Effect of sowing depth on grain yield of winter wheat s. Mahfoozi and d. Hassanpanah agricultural research station of Ardabil

In cold regions, for successful wheat production close attention must be paid to all factors that influence a plant ability to attain maximum winterhardiness and grain yield. In this study the effects of sowing depths on grain yield and winter survival of winter bread wheat (Triticum aestivum L.) was studied in cold regions of Ardabil. An experiment was set up in a randomized block design with four sowing depth treatments (4, 7, 10 and 13 cm) in three replications for two years(1992-93). The results showed that the grain yield was significantly (P < 0.01) differed. The highest yield and less winterkill were obtained from shallow seeding treatment (4 cm). Increases in seeding depth resulted in significantly (P < 0.01) low yield and high winterkill. The relationship between grain yield (Y) and sowing depths was described by a polynomial equation: Y=1.808-158.5X+5.523X__2 where this curve accounted for 91% observed variation in grain yield. It can be concluded that in cold regions of Ardabil, shallow planting compared to deep planting can increase grain yield and minimize winterkilling of winter wheat cultivars.