EFFECTS OF INTRA-ROW SPACING AND RATES OF NPS FERTILIZERON BULB YIELD AND YIELD RELATED TRAITS OF SHALLOT (Allium cepa L.var.ascalonicum Backer) IN CHIRO DISTRICT, WEST HARERGHE, ETHIOPIA

Shallot is one of the widely produced crops in Ethiopia mainly used as condiment and income sources for the producers. The productivity of the crop, however, is low due to various limiting factors of which the soil fertility and the lack of appropriate plant population are among the production constraints. This study, therefore, was undertaken to evaluate the effects of NPS fertilizer and intra-row plant spacing on bulb yield and yield related traits of Improved Huruta shallot variety and to estimatethe cost-benefit for rates of NPS fertilizer and intra-row spacing for shallot production in Chiro district of West Hararghe during 2021/22 main cropping season. The treatments consisted of five rates of NPS fertilizer (0, 50, 100, 150 and 200 kg ha-1 ) and four intra-row plant spacing (5, 7.5,10, and 12.5 cm) in a factorial arrangement laid out in a randomized complete block design with three replications. The results of analysis of variance revealed the significant effect of NPS fertilizer and intra-row spacing on phenology, growth, bulb characteristics and bulb yield of Improved Huruta shallot variety, however, the interaction of the two main factors had nonsignificant effect on all traits. The variety showed significantly delayed days to maturity (135.5) when supplied 200 kg ha-1 NPS fertilizer and when plants were spaced at 12.5 cm (135.93 days) while it showed significantly early maturity (128 days) at plots that did not receive fertilizer and plants spaced at 5 cm (127.47 days). The shallot variety had significantly the tallest plants (69.57 cm), the highest number of leaves per plant (10.79) and the longest leaves length (52.73 cm) when supplied with 200 kg ha 1 NPS. The plants spaced at 12.5 cm had significantly tallest plants (69.49 cm), highest number of leaves per plant (11.15) and longest leaves length (53 cm). The shortest plant height and leaf length andlowest number of leaves per plant were observed at plots that did not receive fertilizer and plants spaced at 5 cm. The variety had the highest and the lowest mean values for bulb characteristics (neck thickness, bulb length and diameter) when supplied with 200 kg ha-1 NPS and not supplied with any fertilizer, respectively. The plants spaced at 12.5 and 5 cm had the highest and the lowest mean valuesfor bulb characteristics, respectively. The plants supplied with 150 kg ha-1 NPS and plants at 10 cm intra-row spacing had higher bulb weight of 128.87 and 147.25g, respectively, while plants without fertilizer and spaced at 5 cm had lower bulb weight of 107.78 and 96.38g, respectively. Bulb dry matter and total soluble solids of 14.55 and 12.2%, respectively, were measured from plants that were supplied with 200 kg ha-1 NPSThe highest total (46.41 t ha-1 ) and marketable (42.56 t ha-1 ) bulb yieldswere obtained from plants that were supplied with 150 kg ha-1 NPS while the highest unmarketable bulb yield (3.61 t ha-1 ) obtained from plants that received 200 kg ha-1 NPS fertilizer.The highest marketable bulb yield of 44.14 t ha-1was obtained from plants spaced at 10 cmwhile the highest total (42.36 t ha-1 ) and unmarketable (3.25 t ha-1 ) bulb yields were obtainedfrom plants spaced at 12.5 cm. Moreover, the highest net benefit (1055915 Birr ha-1 ) with the highest marginal rate of return of 4020.97% was estimated for plants that were supplied with 150 kg ha-1 NPS and spaced at 10 cm intra-row spacing. Thus, it is concluded that Improved Huruta shallot variety grown with the combination of these treatments had a potential forbulb production with acceptable economic return in Chiro district.