Disease - Potato Scab
Causal organism - Streptomyces scabies
Symptoms - It is a common disease & found in areas where potato is cultivated. Due to this disease, light brown to dark brown spot appears on the infected tubers.
This disease is spread rapidly in low moisture condition. This disease survives in field as well as in the storage.
The skin of the infected tuber become rough & cracked and scab like spots appeared on the tubers
Factors which are responsible for spreading this disease are contaminated soil, seed and water.
Damage - This disease is most prevalent in dry, alkaline soils. Due to this disease, there is reduction of quality & crop yield also reduced.
Control - It can be controlled by treating the seeds with Emisan 6 @ 0.25 % (2.5 gm/l of water) for 5-6 minutes before sowing.
Integrated Disease Management - Use certified, disease-free seed potatoes & resistant varieties. Do not irrigate the field in excessive amount.
Maintain good soil moisture & avoid over watering. Follow crop rotation.