Nutrient Management Research Database

Potassium is important in optimizing both crop yield and economic quality. Root ac- tivity and K uptake are generally reduced  during the reproductive phase of crop de- velopment. This study has shown that supplementing sufficient soil K with additional foliar K applications during cantaloupe fruit development and maturation improves fruit marketable quality by increasing firmness and sugar content, and fruit human- health quality by increasing ascorbic acid, beta-carotene, and K levels.

This greenhouse study investigated the effects of foliar poassium applications.

'Cruiser' cantaloupes were grown in a greenhouse using a drip irrigation system, also used for fertigation of plant nutrients.

Immediately following fruit set and through fruit maturation were sprayed to runoff with potassium metalosate or potassium chloride foliar sprays. The use of a surfactant along with the foliar sprays was also tested.

The spray used was 0.08% K.

Foliar K application resulted in higher K concentrations in the fruit and increased fruit firmness

Total fruit sugars were generally higher in plants treated with K while improving the ratio of fructose to sucrose. The higher fructose to sucrose ratio translates into a sweeter tasting fruit.

Vitamin C and vitamin A levels were generally higher when K was applied, regardless of the K source.