- Chlorotic angular leaf spots surrounded by yellowish halo is the most common symptom of pollu.In high ranges circular spots are noticed and occasionally the necrotic portion drops off leaving holes.
- When conditions are favourable leaf spots may join together resulting in leaf blight followed by defoliation.
- The fungus causes necrosis on the stalk of the spike resulting in spike shedding. Infected spikes turn black, shrivel and shed. The infection starts from the tip of the spike and gradually progresses upwards.
- Berries at the proximal end of the spike develop to maturity except that they exhibit minute black spot. Berries close to the diseased portion are smaller in size. It also causes a mild crack on some berries and further development is affected.
- The affected berries dry up gradually and remain as light berries (fungal pollu).In severely infected plantations, defoliation, spike shedding and berry shedding are common.
The infection is noticed during June at the time of spike emergence. Anthracnose disease is mainly spread by the rain splash. Maximum damage is noticed during August-September and the loss ranges from 28-34%.
Observe 20 standards from the plot at random and assess the % of spikes showing symptoms by selecting 10 spikes at random from each standard. Workout the average damage. Less than 2 % mild; 2-4 % moderate and more than 4 % severe.