Management of White ripening period of Zanhuang Jujube

The fruit of Zanhuang jujube in the white ripening stage basically reached the inherent shape and size of the variety; the pericarp was thin, the cell chlorophyll decreased greatly, changed from green to green or milky white; the pulp was green and white, the texture was loose, the fruit juice was less and the sugar content was low. The white ripening period of jujube is the key stage of jujube fruit red management, at this time management should pay attention to the following aspects:

I. do a good job in the control of diseases and insect pests

1. Anthrax. The disease of fruit can be seen in the first and middle of August, such as high temperature and rain in the later stage, accelerating infection. The prevention and control of jujube rust can be combined with the control of jujube rust from late July to mid-August, spraying twice Bordeaux solution and preventing anthracnose infestation of jujube fruit, and spraying 12% green milk copper 7000000fold solution 2x 3 times from late August to early September. Generally stop using the drug after the middle of September.

two。 Fruit shrinkage disease (iron skin disease). Symptoms generally appear in the white ripening period of jujube fruit in August, which can spread suddenly in case of rain, and the peak of the disease is from mid-late August to September. 0.3% borax or boric acid solution can be sprayed in the young fruit stage; 75% chlorothalonil wettable powder 600 times or 80% Dasheng M-45 can be used in the white ripening period of jujube fruit from late July to early August, and the control effect is obvious, or spray agricultural streptomycin 100,140 units / ml or oxytetracycline 140,210 units / ml twice.

3. Fruit cracking. There is often continuous rainy weather in mid-late August, and fruit cracking can be seen. Control methods: first, in the jujube fruit white ripening period according to the climate drought timely irrigation to prevent drought, or before the arrival of the rainy season, jujube orchard covered with grass or film to maintain soil moisture. The second is to properly supplement calcium fertilizer in the middle and later stages of fruit growth, such as 0.2% calcium chloride or a mixture of calcium nitrate and potassium dihydrogen phosphate, and control the amount of nitrogen fertilizer during calcium spraying to prevent excessive nitrogen consumption of calcium. Third, the young fruit is sprayed 1000 times after the fruit tree special day up to 2116, half a month once, even spray 3 times 4 times, can effectively prevent jujube fruit cracking. Fourth, spray fruit protectants such as "plant protective film" 2-3 days before rain to prevent fruit cracking. Once every 10 days, sprayed 2 times in a row. Fifth, before the jujube fruit enters the white ripening period, set up a rain shelter in time. When approaching the white ripening period, cover the greenhouse film in time to prevent the fruit from cracking caused by continuous rain.

4. Pests. The main pests at this stage are scale, red spider, stink bug, peach heart borer, longicorn beetle and so on. It can be targeted at insect pests. 1.8% avermectin EC 2000 μ g 2500 times and 30% chlorpyrifos mixture, or with 70% imidacloprid or 4.5% cypermethrin EC 1000 × 2000 times. The medication was stopped in mid-September.

Do a good job of fertilization and pruning

1. Apply colored fertilizer. Jujube fruit white ripening stage combined with liquid spray 0.4% potassium dihydrogen phosphate solution. Fertilizer such as plant ash and potassium dihydrogen phosphate can also be applied under the canopy before rain.

two。 Trim. As the fruit quality of red jujube was affected by carbon dioxide and light, there were significant differences in fruit weight, color, firmness and soluble solids content. In the adult low-yield jujube orchard, the levels of main branches and backbone branches should be reduced, the distance between layers should be increased, the thickness and crown width of leaf curtain layer should be reduced, and the opening angle of main and lateral branches should be increased to facilitate the rapid drying of fruit surface after rain.

Zanhuang County Forestry Tourism Bureau Lei Ling Shang Sujuan Yu Junjie