Black spot is a fungal disease that is caused by Diplocarpon rosae. It is the most common and serious disease of roses. The fungus infects the leaves and causes them to develop black spots, which can eventually lead to defoliation.

Black spot disease in rose crop

Scientific name: Diplocarbon rosae

Type: Fungal Disease

Target: Leaves

Damage: Black spots on leaves

Environmental favorable factors for pests/Diseases:

Temperature: Temperatures between 20-27°C are ideal for the growth of the fungus Diplocarpon rosae.

Humidity: High humidity levels in the air (above 70%) create a moist environment that allows fungal spores to germinate and spread easily.

Symptoms of Pest/Disease:

Small, brown spots with feathery edges on the upper surface of leaves
Spots growing larger and becoming circular or irregular in shape, turning dark brown to black
Yellowing of the tissue around the spots
Infected leaves turning yellow and dropping prematurely
Defoliation (leaf loss)

Measures to control Pests/Diseases:

Products	Technical Name	Dosage
DR BLIGHT	Metalaxyl-M 3.3% + Chlorothalonil 33.1% SC	300-400 ml/acre
K ZEB	Mancozeb 75% WP	500gm per Acre
Hexa 5 Plus	Hexaconazole 5 % SC	200-250 ml per acre

Measures to control Black spot disease in rose crop