Recently, I stood and received a phone call from farmers in Xiaotan Township. They said that when they poured wheat, they found brown spots on the leaf sheath near the surface of the wheat seedlings. They asked if they were sick and how to prevent it. After my station technicians asked the situation, they immediately contacted plant protection specialists of the County Agriculture Bureau, senior agronomists Miao Lianhe, county agricultural station leader and senior agronomist Guo Peizong, etc. to go to the wheat fields where abnormal conditions occurred.
In the village of Shilipu in Xiaotan Township, villager Li Mou is anxiously waiting for his own wheat field. When we saw us, he took us to the middle of the wheat field and bent down to pull up a few wheat seedlings. He said anxiously, "You see, you see, that's it. This leaf is streaky! It's really anxious!" After taking the wheat seedlings, after careful inspection and analysis, it was determined to be wheat sheath blight.
According to Guo Peizong, the pathogens of wheat sheath blight mainly invade the roots and stem bases of wheat, resulting in a series of symptoms such as rotting buds, dead seedlings, flower stalks, rotten stems, lodging, dry booties, and dry white ears. The rate is above 30%.
Miao Lianhe said that wheat seedlings infected with wheat sheath blight pathogens have gray-brown spots on the leaf sheaths of seedlings from the 3rd to 4th leaf stage, and can spread to the entire leaf sheath. The leaves are dark green, and are immersed in water. When the diseased seedlings die, after the jointing, the wheat plant base leaf sheath appears oval dark green water immersed lesions, later developed into a central grayish-brown, marginal dark brown lesions, oval or slightly moire, after the lesions expand Connected to each other, the diseased leaf sheaths appear light and dense, streaks of staggered texture, collectively referred to as flower stalks. Flower stalks are typical symptoms of sheath blight, and when wheat fields are severely affected, they are due to flower stalks, rotten stalks, main stalks, and large pods. Often can not pull the ear, the formation of dry booting, and although some can heading, but the sharp drop in the number of seeds, pods lean thin, the formation of dry white spike. Plants with lighter disease, although they can normally head their heads, are susceptible to lodging due to damage to the stalks and are likely to result in reduced yields.
Guo Peizong said that because of the wheat sowing date last year and high temperatures in November, and since mid-February of this year, the rapid rise in temperature has been favorable to the occurrence and development of wheat sheath blight. According to a recent survey, wheat sheath blight in Yanjin County. The average disease rate is 11.5%, and the disease is 38%. With the increase of temperature in March, there will be a peak period of infection. Therefore, we must seize the favorable opportunity before March 25 to prevent and cure wheat sheath blight.
Finally, plant protection expert Miao Lianhe prescribes the control of wheat sheath blight: 1. 100-150 ml of 5% Jinggangmycin per acre, and 100-150 kg of water added to the stem base of the wheat; 2. 25 % Triadimefon WP can be used for 20-25 grams per mu, or 12.5% ​​pods, 25-30 grams per mu, plus 50 kg of wheat stems evenly sprayed with water.