What to Do About Deformed Watermelons? A Detailed Guide to the Latest Prevention and Control Methods

Many cucurbit crops produce deformed fruit, and watermelons are no exception; watermelons grow poorly for various reasons and end up deformed. There are many causes of deformed melons, which will be introduced one by one below. The common deformity symptoms are mainly of three kinds, and the content below will cover them specifically. The preventive measures against deformed fruit should be determined according to the cause. So let us take a look together now.

I. Deformity Symptoms and Causes

1. Crooked melon

This often takes the form of a lopsided head, where one side swells up normally while the other side's development lags behind, resulting in this appearance. There are two causes. First, low temperatures when the flower forms lead to incomplete flower development, which then affects the fruit and causes deformity. Second, poor fertilization causes the seeds to grow to one side, and the seedless area does not swell, forming a deformity.

2. Flat melon

This easily occurs in round-fruited varieties: the fruit grows lengthwise in the early stage and crosswise in the later stage. If one of these stages meets low temperatures, growth slows down, while if the other stage has normal temperatures, growth is fast; such uneven development forms a flat deformity. The rind also becomes thicker, and the stem end becomes sunken.

3. Gourd-shaped melon

The direct sign is that the section near the stem end fails to develop while the other section swells up, making the shape look like a gourd. This phenomenon is generally caused by uneven supply of fertilizer and water: usually there is drought in the early stage with insufficient water and fertilizer, and after conditions improve, the early growth has already finished and cannot be reversed. This results in this shape deformity.

II. Prevention and Control Measures

For open-field planting, plant only after temperatures have risen and stabilized, so the flowering period does not encounter low temperatures, or use plastic film mulching. In protected cultivation, no matter what the outside temperature is, the inside must be adjusted to the temperature most suitable for the flowering period. In addition, ventilate less when outside temperatures are low, and ventilate on sunny days. During the fruiting period, maintain a temperature above 25 degrees; automatic regulation is best, and the nighttime temperature must not be lower than 23 degrees so that low temperatures are avoided and growth speed is not affected. Then deformed fruit will not appear. Fertilizer and water supply must be maintained throughout the entire growth cycle. In the early stage of plant growth, apply more nitrogen fertilizer to maintain plant vigor, and water to keep humidity at about 60%. Then, during the flowering and fruiting period, apply heavy fertilizer and water, fertilizing once a month and irrigating once a week.

Deformed watermelons mainly show three deformity symptoms: crooked melons, flat melons, and gourd-shaped melons. The causes of deformity are mainly low temperatures affecting flower development, or low temperatures affecting the growth speed of the fruit. There is also deformity caused by insufficient nutrients and water. By taking preventive measures during the flowering and fruiting period according to the causes, the problem of deformed watermelons can basically be avoided.