cultivars of interest. However, the limitations associated with the comparison of means persist in these systems and considerable information of importance remains buried in the data files. This paper describes an interactive web-based model for head-to-head cultivar grain yield comparisons that calculates relative yields based on the growing season environmental potential at any prospective location in western Canada. By adapting and combining the databases from cooperative and provincial testing programs this decision-making tool also offers the opportunity to make plant breeding programs more effective while reducing the need for extensive post-registration regional testing

Response of wheat and its relatives to low temperatures

Non-Peer Reviewe

A web-based model for estimating winter survival in cereals

Non-Peer ReviewedAn interactive web-based model for estimating winter survival in cereals has been developed for use by farmers, extension workers, and researchers. The model is based on a series of equations that describe acclimation, dehardening, and damage due to low-temperature stress that are consistent with recent interpretation of low-temperature gene regulation. Low-temperature tolerance is estimated on a daily basis relative to stage of phenological development and cultivar cold hardiness potential. The model has been field validated for cereals in Saskatchewan and has been used in the simulation of over wintering for a wide range of species. Because it complies with the known low-temperature responses of cereals and is fully interactive, it can be used as a teaching tool that allows production risks, cause-and-effect processes, and genetic theories to be systematically investigated