In the citrus industry, there is a saying called "yellow" discoloration, only because the yellow dragon disease is too severe, almost no treatment, the diseased fruit tree can only be cut down, once the heart is soft, it may also bring ruin to the entire orchard, and even the entire area of fruit trees.
As the main vector of dragon disease, citrus psyllids have the title of "death" messenger, which is frightening and the most wanted object of growers. However, although expert teachers talk about the prevention and treatment of yellow dragon disease every day, there are still many people who still know little about citrus psyllids, let alone treatment.
Identification of citrus wood lice
Adult citrus psyllids are about 3 mm long , grey-blue with gray-brown markings , and are covered with white powder. The top of the head protrudes like scissors, the compound eyes are dark red, the single eye is 3, orange-red. The picture below shows an adult citrus wood lice, sucking on the sap of young sprouts.
The citrus wood lice nymph has a beautiful translucent appearance, like a layer of gold armor, but it is the deadly "devil" of the citrus industry!
Morphological changes in 5-year-old nymphs.
Young shoots affected by citrus psyllids have withered and new shoots have deformed.
Growth habit of citrus psyllids
Adult citrus lice mostly lay eggs on the host shoots, and after hatching the nymphs, they survive by sucking the sap of the young shoots until the adults feather. Psyllids feed on citrus Xanthosis strains, spawn and multiply, producing a large number of adult carriers, which can spread Xanthas disease by transferring to new plants. The germination period of the buds is the peak of the outbreak of citrus wood lice.
Enlarged citrus psyllid eggs on a microscope
Due to global warming, the winter is getting warmer, and most of the citrus producing areas are located in the southern temperate and subtropical regions, in December the citrus trees began to sprout large areas of winter buds, warm climate and sufficient food for the pathogenic citrus lice to provide excellent breeding conditions, so this month has also become the last peak of yellow dragon disease transmission in the year, fruit growers must be highly cautious!
Citrus wood lice attach to new leaves in large quantities
The prevention programme recommends:
(1) In addition to the winter shoots of fertile oranges in Nanning and other places, it is necessary to erase the late autumn shoots and winter shoots that have not matured in time;
(2) When the leaves are still the size of rice grains, the larvae of the psyllids begin to invade, and it is best to put the shoots uniformly in the areas with many diseases of huanglongbing disease, and adopt the spraying method of "three times at a time" to completely eliminate the psyllids;
(3) China uses the same drug more than 12 times a year, Brazil sprays 6-15 times a year, Florida sprays 8-12 times a year, the number of sprays is more, it is easy to make psyllid resistant, so it is necessary to rotate the drug;
(4) Remove dead branches and leaves and weeds, dig up diseased or weak trees, and reduce the source of insects;
(5) Reduce the planting of surrounding russets and avoid the accumulation of psyllids (there are also people who plant nine incense near the park to attract psyllids to concentrate on culling);
(6) Frequent inspection and detection of the number of pyllids in the park;
(7) Selective protection of natural enemies of pyllids.
Citrus predator Hime Wasp
Interfering with psyllid feeding potions selection:
There are many other ways to control wood lice, and I will talk about it today. Finally, xue nongjun would like to remind everyone that due to the rapid migration speed of wood lice and the high contagiousness of the Yellow Dragon virus carried, the prevention and control of wood lice must not be a matter of a fruit farmer or orchard, and the best way is to jointly prevent and control villages and towns.
Otherwise, if there is a sick orchard in one area, others will inevitably suffer!