EFFECTS OF SEED AND NITROGEN FERTILIZER RATES ON YIELD RELATED TRAITS, YIELD AND GRAIN PROTIEN CONTENT OF BREAD WHEAT (Triticum aestivum L.) In WEST BADEWACHO DISTRICT, SOUTHERN ETHIOPIA

Abstract

Wheat is one of the major crops in the study area cultivated both for home consumption and market. However, low soil fertility and use of inappropriate seeds rates are among the major constraints limiting the productivity of wheat in Ethiopia in general and in the study area in particular. Thus, field experiment was conducted to assess the effect of rates of seed and nitrogen fertilizer on yield related traits, yield, and protein content of bread wheat and to identify economically feasible rates of seed and N fertilizer in the study area. Factorial combination of four seeding rates of wheat (100, 125, 150 and 175 kg ha-1) and four levels of N (0, 23, 46, 69 kg ha-1) fertilizer were laid out in a Randomized Complete Block Design in three replications. A 100 kg of NPS ha-1(19kg N, 38kg P2O5 and 7 kg S) were used as basal fertilizer for all the treatments. The results revealed that plant height, grain yield and aboveground dry biomass yield were significantly (p<0.01) affected by the main effects of N and seed rate while days of heading (DH), days of physiological maturity (DPM), spike length, thousand kernels weight (TKW), straw yield, harvest index and hectoliter weight (HLW) were significantly affected only by the main effect of nitrogen. The highest plant height (93.64 cm), grain yield (5576kg ha-1), aboveground dry biomass yield (13151 kg ha-1) were obtained at the highest N rate of 69 kg ha-1. Similarly, the highest plant height (87.83 cm), grain yield (4544kg ha-1), the highest aboveground dry biomass yield (11667kg ha-1) were recorded at the highest seed rate of 175 kg ha-1.Similarly,the highest days of heading (61.5 days), physiological maturity (110.4days),spike length (9cm),thousand kernels weight (42.12g),straw yield (7584kgha-1),harvest index (42) and hectoliter weight (84.44 kg hl-1) were obtained at the highest rate of N (69 kg N ha-1). The interaction effect of the seed and fertilizer rates also significantly (p< 0.01) affected number of total tillers, productive tillers per m2, number of kernel/spike and grain protein content. The highest numbers of total tillers (560) per m2 and productive tillers (492.4) per m2 were recorded at combination of 69 kg N ha-1with 175 kg seed rate ha-1, while the highest protein content (11.06%) and kernel/spike (47.03) was recorded from the combination of 69 kg N ha-1with seed rate of 125kg ha-1. The partial budget analysis revealed that the highest net return (61842.3 Birr ha-1) with MRR 1279.2% was obtained from combined applications of 69 kg N ha-1 with seed rate of 150 kg ha-1. Based on the result of this study, it can be concluded that bread wheat at seed rate of 150 kg ha-1 and N rate of 69 kg ha-1 to be appropriate with acceptable quality of bread wheat in study area. Keywords: Gra