Nitrogen fertilization as a component of integrated crop management of hot pepper (Capsicum spp.) under tropical lowland conditions

Abstract

In field trials, treatments of hot pepper with various nitrogen application rates between 0 and 500 kg N/ha were combined with mulch treatments in factorialtrials carried out under tropicallowland conditions. Nutrient levels of leaves and fruits were analysed. Crop performance was monitored as plant height, branching and fruiting time, and crop health as incidence and severity of pests and diseases. Crop production was measured as yield of healthy fruits, mean weight of healthy fruits, and mid-harvesttime. In potexperiments in a growth chamber, effects of nitrogen application rates on severity of Cercospora leaf spot were studied. Nitrogen fertilization improved plant growth, but did not influence fruiting time. Increasing nitrogen application rates increased Cercospora leaf spot in growth chamber trials, and Cercospora leaf spot and anthracnose fruit rot in field trials. Negative correlations between nitrogen levels in leaves and incidence of blossom mould and thrips were found. Moderate nitrogen applications (150 kg N/ha) gave best yields in most field trials. Mean fruit weight and mid-harvest time were not affected by the amount of nitrogen applied. With increasing nitrogen application rates, higher nitrogen levels in both leaves and fruits were found. Moderate amounts of nitrogen, balanced with proper amounts of phosphorus and potassium are recommended as a fertilizer component of integrated crop management.