Seed and Seedling Performance of Bread Wheat (Triticum aestivum L.) as Influenced by Rate and In-Season Nitrogen Application

Field and laboratory experiments were conducted in the wheat growing belt of south-eastern Ethiopia to assess effects of rate and in-season N application on seed and seedling performance of local and improved bread wheat varieties. For the field experiments, a factorial combination of four N levels, two bread wheat varieties, and three times of N application were laid out in a Randomized Complete Block Design with three replicates. Laboratory tests were conducted in a Completely Randomized Design with four replicates to evaluate seed germination capacity and seedling vigor. The rate and timing of N application had significant (P = .01) effects on seed hectolitre weight, seed germination capacity and seedling vigor index. 1000-kernels weight was not affected by the rate of N application but significantly influenced by time of N application. Three times split application of N at 120 kg ha-1 resulted in significantly (P = .01) higher hectolitre weight, percentage of normal seedlings, seed germination speed, seedling dry weight and vigor index compared to the other treatments. The results revealed that application of 120 kg N ha-1 in three-split doses with ¼ dose at planting, ½ dose at mid-tillering and ¼ dose at anthesis led to enhanced seed quality and seedling performance of the crop