4 kinds of uncommon diseases and insect pests in grapefruit cultivation

Why do I want to introduce the prevention and treatment of four uncommon diseases, and why not introduce some of the more common diseases, such as Huanglong disease and canker disease? In fact, I have also considered introducing these, but I found that there are solutions to common diseases on the Internet, and I repeat what I have said. Introduce more unusual ones, isn't that what pomelo farmers need more? So what are the four uncommon diseases we introduce today?

There are mainly scab, glue disease, plaster disease and soot disease. Let's start with scab.

Grapefruit tree

This scab mainly harms the young shoots and young fruits of pomelo, which belongs to fungal disease. the damaged tender shoot leaves initially appear oily spots, gradually develop into conical shape, the leaf is protruding on the front, the back of the leaf is concave, and the disease spots accumulate. Resulting in distorted leaves to deciduous leaves, young fruits often grow tumor-like protuberances, or sunken cracks. The deformity of young fruit affects the appearance and quality. The methods of prevention and control are the same as those of anthracnose, which should be used before the onset of anthracnose in the tender shoot stage and young fruit stage.

The second gum disease, which is also a fungal disease, mainly harms the trunk and main branches, causing bark rupture, gum and phloem decay, also known as "resin disease", as well as peeling gum from the ring, resulting in yellow leaves on the top and weakness of the tree. It is more likely to be infected by bacteria when the tree is boron deficient and drought.

Grapefruit tree

Prevention and control methods:

The main results are as follows: (1) rational and balanced fertilization should be applied to strengthen cultivation management and increase the application of "the way of field" or "bigger" organic bacterial fertilizer. Pomelo trees are sprayed with liquid boron fertilizer 3 times and 4 times a year.

(2) scrape off the rotten skin colloid of the diseased part and apply the fruit tree healing agent or 70% methyl topiramate 20: 50 times.

(3) spray protection, the whole tree was sprayed with copper sulfate alkali solution of 1: 1, 4: 1, 250: 1 before spring shoot germination.

The third plaster disease, this disease is also a fungal disease, harming the trunk and branches. With brown or gray-white military shape, the mycelium membrane is round or oblong close to the branches, like a plaster. Old orchard. The orchard with hidden crown, high humidity in orchard and serious occurrence of scale insects is more serious in orchard.

Grapefruit tree

Prevention and control measures:

1 scale insects should be controlled in time, and Jinggangmycin should be used in disease control.

(2) it can be prevented and treated with pine alkali mixture in winter, and the diseased bacteria should be scraped with bamboo or iron wire before spraying. You can also apply 200 times sulfur suspension to the disease department.

(3) do a good job of pruning in winter and summer, increase the transmittance of the canopy chamber and reduce concealment.

The fourth coal smoke disease

The disease is covered by soot on the surface of leaves, branches and fruits, which seriously affects photosynthesis, resulting in tree potential decline, yield decline and quality decline, which belongs to fungal disease. the disease spreads with the excreta of aphids, scale, whitefly and other pests as the medium.

Prevention and control measures:

(1) reasonable rice fat, proper pruning and improving light transmittance.

(2) timely control of aphids, scales, whiteflies and other pests is the fundamental measure to prevent the occurrence of soot disease.

(3) spraying with pine alkali mixture plus Kunsheng vegetable oil 500 times or mineral oil agents such as 200 times green glume can peel off the soot disease.