Molybdenum Deficiency of Cucurbit Crops
Return to Physiological and Nutrient Disorders
Molybdenum deficiency usually affects muskmelons grown on dark heavy soils with a pH below 6.0. Heavy applications of ammonium nitrate through the drip lines may lower the pH in the plant root zone and contribute to either manganese toxicity or molybdenum deficiency. Other cucurbits do not show symptoms under the same growing conditions. Molybdenum deficiency usually is seen in the crown leaves about the time the plants begin to vine. Leaves become pale green to slightly chlorotic between the veins. As symptoms progress, the leaf margins become necrotic and plant growth ceases.
Molybdenum deficiency.
(Photo: Terry Jones, University of Kentucky)
Management:
- Maintain a soil pH between 6.0 to 6.5.
- Foliar treatments with sodium molybdate will help alleviate symptoms and permit normal growth.
