While the heavy monsoon rain has ended in India, the bad news continues for rubber farmers in Kerala as many rubber plantations have been infected with the fungus phytophthora meadii, which is expected to lead to a decline of up to 35% in latex production, according to India’s Rubber Board. Continuous heavy rain makes rubber trees susceptible to phytophthora meadii, commonly known as rubber leaf drop. As its name suggests, the fungal attack results in abnormal fall of leaves.
This disease can hit the rubber sector badly as the endless rains during July has already resulted in the sharpest fall in monthly production of natural rubber in the last four years. The monthly output showed a drop of 32.4% in July. The production was 46,000 tonnes as against 68,000 tonnes on year-on-year basis, according to the Rubber Board. “The disease leads to a situation similar to the withering of trees in December and January. It can reduce latex production as the absence of leaves stops photosynthesis. Seven days of continuous rain is enough to make a conducive atmosphere for the growth of the fungus. It is a water-loving fungi. However, just a sunny day in between these seven days is enough to destroy its spores. Unfortunately, the recent rain was incessant for weeks together,” Bindu Roy, Senior Scientist at Rubber Research Institute in Kottayam.
The fungi can infect the barks of mature rubber trees of tapping age and rot shoots of young trees. Unless treated, infections result in uneven regeneration of the bark, which makes subsequent tapping difficult or impossible. “In an advanced stage, the latex gets coagulated between the wood and the bark. The disease can be prevented by prophylactic spraying, normally by May, before the onset of the monsoon,” Bindu said. Phytophthora meadii infection in rubber plantations has been reported in Maharashtra and Karnataka states too.