Why do grapefruit trees have pests in their roots after they bear fruit?

Fruit trees enter the harvest period too early, and too many fruits cause fruit trees to decay prematurely and form small old trees, attracting too many pests and bacteria, and serious pests and diseases occur in the orchard.

Solution: Delay the fruit tree to enter the harvest period too early, thin the fruit and reduce excessive fruit hanging.

Apply more compost, apply less chemical fertilizer, use special pesticides for the underground roots of fruit trees to irrigate the roots, and brush the main stem of fruit trees with lime plaster.

Grapefruit root insects are mainly ground nematodes, ground maggots, drilling wood insects, etc., or to focus on prevention and control, with avidi insect granules and chemical fertilizers applied under the tree, so that the effect will be better. Hope mine can help everyone.

Because many pests like the fruit of the grapefruit tree very much, and the fruit of the grapefruit tree is very nutritious.

Attracts pests. The fruit will give off some aroma that attracts nearby pests to come and eat.

The grapefruit tree is a disease of white spot disease, you have to find an agricultural expert quickly**, otherwise there will be no fruit next year.

Caused by insect infestation. Blowing Miansuke. Scale insects.

It is not stated that there is any insect, and it is presumed to be a larva of the longhorn beetle (Ox horn).

The mother worm lays eggs in the low trunk, and the larvae eat the trunk after hatching, affecting the transport of water and nutrients. In light cases, the leaves turn yellow and fall, and in severe cases, the grapefruit trees will wither and die.

Methods of control of insect infestations that have already occurred:

1) Pierce the hole with wire to kill the larvae.

2) Pesticide store buy plus water suspension, dilute 100 times, and stuff it into the hole with cotton or cloth dipped in the potion to poison.

Adult insects have been found, but the pest has not yet occurred Prevention and control methods:

1) Add a protective water suspension, dilute 50 100 times, and spray the trunk 60 above the ground.

2) Dry coat lime milk or wrap it with plastic cloth (or net) a few meters below the ground to prevent spawning.

When it comes to plant diseases, I believe everyone is familiar with them, as long as they are plants, they are prone to diseases in the process of growth. The parts of plants that produce diseases include branches, leaves, and fruits, so what are the symptoms of various diseases of grapefruit leaves? Next, Baibai Safety Net will explain it to you.

1. Grapefruit scab disease.

Symptoms of harm. It is mainly harmful to the young leaves, flowers and young fruits of spring, late autumn and winter shoots. When the disease is severe, it causes a large number of fallen leaves, fallen flowers and fruits, and the damaged fruits are deformed, the quality deteriorates, and the commodity grade is low.

At the beginning, the affected leaves appear with small round spots in the form of water stains, and then turn waxy yellow. The lesions expand with the growth of the leaves, and gradually become corked, and the leaves bulge to one side of the leaf to form a cone-shaped scab, and the other side is concave inward, and the leaves with many lesions are twisted and deformed, which seriously causes defoliation.

2. Grapefruit anthracnose.

Symptoms of harm. Grapefruit anthracnose can damage leaves, shoots, and fruits. The leaves and branches are in a rainy and humid climate, and the leaf tips are pale cyan with dark brown patches, such as boiling water, and the margins are not significant; The tender shoots are scalded in boiling water and acutely withered.

In short, humid climates that soon become clear, it is manifested as chronic symptoms: leaf spots round or amorphous, marginal dark brown, slightly arched, grayish-brown to grayish-white in the middle, often whorled on the spot;

3. Grapefruit macular disease.

Symptoms of harm. Grapefruit yellow spot disease, the affected plant produces dozens or hundreds of spots on a single leaf, which hinders photosynthesis, weakens the tree, and causes a large number of fruit drops.

Symptoms of leaf damage: The leaves of the grapefruit tree are harmed by yellow spot disease, and one or several oil-soaked small yellow spots are born on the back of the leaves at the beginning, and the lesions will gradually turn into yellow-brown patches as the leaves grow. Or produce russet brown slightly convex small lesions on the leaf surface, then slightly expanded, slightly concave in the middle, become gray-brown round to oval mold spots, and the later disease part ** becomes gray-white, causing a large number of defoliation when the disease is serious.

Fourth, grapefruit bituminous coal disease.

Symptoms of harm. At the beginning of the onset of soot disease, a layer of dark brown mold is produced on the surface of leaves, branches or fruits, and then gradually develops into a black velvety mold layer covering the diseased part.

During the growth of the grapefruit tree, the leaves are curled, which may be due to viral disease or anthracnose. If the pomelo tree is diseased, it is necessary to cut off the diseased leaves of the pomelo tree and burn them intensively to avoid the spread of the disease. After pruning the diseased wheel leaves, the grapefruit tree can be sprayed with drugs such as carbendazim, methyl tobuzin, zeczeb or chlorothalonil to remove the disease.

The leaves of the grapefruit tree rolled up what medicine.

The curling leaves of the grapefruit tree may also be caused by insect infestation, and in severe cases, the leaves may turn yellow, wilt or fall off. If there are insect pests on the grapefruit tree, such as red spiders or scale insects, it is necessary to cut off the insect leaves in time and burn them intensively. After pruning the insect leaves, the pomelo tree can be sprayed with agents such as dimethoate, worm forest or pyrethrin.

The leaves of the grapefruit tree rolled up what medicine.

The curled or yellowing of the leaves of the grapefruit tree during growth may also be caused by improper maintenance. During the maintenance period, insufficient water or lack of fertilizer can cause the leaves of the grapefruit tree to turn yellow. If it is caused by insufficient water or fertilizer, it needs to be watered appropriately, and a compound fertilizer containing nitrogen, phosphorus and potassium should be applied to the grapefruit tree to make it grow normally.

The leaves of the grapefruit tree with the letter roll up what medicine to fight.

During the maintenance period, in order to avoid pests and diseases in the pomelo tree, proper watering and fertilization are required. Reasonable maintenance methods are conducive to the growth of pomelo trees and can enhance the disease resistance of pomelo trees. During the maintenance period, you can regularly spray fungicides on pomelo trees, generally 20 to 30 days can be sprayed once a time, which can prevent pests and diseases.

It is not a disease or an insect infestation - scale insects, and the specific species should be - sagittal scales.

Use two fungicides and spray them with water together with a compound mixture.

Summary. Grapefruit anthracnose pathogen generally overwinters in the diseased part of fruit trees (diseased leaves, diseased branches, diseased fruits), and is spread by wind, rain and insects when the environment is suitable in the second year, and invades from stomata or wounds to cause disease. Anthracnose is easy to occur due to high temperature and humidity environment, or fruit trees are damaged by frost or drought, or orchards are waterlogged, or orchard soil is clay, or orchard soil organic matter content is low, or orchards are biased with nitrogen fertilizer, or orchards have high groundwater levels and poor drainage.

There are many types of scale insects that occur on pomelo trees, including blowing scales, red wax scales, black spot scales, sagittal scales, brown round scales, and chaff scales. If the adult sucks the juice of the branches, stems, leaves and fruits with the stinging and suction mouthparts, the affected plants cannot extract new shoots, yellow leaves and withered branches, fallen leaves, fallen fruits, and even died in patches, causing a large amount of soot disease.

Grapefruit anthracnose pathogen generally overwinters in the diseased part of fruit trees (diseased leaves, diseased branches, diseased fruits), and is spread by wind, rain and insects when the environment is suitable in the second year, and invades from stomata or wounds to cause disease. Anthracnose is easy to occur due to high temperature and humidity environment, frost damage or drought of fruit-type pickpockets, or waterlogging of orchards, or clay soil in orchards, or low organic matter content in orchard soils, or partial application of nitrogen fertilizer in orchards, or high groundwater level and poor drainage of orchards. There are many kinds of scale insects that occur on pomelo trees, and the common ones are blowing cotton scale, red wax scale, Buyuchang black spot scale, sagittal scale, brown round scale, chaff scale, etc.

If the adult insect sucks the juice of the branches, stems, leaves, and fruits with the stinging and sucking mouthparts, the affected plant can not extract new shoots, the leaves are yellow and the branches are withered, the leaves and fruits are dropped, and even the plants die, and a large number of soot diseases are produced.

How can it be prevented? 1) Clear the garden thoroughly. After harvesting, cut off diseased branches and leaves, clean up diseased fruits and fruits, and burn them on the spot.

After the garden is cleared, spray stone sulfur mixture to eliminate the source of overwintering disease. (2) Timely prevention and control of pests of infectious disease sources during each potato pulling period. Such as leaf miners and malignant leaf insects.

3) Spray every other day after the new shoots are exposed (before cutting) and after the flowers. The choice of the people of the state of Kezhi is 1:2:

100 times the amount of Bordeaux solution, 600-1000 units per milliliter of agricultural streptomycin plus 1% ethanol solution, 50% zebsen aqueous solution 500-800 times, 50% antibacterial special powder 500-800 times solution, etc.