Growth, Fruit Yield and Proximate Composition Responses of Hot Pepper (Capsicum annuum L; Rodo Variety) to Potassium Fertilizer Application at Ado-Ekiti, Nigeria

Abstract

Potassium (K) fertilizer application, as a component of the improved technologies necessary to maximize crop yield and quality, is often used to correct the plant, soil and environmental factors that limit K availability. The effects of 0, 30, 60 and 90 kg K2O ha-1 were studied on hot pepper (Capsicum annuum L; Atarodovariety) in 2014 and 2015 on the Teaching and Research Farm, Ekiti State University, Ado-Ekiti Nigeria in a Randomized Complete Block Design with four replicates. Each K rate was mixed with 75 kg N and 25 kg P2O5 ha-1 and applied 2 weeks after transplanting 5-week old seedlings spaced 60 cm × 40 cm apart. The data of growth parameters were collected at 2 weeks after treatment (WAT) and fortnightly till 10 WAT, number and weight of ripe fruits and fruit proximate composition. The plant height, number of leaves, leaf area and dry matter increased with age and K rates to highest values at 10 WAT and 90 kg K2O ha-1 in both years. The number of fruits, fruit and seed yield ha-1, fruit size, fruit length and breadth and pericarp thickness increased linearly from the control to the highest values at 90 kg K2O ha-1.The number of fruits and yield at 90 kg K2O ha-1 were 1.253×106, 14.24 t ha-1; and 3.73×106, 14.94 t ha-1 in 2014 and 2015, respectively but the 60 kg K2O ha-1 gave the highest agronomic efficiency. The slight increase in fruit moisture content would not predispose fruits to deterioration while the crude protein and fat, carbohydrate and ash contents, vitamin C and mineral nutrients increased significantly making K application necessary to balance the fertilizer protocol for optimum hot pepper production.