Why Watermelon Seedlings Emerge Unevenly and Preventive Measures

It is now the season for raising watermelon seedlings, but many farmers report that their seedlings emerge unevenly. When raising seedlings in plug trays, they find that the plug trays on the outermost edge of the seedling bed produce watermelon seedlings that emerge unevenly. So what causes uneven emergence in watermelons? Follow the editor and take a look.

1. Causes of Uneven Emergence

1. Unsuitable temperature

Watermelon is a heat-tolerant crop. Throughout its growth and development, it has relatively high temperature requirements. The minimum temperature it needs for growth is 10 degrees, the maximum is 40 degrees, and the suitable temperature is between 25-30 degrees. If the ground temperature is too low, it will affect the development of the watermelon root system, and the nutrients will not be able to meet the normal growth and development needs of the watermelon seedlings. At this time, the phenomenon of uneven emergence will occur.

2. Soil crusting

When the seedling bed is crusted and has poor air permeability, it will cause the oxygen content in the soil to sow, causing the seed embryo to grow slowly and delaying germination. At the same time, soil crusting in the seedling bed will also increase the difficulty of the seeds pushing through the soil during germination, thus causing slow emergence and resulting in uneven emergence.

3. Excessive fertilization

If the amount of fertilizer applied is too large or too concentrated, the root system cannot grow downward or gets burned, and it cannot absorb fertilizer and water, thus affecting growth. Or if the base fertilizer is applied too deep, the fertilizer in the upper layer sows, and uneven emergence will also occur. In addition, watermelon likes moisture and tolerates drought, but does not tolerate waterlogging. When soil moisture is too high, it will cause root rot, making it unable to absorb nutrients, and its growth will be slow. When the soil is dry, it cannot meet the fertilizer and water supply for the plants, which will cause uneven emergence.

4. Root-knot nematodes

Watermelon root-knot nematodes only harm the roots, especially the young and tender parts of the root system. The roots damaged by root-knot nematodes will grow root knots of different sizes and shapes, hindering the root system's absorption of nutrients and water. When nutrients and water cannot be supplied adequately, uneven seedlings are likely to occur. Moreover, when root-knot nematodes cause damage, they also create wounds, through which a large number of pathogens invade and cause damage together with the root-knot nematodes.

2. Preventive Measures

First, choose seedlings with strong disease resistance, sow in disease-free soil, and disinfect the seedling bed before planting. Then strengthen field management, apply more decomposed organic fertilizer, increase the soil organic matter content, promote new root growth, and enhance the disease resistance of the plants. At the same time, prevent the seedling bed from crusting, water thoroughly before sowing, do not water or water less during the emergence period, and prevent rain exposure during the rainy season. Before planting, the soil should be plowed. In fields with severe soil-borne diseases, paddy-upland rotation can be carried out. To prevent watermelon root-knot nematodes, farmers can apply Yinghui nematode-killing agent Ligensha granules by furrow application, hole application, or broadcasting over the whole field before transplanting watermelons.

The above is an introduction to the causes of uneven watermelon emergence and preventive measures. We hope it can help you. To learn more related knowledge, please stay tuned to us.