Artificial pollination technique of Litchi and Longan

Litchi and longan are dioecious insect-pollinated and wind-pollinated flowers, which are fertilized by insects and wind pollination. Artificial pollination is an important measure to increase the rate of fruit setting in the case of lack of bee source or bad weather. However, artificial pollination must pay attention to technology, including pollen collection and pollination methods. First, pollen collection (1) Note: the time to collect pollen should be on a sunny day. The pollen in sunny days developed well and the germination rate was high, while the pollen collected in overcast and rainy days had low germination rate. At the same time, varieties with high pollen germination rate should be selected to collect pollen. The pollen germination rate of March Red, Nuomici, Huaizhi and other varieties is as high as 80%, while that of Shuidong and Feizixiao is only 20% and 30%. (2) Pollen collection method 1. Gently shake branches to collect pollen and spread plastic film under the tree, gently shake branches to make blooming male flowers or pollen fall. After collecting male flowers, they are stirred, soaked and filtered in water, that is, "pollen water" is obtained. and spray it on the trees where the female flowers are in full bloom. Most of the male flowers collected by this method have withered and most of the pollen has lost their vitality; on the other hand, even if some fresh pollen is immersed in water for too long, the tannin exudated from the flowers restrains the pollen germination and reduces the pollination efficiency. 2. Wet towels with pollen gently pat the wet towels on the ears of male flowers in full bloom, pat 5-6 ears of flowers, and then wash them into the water for many times to obtain yellowish pollen water, which is immediately sprayed on the trees with female flowers in full bloom after filtration. this pollination method is efficient, the pollen collected is of the best quality and the germination rate is high. 2. The method of artificial pollination (1) pollination points for attention the best pollination temperature is 20-25 ℃. Spray when the female flowers are in full bloom from 7:00 to 9:00 in sunny days, at noon in cold days, and after sunny days in rainy days. If the concentration of pollen water is calculated in terms of 100 kg tree area, it is necessary to use 2 grams of pure pollen, or add pollen to clear water and fully stir until the clear water is light yellow, then filter and spray; you can also add 10 grams of borax to 100 kg pollen water, stir evenly and spray with it. (2) the pollination method combines the collected pollen with water into pollen water (generally light yellow), which is sprayed on the female flowers in full bloom. This method is often used in sunny days, which can not only dilute the excessive nectar on the stigma, but also maintain a certain degree of humidity on the stigma, which is beneficial to fertilization. Pollen water should be sprayed immediately, and the whole process of pollination and pollination should not exceed 20 minutes, otherwise it will make the pollen lose its vitality and affect the effect of pollination. Third, auxiliary measures to improve pollination effect (1) shake flowers after rain to prevent "retting flowers" litchi and longan flowers are large, small and dense flowers, when the florescence meets overcast and rainy weather, the anther is difficult to crack, there is a phenomenon of "retting flowers". Therefore, it is necessary to shake branches in time after rain, shake off withered flowers and water droplets on their ears, and speed up the air-drying of flowers to facilitate pollination and fertilization. (2) spraying water on dry days to prevent "baked flowers" litchi and longan from experiencing continuous high temperature and dry weather during florescence, the florets secrete more honey, the concentration is high, and the flowers are easy to wither and wither, which is not conducive to pollen germination and affect fertilization. In order to prevent "baking flowers", it is appropriate to irrigate or spray water in the morning or afternoon to improve soil and atmospheric humidity. Combined with pollen spray water, the effect is the best.