EVALUATION OF LEVELS OF NPS FERTILIZER ON HEAD CABBAGE (Brassica oleracea var. capitata L.) PRODUCTION DURING THE TWO MAIN GROWING SEASONS IN CHIHA DISTRICT, ETHIOPIA

Cabbage is one of the most important vegetables in Ethiopia. Its production and productivity are mainly affected by biotic and abiotic factors. Among the abiotic factors, the lack of soil fertility is a critical issue in Chiha district. This study aimed to evaluate the effect of NPSB fertilizer levels on cabbage growth and yield components during the two main growing seasons in the study area. A field experiment was conducted at Wolkite University, Department of Horticulture field site during 2020 and 2021 main cropping seasons under rain-fed condition. The total treatment combinations were seven [T1 (0 kg/ha NPS), T2 (50 kg/ha NPS), T3 (100 kg/ha NPS), T4 (150 kg/ha NPS), T5 (200 kg/ha NPS), T6 (250 kg/ha NPS), and T7 (300 kg/ha NPS)] levels respectively. The design of the experiment was laid out in a randomized complete block design (RCBD) within three replications. The data were collected and analyzed using SAS 9.4 software. The growth and yield components of cabbage was highly affected (P < 0.01) by the levels of NPS fertilizer. In both testing years, the application of NPS at the level of 300 kg/ha gave the highest yield and yield-related components of cabbage in the study area. The earliest days to 50% head formation (76.33 days, 76.35 days) and days to 90% maturity (92.33 days, 92.37 days), the lowest head diameter (5.27 cm, 5.20 cm ) and head weight (0.76 kg/plant, 0.75 kg/plant) were recorded from the application of 300 kg/ha NPS fertilizer in 2020 and 2021 main growing season of Chiha district, respectively. The results showed that higher application of NPS fertilizer increased the yield of cabbage. Therefore, based on the results obtained, growers use NPS fertilizer at the levels of 195, 114, 21 kg/ha for optimum cabbage production and could be recommended to gate maximum cabbage yield in the accepted marginal rate of return in Chiha district.