Yellow leaves in the middle and lower leaves have always been an important issue for the tomato growers in the autumn. With the end of the high-temperature season, the autumn delay tomatoes have entered the results period, how to prevent yellow leaves have high yield, will be the focus of the next autumn delay tomato management. I. Analysis of yellow leaves in middle and lower leaves 1. Roots are stunted. Late autumn tomatoes are in the summer high temperature period, which is not conducive to the cultivation of robust roots. First of all, the high temperature environment is not conducive to the growth of roots, and the roots are aging rapidly. Next, under the high temperature environment, the soil moisture of the farmers is high, which is not conducive to the roots under the bar, the root volume is small, and the root is shallow. At the same time, the high temperature environment will cause the plant to be susceptible to root growth. The poor roots of the root system are poor, and the ability of the plants to absorb nutrients and water is weak. As a result, it is easy to cause nutrient deficiency and the plants are weak yellow leaves. 2. The bad environment leads to aging of the leaves. After the tomato enters the fruiting stage, the leaves are generally dense. In combination with the high temperature environment during the fall, it is easy to form a closed environment with high temperature and high humidity in the lower part of the plant, resulting in premature yellowing of the leaves. This situation is particularly easy at the front face of the greenhouse. appear. 3. Unreasonable fruit retention results in insufficient nutrient supply to the plant. The leaves are the suppliers of fruit nutrition. A reasonable amount of fruit is the prerequisite for the healthy growth of the plants. Many farmers in the production are unwilling to thin the fruit, leading to more fruits in the early period. For example, large tomatoes generally have 3 to 4 fruit per panicle, while some farmers leave 5 to 6 fruits, which leads to excessive fruit consumption. The plant growth is weak and the functional leaves near the fruit are susceptible to yellowing. 4. Mg deficiency. Magnesium is involved in the synthesis of cell chloroplasts, and the lack of magnesium in the plant causes yellowing between the veins in the middle and lower leaves. Therefore, magnesium deficiency is also an important factor in the production of yellow leaves on the upper and lower leaves. Second, prevention and control plan 1. Raise the roots. Well-grown roots are the basis for preventing yellow leaves. Autumn delayed tomato rooting should pay attention to the following issues: rational watering, proper control of watering after easing seedlings, diligent ploughing, and promotion of root barrowing; rational selection of rooting Agents, roots, hair root combination, slow seedlings should be selected nutrient rooting agent if more beneficial, etc., to promote rapid seedlings. After easing the seedlings, stimulating hormone rooting agents such as alginic acid, chitin, etc. can be used to promote new roots. 2. Reasonably leave fruit. Do not leave too much fruit in the first three panicles, and control 3 to 4 fruit per panicle for large tomatoes. 3. To maintain a transparent environment in the shed, timely pruning and leafing, the number of insect nets is not too high, generally about 60 mesh is appropriate. 4. Foliar application of supplementary nutrition and increased resistance to foliar fertilizers. Spraying magnesium-containing foliar fertilizers can be used according to the conditions. Frozen Fresh Peaches, Frozen Mandarin Orange, IQF Yellow Clingstone Peach, IQF Mandarin Orange Segments, Frozen Peach Halves, Frozen Peach Dices ZHEJIANG FOMDAS FOODS CO., LTD. , https://www.fomdasfoods.com