Date of Seeding, Fall Growth, and Winter Survival of Winter Wheat and Rye

Abstract

AbstractIn the northern part of the North American Great Plains the level of cultivar winterhardiness required for winter cereal production is extremely high. Therefore, for successful production in this area close attention must be paid to all factors that influence a plant's ability to attain maximum winterhardiness. In this study, the influence of date of seeding on fall growth and winter survival of winter wheat (Triticum aestivum L.) and rye (Secale cereale L.) was assessed in seven trials grown on udic and typic boroll soils in the northcentral part of the agricultural area of Saskatchewan. In these trials, four wheat and two rye cultivars were seeded at 2 week intervals between 1 August and 15 October in each of 3 years. During this period, rye accumulated shoot dry matter at twice the rate of wheat. However, as expected, a decrease in shoot dry weight of both wheat and rye occurred with each succeeding delay in seeding date. The only meaningful winter damage that was observed in the rye was for the last two seeding dates with ‘Cougar’. The effect of date of seeding on survival of wheat was not consistent among trials. However, average survival was highest for the 15 August and 1 September seeding dates. This was 4 to 6 weeks prior to the onset of fall conditions favorable for cold acclimation. Differences in survival among wheat cultivars were not influenced by seeding date. This allowed for utilization of the Field Survival Index to evaluate the relative effects of suboptimal seeding dates on winter survival potential of cultivars. These results demonstrate that the Field Survival Index can be used to evaluate the effects of certain management practices in addition to inherent cultivar potential on winter survival.