Control scheme of grape downy mildew in young fruit stage

Grape downy mildew is one of the common diseases in grape, especially in the case of heavy rainfall and long duration this year, grape downy mildew occurs particularly seriously. In recent years, grape downy mildew is not only harmful to leaves and new shoots, but also to young fruits. This paper mainly introduces the control scheme of grape downy mildew in young fruit stage.

After Xiehua sets the fruit, downy mildew damages the young fruit.

Downy mildew harms young fruits after Jufeng physiological fruit drop period

Downy mildew after physiological fruit drop in Wenke harms young fruit

Downy mildew harms fruits during summer black sealing period

Grape downy mildew is harmful to the fruit, after the hard core stage, there is no obvious mildew layer in the disease site, and the symptoms are similar to the grape diseases and insect pests caused by sunburn, so we should pay attention to the distinction.

When grape downy mildew is seriously damaged, the symptoms are similar to boron deficiency. The difference lies in: grape downy mildew harms the fruit, especially after the fruit is enlarged, it generally occurs and shows symptoms from the position of the fruit stalk, and the disease spot will be sunken dark brown, while boron deficiency will show symptoms of the whole fruit, the fruit is not sunken, and the flesh will be lignified. Let's take a look at the comparative photos:

Grape downy mildew boron deficiency causes grape diseases and insect pests

Let's take a look at the profile comparison photos:

Grape diseases and insect pests caused by boron deficiency of grape downy mildew

Grape downy mildew resistance among different varieties: Wenke is easy to infect grape downy mildew, followed by summer black, and Jufeng is more resistant to grape downy mildew than Wenck and summer black. The occurrence conditions of grape downy mildew are as follows: high humidity, high temperature, high rainfall, dew, fog and other wet weather conditions. The following is to explain the prevention and control of grape downy mildew in young fruit stage: before flowering, before flowering and after fruit setting, when there is fog, dew and humidity after rain or when there is fog, dew and humidity after rain, before bagging, especially in open-air cultivation: before flowering: 1500 times Xiehua after fruit setting: special 1500 times grape downy mildew infecting fruit first aid scheme: Gao Fu Shuai 750x washing fruit After an interval of 2-3 days, the whole plant was sprayed with special 1000 times of the whole plant, focusing on the ear. After 5-7 days, it was treated with Amwash 750x + Amida 1500 times. If grape downy mildew is found to infect the fruit, the diseased fruit should be removed as soon as possible after the first medication, taken out of the garden for treatment, and then alternately used with other grape downy mildew agents to avoid resistance. When grape downy mildew is particularly serious, spray with special 750 times + an washing 750 times. Why should we choose safe washing, Gao Fu Shuai and Special for the prevention and control of grape downy mildew in young fruit stage? Safe washing, high wealth and handsome, special suspending agents, safe and efficient, used to wash fruit, do not hurt young fruit, do not pollute fruit surface; and good quick effect, long effective period. Attached are the experimental photos of Gao Fu Shuai 50 times + Amida 1500 times for the control of Wenke grape downy mildew.

Before the May 13 trial, 3 days after the May 16 trial.

Before the May 13 trial, 3 days after the May 16 trial.

It is suggested that in addition to chemical control, rain shelter should be built in areas with conditions to strengthen the management of grape vines and reduce the occurrence and harm of grape downy mildew.