What causes yellow leaves on melons
Yellow leaves appearing during melon cultivation is a fairly common phenomenon. It affects the overall yield of melons, greatly reduces melon quality, and if poorly managed, can also affect the sweetness of the melons. So why do melon leaves turn yellow? Let's find out together with the editor.
1. Nutrient deficiency
Melons need a variety of nutrients during growth, and the main cause of yellow leaves on melons is nutrient deficiency. Nitrogen deficiency, phosphorus deficiency, potassium deficiency, calcium deficiency, iron deficiency, copper deficiency and magnesium deficiency can all cause leaves to turn yellow. Moreover, the symptoms of each deficiency differ. With nitrogen deficiency, leaves turn yellow-green, old leaves dry up, and new leaves are small and few; with phosphorus deficiency, plants are short and stunted, and leaves are dark green and dull; with potassium deficiency, the leaf margins turn yellow first and gradually become scorched, and in severe cases the entire leaf withers; with calcium deficiency, the leaf margins turn yellow, but old leaves remain green; with iron deficiency, leaves become pale yellow, but the veins remain green, and later the entire leaf loses its green color and drops off; with copper deficiency, the green at the leaf tips gradually fades; with magnesium deficiency, the leaf color turns yellow, most obviously at the leaf tips, but the veins remain green.
2. Fertilizer damage
Somewhat similar to nutrient deficiency, if too much fertilizer is applied during cultivation, it will cause fertilizer damage to the plants, which is also a common cause of yellow leaves. Especially just after fertilizing or after spraying, yellow leaves usually appear within 1-2 days, over a relatively large and fairly widespread area. For yellow leaves caused by fertilizer damage, increasing watering or spraying urea as a foliar fertilizer can relieve the symptoms.
3. Climatic reasons
Yellow leaves on melons are also somewhat related to climate. Many farmers use black plastic film mulching technology to raise soil temperature and speed up melon growth, but during the hot summer period, black film not only absorbs heat but also prevents heat from dissipating, thus affecting root growth and causing premature aging and yellow leaves. In addition, prolonged rainy weather or a closed, crowded canopy between plants can also cause leaf yellowing, so during cultivation, pay attention to climate changes and carry out proper management.
4. Diseases
Another cause of yellow leaves is disease. The representative disease is bacterial leaf blight, also called leaf spot disease, which mainly occurs in high-temperature and high-humidity environments and spreads very easily. When the disease occurs, yellow-brown lesions appear on the leaves, gradually expand and merge, and in the later stage cause large areas of dead spots on the leaves, preventing the leaves from carrying out normal photosynthesis. In the early stage of the disease, streptomycin can be sprayed for control, and at the peak of the disease, azole fungicides mixed with thiodiazole-copper or longkejun can be used for control.
The above is an introduction to what causes yellow leaves on melons. We hope it helps you. To learn more related knowledge, please stay tuned to us.