Effects of plant spacing and variety on growth bulb yield of garlic (Allium sativum L) at Koga Irrigation Scheme, Ethiopia

Abstract

Garlic (Allium sativum L.) is a widely cultivated and economically important crop, valued both as a condiment and a cash crop. However, its production and productivity is often low, which is obviously influenced with plant population and the variety used. A field study was therefore conducted to evaluate the growth and yield performance of garlic varieties under varying intra- and inter-row spacing during the main cropping season at the Koga Irrigation Scheme. The experiment followed a factorial arrangement of three inter-row spacing (20 cm, 30 cm, and 40 cm), three intra-row spacing (5 cm, 10 cm, and 15 cm), and three garlic varieties (Chelenko I, Tseday, local variety) laid out in a Randomized Complete Block Design (RCBD) with three replications. The results demonstrated that the length and diameter of bulbs were significantly affected by spacing and variety. Chelenko I exhibited superior agronomic performance, achieving the highest bulb length (3.737 cm) and bulb diameter (3.972 cm). The 10 cm × 30 cm spacing produced the largest bulb (4.232 cm in diameter and 3.908 cm in length). The highest fresh biomass yield (134.27 g plant⁻¹), dry biomass yield (61.40 g plant⁻¹), dry matter content (30.70%), and mean bulb weight (41.59 g) were obtained with Chelenko I at 10 cm x 30 cm spacing. The maximum total bulb yield (14.737 t ha⁻¹) was recorded with Chelenko I at 5 cm x 20 cm spacing. In conclusion, Chelenko I planted at 10 cm intra-row and 30 cm inter-row spacing is recommended for enhanced growth yield and bulb quality at Koga Irrigation Scheme. As the study was conducted in one location and season, it is also recommended to repeat the study in more locations and seasons.