Tobacco blackhead disease
Symptoms Tobacco can develop from the seedling stage to the adult plant stage, and mainly damages the aerial parts. The infection at the nursery stage began in two true leaf stages, with lesions on the main veins or lateral veins of the first leaves. The lesions quickly spread along the midrib to the petiole and formed round to oval spots with a size of 0.2-0.3. In mm, it expands into stripe spots upwards and downwards, and as a result, the top bud bends to the lesioned side, and the diseased side of the diseased plant leaves wither, the whole plant assumes a state of “preferably dryâ€, and the severe plant withered. Cut open the disease stem from the base to the end of the vascular bundle with obvious black lines, near the black line at the veins change black hair wrinkles, stems close dense black spots, the pathogenic conidia plate. The field symptoms are similar to those in the bedtime. Control methods (1) During the transplanting period, the thiophanate-methyl herbicide was applied to the soil, and 0.5 kg of each 667 m2 of the drug was mixed with a small amount of fine dry soil to be uniformly applied to the transplanting hole. (2) Continuous spraying of 50% thiophanate-methyl WP (500 times) or 50% carbendazim WP (600 times) and 50% benomyl WP (1500 times). Matcha Tea Kit,Matcha Tea Private Label,Matcha Powder Private Label,Matcha Private Label SHAOXING ROYAL TEA VILLAGE CO.,LTD , https://www.yccmatcha.com
The pathogen, Colletotrichum capsici (Sdy) Bulter & Bisby fnicotianae GM Zhang & GZ Jiang, said that the bacterium is a fungus of the subphylum Aspergillus spp. The conidiophore contains densely rod-shaped single-celled conidiophores, terminal conidia, conidia with crescents and cylindrics: the former is sometimes slightly straight, the unit cells are colorless, and size is 12-162.5. -5.5 (μm). Cylindrical unit cells are colorless, size 9.8-41.52.3-7.7 (μm). Bristles scattered on the conidia plate, dark brown, with 1-5 diaphragm, size 65-1224.5-5.5 (μm). The growth temperature limit of this bacterium is 5-38.5°C, and the optimum temperature is 32°C. Adapt to pH 1.8-11.5, the optimum pH is 4.5-9.6.
Transmission routes and pathogenic conditions The pathogens use hyphae to overwinter in the soil or on the sick. In the soil, the bacteria can survive for 3 years. In addition, organic fertilizers with pathogens can also infect. The conidia produced by the diseased department were transmitted through wind and rain or water and repeatedly infested. From July to August, it is prone to rain and high humidity. The terrain is low and the soil is heavy and heavy.