Jujube Pest Control Technology

(I) Major diseases
1. Jujube disease: The disease is a serious disease on Chinese jujube trees. The diseased trees rarely result, so the diseased tree is also known as the common jujube tree. Three to four years after the onset of the whole plant death. Generally after the flowering, there are obvious symptoms, mainly manifested as abnormal germination of flowering leaves and main buds, resulting in the phenomenon of leafy branches. The disease is mainly transmitted by grafting, and fleas are also the media.
Prevention and control measures: (1) Completely excavate seriously ill trees and their root causes and diseases, repair diseased branches and concentrate burn. The diseased branches were cut off before deciduous deciduous trees, girdling was performed at the base of the branches before germination to prevent the pathogenic organisms from running with the tree nutrients, and tetracycline and oxytetracycline (10 million units) were injected or rooted. (2) Cultivation of disease-free seedlings. (3) Selection of disease-resistant varieties and rootstocks. (4) The scion and grafting tools were sterilized with 1000 PPM (1000 mg/L) tetracycline hydrochloride for 30 minutes during nursery. (5) Strengthen the management of orchards and enhance the resistance of trees to disease.
2. Jujube rust: Occurs mainly on the leaves. In the early stage, light green dots are scattered on the back of the leaves, light grayish-brown, and later the lesions are yellowish-brown. It is the uredia spores heap of pathogens, corresponding to the uredia spores heap. Irregular green dots occur at the edge of the leaf surface, making the leaves into a flower-like shape, losing luster, and finally falling off. It usually occurs in June-August each year in the rainy season.
Prevention and control measures: (1) Completely remove fallen leaves in winter and concentrate watering or deep burying to eliminate the source of sterilization. (2) A 1:2:200-fold Bordeaux mixture was sprayed at the peak of onset in early July and early August to control the occurrence of diseases. Onset can also be sprayed with 1000 times triadimefon.
3, jujube anthracnose: the main harm to fruit, but also infringed on the date hanging (results) leaves and other green organs. After the fruit became infected, the fruit surface first appeared pale yellow stain spots and gradually enlarged to form irregular yellow-brown patches. In the middle depression, the later lesions were further expanded into pieces, causing the fruit to fall early. After the damage, the leaves turned yellow and fell early, and some branches were hanging in the form of coke. The initial infection begins with the young fruit after flowering, and the white-maturity period to the high-temperature, high-humidity period during ripening cause large-scale occurrence.
Prevention and control measures: (1) In winter, pruning removes the residual fruits of the dead branches and old dates, so as to reduce the source of the disease. (2) In the ripening period of jujube fruit, spraying 75% chlorothalonil 800 times 2-3 times (10 days once), can also be combined to prevent jujube rust, spray 1:2:200 times Bordeaux mixture.
4, fruit cracking fruit: This disease is a physiological disease, the North species of South cited the most vulnerable to disease. When the fruit is close to maturity, if it is raining day after day, the fruit surface will crack, the flesh will be exposed, the rot will turn acid, and the food value will be lost. Causes of cracking are mainly due to: jujube ripening period increased sugar content, peel elasticity decreased, from tough to brittle, excessive absorption into the rainy days after the increase in pulp bulge, resulting in rupture of the epidermis, and fruit cracking and species, flesh elasticity Large, thin varieties of cuticles and peels easily break fruit. In addition, lack of calcium and potassium can also increase the degree of cracking. Especially after a long drought, a sudden drop in rainstorm can easily cause cracking.
Prevention and control measures: (1) Reasonable pruning, improvement of ventilation and light transmission conditions, conducive to rapid drying of the rainy surface. (2) Strengthen drainage during irrigation and rainy days when drought occurs. (3) Spraying 300 mg/L calcium chloride + 0.2% potassium dihydrogen phosphate (KH2PO4) water-soluble once every 10 to 20 days from the beginning of July can significantly reduce cracking. (4) Appropriately increase calcium and potassium fertilizers. (5) Harvest the cracking fruit in advance to the white mature stage. (6) Select planted crack resistant varieties.