What are the causes of and control methods for watermelon hollow heart?

Watermelon hollow heart, also known as water-shedding melon, and in summer also called high-temperature fermented melon, is a phenomenon in which only the flesh texture becomes soft and the flesh color darkens; in severe cases the flesh has a sour and rancid taste, loses its commercial value, and causes huge economic losses to farmers. So what are the causes of watermelon hollow heart? How should it be controlled? Let's take a look together.

I. Causes of watermelon hollow heart

1. Variety. The watermelon hollow heart phenomenon has some relationship with variety; generally, varieties with loose flesh texture are prone to hollow heart, whereas varieties with firmer flesh texture have a lower chance of developing hollow heart.

2. Continuous cropping. During the growth of watermelon, its root system secretes a substance called salicylic acid, which is a harmful substance. If continuous cropping is carried out for many years, it will lead to an extremely high content of salicylic acid in the soil, thereby acidifying the soil. When watermelon is affected by this substance during later growth, changes are triggered, and the chance of hollow heart occurring is greater.

3. High temperature. High temperature is also one of the most common causes of watermelon hollow heart. When watermelon grows for a long time at a high temperature above 35 degrees, its leaf photosynthesis is inhibited, thereby damaging the normal function of the leaves and affecting normal plant growth.

4. Lack of water or waterlogging. During the watermelon expansion period, if there is drought and lack of water, or excessive watering causes normal waterlogging, both will affect the root system's absorption capacity. Sharp changes between dry and wet soil affect nutrient synthesis, causing nutrients and water to flow backward and forming hollow heart.

5. Diseases. Diseases can also cause watermelon hollow heart. For example, when viral disease and anthracnose occur severely, or green mottle virus disease, they can also cause watermelon flesh to soften, produce an off odor, and develop hollow heart.

6. Harvesting too late. If watermelon is not harvested in time after ripening, it is easy for the watermelon to become overripe and develop hollow heart.

II. Control methods

1. Variety selection. For summer and autumn watermelon crops, choose varieties with strong disease resistance, tolerance to high temperature, robust growth, and resistance to early aging.

2. Temperature and humidity management. During summer high temperatures, the fruit should be covered with leaves to avoid direct sunlight. If there are not enough leaves, weeds or waste paper can be used for covering to reduce the adverse effects of weather and disease on the roots. If growing in a greenhouse, promptly open the front and rear films and side films to increase ventilation and achieve cooling and dehumidification; outside the greenhouse, an external shade film can also be installed.

3. Pruning. Prune appropriately, and when necessary leave 1-2 side branches to ensure the plant has a certain number of functional leaves, maintain relatively high photosynthetic efficiency, and promote normal fruit development. Do not prune under drought conditions.

4. Fertilizer and water management and disease control. After watermelon sets fruit, its water demand increases greatly, so appropriate topdressing and increased watering are needed, and trace-element foliar fertilizer should be sprayed to promote robust plant growth, improve stress resistance, and prevent early aging.

The above is an introduction to the causes of and control methods for watermelon hollow heart. We hope it can help you. If you want to learn more related knowledge, please keep following us.