Artificial pollination of pear trees ensures success rate

Pear is a kind of self-pollinating tree species with strong self-fertility. Most of them are self-pollinating and sterile. A small number of them can self-pollinate vigorously, but the rate of self-pollinating is very low. For this reason, pear trees are usually planted by artificial pollination. In the Hongzhiyi area of Salt Lake area, pear farmers collect yellow pear pollen to pollinate crisp pear; in Longju town of Salt Lake area, pear farmers even go to Sichuan to collect pollen to pollinate red crisp pear. In recent years, the demand for artificial pollination has also led to pollen business. In some villages, there are more than ten pollen sellers, and the price gap is not small. Whether collecting pollen for artificial pollination or purchasing commercial pollen for artificial pollination, there will be two different results: some fruit setting rate is high, some fruit setting rate is not ideal.
There are many factors affecting fruit setting rate, among which pollen activity should not be neglected.
How much pollen is needed per mu?
The pollens of different species of pear trees are similar in morphology, mostly elliptic or oval, and their size ranges from 30.19 to 44.38 x 27.09 to 42.57 microns. This size is a little abstract, how to visualize the size and weight of a pollen grain? According to the calculation of the largest pollen grains of pear trees, at least 230 to 300 pollens can be placed in a centimeter of length. The number of pollens per cubic centimeter is about 12 million to 270,000. At present, no one has calculated the proportion of pollen, but we know that the proportion of water is 1. Let's calculate the proportion of pollen by 3 for the time being. The number of pollen per gram is at least 4 million grains.
Up. If each pollen is active, it can be pollinated. If 20,000 pears are left per mu and refined pollen per gram, at least 200 mu of pear orchard can be pollinated. In fact, the activity of pollen is far less than this high, and most of the pollen will not fall on the stigma. Therefore, only 20 grams of refined pollen is recommended for artificial pollination, and the safety factor is increased by 4,000 times on the basis of theoretical accounting. That is to say, using 20 grams of refined pollen per mu only needs to ensure that one pollen tube is used in 4000 pollen grains.
Pollen germination rate experiments are carried out by regular manufacturers before pollen leaves the factory. Some people will do similar experiments for the common people when they sell pollen in villages and alleys. But how high is the germination rate of pollen qualified after all? It is understood that there is no specific standard at present. Jinqiang, a teacher from the Department of Horticulture, Sichuan Agricultural College, published a paper "Study on the Characteristics of Flower Organs and Pollen Vitality of Pear Trees" in 1985. The paper clarified that the pollen germination rates of Jinhua, Chonghua, Huaxi, Xueshan No. 1 and Zaobai were all above 80%; Zaobu and Chetou were next, the germination rates were above 60%; Jinchuan, Apple Pear and Jingbai were again germinated. The bud percentage was over 30%. The above species pollinate each other without affecting the yield. Only species with germination rate less than 10% can not be used as pollinating trees. Thus, only 30% of the pollen germination rate can meet the fruit setting requirements. Although the pollen grains are very small and the amount of pollen is very large, the germination rate only needs not less than 30%, but after all, the higher the activity of pollen, the more stable it is. When people collect pollen by themselves, it is best to stick to pollen activity as far as possible.
This requires us to understand the following knowledge:
1. Pollen of different developmental stages has different viability. Except for Apple pear, the pollen germination rate of budding flowers in the early flowering stage was below 30%, the pollen germination rate of thoroughly open flowers in the full flowering stage reached the peak of germination, and the pollen germination rate decreased to less than 20% when the flowers withered in the final flowering stage. It can be seen that with the development and sophistication of pollen, the vitality of pollen gradually strengthens, and the vigor of pollen is strongest in blooming flowers. At the end of flowering, the temperature rises, the metabolism of pollen itself is vigorous, and the vigor decreases quickly, even the vitality is completely lost.
2. The best way to collect pollen from Daling is to collect pollen. The so-called big bell flower, that is, the flower that will open in a day or two, is characterized by the opening of the petal, but not completely open. In production, some people pick flowers whose bones or petals are not open, and the pollen activity of such flowers is not high.
3. It is best to add a little sucrose to liquid powder spraying. According to Jinqiang's experiment, sucrose concentration has a direct impact on pollen germination. The optimum concentration of sucrose in pollen germination medium is 5%. In this medium, the pollen germinates quickly and the length of pollen tube is not easy to rupture. On 10% sucrose medium, the pollen grains sprouted well, but the pollen tube was very short and easy to rupture; 15% sucrose medium significantly inhibited pollen germination. It can be seen that when the liquid powder is sprayed, it will be better to take half a half sucrose in the pollen solution of each 30 jin spray.

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