When the tomato greenhouse is cultivated over the winter, the whole half of the fruiting period is at a relatively low temperature, and the humidity in the greenhouse is relatively large. The pollen of the tomato is not easy to naturally pollinate. Therefore, it can be taken at sunny noon to knock flowers or release the bumblebee to assist in pollination. To increase the fruit setting rate. At present, most farmers still use growth hormone, anti-arsin, to promote and ensure fruit set, but they must strictly master the correct use of the method. Selection of anti-dropping agent The use of 2,4-D is not recommended. 2,4-D was originally a herbicide, and it has a strong medicinal property and is prone to phytotoxicity. It has been reported many times in foreign countries and is harmful to humans. It has long been banned from use internationally. The use of anti-dropping elements is safer. The chemical name of the anti-dropping substance is p-chlorophenoxyacetic acid, also known as “tomato spiritâ€. Using spray technology can save labor and time, and can also promote fruit setting. Experiments have shown that compared with 2,4-D and anti-escaped substances, 2,4-D has a rapid drug effect, good effect of flower protection and fruit protection, but it is prone to produce deformed fruit; anti-dropping agents are safe and difficult to produce deformed fruit, but Slower drug effect. The use of anti-dropping agents can greatly reduce the malformation rate, and the use concentration is also significantly lower than the concentration of 2,4-D. Use of anti-dropping agent The use concentration of rhododendron is generally 14-16mg/L, the effect is too low, the effect is not significant, too high prone to deformed fruit, empty fruit. The concentration should also change with the change of the outside temperature. In general, the low limit is taken when the temperature is high, and the high limit is taken when the temperature is low. Before the application, it is best to carry out the pod flower test: Select a few normal flowers. If the ovary of the florets begins to swell in 4-5 days, it means that the concentration is appropriate, and this concentration can be used. Premature enlargement indicates that the concentration is too large, and late enlargement indicates that the concentration is too small. Spraying suitable period and spraying part Nowadays, there are many anti-eruption ingredients on the market. In terms of use, some write down the use of anti-dropping agents to reduce the concentration as much as possible. This is good, but at the same time, the place where the anti-dropping agent is sprayed is full. Spraying plants, this is completely wrong, which is a misleading use of anti-dropping agents. 1 During the spray season, small sprayers are used to spray flowers. When a flower head has 2-3 flowers open, spraying is best. Do not spray flowers with the first flower bud on the first flower bud. This will affect the flowering results of the later flowers, and it is easy to produce phytotoxicity. Do not spray the anti-dropping agent liquid on the young leaves and growing points (brain heads) when spraying, otherwise phytotoxicity may also occur. 2 When the sprayed flowers are sprayed, they should be sprayed on the back of the flower, that is, at the pedicel and calyx, instead of being sprayed on the petals. This is because the root cause of tomato shedding is the increase of abscisic acid concentration at the junction of calyx and pedicel. When the abscisic acid reaches a certain concentration, it causes the detachment of the pedicel and calyx. The root cause is the imbalance between the concentration of abscisic acid and auxin. In this way, as long as we suppress the increase of abscisic acid at the junction of the calyx and pedicel, we can promote fruit set in the tomato, and spray the rhizoma on the junction of the calyx and pedicel to effectively inhibit the formation of abscisic acid and promote auxin. Formation. Usually a flower spray once, you can set fruit more than two. 3 The spray temperature is mainly based on the weather and the temperature in the shed. The spray temperature is best when the temperature is within 20°C-25°C. Therefore, during the period of September-October or early May-June when the temperature is relatively high, it is generally best to spray after 5:00 PM; in late autumn and March-March, it is between 9:00-10:00 AM or 3:00-4:00 pm is best. Choose from cloudy or sunny in the cold winter time from 10:00 am to 2:00 pm, when the greenhouse temperature is around 15 °C, you can spray flowers. However, do not spray on rainy days, because after the spraying of anti-dropping agent, the rainy day is not easy to dry the anti-dropping liquid, the residual liquid will be transmitted to the growing point and the occurrence of phytotoxicity. 4 spray interval spray anti-dropping interval days, in the spring and autumn, high humidity, the general interval of 3-4 days, early spring when the temperature is low, every 5-6 days, generally seen in the last spray When the flower is wilt and the fruit begins to inflate and set fruit, it will be sprayed once again, so that the flower spray will not be repeated. If it encounters continuous rainy days, it is effective to spray the opened tomato flower after the weather is fine. Post-spray field management In order to increase economic efficiency, timely picking-off fruit (disease, malformed fruit, cracked fruit, and small fruit) worthless or of low value should be removed in the young fruit period. Because some tomato varieties have strong growth potential and strong fruit set, such as foreign FA-189, FA-516, Hao Weisite, Bingying, FA-1420, domestic Zheza, Yuxiu series, after the use of anti-dropping agent, Sometimes the result of single panicles is too much, so take appropriate fruit thinning. Plants in normal growth state usually have 2-3 first spikes, leaving 3-4 per ear, and a maximum of 5 per plant. Do not produce too much of a single spike and require ear and ear energy results, especially for each spike. Require uniform size, when a fruit has 3-4 small fruit, the back of the flower or small fruit must be promptly removed, in short, the requirements of the harvest of fruit are uniform quality fruit.