DATE AND RATE OF SEEDING OF WINTER CEREALS IN CENTRAL ALBERTA

Winter survival is often the most limiting factor for the use of winter cereals for grain production in the Black soil zones of the Canadian prairies. Production practices that optimize winter survival are an important part of extending the winter cereal acreage in this area. In this study, three dates of fall seeding (late August, early September, and late September) at two rates of seeding (258 and 328 seeds m(-2)) were investigated in 1988-1989, 1989-1990, and 1991-1992, at Lacombe, AB, using Musketeer fall rye (Secale cereale L.), Norstar and Norwin winter wheats (Triticum aestivum L. EM Thell), and Decade and Wintri winter triticales (X Triticosecale Rimpani Wit.). Survival was found to be best in all years when planting was conducted in late August and early September (78-99% survival). In both 1989 and 1990 the early planting resulted in the lowest yields (3.09 and 3.91 t ha(-1)), while in 1992 the latest planting resulted in the lowest yields (0.92 t h(-1)). The early seeding resulted in earlier maturity in 1989 and 1992 (1-13 d). Test weight and kernel weight decreased with later planting (10-116 kg m(-3) and 1-3.4 mg, respectively). Kernel protein was generally not affected by the treatments but was higher in some later planted material (0.2-1.0 g 100 g(-1)). Seeding rates were without effect on most traits, except grain yield in 1992 and kernel weight in 1990 and 1992 when rate effects varied among seeding dates. Date of seeding did not affect plant height except in 1992 when the later planted material was shorter. For all cultivars, survival was decreased with the late planting thereby increasing the risk of crop production. The window for seeding winter cereals in central Alberta is wider for the hardier cultivars and if forced to seed late, these cultivars should be selected.