What are the methods for controlling pests and diseases of jasmine?
Diseases of jasmine during its growth period include: jasmine stem rot and southern blight; pests include: jasmine leaf borer, scale insects, and carmine spider mite.
(1) Jasmine stem rot. This disease occurs at the base of the stem. In the early stage, the lesions are brown spots with a water-soaked appearance. The lesions extend longitudinally into streaks. The edges are dark brown, the interior grayish-brown; in the later stage, the lesion tissue rots and splits longitudinally, and black granular bodies appear. This disease occurs year-round during greenhouse maintenance, and is especially severe in early spring. It also occurs in August-September when plants are maintained outdoors. High temperature and humid conditions favor the occurrence of the disease.
Control methods: (1) When potting the plants, spray with 0.2-0.4 degree lime sulfur mixture; (2) You can apply 70% thiophanate at 600-1000 times dilution to smear the lesions or coat the branches and trunk, or use thiram at 500 times dilution, which also gives good results.
(2) Southern blight. For the damage situation and control methods of southern blight, see clivia southern blight.
(3) Jasmine leaf borer. The jasmine leaf borer is one of the main pests of jasmine. Its larvae feed on jasmine leaves, flower buds, small branches, and new shoots. Once the bark of small branches is eaten, they die immediately; seedlings die once damaged, seriously affecting the growth and flowering of jasmine.
Control methods: (1) In winter or early spring, remove dead branches from the plants and fallen leaves on the ground, and burn them in a centralized manner; (2) Thin the leaves appropriately to facilitate ventilation; promptly hand-pick and kill the eggs, larvae, and pupae on the leaves. (3) During the jasmine growth period, spray with 50% trichlorfon wettable powder at 6000 times dilution, which has a very good control effect.
(4) Carmine spider mite. The carmine spider mite is also known as the cotton red spider mite. It can harm many flowers and many greenhouse plants. Jasmine is one of the commonly damaged flowers. The leaves of affected flowers initially show small yellowish-white spots, which gradually turn red and spread to the entire leaf, causing the leaves to curl, turn yellow, and drop off. This mite develops very quickly and causes severe damage, affecting the growth and flowering of ornamental plants.
Control methods: In winter, weed and clean the flower garden, and irrigate the garden plot, which can eliminate overwintering mite sources. During the period when red spider mites are causing damage, spray with 40% dicofol emulsifiable concentrate at 1500-2000 times dilution (or 50% tetradifon wettable powder at 1500-2000 times dilution, or 40% omethoate at 1000-1500 times dilution) for control, spraying once every 7 days, 2-3 sprays in total, with good results. When spraying, spray the undersides of the leaves, and be sure to spray the inner branches and leaves in the middle and lower parts of the plants.