Citrus Huanglongbing is rampant, what should farmers do?

"A small test paper can help the whole orchard resist citrus Huanglongbing." The innovative and entrepreneurial team "Tang Xin Tang Yi" led by students from the School of Pharmacy of Nankai University is committed to the research and development of rapid and early detection technology for citrus diseases, so that fruit trees can stay away from diseases as soon as possible. Since 20 19, their technology has been explored and applied in many nursery bases and thousands of acres of navel orange orchards in southern Jiangxi, guarding this "orange sea" that brings hope of getting rich.

Citrus Huanglongbing is a national quarantine disease that seriously threatens the safety of citrus industry, and it is called cancer on citrus trees. Infected citrus loses its fruiting ability or even dies within 3~5 years, spreading and causing the destruction of the whole garden. At present, the situation of citrus Huanglongbing is very serious, and citrus Huanglongbing is often reported in various areas of Shuifu County, Yunnan Province. In recent years, Shuifu County has taken effective measures to strengthen the prevention and control of citrus Huanglongbing, prevent the spread of citrus Huanglongbing from the source, and ensure the safety of citrus production in this area.

Mottled yellowing is a typical feature of Huanglongbing leaves, which is characterized by asymmetric yellowing spots, which is different from uniform yellowing caused by element deficiency.

Leaf mottling is due to the gradual accumulation of Huanglongbing pathogens in citrus leaves, which leads to phloem necrosis of leaf veins.

From the picture, we find that most leaves turn yellow from the bottom. If they also show hardness and brittleness, there is a high possibility of Huanglongbing.

How to deal with it?

"In the area where Huanglongbing occurs, most fruit farmers still regard the immortal red spider as the biggest pest of citrus, but they don't pay attention to or even know about psyllids that can infect Huanglongbing and destroy citrus." Deng Mingxue emphasized that the change of ideas is very important. First of all, we should establish the idea that citrus Huanglongbing is the biggest disease and citrus psylla is the biggest pest. In addition, any disease is mainly prevention, such as scab, anthrax, skin diseases and ulcers, especially the control of the devastating disease Huanglong. Doing a good job of prevention, planting disease-free seedlings is the basis, and killing citrus psyllids is the basis. Killing psyllids is more important than cutting down diseased trees. Only under the premise of effectively killing psyllids can diseased trees be cut down and excavated, otherwise pathogens will spread.

If this tree is diagnosed with Huanglong disease, it needs to patrol the garden carefully to see if there is a similar disease. Because there are many psyllids in July and August, it is necessary to kill psyllids first, and then treat the diseased trees. Chlorpyrifos, cypermethrin and nicotine can be selected as agents.

If it is not Huanglongbing, but physiological yellowing, it is recommended to take the sea elf biostimulant.

After cutting down trees, it is best to remove diseased trees together with their roots to prevent them from becoming new sources of infection.