Detailed Guide to Identifying and Controlling Anthracnose Symptoms

OrchidsAnthracnose: It mainly damages the leaves. In the early stage of the disease, dark brown spots appear on the leaves, surrounded by a faded green halo. After the spots expand, they become oval or elongated. The edges are dark brown, the interior is yellowish brown, and the spots are slightly raised. Later, black granular bodies appear on the spots. Under humid conditions, the black granular bodies exude a pink gelatinous substance, namely the pathogen's acervuli and conidial masses. Anthracnose occurs over a long period, with the most severe incidence in July and August. Control: (1) Ensure ventilation and light transmission. (2) Fertilize reasonably to improve disease resistance; during the growing period, control the application of nitrogen fertilizer and apply appropriately more phosphorus and potassium fertilizer. (3) In the early stage of the disease, spray 50% carbendazim or 70% thiophanate-methyl wettable powder at 500-800 times dilution.