How do you prevent and control southern blight when growing jasmine?
How do you prevent and control jasmine southern blight? What causes jasmine southern blight? Please give an introduction. Jasmine southern blight is the most serious disease of jasmine. When the disease is severe, it causes the plants to die, affecting yield. Jasmine southern blight occurs at the root collar and roots, and when conditions are suitable it can spread to the lower leaves. Root collar...
How do you prevent and control jasmine southern blight? What causes jasmine southern blight? Please give an introductionJasmine southern blight is the most serious disease of jasmine. When the disease is severe, it causes the plants to die, affecting yield. Jasmine southern blight occurs at the root collar and roots, and when conditions are suitable it can spread to the lower leaves. The root collar turns brown and rots, gradually spreading and expanding, producing a white silky film, mostly radiating outward, especially noticeable at the edges. The silky hyphae can spread to the soil near the root collar, and in severe cases the entire pot of soil is filled with white hyphae. Later, sclerotia form on the silky film. The sclerotia are initially white, gradually darkening to yellow, tea-brown, and finally dark brown, about the size of rapeseed. After the cortex rots and dies, the leaves wither and drop off, and in severe cases the whole plant dies.
The jasmine southern blight pathogen mainly spreads through the soil as hyphae, and long-distance transmission relies on flowing water or the human movement of diseased seedlings, diseased soil, and diseased pots. The disease is likely to occur when garbage soil or vegetable garden soil is used when changing potting soil; the disease is severe under continuous cropping or when diseased potting soil is used continuously; high humidity makes the disease likely to occur.
Jasmine southern blight can be prevented and controlled by referring to the following methods:
Horticultural control:Practice crop rotation, and treat diseased potting soil in a centralized way, preferably by dumping it into rice fields. Potting soil should be taken from disease-free plots, preferably rice field soil. Organic fertilizer must be fully decomposed; propagation material should be cut from disease-free plants; avoid dense stacking when overwintering in a greenhouse.
Remove diseased plants and disinfect the soil:When diseased plants are found early, they should be promptly removed and burned or buried deep. The disease holes should be drenched with 86.2% Copper Master 800-1200 times dilution, or 50% amobam 500 times dilution, or sprinkled with lime powder. The removal of diseased plants should be carried out before sclerotia form.
Chemical control:Use 1 kg of 50% Tuzet per mu for control; in the early stage of the disease, drench with 50% amobam 1000 times dilution, and apply control once more after 7-10 days to kill the pathogen in the soil.
After the disease occurs, use 70% thiophanate-methyl 1000 times dilution or 50% carbendazim 1000 times dilution, and sprinkle it on the soil around the base of the plant stems to inhibit the spread of the disease. Then water with other fungicides later. For potting soil, a Trichoderma bran preparation can be used, mixed into the soil at 0.5% of the soil weight, and used after potting; alternatively, part of the potting soil can be dug out and replaced with soil mixed with the preparation.
Physical control:Sterilize the potting soil by heating.
Biological control:Using the antagonistic fungus Trichoderma harzianum to control jasmine southern blight has good results. First culture the Trichoderma strain well, then mix it onto sterilized bran to make a Trichoderma preparation. When using the Trichoderma preparation, mix it evenly with fine soil and apply it to the soil. The soil must maintain a certain humidity to promote the mass growth and reproduction of Trichoderma in the soil, thereby inhibiting the growth of the southern blight pathogen and achieving the purpose of disease prevention.
Rational fertilization:Applying undecomposed organic fertilizer to the soil surface will aggravate the occurrence of southern blight, so organic fertilizer (such as manure, etc.) should be used as a base fertilizer and buried deep in the lower soil layer. If used as a topdressing, it must be fully decomposed before application.
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