Although green plants are indispensable to water, in the whole process of plant growth, the requirements for water are sometimes more and sometimes less, and there is a certain periodicity. In the whole process of po membrane greenhouse vegetable management method, it should be closely around the regularity of green plants to take effective action, and it is not suitable for watering casually by subjective intention. Under the general condition, in the basic condition of sufficient soil moisture, the water consumption of vegetables in the middle and late stage of emergence and growth and development is less, and the water consumption is large in the bearing period.

Warm tips, in addition to the application of cost-effective plastic po film greenhouse film cover, in the greenhouse vegetable planting production, it is necessary to look at the comprehensive assessment is not to water the vegetables. Look at the sky, look at the ground and look at the seedlings.

First, look at the seedlings. The seedling often said here refers to the vegetable plant, and does not refer to a special growth period. Whether it is a luffa, or tomatoes or even Chaotian pepper and other vegetables, when the water supply is too much, its growth and development rate is fast, the color of the leaves and stems is light and even dark, the node is long and thin, the leaves are large and thin, and the stem tip is higher than the lower leaves. In contrast, under the condition of less water, the leaves are dense but dim, the stem nodes are short and thick, the stem tips are smaller than the height to width ratio of the leaves, and the plants are shorter. Naturally, the main performance is also related to standards such as water supply level, temperature and nutrient composition. For example, when there is little water at high temperature, the leaves of the loofah have a burnt edge, that is, the edge of the leaf becomes withered. Further developing the trend, in the afternoon the leaves wilt; In the case of more nutrients, more water, the plant also has the appearance of numerous flowers, thick and long stems, less blooming or heavy flowers. There is too much water in the soil layer for a long time, and when the temperature is slightly low, the roots will be red or brown, and the roots will be no or rot. If the soil layer is in a drought situation for a long time, the growth and development of roots will gradually change from multiple branches to fewer roots and no roots.

Therefore, to distinguish whether to water vegetables, one needs to look at the growth and development stage of vegetables in the po film greenhouse, seedling emergence to avoid watering or not watering, but for the application of vegetables po film greenhouse planted vegetables, generally large seedlings transplanting, transplanting quickly into the flowering period, in the water management method is not suitable for excessive drain water squatting, should be easily manipulated. Most vegetables are sensitive to water at the beginning before blooming, so pay special attention to it. As a result, the water consumption is large at the ripening stage, and the water must be drained when the fruit is in the middle and late stage of fruit production and the fruit is removed from the bag. Second, we need to look at the main performance of the vegetable plant, according to the growth of the plant, the color of the tea, the length of the stem node and its rhizomes. This kind of discrimination should also be combined with the characteristics of the type and type of vegetables, the supply level of nutrients, and the temperature transition, etc., for comprehensive analysis.