Measures of controlling shoot and promoting flower in longan

1. Timely pruning

If you plan to put the autumn shoot neatly once, it will be pruned a little later after harvest, which can be carried out when the branches begin to sprout about 10-15 days after fruit harvest. The retraction and pruning of fruit branches should not be overweight, and more leaves should be retained, which is beneficial to the restoration of tree potential. If you plan to put autumn shoots twice, pruning should be carried out immediately after fruit harvest, so as to promote early germination and growth of autumn shoots.

2. Fertilization to promote shoot.

(1) attack tip fertilizer

When the new shoots began to sprout, nitrogen fertilizer was the main fertilizer, and a certain amount of phosphorus and potassium fertilizer was properly applied. According to the fruit yield of 50 kg per plant, urea and imported compound fertilizer were applied to each plant.

(2) strong shoot fertilizer

When the new shoot elongation basically stopped and the leaf color turned green, the main fertilizer was phosphorus and potash fertilizer. According to the fruit yield of 50 kg per plant, 0.50 kg of potassium sulfate was applied per plant and 0.25 kg of imported compound fertilizer was applied. Ring-shaped trenches were opened under the crown dripping line or 4 or 6 radiation ditches were dug under the crown.

(3) foliar topdressing

0.3% potassium dihydrogen phosphate + 0.2% urea or 800 times liquid foliar fertilizer can be sprayed every 5 to 7 days for 2 consecutive times, so as to promote the maturity and fullness of autumn shoots within the planned time.

3. Prevent winter shoots from growing and promote flower bud differentiation.

(1) making fertilizer and water

Control the amount of nitrogen fertilizer in late autumn and winter. Spraying hormone to kill winter shoots from late November to early December, the winter shoots must be sprayed with 1.0% 1.5% urea or 500% 600 mg / L ethephon before the buds grow to 5 cm.

(2) artificial tip picking

The winter shoots of longan are mainly early winter shoots, or the leaves on winter shoots are removed. It usually takes place in the first and middle of December.

(3) Tree damage to promote flower.

For the fruiting trees with relatively strong tree potential, the tree body damage measures such as ring cutting, ring peeling, root cutting and root exposure were adopted in the first ten days of December after the last shoot matured, combined with spraying foliar fertilizer containing phosphorus, potassium and trace elements to increase the nutrient accumulation of branches and shoots and promote flower bud differentiation.

(4) Ring cutting and ring peeling technology

Generally, the secondary or tertiary branches are cut 1 to 1.5 times, or half-moon or closed ring peeling is used to reach the xylem without harming the xylem.

(5) Root-cutting technique.

Before the winter shoot is released, lime can be applied in the tree basin, each tree is 0.5 kilogram, and the topsoil is 15-20 centimeters deep in the crown dripping line to cut and expose roots.

Through the tree damage technology, the vegetative growth of the tree can be reduced, the water absorption can be reduced, and the winter shoot exhalation can be inhibited. Weak trees and poorly managed orchards should be used cautiously, and only one of the above-ground and underground parts should be selected to avoid excessive damage to the trees. The tree is weak.

(6) spraying medicine to control shoot and promote flower.

Spray 40% ethene 300 mg / L in the first and middle of December. Spray to the leaf surface wet for the degree, do not spray the leaf surface too wet dripping, lest the dose is too large, resulting in a large number of fallen leaves, weak trees and old trees do not spray. Or spraying anthocyanin twice in the same period, the concentration of anthocyanin is 10 ml to 12.5-15.0 kg of water. After the first and middle of January, choose the mixture of 3000 times of Aiduo + 0.15% glucose, or 2000 times of cytokinin, spray once every 7-10 days, 2-3 times in succession, in order to promote the formation of buds.

4. Apply attack flower fertilizer

(1) Chemical fertilizer for flower bud differentiation

Before and after the Winter Solstice, 25 kg of farm manure, 1.0 kg of calcium magnesium phosphate fertilizer and 0.5 kg of potash fertilizer were applied per plant.

(2) Zhuanhua fertilizer

Before and after the Beginning of Spring, imported compound fertilizer 0.250.50kg, potassium sulfate 0.51.0kg, urea 0.250.50kg.