Identification and prevention of several typical diseases of tomato in greenhouses

Summary. Potato leaf blight mainly damages its leaves, and in most cases it is the first to start on the senescent leaves of the lower part of the plant in the middle and late stages of potato growth. At the beginning of leaf blight, the leaves will show greenish-brown necrotic spots, and then gradually develop into nearly round, and if they are allowed to develop, they will be "V" gray-brown, or even reddish-brown large necrotic spots, with inconspicuous wheel lines, the outer edge often fades green and yellow, and the diseased leaves will die and scorch at the end; Sometimes there are dark brown dots on the lesions on the leaves, which are the conidia of the fungus.

Sometimes it will infect the stems and vines, forming amorphous gray-brown necrotic spots, and in the later stage of the disease, small brown spots will be produced in the diseased area.

Potato leaves have transparent spots, what disease.

It seems to be the first.

If it is caused by ladybug damage, it should be prevented immediately. It is also commonly known as "Sister Hua" cannibalizing leaves.

The 17 diseases include: cataplexy, blight, viral fighting disease, leaf mold, early blight, bacterial luminess cochalopathy, gray mold, bacterial canker, bacterial medullary necrosis, gray leaf spot, spot blight, bacterial wilt, sclerotinia sclerotinia disease, wilt, black spot, gray spot and late blight.

It seems that there are no bugs.

Potato leaves with transparent spots are eaten by ladybugs.

It's the virus, the seeds.

Is it a blight.

Potato leaf blight mainly damages its leaves, and in most cases, it is the senescent leaves of the lower part of the plant that start to develop first in the middle and late stages of potato growth. At the beginning of leaf blight, the leaves will show greenish-brown necrotic and cracked blue spots, and then will gradually develop into nearly round, and if it is allowed to develop, it will be "V" shaped gray-brown, or even reddish-brown large necrotic spots, with inconspicuous wheel lines, the outer edge often fades green and yellow, and the diseased leaves will die and burn in the end; Sometimes there are dark brown dots on the lesions on the leaves, which are the conidia of the fungus. Sometimes it will infect the stems and vines, forming amorphous gray source burning brown necrotic spots, and in the later stage of the disease, small brown spots will be produced in the diseased area.

Tomato late blight, also known as tomato blight, is a disease that occurs on tomatoes caused by Phytophthora infestation. Tomato late blight can occur in the whole growth period of tomato, seedlings, leaves, stems and fruits.

1. Use black light to trap and kill, or you can use sweet and sour trapping.

2. Capture early in the morning.

3. Pesticide control: 1. 75 grams of phosphine per mu, add 50 kg of water, and sow the land after spraying to kill tigers in small fields % dichlorvos 1000 times liquid to kill cotton bollworm % trichlorfon 25-50 grams plus an appropriate amount of water, spray on 5 kg of fresh vegetable leaves as poisonous bait to kill mole crickets % phoxtaphos 100 times liquid seed dressing and treatment of soil to prevent grubs.

Choose disease-resistant and tolerant varieties with good commerciality and high yield according to local conditions. The seeds are treated with high temperature to kill pathogenic bacteria attached to the surface. Disinfection methods are selected for the main diseases in the area.

After planting, it is necessary to properly apply some fertile leaf foliar fertilizer to quickly supplement nutrients for tomatoes and restore growth.

Installation of insect nets: The air vent of the shed is closed with an insect-proof net, with a hole diameter of 25 to 40 mesh and a width of 1 to 1 meter, covering the air outlet. Appropriate application of phosphorus and potassium fertilizers can improve the disease resistance of plants.

Drip irrigation and dark irrigation technology are used to prevent flooding. In the early stage of the disease, remove the residual petals and stigma in time, remove the diseased leaves and fruits, and pull out the diseased plants to prevent the spread of the disease.