Soil applications of NPK affect fruit quality and shelf-life of ‘Cristalina’ cactus pear

Abstract

Introduction. Studies of NPK application in cactus pear have focused on their effects on fruit yield and quality at harvest. Their effects on fruit postharvest life have been neglected. Our objective was therefore to study the influence of soil-applied NPK on some fruit quality attributes after three or four weeks of storage at room conditions for ‘Cristalina’ cactus pear. Materials and methods. The experiment was carried out in a commercial orchard in 2004, 2005, and 2006. Application rates were: 0, 30, 60, and 90 kg N ha-1 ; 0, 30, 45, and 60 kg P ha-1 , and 0, 30, and 60 kg K ha-1 . These rates were arranged in an incomplete factorial matrix in a randomised complete block design with three replications. Nine fruit per treatment (three per replication) were randomly harvested and stored for three or four weeks at room temperature. The measured fruit quality parameters were: weight, pulp to peel ratio, flesh firmness (FF), total soluble solids concentration (TSSC), dry matter concentration of pulp (DMCP), and fruit weight loss (FWL). Results and discussion. After storage, FF was the same among treatments for all years. The TSSC and DMCP were similar among treatments but tended to be lower with high rates of N. The rate of 90 kg N ha-1 increased the FWL. Conclusion. NPK applications produced inconsistent results; therefore, further research is needed in order to address the fruit quality of cactus pear as key for marketing and for consumers’ acceptance.