Response of Head Cabbage (Brassica Oleracea L.) to Different Rates of Inorganic Nitrogen Fertilizer and Farmyard Manure at Bore, Southern Oromia, Ethiopia

Abstract

Cabbage (Brassica oleracea L.) is the second most important vegetable crop in Ethiopia in area coverage as well as level of production next to red pepper. However, yield of the crop is often constrained by low and imbalanced nutrient supply. This study was conducted at the Bore Agricultural Research Center (BoARC) during the main cropping season to assess the response of N and FYM on growth and yield of cabbage. The treatments consisted of factorial combinations of five levels of N (0, 59,119, 235 and 294 kg N ha^-1) and four levels of FYM (0, 3, 6 and 10 t ha^-1) and were laid out in RCBD with three replications. The ANOVA results showed that interaction effect of N and FYM significantly (P<0.001) difference on plant height, number of expanded leaves, days to head initiation, days to 90% maturity, head height, head diameter, untrimmed head weight, trimmed head weight, yield with and without wrapper and biomass of yield. There was a Significance differences between the mean plant heights (43.2cm) of head cabbage observed versus FYM of (10 t ha^-1) with each level of N (235 kg ha^-1) for plant height. However, the combined effect of highest N (294 kg ha^-1) and highest FYM (10 t ha^-1) recorded maximum number of leaves (16.66), shortest days to head initiation (63.33) and early days to maturity (112). And also the interaction effect of both N and FYM (235 kg + 6 t ha-1), respectively was highly significantly (P<0.001) recorded highest head height (18.14cm), highest head diameter (17.03cm), highest untrimmed head weight (2296.67g), highest trimmed head weight (1766.67g), maximum (107.47 t ha^-1) yield with wrapper head cabbage, highest head yield without wrapper (72.36 t ha^-1)  and maximum biomass yield (107.47 t ha^-1) of head cabbage. There was an increasing trend in the yield without wrapper or marketable head yield parameter with the increasing in the rate till combined application of 235 kg N ha^-1 from UREA and 6 t FYM ha^-1, but the yield declined above these combinations. Based on partial budget analysis the highest net benefit was obtained from treatment combinations of 235 kg N ha^-1 with 6 t ha^-1 with a marginal rate of return 2535.31%. The most attractive rates for the producers with low cost of production and higher benefits in this case were treatment combination of 235 kg N ha^-1 with 6 t ha^-1. Generally results of the study suggested that head cabbage responded well to the combined application of N and FYM and application of 235 kg N ha^-1 + 6 t FYM ha^-1 can give optimum cabbage head yield in the study area.

Keywords: FYM, N, Thomas F1, Trimmed Head, Untrimmed Head, Yield with Wrapper, Yield without Wrapper

DOI: 10.7176/JAAS/52-03