Wood lice is the only vector of yellow dragon disease transmission, usually in the early and middle of March each year began to lay eggs and breed on the new citrus shoots, and then with the increase in the density of the insect population and endanger the new shoots, early May is the first peak of adult insects of the year, early July and early September for the second and third peaks, October to November or even December nymph production; as long as there are young shoots, wood lice adults will lay eggs again, producing nymphs (larvae) as pests.
It's usually the Asian psyllid that's active in China and other Asian regions, so take a look at this guy's ugly face:
This guy can wreak havoc on orchards
The most typical disasters that bring to the fruit are:
(1) The fruit changes from large to small (shrinkage);
(2) The fruit is unevenly green and yellow, unevenly colored (red-nosed fruit);
(3) Fruit deformity (oblique shoulder fruit);
(4) The peel changes from elastic and plump to soft and wrinkled;
(5) The fruity taste changes from sweet to sour;
(6) Reduction of dried fruit juice;
(7) Pulp fibrosis does not become slag;
(8) The fruit loses its commodity value.
The most typical disasters that can bring to the leaves are:
(1) In the early stage, a small amount of local uniform yellowing of leaf tips appeared, and the yellowing of whole fruit leaves often appeared in the middle and late stages (especially in the winter low temperature period, it is most likely to appear);
(2) Appears mottled yellowing leaves (often appear in the middle and lower part of the inner chamber of fruit trees);
(3) Deficiency of yellowing leaves;
(4) The blade becomes smaller;
(5) The leaves are hardened and fragile.
The leaves are uniformly yellowed
The focus of control is to select detoxified seedlings, but also to strictly guard against wood lice, it is recommended that the orchard be inspected every 7 to 10 days during the growth period of young shoots. If you find a psyllid, you must spray it quickly to kill.
Commonly used pesticides: 22% insect mite killing emulsion 1000 times, 3% diaomu emulsion 1500 to 2000 times, 51.5% agricultural enemy fall emulsion 1000 times, iron riding 1500 times, 3% wood-catching ling emulsion 1500 times, 2.5% imidacloprid soluble powder 2500 times, 20% cypermethrin emulsion 2000 times, 2.5% cypermethrin emulsion 2000 times, 2.5% high-efficiency cypermethrin emulsion 2000 times.
Finally, regularly check the yellow dragon disease tree, when the diseased tree is found, it is necessary to check whether the diseased tree has wood lice, generally spray the wood lice first, and then dig up the diseased tree as soon as possible (if only the diseased tree is cut down, the tree pocket is not cleared to do a good job of suppressing the tree pocket).
Article Source:
Gan Haifeng, special technical consultant of 191 Citrus Service Center
Professor He Xinhua, College of Agriculture, Guangxi University
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