Causes and control of empty buds of Chinese chestnut

Chinese chestnut, also known as chestnut, Fagaceae, is native to China, distributed in Vietnam, Taiwan and Chinese mainland, growing at an altitude of 370-2800 meters, mostly in mountains, and has been widely cultivated. Chestnuts are rich in nutrients, and their vitamin C content is higher than that of tomatoes and ten times higher than that of apples. Chinese chestnut has a wide range of adaptation to climatic and soil conditions. The suitable annual average temperature is 10.5 ℃. If the temperature is too high and the hibernation is insufficient, it will lead to poor growth and development, and if the temperature is too low, it is easy to cause chestnut to suffer frost damage. Chinese chestnut not only likes the soil moisture, but also afraid of the influence of rain and waterlogging. if the rainfall is too much and the soil is stagnant for a long time, it is very easy to affect the root system, especially the mycorrhizal growth. Therefore, it is not suitable to develop chestnut garden in low-lying areas prone to waterlogging.

The empty bud of Chinese chestnut is also called empty canopy and empty shell, while the fruit grower is called "mute chestnut". The empty bract rate of Chinese chestnut is generally about 15%, the high 80%, and some almost the whole plant empty bud. Therefore, preventing empty buds is the key to improve the yield and quality of Chinese chestnut.

The seed setting rate of cross-pollination of Chinese chestnut with reasonable pollination is high, and self-pollination is often not easy to bear fruit. Therefore, when planting, we should select the excellent varieties with high seed setting rate, and pay attention to the selection of pollination trees. There are many varieties of Chinese chestnut in different places, and the pollination combinations are different. For example, the main variety is Gannong 77Muo01, and its pollination combinations are Gannong 77-02 and Gannong 77Muo04 respectively. The number of pollination trees should account for about 1 / 3 of the total number of trees. The practice shows that the reasonable selection of pollination combination can greatly increase the seed setting rate and the yield of Chinese chestnut.

Chestnut trees with proper thinning of male flowers are monoecious, with male inflorescences blooming first and female inflorescences blooming later. When the male inflorescence is 2cm long, 90% of the male flowers are removed, which not only does not affect the normal pollination of the tree, but also has beautiful leaves, high seed setting rate, increased single fruit weight, and can mature 7-10 days earlier, so that it can be harvested and listed early. The proper removal of male flowers from Chinese chestnut is indeed a measure to increase production and income, especially for young trees.

The application of boron fertilizer in Chinese chestnut is very sensitive to boron, especially in boron-deficient soil, which can effectively reduce the empty bract rate and increase the yield per plant. The specific application methods are as follows: first, boron is applied in the budding stage, combined with budding fertilizer in early spring, borax is applied to the soil, generally, 100 grams of borax is applied to each plant, and more boron can be applied in the soil with boron deficiency. Second, boron spraying at flowering stage, 100 grams of borax per 15 ha and 50 kg of water are sprayed evenly on female flowers, and the concentration of boron spraying can be increased appropriately for those with high empty bract rate. After applying boron and spraying boron, the empty bract rate of Chinese chestnut can be reduced by 20% to 30%, and the yield can be increased by 3% to 4 times.