The relationship between mineral nutrition and fruit yield components in melon grown in recirculating nutrient solution culture

Several experiments were conducted in spring or summer of five different years using different composition of the nutrient solutions in order to investigate the relationship between mineral nutrition and fruit yield components in greenhouse melons grown with nutrient film technique. Increasing the ion concentration of the recirculating nutrient solution increased leaf mineral content and the total mineral uptake by the crop. When the plants were grown with the same composition of the recirculating solution, leaf mineral status was not significantly affected by growing season, which instead clearly influenced plant growth and fruit production. Compared to spring, the plants grown in summer showed faster growth and development, but produced fewer fruits of larger size and poorer quality due to reduced sugar content. Mineral nutrition did not influence fruitset, since fruit yield and sugar content were related, over a wide range, neither to the composition of the nutrient solution nor to the amount of nutrients absorbed by the crop over the whole growing period.