The symptoms are also known as wheat snow rot leaf blight and red snow rot. From the germination period to the maturity of wheat can be disease. Produced bud rot, seedling dry, sheath rot, leaf dry, ear rot and other symptoms, including leaf blight and sheath rot is the most important. After germination of bud rot and seedlings, the radicles, radicle sheaths, coleoptiles and other rots were discolored, with less radicles and shorter roots. On the coleoptile, bar-shaped to oblong dark brown spots, severe rot and superficial white hyphae. The leaf sheath of the base of the pathogen becomes brown and necrotic and develops towards the base of the leaf, causing the entire leaf to turn brown or yellow to die. The diseased seedlings grow weak, the roots are underdeveloped or short, the seedlings are short, and the first and the second leaves are shortened. When the disease is heavy, the whole plant is immersed in brownish rot or dies, the dead seedlings fall down, and the surface has white mycelium. After the root rot and the sheath rotted, the diseased parts of the basal pedicels moved upwards after the jointing. The leaf sheaths of the 1-2 bases of the diseased plants browned and rotted. After the leaf sheaths died, they changed from dark brown to light yellow, and the leaves connected to the leaf sheaths were also infected or rapidly browned. Withered. The sheath rot mostly originates from the junction between the upper leaf sheath and the leaf blade, and then develops toward the base of the leaf blade and the lower part of the leaf sheath. The diseased leaf sheath becomes yellowish or yellow-brown, and the discolored part has no obvious edge. When the humidity is high, the sparse red mold-like growth occurs. Things. The upper leaf sheath can cause the flag leaf and the next leaf to die after infection. The leaves of the adult plants of the withered leaves became water-immersed at the beginning of the disease, and later expanded into ovals to large round spots. Occurred in the margin of the leaves are mostly semi-circular, size 1 ~ 4cm, I was 2 ~ 3cm, edge gray hair color, brown stain between the leaves, was invasively spread to the surrounding, forming a few obvious ringwheel layer, Brick red molds are visible on the lesions. When the humidity is large, the white hyphae layer appears on the edges of the lesion, and sometimes the diseased part is finely black, ie, the pathogenic ascus capsule. Most diseased leaves later died. Spikelets with individual spikelets or a few spikelets on their heads, immersed black-brown patches on glumes, red molds, brown rot on the axis of the spikelets, brown rot in individual panicles, severe yellowing and yellowing in full ears The diseased grains are easy to wrinkle and brown, showing superficial white mycelia. The pathogen Gerlachia nivalis (Ces. ex Sacc.) Gams and Mull. Synonyms G.nivale (Ces.) W.Gams et E.Mull., Fusarium nivale (Fr.)Ces. The pathogen produces conidiophores on diseased leaves, forming conidia. Conidia crescents, blunt at both ends, no pods, colorless, with 0 to 3 diaphragms, mostly 1 diaphragm, size 11.3 to 22.82.3 to 3.3 (μm). The sexual state is Monographella nivalis (Schaffnit) E. Mull. Ascospora sacred, beaded to ovate, size 160–25090–100(μm), apical papillary, vented, ascaria shell wall thickened with inside and outside Floor. Ascospores rod-shaped to cylindrical, size 40 ~ 703.5 ~ 6.5 (μm). There are 6 to 8 ascospores in the ascospores. Ascospores are spindle-shaped or elliptical, colorless and transparent, with 1 to 3 compartments, and sizes ranging from 10 to 183.6 to 4.5 (μm). Transmission routes and disease conditions The diseased locust infects leaf sheaths after wintering on the seeds, soil and diseased bodies, and then spreads to other sites and repeats infections several times to spread the disease. The temperature limit for the growth of the bacteria is -2 to 30°C, and the optimum temperature is 19 to 21°C. In the northwest where rainfall is high in April-May, low temperature and humidity are favorable for the disease. The wheat area of ​​the Qinghai-Tibet Plateau is rainy from July to August, and the temperature is low. In addition to damaging the leaves, it can also cause ear rot. Wet and rainy and relatively cold damp mountainous areas and plain irrigation areas are prone to disease. More than 20 days after the heading of wheat, the incidence of leaf above the rainfall is more affected. During the jointing and booting of wheat, the wheat suffered freezing injury and the disease resistance was reduced. There is a significant difference in disease resistance among varieties. In the spring wheat growing area, wheat grouting to milk ripening stage is the epidemic of the disease. In the cultivation and management measures, water and fertilizer management, sowing date, and density are closely related to the disease. Excessive spring irrigation, excessive watering, late fertility flood irrigation or soil viscosity, high groundwater level, high humidity in the field, excessive nitrogen fertilizer application, too late to apply the disease. Sowing too early, the amount of sowing in the field is too heavy. Control methods (1) Selection of disease-resistant varieties and disease-free seeds such as: Zhengzhou No. 3, Huapei 28, Xiaojing No. 6, Zhoumai No. 10, Abo, Xinong 88, Xinong 881, Fengchan No. 3, Qinmai No. 12 is more resistant to disease. The disease-free seed field is reserved. (2) timely sowing, rational close planting. For the dwarf varieties with strong tillering, we must pay special attention to controlling the seeding rate. The use of compost or fermented organic fertilizer is sufficient to avoid partial application, over-application of nitrogen fertilizer, and proper control of top dressing. Filling in winter, spring, as far as possible without irrigation or less irrigation. In early spring, it is forbidden to carry water and flood irrigation. (3) For areas with low humidity, high fertility and dense planting, which may have onset of plots or severe onset of autumn seedlings, spray 80% carbendazim ultrafine powder 1000 times before and after winter and 50 g per 667m2 Ultra low volume or conventional spray. Also available are 36% Thiophanate Suspension 500x, 50% Benomyl WP 1500x, and 25% Triadimefon EC 2000x. Tri Fold Wheelchair Ramps,Folding Suitcase Ramp,Suitcase Ramps For Scooters,Suitcase Ramps For Wheelchairs Active Life Healthcare Co.,Ltd , https://www.alh-med.com