Relationship between Concentration of Nutrient Solution and Uptake of Nutrients in Muskmelon Grown in Rockwool

Abstract

The relationship between nutrient concentration and uptake of nutrients by muskmelon (Cucumis melo L. cv. Earl's Favourite) grown in rockwool was studied to determine mineral absorption characteristics. Muskmelons were supplied one-third, two-thirds, and full strength Enshi solution. Leaf and stem fresh weights were markedly reduced when the plants were grown in one-third strength. Fresh weight and soluble solids content of fruits were highest in plants grown in full strength, followed by two-thirds, and one-third strength, respectively, but there were no distinct differences in their external appearance. During the early growth stages, the uptake rate of mineral elements (me/plant day) and the uptake concentration (uptake ratio of mineral elements to nutrient solution, me/liter) were highest in plants grown in full strength, followed by two-thirds, and one-third strength, respectively, but the uptake rate and concentration did not differ among treat- ments during growth after pollination. These results suggest that in rockwool culture of muskmelon, maintaining a higher nutrient concentration until pollination or pinching re-sults in higher yield and quality of fruit. Furthermore, these findings also suggest that mineral concentration in the root environment is not as critical to nutrient uptake and fruit production at later stages.