Sri Lanka rubber plantations face devastation from Pestalotiopsis leaf disease
ECONOMYNEXT – A leaf fall disease caused by Pestalotiopsis, a fungus has begun to ravage Sri Lanka’s rubber plantations and could reach epidemic proportions in the coming rainy season and hit yields, an industry body has warned.
“High humidity favours the spread of the disease causing defoliation and a considerable yield loss and ultimately the death of the tree,” The Colombo Rubber Traders’ Association (CRTA) said in a statement.
“The disease may reach epidemic proportions in coming monsoon period of this year starting from mid-April and hence all stakeholders are requested to be vigilant about this threat to the rubber plantation…”
Pestalotiopsis causes circular patches in leafs and should not be mistaken for normal leaf fall during wintering.
Rubber plantation owners are strongly advised to contact scientists at the Rubber Research Institute for advice and assistance, the CRTA said.
According to an information note by Sri Lanka’s Rubber Research Institute, Pesta had first been reported in Sri Lanka on July 2019.
The disease had started to spread in Kaluthara, Ratnapura and Galle districts in the 2019 monsoon period leaving about 4,000 hectares affected by the end of the year.
Over 380,000 hectares of rubber in Indonesia had been ravaged by the leaf disease by that time RRI said.
The outbreak has been estimated to reduce 70 – 90 percent of productivity in the worst affected areas and about 30 – 50 percent in moderate affected regions in Indonesia, the RRI said.
The CRTA said the disease is now ravaging plantations in Malaysia, India, Thailand, Cameroon and Papua New Guinea.
“In these countries, the disease is spreading at an alarming rate causing a considerable yield loss,” CRTA said.
All rubber clones grown are susceptible to the disease there was no resistant clone, the CRTA said.
The areas affected by the disease have to isolated and treated with fungicide.
“Chemical spraying should be done at the early stages of development of the disease,” the CRTA said.
The treatment protocol is still being developed and trials are being done with drones spraying fungicides 5 metres above the canopy. (Colombo/Mar18/2021)