There are techniques for removing males from Chinese chestnut.

Castanea mollissima belongs to the same species of different flowers, and the number of male flowers is 1200-2000 times that of female flowers. Male flowers bloom first, 8-10 days earlier than female flowers, the florescence is longer, can last 17-18 days, and the amount of pollen is large. Therefore, under the premise of ensuring pollination, timely dredging a large number of male flowers, in order to reduce the nutrients consumed by male flowers, and improve flower quality and fruit setting rate. This paper introduces the simple techniques of castration of Chinese chestnut.

1. Time of emasculating

The florescence of Castanea mollissima is about one month after sprouting, and the best time for castration is when the male inflorescence begins to be thinned when the length of the male inflorescence reaches 1-5 cm. The difference between male inflorescence and female inflorescence is that male inflorescence is spike, female inflorescence is stigma dilated and involucre is exposed.

2. Techniques of emasculating

The ratio of female to male flowers of Castanea mollissima can still meet the need of pollination when the ratio of female to male flowers reaches 1 ∶ 120, so the amount of de-male flowers accounts for 80% and 90% of the male inflorescence. When pruning ① in winter, pay attention to the thinning of weak twigs or heavy truncation of male flowers. When sprouting, ② erased the buds in the lower part of the fruiting branch, removed the newly grown male flowers, and removed the front tip of the fruit. ③ should pay attention to removing the inflorescences in the inner chamber and leaving the male flowers on the top of the crown and on the outer branches to facilitate pollination. At the early stage of inflorescence formation (the whole inflorescence is less than 2 cm), ④ retained 3-4 bisexual inflorescences in the upper part of the new shoot and erased all the lower male inflorescences. ⑤ was castrated with androstol. Through the experiment, it is better to spray 1000-1300 times solution when the male flower of Castanea mollissima grows about 10 cm and the mixed inflorescence is 2-3 cm. The leaves began to roll up 3 days after spraying, which belonged to normal pharmacological reaction, the male began to fall at 5 days, reached the peak at 7-8 days, and the efficacy was maintained for 10 days. If the effect is not satisfactory, you can spray it again. Note that when the spraying concentration is too high, the leaves may be hurt; if the concentration is too low, the male flowers are not easy to fall off; the spraying time should not be too early, otherwise the leaves will roll up seriously. The amount of spray should be controlled by spraying evenly without flowing medicine. Each knapsack sprayer should add a 10 ml hydrophobic androstol spray to 8-year-old chestnut trees.

Matters needing attention

Chinese chestnut is a wind-borne flower and fruit tree, and a single grain of pollen flies far in strong winds. The wind is no more than 20 meters when the wind is weak. Artificial pollination can be carried out. Stamen pollen has strong vitality and can be kept germinating for up to one month when stored at room temperature.