Reasons for melons turning into melons in vegetables

Hua melon, that is, the new melon just sat down and the developing melon strips, the growth stagnated, from the tip to the whole melon gradually yellowed, withered, and finally withered. Chemical melon is a common problem in the production of melons and vegetables, which directly affects the yield and output value. Especially in greenhouse cultivation, if not managed properly, the melon conversion rate can be as high as 30% and 60%. The reasons for the occurrence of melons are various, generally speaking, the development of melons stops because they do not get enough nutrients in the process of growth. The specific reasons are as follows:

1. The temperature is not suitable

The daytime temperature is too high (ultra-high 35 ℃) or too low (below 20 ℃). When the daytime temperature is higher than 32 ℃ and the night temperature is lower than 18 ℃, the photosynthesis will be blocked, the assimilation products will be reduced, the respiratory consumption will be increased, and the nutrients will accumulate less, which will lead to malnutrition and melons.

Melon vegetables suffer from low temperature and cold injury during the growth period, especially the ground temperature is too low, resulting in poor root development, reduced absorptive capacity, insufficient nutritional supply of melon strips and melons.

Second, low concentration of carbon dioxide

Melons and vegetables are generally very sensitive to changes in the concentration of carbon dioxide. If the concentration of carbon dioxide in the greenhouse is too low, it is easy to melt melons.

Third, the cultivation density is too high and the supply of fertilizer and water is unreasonable.

The cultivation density is too high, even shady, poor ventilation, resulting in closure, unreasonable frame shape, not conducive to photosynthesis, less assimilation products, easy to cause melons. Lack of water and fertilizer or lack of trace elements caused by improper fertilization also affect photosynthesis.

4. Parthenocarpy

There is a large temperature difference between day and night in the early stage of seedling raising and growth in solar greenhouse, resulting in more female flowers and less male flowers. at this time, insects are not active and lack of pollination media, and they are mainly parthenocarpy, and varieties with weak parthenocarpy are easy to turn melons.

5. Overgrowth of stems and leaves

Due to such factors as sufficient nitrogen and water, high night temperature, topdressing before root melon sitting, temporary empty seedlings, and still sufficient supply of water and fertilizer on the plant, the stem is thick and the node is long, the leaf is thin and big, and the growth is too prosperous, while the melon strips grow slowly. female flowers and young melons do not get assimilation products and melt away.

VI. Overgrowth of flowers and fruits

If there are too many female flowers and young melons on the plant, the limited assimilation products can only be distributed to big melons or some female flowers and young melons, which will cause most of the female flowers and young melons to melt. During the peak period of plant growth and fruiting, if the lower melons are not harvested in time, it is easy to cause the melons in the upper part to melt away.

7. Serious harm to diseases and insect pests

Downy mildew, bacterial angular spot, anthracnose, powdery mildew, scab and so on, will directly harm the leaves, cause leaf necrosis, and seriously cause the whole leaf or the whole plant to dry up, unable to carry out photosynthesis and turn melon. Aphids, tea yellow mites, whitefly and other pests destroy photosynthesis and cause malnutrition by absorbing the leaves of melons and vegetables and polluting them.

VIII. Drug damage

The selection of chemicals is unreasonable, the concentration of spraying is too high or too frequent, so that melons and vegetables suffer drug damage, aging and drying up, and the photosynthetic capacity of leaves decreases or even loses. In addition, mechanical damage during management may also cause damage to young melons.