Response of chickpea to different sowing dates and seed rates under rainfed conditions

Abstract:

In southwestern Ethiopia, chickpea is typically sown with little regard for the optimal thermal window, and seed rates vary widely among smallholders. A farmer in the Jimma zone, for example, may sow anywhere between late September and early December using 60-120 kg seed ha⁻¹, often with disappointing yields. This research tested the interaction between four sowing dates (15 October, 1 November, 15 November, and 1 December) and three seed rates (60, 80, and 100 kg ha⁻¹) on chickpea (Cicer arietinum L. cv. Arerti) performance at the Oromia Institute of Agricultural Sciences, Jimma, during the 2023 post-rainy season. A factorial randomized complete block design with three replications was used. The 1 November sowing at 80 kg ha⁻¹ gave the highest grain yield (2.14 t ha⁻¹), significantly above the earliest and latest sowings. Pods per plant peaked at 41.7 under this treatment, and 100-seed weight reached 24.1 g. Delayed sowing to 1 December cut yield by 29.0% due to terminal moisture stress during pod filling. Increasing seed rate from 60 to 80 kg ha⁻¹ improved yield by 14.3%, but the further increase to 100 kg ha⁻¹ didn’t provide an additional advantage and instead reduced pods per plant through intra-specific competition. These results indicate that sowing chickpea in early November at 80 kg ha⁻¹ under Jimma’s rainfed conditions captures the best combination of moisture availability and thermal time for yield maximisation.