Buckwheat white mold

Symptoms mainly affect the leaves. At the time of initial onset, pale green or yellow spots with no obvious edges were produced on the leaves, and the lesion expansion was sometimes limited by veins. The white mold on the back of the leaves is the pathogenic conidia and conidia.

The pathogen Ramularia anomala Peck is called a special-shaped column septum and belongs to the fungus Deinophyta spp. The fruiting body was born on the back of the leaf, with only a few cells in the sub-segment; the conidiophore stalk was colorless, dense, with no septum, and occasionally branched at the top, without a geniculate ganglion, with a rounded top, size 15-602-3 (μm); The conidiophores were clustered, single-celled, colorless and transparent, and the uppermost conidium tip was bluntly rounded, with a size of 12-183-4 (μm).

Transmission routes and disease conditions The disease exists in the south all year round. The diseased spores are transmitted by wind and rain or water droplets, but there is no overwintering problem. In the north, mycelia and conidia are overwhelmed with the remains of the diseased body. . The first infestation occurred with conidia in the following year, and the spores generated in the diseased part were re-infected by airflow and rain spattering. Humidity is a decisive factor in the spread of the disease, and the incidence of heavy rainfall in the year is heavy.

Control methods (1) Application of fully decomposed organic fertilizer. (2) Proper close planting to avoid excessive watering. (3) Spray 75% chlorothalonil wettable powder 1000 times liquid plus 70% thiophanate-methyl wettable powder 1000 times liquid or 40% polysulfide suspension 600 times liquid, 50% fast-inking wettable powder 2000 times Liquid, every 7-10 days, continuous control 2-3 times.