How to prevent and cure the fruit shrinkage disease of jujube

Jujube fruit shrinkage disease is a new disease of jujube, which often occurs mixed with anthracnose. When the disease occurs, the yield of the light is reduced, and the serious one is out of harvest. Recently, huge losses have been caused in the jujube area of our city.

The disease is mainly harmful to jujube fruit, causing rotten jujube and falling jujube. The disease occurred in the coloring period of jujube fruit, which began in mid-late July and peaked in mid-late August. The injured jujube fruit first appeared a yellowish halo in the shoulder and carcass, and then gradually expanded into round or irregular water-stained internal color spots, with round brown spots in the middle, soft and atrophied pulp in the disease area, and the diseased fruit was easy to fall off in the early stage. The diseased fruit is small, wrinkled, thin, the diseased tissue is spongy necrotic, and the bitter taste loses its edible value. The occurrence of the disease is related to air temperature, rainfall, jujube fruit development period and other factors. Jujube fruit enters the coloring period. When the ten-day temperature is 23oC-26oC, the disease is easy to break out in rainy or foggy weather.

At present, there is no final conclusion on the pathogen of jujube fruit shrinkage disease. One view is that it is caused by Erwinia jujube in bacteria, the other is caused by small cavity shell bacteria in fungi, and some think that it is caused by two kinds of bacteria.

Comprehensive control of jujube fruit shrinkage disease should be strengthened, and the main techniques are as follows:

1. Scientific management. Increase the application of organic fertilizer and phosphorus and potassium fertilizer, less nitrogen fertilizer, reasonable intercropping, avoid intercropping long-stalk crops, improve the ventilation and light transmission conditions of jujube orchard, set appropriate amount of fruit, in order to enhance the tree potential and improve the disease resistance of jujube trees.

2. Clean the orchard and eradicate the source of bacteria. In autumn and winter, the diseased fruit and rotten fruit of jujube orchard were thoroughly removed and concentrated treatment to reduce the source of bacteria. The jujube tree was sprayed with 3 to 5 Baumedu stone sulfur mixture before sprouting.

3. Reasonable spraying. According to the temperature and rainfall, the first spraying time was from late July to early August, and the interval was about 10 days. 10 to 15 days before the harvest of jujube fruit was the key period for prevention and control. At present, the more effective agents are: agricultural streptomycin 70 to 140units / ml, oxytetracycline 140 to 210units / ml, kanamycin 140units / ml; for fungal fruit shrinkage, 75% chlorothalonil wettable powder can be used 600x. According to the experiment, spraying 50% jujube fruit ning No. 1 wettable powder before the peak of the disease is 600 times, and the control effect is obvious. Spray should be uniform and thoughtful, the fog point should be fine, so that all the fruit noodles are covered with medicine, and make up spraying in time in case of rain.