Growth and yield components of bread wheat as affected by seed and nitrogen-phosphorous fertilizer rates in Burie District, Northwestern Ethiopia

Achieving high bread wheat (Triticum aestivum L.) productivity in a specific region is challenging without clear guidelines on optimal seeding rates and nitrogen-phosphorus (NP) fertilizer levels. The study aimed to determine the optimal seeding rate and NP fertilizer levels for maximizing bread wheat productivity in Burie District, Northwestern Ethiopia, during the 2021 and 2022 main cropping seasons. Factorial combinations of four seed rates (100, 120, 150, and 200 kg ha-1) and four NP fertilizer rates (64-46, 87-46, 96-69, and 119-69 kg ha-1 of N-P2O5) were examined in a randomized complete block design with three replications. Data on various growth and yield parameters were collected and analyzed using SAS 9.4, with mean separation for significant treatments determined by the least significant difference. The combined analysis revealed significant interactions between seed and NP fertilizer rates, affecting parameters such as days to 90% physiological maturity, plant height, number of effective tillers, spike length, number of kernels per spike, 1000-kernel weight, aboveground dry biomass yield, and grain yield. Days to 50% heading, straw yield, and harvest index were significantly influenced by the main effects of seed and NP fertilizer rates. The highest values for days to 90% maturity, number of effective tillers, and 1000-kernel weight were observed with the lowest seeding rate (100 kg ha-1) combined with the highest NP fertilizer level (119-69 kg ha-1). The highest grain yield (3.70 t ha-1) was achieved with a seeding rate of 150 kg ha-1 and NP fertilizer level of 96-69 kg ha-1, which also yielded the highest net benefit ($1355.60 ha-1) with an acceptable marginal rate of return (8.98%). This treatment combination is recommended for bread wheat production in the Burie district and similar agroecology.