Brown Spot
Brown spot is a fungal disease mainly caused by Rhizoctonia solani.
Symptoms:
The lower leaves begin to get sick and gradually spread to the upper part. At the initial stage, they are round or oval, purplish brown, and at the later stage, they are black, with a diameter of 5-10 mm. The boundary is clear. In severe cases, the disease spots can be connected into pieces, causing the leaves to wither and fall off, affecting flowering.
Occurrence regularity:
The pathogen survived the adverse environmental conditions with the sclerotia or mycelium on the plant residue. Sclerotium has a strong ability to withstand high and low temperatures, and the suitable temperature for infection and disease is 21 ℃ – 32 ℃.
