Rubber (Hevea brasiliensis)
Abnormal leaf fall (Phytophthora meadii)
Symptoms
- Abnormal leaf fall occurs during June-August, while general leaf fall occurs during December-January
- The conspicuous symptom is the formation of coagulated latex at the point of entry of the pathogen.
- A dark brown discoloration of the petiole
- Petiole infection results in premature defoliation.
- The leaves may sometimes remain attached to the petiole.
- Bronze coloured discoloration of the young foliage.
- Circular brownish water soaked lesions appear on the leaf lamina.
- Several of the lesions coalesce together causing rotting of the tissues
- During south west monsoon period, the fruits rot.
Management
- Prophylactic spraying of the foliage prior to the onset of southwest monsoon with 1 per cent Bordeaux mixture (3000-4000 l/ha) or oil based copper oxychloride (30-40 litres of COC-oil mixture per ha mixed in 1:5 proportion) is recommended.
