Variation in nutrient contents of banana cultivars grown at Kabanyolo
Abstract
Productivity of the commonly grown cooking bananas in Uganda is low and is associated with poor soil fertility. A study was conducted at Kabanyolo to assess nutrient uptake by the cultivars (Mpologoma, Kibuzi and Kisansa) under uniform soil fertility management. Soil samples were taken from the banana plantation using a random cluster sampling approach at a depth of 0-30cm from three points around but 20 cm away from the mat and respective foliar tissues of each the cultivar were also collected. Results of the analysis of variance for the foliar major nutrients in the cultivars were above critical threshold for optimal growth and showed significant(P<0.05) differences in accumulation of foliar N amongst cultivars with the highest N uptake obtained in Kibuzi and the lowest in Mpologoma. Simple linear regressions between foliar nutrients and soil properties by the cultivar were positive for foliar P and exchangeable Ca (r2=0.55) and with soil pH (r2=0.30) for Mpologoma; foliar P and soil pH were negatively related ( r2=0.63) for Kisansa and foliar K and exchangeable K were positive for all the cultivars; Mpologoma (r2=0.58), Kibuzi(r2=0.41) and Kisansa(r2=0.57).
These results indicate the need for supply of N, Ca and K for improved production of the banana cultivars and also attention to pH to manage P in some cases. The nutrient ratios within tissues and soils need to be assessed under the current management as this influence growth more than achieving critical uptake limits, and could guide management intervention strategies.