Effects of Phosphorus Fertilizer on Plant Growth, Fruit Yield and Proximate Composition of Hot Pepper (Capsicum annuum, Rodo Variety)

Phosphorus deficiency is widespread in the soils in Nigeria which makes phosphorus fertilizer application at appropriate rates a component of the improved technologies needed for hot pepper (Capsicum annuum L) production. Atarodo (rodo) variety of hot pepper is cultivated in all agro-ecological zones and gives low fruit yields of variable quality which should be maximized with phosphorus fertilizer use but the information on the requirements is limited. The growth and fruit yield responses of rodo to phosphorus fertilizer were evaluated in 2013 and 2014 at Ado-Ekiti, southwest Nigeria in order to determine the optimum rates. The phosphorus fertilizer was applied at 0, 20, 40 and 60 kg P2O5 ha-1 in four replicates arranged in randomized complete block design. Data were collected on growth parameters from 2 weeks after fertilizer treatment and at 2-week intervals, number and weight of ripe fruits, fruit parameters and proximate composition, vitamin C and mineral contents. The growth parameters increased with age; plant height, number of leaves, leaf area and dry matter yield of plant portions showed linear increase up to the 60 kg P2O5 ha-1 rate. The 60 kg P2O5 ha-1 rate gave the highest fruit and seed yields in both years but the agronomic efficiency was maximized at 60 and 20 kg P2O5 ha-1 in 2013 and 2014 respectively. The fruit proximate composition, minerals and vitamin C contents increased to the highest values at 60 kg P205 ha-1. The linear responses to 60 kg P2O5 ha-1 in soils containing low available P suggest that higher rates and soils with variable P contents should be the focus to attain the optimum rates.