Common Diseases and Pests of Melons and Their Control Methods
Melon is also called oriental melon and apple melon, but it looks different from the oriental melon. The oriental melon's skin is yellowish, while the melon's skin is green. Strictly speaking, the melon is a type of oriental melon. The melon was originally a wild fruit, and in recent years it has been planted on a large scale. Although the melon was previously a wild fruit, it can also suffer from many diseases and pests. So what diseases and pests will occur? How can they be controlled? Let's take a look below!
1. Damping-off
Damping-off generally occurs during the melon seedling stage. After the melon seedlings emerge, the part of the seedling stem that touches the ground begins to form a water-soaked area, showing a yellow-brown linear shape, which causes the seedlings to collapse, lack water, and finally wilt and die. It mainly occurs under conditions of low temperature and high humidity. The main pathogen is a type of fruit rot Pythium, and the pathogen overwinters as oospores in the soil and diseased residues. They can survive in the soil for a long time. In spring, they spread through wind and rain, irrigation water, and other media. In the seedling soil, fully decomposed farmyard manure must be used, the seeds must be disinfected, and seed dressing must be done with chemicals. After the disease occurs, chemicals such as copper-ammonium mixture can be used for control.
2. Melon Stem Rot
Stem rot mainly harms the stems and roots of melons. During the adult plant stage of melons, the epidermis of the root-crown area near the ground begins to become water-soaked, gradually cracks, and shows traces of peeling. Then coffee-colored sap begins to seep out. In severe cases, it causes the melon to wilt and die. It mainly causes the fruit rind to dry and crack, and then a large number of black dot-like substances are produced. These black dot-like substances are the conidia and microsclerotia of the disease. The main cause of the disease is being in a high-temperature and high-humidity state for a long time, and then the plant has a large number of wounds. After overwintering, the pathogen enters through the wounds. Continuous cropping must not be practiced, and crop rotation of at least three years must be implemented. After harvest, all diseased residues must be thoroughly removed, the planting density must be reasonably controlled, fertilization must be controlled, and attention must be paid to draining accumulated water from the field.
3. Bacterial Wilt
The main part harmed by bacterial wilt is the melon's stem and vine. Bacterial wilt causes the stem and vine to begin to become thinner, also showing water-soaked symptoms. The vines at the top begin to wilt, and in the later stage, due to insufficient nutrient supply, the whole plant withers and dies. Cut open the stem and vine of a diseased dead plant, then squeeze the diseased area with your hand, and you will find a milky white liquid flowing out. The main pathogen is Erwinia, and these pathogens overwinter in the bodies of leaf-eating insects and diseased residues. In spring, they infect through insects and wounds on the plants. The main control method is also to avoid continuous cropping, promptly clean up diseased residues in the garden, and after the disease occurs, streptomycin for agricultural use can be sprayed for control.
4. Melon Soft Rot
Soft rot mainly harms melon fruits, and occasionally also causes some harm to vines. Like the previous three diseases, the affected parts begin to show water-soaked symptoms. These water-soaked areas begin to expand, then become slightly sunken, and the affected areas become somewhat soft. In the later stage, they begin to rot and are accompanied by a certain odor. The main harmful pathogen is the soft rot subspecies of Erwinia, which overwinters in diseased residues and soil and spreads through insects, wounds, wind and rain, and all other media. Pay attention to crop rotation, remove diseased residues, and pay attention to drainage to prevent disease. Chemicals such as xinzhisu can be sprayed for control.
The above are four relatively common diseases of melons. It is not difficult to see that most of these pathogens overwinter by attaching to diseased residues and soil. Then in spring, they all emerge to harm the fruits. Therefore, after harvest, the soil must be disinfected, diseased residues must be centrally destroyed, and continuous cropping must be avoided. Melon diseases must be carefully inspected and corresponding measures taken, so that melons can achieve high yields.