GROWTH AND BULB YIELD OF ONION (Allium cepa Var. cepa) VARIETIES IN RESPONSE TO NPSB FERTILIZER AT CHEHA DISTRICT, GURAGE ZONE

Abstract

Onion (Allium cepa L.) is one of the most important vegetable crops commercially grown in the world. It is a high value and income generating vegetable crops for most small scale farmers and commercial growers in Ethiopia. However, the productivity of onion is low at national as well as regional levels; due to various limiting factors such as lack of improved varieties and low soil fertility. Accordingly, a field experiment was conducted to evaluate growth and yield response of onion varieties to NPSB fertilizer rates at Cheha district, Guraghe zone during 2022 cropping season. The experiment was consisted of four onion varieties (Bombay Red, Nafid, Nafis and Nasik Red) and four levels of NPSB fertilizer (0, 195, 244 and 293 kg ha-1) combined factoriallly and laid out in Randomized Complete Block Design with three replications. Yield and yield related parameters were recorded and subjected to analysis of variance. The analysis of variance for agronomic parameters showed that the main effects; variety and application of NPSB blended fertilizer rate were significant for almost all traits. Similarly all yield and yield related traits were significantly influenced by the interaction of varieties and NPSB fertilizer rate except plant height. The highest values for most of the response variables were recorded from variety Nafis combined with NPSB at rate of 293 kg ha-1.The partial budget analysis revealed that the highest net benefit 414255(ETB ha-1) with acceptable MRR was obtained from the variety Nafis combined with application of 244 kg ha-1 of NPSB fertilizer. Hence, the use of Nafis onion variety and application of 244 kgha-1 NPSB fertilizer rate was economically feasible and can be recommended for optimum production of onion in the study area and other areas having similar agro-ecology. However, as the experiment was done for only one season and single location, it has to be repeated over seasons and locations to have conclusive recommendation.