EFFECTS OF SEED AND BLENDED FERTILIZER RATES ON YIELD AND YIELD COMPONENTS OF BREAD WHEAT (Triticum aestivum L.) AT DUNA DISTRICT, HADIYA ZONE, SOUTHERN ETHIOPIA

Abstract

Bread wheat is one of the major staple and strategic food security crops in Ethiopia. However, the production and productivity of the crop are far below the global average. This is partly due to the low soil fertility and poor crop management practices including the use of suboptimal seed and fertilizers rates. Hence, this experiment was conducted to assess the effect of seed and blended fertilizer (NPSB) rates on the growth and yield of bread wheat; and determine the economically feasible seed and NPSB fertilizers rates for wheat production in the study area. Treatments consisting of four levels of seed rates (80, 100, 120, and 140 kg ha1 ) and four levels of blended NPSB fertilizers (0, 50, 100, and 150 kg ha-1 ), was laid out in a Randomized Complete Block design in factorial combinations with four replications. Data were collected on phenology, growth, and yield parameters and subjected to ANOVA using SAS software version 9.0. Results revealed that the days to heading, days to physiological maturity, plant height, spike length, thousand kernels weight, straw yield, and above-ground dry biomass were significantly (p<0.01) affected by the main effect of seed and NPSB fertilizer rates. The longest days to heading, days to physiological maturity, and spike length were recorded at 80 kg ha-1 seed rate. The maximum thousand kernels weight was obtained from the 120 kg ha-1 seed rate. However, the tallest plant height, straw yield, and above-ground dry biomass were recorded at 140 kg ha-1 seed rate. The tallest plant height, spike length, number of kernels spike-1 , thousand kernels weight, straw yield, and above-ground dry biomass were obtained from 150 kg ha-1 NPSB rate. However, the longest days to heading and days to physiological maturity were recorded from the control. The treatment interactions significantly (p<0.05) affected the number of total tillers, number of productive tillers, grain yield, and harvest index. The highest number of total and productive tillers were recorded at the combination of 140 kg ha-1 seed rate with 150 kg ha-1 NPSB fertilizer rate. However, the highest grain yield and harvest index were recorded from the combination of 120 kg ha-1 seed and 150 kg ha-1 NPSB fertilizer rates. Grain yield was strongly and positively correlated with plant height, number of total tillers, number of productive tillers, number of kernel spike-1 and above-ground dry biomass. As per the partial budget analysis the highest net benefit of 81,914 ETB ha-1 was obtained from the combined application of 120 kg ha-1 seed rate with 150 kg ha-1 NPSB fertilizer with a MRR of 988.2%. Hence, the combination of 120 kg ha-1 seed and 150 kg ha-1 NPSB fertilizer rates are profitable than other combinations, therefore this combination can be recommended for wheat production in the Duna District and areas sharing similar agro-ecology.