How to prevent and control jujube anthracnose? Sharing practical methods
1. Symptoms: Infected fruit first shows red-brown spots, after which the lesions gradually enlarge, surrounded by a pale yellow halo; finally the lesion color turns dark brown, slightly sunken but then expanding slowly, and the lesion shapes are diverse, including round, oval or spindle-shaped. The flesh inside the lesion gradually changes from green to brown, becomes necrotic,...
1. Symptoms: Infected fruit first shows red-brown spots, after which the lesions gradually enlarge, surrounded by a pale yellow halo; finally the lesion color turns dark brown, slightly sunken but then expanding slowly, and the lesion shapes are diverse, including round, oval or spindle-shaped. The flesh inside the lesion gradually changes from green to brown, becomes necrotic, and turns black or dark brown. The fruit generally does not drop, but in the later stage or when there are many lesions it tends to rot and drop, and a few shrivel into mummified fruit hanging on the tree.
2. Prevention and control methods
1. Agricultural control
(1) Combined with pruning, carry out thorough orchard cleanup: cut off fruit-bearing shoots, diseased and insect-damaged branches and dead branches remaining on the tree; combined with applying base fertilizer, clean up fallen fruit-bearing shoots, jujube leaves, etc., bury them at the bottom of the fertilization pits, and carry out deep winter plowing to eliminate the pathogen.
(2) Strengthen integrated management of the jujube orchard and increase the application of organic fertilizer.
(3) Reasonable intercropping. Intercrop low-stalk crops such as peanuts and sweet potatoes in the jujube orchard to reduce air humidity in the orchard and lessen disease occurrence.
(4) Change the jujube processing method and adopt the heated baking method to prevent the high-temperature and high-humidity environmental conditions from promoting disease onset.
2. Chemical control
Before disease onset, generally in late June, dilute Liangguoan at 400-600 times, and at the same time add a certain amount of penetrant or a low-toxicity chemical agent with strong systemic action and spray to eliminate the pathogen source on the tree; near the disease onset period, it can be combined with the control of jujube rust and sprayed once more in mid-to-late July; during the disease onset period, generally around mid-August, spray once every 10-15 days, for 2-3 consecutive sprays, and generally finish application by early-to-mid September.