24d butyl herbicide has an effect on fruit setting of grapes at flowering stage. Grape soon showed symptoms after being infected with herbicide, which mainly showed that the leaves rolled forward vertically, and irregular spots appeared at the tip, edge and middle of the leaves. In severe cases, the whole leaf is dry, and the symptoms in young parts are more serious. The symptoms of early germination are slightly lighter, and the symptoms of late germination are heavier. Judging from the damaged varieties, Eurasian species are heavier, while European and American hybrids are relatively lighter. The grape varieties of Peking University and Mountain Grape suffered more; Jingya leaf curl is more serious than Jufeng. Wine grape varieties such as Merlot and Cabernet Sauvignon, and table grape varieties such as Red Globe and Baijixin suffered serious damage and their leaves withered severely. With the passage of time, the new shoots of the plant are severely twisted, the leaves are deformed, the veins are yellow and other symptoms, and the inflorescence becomes hard, deformed, faded and red. Within 0/5 days after injury/kloc-,every time it rains, it can cause the drug injury to rebound and aggravate the harm degree. About 1 month after injury, the symptoms of phytotoxicity improved obviously and the plants began to grow again. However, the new leaves and inflorescences are obviously yellow, and the growth potential is obviously weakened. At this time, the symptoms of plants that germinate late and get sick seriously in advance are lighter than those of plants that germinate early; Jingya variety with severe early symptoms is superior to Kyoho variety in restoring growth and fruit setting. Wine grape varieties such as Cabernet Sauvignon and Merlot recovered quickly. Judging from the fruit drop, the fruit drop of Jingya is better than that of Jufeng, and it is almost unaffected. Cabernet Sauvignon, Merlot and other wine grape varieties have good fruit setting and little damage. Jufeng and Vitis amurensis series varieties have poor fruit setting, serious size and grain, low fruit setting rate and some whole inflorescences fall off; Red balls, white hearts and other Eurasian edible grapes are almost never harvested.

In the middle and late stage, the damaged plants showed delayed fruit ripening, decreased sugar content and serious fruit cracking. Grapes can't be stored after harvest, and they rot badly. Therefore, grapes damaged by 2.4D butyl herbicide cannot be preserved for a long time and can only be sold in season. By observing the plants injured by drugs last year, this spring, they were affected in cold prevention, germination, fruiting and so on.

Two. Relief method

1. Management Measures The municipal and county governments respectively issued the documents "Prohibiting the use of 2.4D butyl ester and herbicide containing 2.4D butyl ester within 500m of vineyards" and "Prohibiting the sale of 2.4D butyl ester and herbicide containing 2.4D butyl ester in the whole city". Agriculture, industry and commerce, technical supervision and other departments to carry out joint inspection and rectification of the city's pesticide market, prohibit the sale of 2.4D butyl ester and herbicides containing 2.4D butyl ester. Experts in grape planting and plant protection in the province were also hired to give lectures to fruit farmers, improve their management skills and strive to minimize losses.

2. Technical measures

(1) Strengthen the management of fertilizer and water, irrigate the damaged plants in time, apply fertilizer in time, loosen the soil in the planting ditch, so as to raise the ground temperature, promote the rapid growth of roots and new shoots, disperse and decompose the pesticide residue concentration on plants as soon as possible, enhance the resistance of trees and alleviate the symptoms of phytotoxicity.

(2) Strengthen pruning in summer and strictly control the fruit setting of plants.

The old leaves of the damaged plants have basically lost their functions, so the main shoots should be picked in the later stage and 2-3 leaves should be left as much as possible. And leave 2-3 sprouted secondary branches at the top to pick the core, so as to increase the photosynthetic capacity of the tree.

The fruit load of damaged plants should be strictly controlled, the load of lightly damaged plants should be determined according to 50% of the original yield, and the ear of severely damaged plants should be thinned. Controlling the fruit load can reduce the burden on plants, restore the normal growth of plants as soon as possible, and better reserve nutrition for the coming year.

(3) spraying foliar fertilizer

After finding symptoms, foliar fertilizer should be sprayed on the affected plants in time to increase the resistance of trees and restore their growth as soon as possible. The foliar fertilizers sprayed are: Bihu, Brassica, Dayun 120, Lufeng, Gaomeishi, Plant Power 2003, etc. In order to achieve the effect of foliar fertilizer, it can be sprayed 1 time every 2-3 days and continuously.

(4) ear shaping and bagging

Through ear shaping, bagging and empty production, the quality and commodity of fruit are improved, and the market sales price is raised, so as to achieve the goal of reducing production and harvesting after the disaster.

(5) scarifying the soil at night and erecting it at night

Although the government has taken administrative intervention measures to prohibit the use and sale of 2.4D butyl herbicide, some farmers should use 2.4D butyl herbicide in corn fields in 2008. In order to prevent the recurrence of phytotoxicity, the vineyards in the whole city have taken the measures of spreading soil at night and planting at night to avoid putting them on the shelves during the application of herbicides in corn fields. Because plants are put on shelves late, germinated plants should be put on shelves after 2 pm to prevent young shoots from being damaged by sun burning and wind burning. Practice shows that the method of spreading soil and planting at night can effectively avoid the occurrence of phytotoxicity.

(6) Scientific planning and centralized contiguous.

2.4D Butyl ester phytotoxicity also occurs frequently in other grape producing areas in China. At present, there is no better remedy for grape plants damaged in production. It is impossible to completely eliminate sales and use by administrative intervention. There is no mandatory regulation on the use of 2.4D butyl herbicide in ordinary farmland in China. This year, the Ministry of Agriculture issued a regulation that "2.4D butyl herbicide is not allowed to be used in the range of broad-leaved agricultural and forestry crops 100 meters". Nevertheless, it is impossible to control and avoid the occurrence of phytotoxicity.