Short essay on Powdery mildew of Peas (Erysiphe polygoni)

This is a fungal disease of peas. The casual organism is Erysiphe polygoni which is an obligate parasite.

The disease is worldwide in occurrence. Early varieties cause less damage i.e. the varieties maturing in January, generally escape the disease. Late maturing peas when infected during their pod forming state, maximum damage are caused.

Symptoms

The disease first appears on the leaves and then spreads to other green parts of the plant. The attack is characterized by appearance of small, white patches on both

(iv) Hot weather deep ploughing.

(v) Rotation of crop, organic amendments, seed disinfection.

(vi) Early varieties preferred.

The third control measure is eradication. The diseased plant parts or even the entire diseased plants may be spotted early and should be burnt or buried to eliminate the pathogen.

The fourth measure is chemotherapy, i.e. chemical treatment of the affected plants. Sulphur dustings at the rate of 25-30 lbs per acre are effective to check the spread of the disease.