Symptoms mainly occur in the ear, and the ear is extracted earlier than the ear. The initial disease spiked with a gray film on the outside of the spikelet, matured and ruptured, and the black powder (the chlamydospore of the pathogen) was scattered. After the black powder was blown away, only the bare cob was left. Spikelets on the diseased ear were all destroyed or partially destroyed, and only the upper part survived with a large number of spikes. In general, there are sick ears in the main stem and tillers, but some of the tillers in disease resistant varieties do not develop. When wheat was infected by both smut and smut, the ear of the diseased ear appeared blackhead and the lower part was scattered black ear. Occasionally, smut germs also invade the leaves and stems and grow a strip of black spores on them. China leading manufacturers and suppliers of Active Pharmaceutical Ingredient, Mupirocin , Mupirocin Calcium, and we specialize in Sodium Fusidate, Fusidic Acid. Active Pharmaceutical Ingredient, Mupirocin, Mupirocin Calcium, Fusidic Acid, Sodium Fusidate Manufacturer Fuzhou Contay Biotechnology Co., Ltd , https://www.contaybio.com
The pathogen Ustilago nuda (Jens.) Rostr. said bare black powder fungus, is a basidiomycotina subphylum fungi. The synonymous U.tritici (Pers.) Rostr. is a spherical, brown, slightly pale side with a stinging surface, 5-9 μm in diameter. Chlamydospore germination temperature limit 5-35 °C, with 20-25 °C optimum. When germinating, the hyphae are born and no basidiospores are produced. Infestation of wheat leads to smut, which has the phenomenon of host specialization. The bacteria on wheat cannot infect barley, but the bacteria on barley can infect wheat. The chlamydospore germination produces only four cell burdens and no basidiospores are produced.
Spreading Pathways and Incidences Scattered smut is a flower-infested disease that only infects once a year. Seed-borne seeds are the only way to spread the disease. The germs latent in the seed embryos with hyphae and the appearance is not obvious. When the bred seeds germinate, the untreated mycelium begins to germinate, and grows upward with the growth point of the wheat and invades the ear primordium. At the time of booting, the mycelium develops rapidly, turning the wheat ears into black powder. The chlamydospores fell on the Jiansui in the flowering stage with the wind, and they fell on the wet stigma and germinated to produce the first hyphae. The first hyphae produced four cells to give rise to filamentous binding tubes, and the opposite sex combined to form the double nuclear invasion invader. Room, before the bead is not hardened into the ovule, hidden in it, when the seed matures, the mycelium membrane is slightly thickened, in which dormancy, no symptoms appear in the year, the next year onset, and invades the seeds of the second year of latent invasion. Dyeing cycle. C. verrucosa spores can germinate just after 24 hours, with a temperature range of 5-35°C and an optimum of 20-25°C. The chlamydospores live for only a few weeks in the field and there is no possibility of wintering (or crossing summer). During the period of wheat annumization, the air has high humidity, and it is usually conducive to germination and infiltration of spores.
Control methods (1) Soaking with warm soup 1 Soaking with variable temperature Soak wheat seeds with cold water for 4–6 hours, then dip them with warm water of 52–55°C for 1–2 minutes, so that the seed temperature rises to 50°C, and then remove. Into 56 °C warm water, so that the water temperature dropped to 55 °C soaked for 5 minutes, then quickly remove the cold water after cooling and sowing. 2 Constant temperature soaking The wheat seeds are placed in 50-55°C hot water and stirred immediately so that the water temperature quickly stabilizes to 45°C. After soaking for 3 hours, remove and move into cold water to cool. Allow to dry after sowing. (2) Lime seed soaked with high-quality lime 0.5kg, dissolved in 50kg of water, filter out the residue after soaking 30kg of selected wheat seeds, requiring the surface of the seed higher than 10-15cm, the seed thickness does not exceed 66cm, soaking time temperature of 20 °C Soaking for 3-5 days, the temperature of 25 °C soaked 2-3 days, 30 °C soaked 1 day, after soaking no longer wash with water, spread out after drying can be sown. (3) Seed dressing seed weight) 63% of the 75% chloridone wettable powder dressing, or seed dressing 0.08% -0.1% of 20% triadimefon EC. Can also be used 40% seed dressing double wettable powder 0.1kg, mix wheat seed 50kg or use 50% carbendazim wettable powder 0.1kg, 5kg water, mixed wheat seed 50kg, mix and boring after 6 hours, can cure black Head disease.