Control method of watermelon Fusarium wilt What medicine does watermelon Fusarium wilt take?

Watermelon blight, also known as watermelon blight, usually occurs in seedling stage and early growth

Control method of watermelon Fusarium wilt What medicine does watermelon Fusarium wilt take?

Watermelon blight, also known as watermelon blight, usually occurs in seedling stage and early growth stage. It is an important disease in high temperature and rainy period, especially in rainy years of watermelon growth period. Let's take a look at the prevention and control methods of watermelon wilt!

First, the symptoms of watermelon wilt

In the early stage of root neck disease, dark green waterlogging spots were produced, which developed rapidly and surrounded the stem base. The whole plant was soft rot, atrophy, wilting and death, leaves withered and vascular bundles remained unchanged.

When the leaves are sick, dark green waterlogging spots are produced, which quickly expand into large round or irregular yellow-brown spots. When the humidity is high, the whole leaves rot, and the diseased leaves are light brown, which is easy to break after drying.

When the stem was killed, it was a dark green spindle depression with water stains and died above the diseased part.

The damage of fruit is dark green and round, with water stains, which quickly spread to the whole fruit surface. The fruit is soft and rotten, and a layer of sparse white mold grows on the surface of the diseased spot.

Second, the occurrence law of watermelon Fusarium wilt

The pathogen overwinters in soil or immature manure with oospores, chlamydospores and mycelium. In the following year, oospores and chlamydospores spread through rain, irrigation water and soil tillage, and invaded or directly penetrated the host epidermis from stomata, causing primary infection.

Spores produced on diseased plants are reinfected by wind and rain. The optimum temperature for the development of pathogenic bacteria is 28-30℃. When the ten-day average temperature is 23℃, melon vines begin to get sick in the field, and the relative humidity above 85% is the decisive factor for the epidemic of the disease.

Warm and humid conditions are conducive to the onset; Low-lying land, poor drainage, uneven ridges, plots prone to water accumulation and continuous cropping for many years, as well as excessive watering, excessive planting, excessive application of nitrogen fertilizer or insufficient application of manure will aggravate the occurrence of diseases.

Third, the control methods of watermelon Fusarium wilt

1. Variety Selection Among more than 60 watermelon varieties introduced in China in recent years, Xiang Watermelon No.3, No.4 and No.6, Hunan Qinseedless Watermelon, Qiongxue and Qinghongbao are disease-resistant.

As for some varieties with strong disease resistance, such as Xin Jing 1, Zhengza No.5, Xinhongbao, Jinhuabao, Tezaojialong, Yunzhong 1, Changmi 1 and 2, Zhongyu 1, Xiabao No.3, Bafengshou No.3 and Qiongsu, etc. Whether they are also resistant to Fusarium wilt needs further observation and identification.

2. For non-cucurbit crops that have been controlled by agriculture and rotated for more than 3 years, clean up the fields, cut off the infection source of overwintering bacteria, pull out the diseased plants in time, and bury them in a centralized way or burn them, without using immature organic fertilizers with diseased bodies.

Reasonable close planting, deep furrow and high border cultivation, timely drainage after rain, and control field humidity. Watermelon cultivated in protected areas should be irrigated with small amount of water or drip irrigation under film to save water and keep warm and reduce humidity in the shed. Flood irrigation and string irrigation are prohibited.

4. What medicine can be used to fight watermelon Fusarium wilt? 700 times of 72% phenylurea-manganese-zinc (Kelv) wettable powder, 2,500 times of 50% dimethomorph (Anke) wettable powder, or 800 times of 72.2% propamocarb hydrochloride (Pulv, regenerated) aqueous solution, and 500 times of 58% metalaxyl-manganese-zinc (Jin Lei) wettable powder. 500 times solution of Mn-Zn (antiviral alum) wettable powder, once every 7 ~ 10 day, for 3 ~ 4 times continuously.

If necessary, the above fungicides can also be used to irrigate the roots, and each plant can be irrigated with 0.25 ~ 0.4 liters of liquid medicine. If spraying and root irrigation can be carried out at the same time, the control effect will be obviously improved.