Measures to control the overpopulation of vegetables in greenhouses are exquisite

Leggy is a problem that easily occurs during the growth of vegetables in autumn and winter. Leggy fruit and vegetables are prone to phenomena such as slender stems, thin and light green leaves, tender tissues, sparse roots, few and late flowering, and difficulty in setting fruits. So how to control prosperity?

Causes of leggy growth

Insufficient light (the plant grows too fast in internodes under low light or too short illumination time), too high temperature (the temperature at night is too high, and the plant will consume too many photosynthetic products and nutrients due to intensified respiration) , too much nitrogen fertilizer (too much top-dressing nitrogen fertilizer in the seedling stage or too frequently), too much water (excessive soil moisture leads to a reduction in soil air content and reduced root activity), and too dense planting (plants block each other’s light and compete for each other). moisture, air), etc.

Measures to control excessive growth

One is to control the temperature. Excessive temperature at night is an important reason for the vigorous growth of plants. Each crop has its own suitable growth temperature. For example, the suitable growth temperature for eggplant during the flowering and fruit-setting period is 25-30°C during the day and 15-20°C at night.

The second is fertilizer and water regulation. When the plants are too vigorous, avoid flooding with large amounts of water. Water in alternate rows and half a furrow at a time. When the plants are very weak, water twice in a row to promote growth, and at the same time apply chitin and other root-promoting fertilizers.

The third is hormone regulation. The concentration of plant growth regulators such as Mepiquat and Paclobutrazol must be used with caution. When the plants are just showing vigorous growth, it is recommended to use Mepiquat chloride 10% SP 750 times solution or Chlormequat 50% SL 1500 times solution. If the control effect is not good, spray again after about 5 days. If the plant has grown seriously, you can spray it with Paclobutrazol 15% WP 1500 times. Note that spraying plant growth regulators is different from spraying fungicides. It does not need to be fully sprayed. It should be sprayed all the way to the top quickly and avoid repeating.

The fourth is plant adjustment (including fruit retention and fork removal, etc.). The flowering and fruiting period is the key to adjusting the growth of the plant. Depending on the situation, you can choose whether to retain the fruit and remove the forks. Plants that are growing vigorously should retain fruits and keep as many fruits as possible; if the plants are growing weakly, thin the fruits early and retain less fruits. In the same way, vigorously growing plants can be pruned early, while weakly growing plants should be pruned later. Because there is a corresponding relationship between the above-ground and underground root systems, to enhance growth, it is necessary to leave branches temporarily, and then remove them in time when the tree is strong.