1. Symptoms

Broken leaf disease damages the tip or edge of tobacco leaves. The lesions are irregular in shape, brown, mixed with irregular white spots, causing broken leaf tips and leaf margins. In the later stage, small black spots are scattered on the disease spots, that is, the ascus of the pathogen, and intermittent gray-white lightning-like dead spots often appear along the edge of the veins in the middle of the leaves. , Irregular broken perforated spots.

2. Prevention methods

(1) After harvesting, remove litter and fallen leaves in the field and burn them in time. Turn over the land in time to bury the diseased plant residues scattered in the field deep in the soil, plant reasonably densely, and increase phosphorus and potassium fertilizers to promote the growth of tobacco plants and enhance disease resistance.

(2) If the disease is found in the field, apply pesticides to prevent and control the whole field in time. In combination with the prevention and control of other diseases, the following agents can be used:

Carbendazim 50%WP 600-800 times liquid;

Thiophanate-methyl 70%WP 800-1000 times liquid;

Benomyl 50%WP 1000 times liquid;

2000 times liquid of Propiconazole 25%EC + 500 times liquid of Thiram 50%WP, spray evenly with 500g-600g pesticide with 100L water for 666m³.