TheNaturePlanet

The rotting of watermelons during the fruiting period is mostly related to pests and diseases as well as improper environmental management, and targeted prevention and control are required. Let's talk about it in detail today.

### I. Main Causes

1. **Pest and Disease Infestation**
- **Bacterial soft rot**: In high-temperature and high-humidity environments, the pathogen invades through wounds, causing the flesh to rot and emit a foul odor, with water-soaked lesions appearing on the rind.
- **Charcoal rot**: Brown lesions form starting from the fruit stalk, gradually spreading to the entire fruit, and black pycnidia are produced in the later stage.
- **Fruit fly damage**: Larvae bore into the flesh, leading to internal rot, with visible insect holes and mucus on the outside.

2. **Environment and Management**
- **Water imbalance**: Sudden irrigation after a long drought or excessive rain can easily cause cracked melons or blossom-end rot.
- **Fertilizer imbalance**: Excessive nitrogen fertilizer makes the rind thin; deficiencies in calcium and boron increase the brittleness of the rind, exacerbating fruit cracking.
- **Physical damage**: Wounds caused by field operations or pest infestations provide channels for pathogen invasion.

### II. Preventive Measures

1. **Variety Selection and Pollination**: Choose disease-resistant varieties. Mark well during artificial pollination to avoid misshapen fruits due to uneven pollination.
2. **Water and Fertilizer Management**: Spray calcium and boron fertilizers on the leaves during the fruiting period, and control the amount of nitrogen fertilizer; avoid flood irrigation and keep soil moisture stable.
3. **Pest and Disease Control**: Hang fruit fly sticky traps and promptly remove diseased fruits; spray Bordeaux mixture or mancozeb-based agents after rain to prevent diseases.
4. **Farm Operations**: Prune and pinch after the dew has dried to reduce mechanical damage, and timely remove misshapen fruits.

### III. Emergency Treatment

If rotten fruits have already appeared, it is necessary to immediately remove the diseased fruits and inspect the surrounding plants to prevent the spread of the disease.