The effect of salinity on yield and fruit quality of pepper grown in perlite

Abstract

To determine the effect of irrigation with saline water (15 and 30 mM NaCl) on yield and quality of peppers, plants were grown hydroponically under greenhouse conditions in perlite, a common growing medium used for commercial cultivation. Fruits were collected in three states of maturity (green, turning and red states) and the changes in fruit quality that take place during these maturity stages were studied also, in order to find the optimal harvest time, with respect to fruit quality. With these moderate salinity levels, there was a linear relationship between NaCl concentration and reduction of the total yield of pepper. Although the number of marketable fruits was strongly reduced with regard to the total fruit number, the marketable yield did not decrease in the same proportion due to the increase of mean marketable fruit weight. Although salinity also reduced the fruit size, the number of marketable fruits was the more important cause of marketable yield reduction. The climatic conditions of the spring-summer season produced a high incidence of blossom-end rot, this being the main cause of the marketable yield reduction with the saline treatments. The red state of pepper fruits was the most appropriate since these fruits had greater firmness than turning or green fruits when cultivated under moderate salinity, as well as higher total soluble solids values.