The reason why summer squash in greenhouse turns into melon in early spring

When zucchini is cultivated in greenhouse in early spring, it is easy to stop fruit expansion, yellowing and wilting. Finally, it becomes dry and shrunken, and this symptom may occur before and after flowering, commonly known as melon. The causes of melon are as follows: (1) when cultivated in early spring, the assimilation function of leaves decreased and the photosynthetic accumulation of plants was less. (2) because zucchini is a cross-pollinated vegetable, the pollen is stunted under low temperature and high humidity, and it is not easy to distribute pollen, so the female flower can not accept pollen fertilization, which leads to melon. (3) under the influence of low temperature and short day light in greenhouse cultivation in early spring, zucchini had more female flowers and less male flowers, resulting in poor pollination and melons. Some varieties have hypoplastic pollen at low temperature, which can also cause melons. Prevention and control methods: first, to cultivate strong plants to promote the growth and development of plants; secondly, to control the night temperature to prevent excessive night temperature to reduce respiratory consumption; at the same time, the application of carbon dioxide gas fertilizer before ventilation to promote assimilation; third, the use of artificial pollination or hormone treatment. Artificial pollination should be carried out before 9 o'clock in the morning on a sunny day, pick the male flowers in full bloom, tear off the petals, put the whole stamens directly on the stigma of male flowers, and carry out artificial pollination. Or using 20Mel 40mg / L 2mae 4Mel D to smear the fruit stalk, and using 80Mel 150mg / L gibberellin to spray fruit, it also has a good effect on flower protection and fruit protection.