What are the key points of summer management techniques for jujube trees?
1. Increasing fruit set rate
(1) Remove root suckers. Root suckers consume a large amount of nutrients, and any root suckers found should be dug out promptly. (2) Remove buds and pinch off tips. Control the sprouting of jujube heads; all new buds with no space in the inner canopy should be removed, leaving only a few jujube hanging fruiting shoots. (3) Girdling. When 30%-40% of the flowers have opened, trunk girdling can be carried out. The width of the girdle should be 1/10 of the trunk diameter. It should be done without damaging the xylem, and the girdle cut should have no ragged edges. After girdling, apply a 200-fold solution of carbendazim and seal it with clear adhesive tape. (4) After girdling, spray the plant with 2.5-3.5 kg of ice in the morning or afternoon. Alternatively, during the flowering period of jujube trees, spray 5 ppm of 2,4-D or 10 ppm of sodium naphthaleneacetate solution.
2. Fruit thinning After fruit set, if there is a relatively large amount of fruit, fruit thinning should be carried out, and 3-5 fruits can be left on each jujube hanging fruiting shoot.
3. Branch thinning New jujube heads sprouting from jujube spurs, inner canopy branches, and water sprouts on scaffold branches produce poor-quality fruit and have a low fruit set rate. In order to save nutrients, improve fruit quality, and improve ventilation and light conditions, jujube heads sprouted from jujube spurs, water sprouts sprouting on scaffold branches at all levels, as well as dense branches and crossing branches in the inner canopy, should be removed promptly before they become woody.
4. Pest and disease control
(1) Peach fruit borer, tortoise wax scale, yellow-spotted stink bug, etc. A 5000-fold solution of mite clear or a 2000-fold solution of xinmieli, plus a 600-fold solution of penconazole, can be used for control. (2) Anthracnose and jujube leaf spot disease. A 800-fold solution of thiophanate-methyl can be sprayed for control. (3) Longhorn beetles. They can be captured manually in the morning when longhorn beetles come out to move around, so as to reduce damage. (4) Control jujube rust mites, red spiders, and jujube leaf roller. When there are more than 0.5 jujube rust mites per 100 leaves, spray a 300-500-fold solution of 50% sulfur suspension concentrate for control. Spray once every 10-15 days, and 2-3 consecutive sprays are sufficient.