Effect of seed rate and irrigation interval on yield components and yield of bread wheat (Triticum aestivum L.) at Mekane Selam district, South Wollo, Ethiopia

Determination of optimum seed rate and planning suitable irrigation strategy are important practices to increase productivity of wheat under irrigation. Thus, a study was undertaken to determine the effects of irrigation intervals (5, 8, 11 and 14 days) and seed rate (75, 100, 125 and 150 kg ha^-1) on yield components and yield of bread wheat during 2019 cropping season (November to April). Wheat variety ADEL-6 was used as test crop. The experimental design was split plot design with three replications using irrigation interval as the main plot factor and seed rate as sub-plot factor. Results showed that the interaction effect of irrigation interval and seed rate had highly significant (P<0.01) effect on number of total tillers, effective tillers, grain yield, aboveground dry biomass yield, straw yield and harvest index. The highest number of total tillers (54.33) and effective tillers (49.33) per 0.5 m mid length row were obtained from the seed rate of 150 kg ha^-1 with irrigation interval of 5 days. On the other hand, the highest grain yield (5.40 t ha^-1), the highest biomass yield (13.34 t ha^-1) and the highest straw yield (7.95 t ha^-1) were obtained from seed rate of 100 kg ha^-1 and irrigation interval of 11 days which were statistically at par with the seed rate of 100 kg ha^-1 and irrigation interval of 8 days. The partial budget analysis also showed that the highest net benefit (37375 Birr ha^-1) was recorded from the combination of seed rate of 100 kg ha^-1 and irrigation interval of 11 days followed by seed rate of 100 kg ha^-1 and irrigation interval of 8 days with net benefit of 34156 Birr ha^-1. Thus, from the result of the study, it can tentatively be concluded that use of 100 kg ha^-1 seed rate and irrigation interval ranging from 8 to 11 days can improve the productivity of bread wheat in the study area.