Wednesday, 24 March 2010

Mealybugs cross Thai border

Photo by: Heng Chivoan
Workers in Battambang province cut cassava in preparation for drying

via CAAI News Media

Wednesday, 24 March 2010 15:04 Vong Sokheng and James O’toole

A PEST that has figured in the destruction of millions of tonnes of cassava crops in Thailand has spread to Cambodia, members of the Kingdom’s agriculture sector said Tuesday, sparking concerns that Cambodian cassava crops could be at risk as well.

Som Yen, director at cassava broker Malai Trading Company in Banteay Meanchey province, said he discovered cassava mealybugs – small, white pests that destroy cassava – earlier this year in Banteay Meanchey, where he estimated that they had destroyed between 300 and 500 hectares’ worth of cassava. Most farmers in Banteay Meanchey’s Malai district had been affected, he added.

“Due to Thailand’s experience with the mealybugs, I am concerned that they could spread to other areas, but we will have to wait and see the effects when villagers begin harvesting their cassava after the rainy season,” he said.

Pu Thu, a cassava cultivator in Banteay Meanchey’s Svay Chek district, said his land had not been affected by the mealybugs, though he said they had spread to other parts of Svay Chek.

“I don’t yet know what I will do to stop the mealybug from spreading into my area,” he said.

In Thailand, the Bangkok Post said in a report last month, cassava mealybugs are one factor contributing to a blight that the country’s Office of Agricultural Economics said could reduce 2009-10 cassava yields there to 23 million tonnes, down from an earlier projection of 29 million tonnes.

Private-sector analysts, the report added, predicted the yields could drop to as low as 20 million tonnes, with 27 Thai provinces and roughly 100,000 hectares of cassava crops affected by the mealybugs. With Thailand’s cassava industry worth US$1.5 billion annually, according to the International Centre for Tropical Agriculture (CIAT), such declines could constitute hundreds of millions of dollars in losses.

In a statement released in January on the cassava blight in Thailand, CIAT described the cassava mealybugs as “sap-sucking insects [that] weaken plants, resulting in leaf distortion and lower root yields”. Mites and bacteria have also contributed to the crops’ destruction in
Thailand, CIAT added.

“These pests and diseases will place a huge strain on Thailand’s cassava production,” Tin Maung Aye, a cassava specialist in CIAT’s Asia office, said in the statement. “There will be widespread economic and social implications.”

Heng Bunhor, chief of Banteay Meanchey’s provincial agriculture department, said the government was aware of the issue but was still formulating a response.

“We know there is a white bug that has spread into the cassava plantations, but we don’t have a report about where exactly it has spread,” he said.

“The first step is that we have to educate people about the spread of the bug, and we must monitor the cassava seeds to stop the spread.”

John Macgregor, communications director for the Cambodian War Amputees Rehabilitation Society, which operates a cassava starch factory in Battambang province, said his organisation had been in touch with the International Institute of Tropical Agriculture (IITA) in Benin about obtaining the Apoanagyrus lopezi wasp, a mealybug predator, for introduction in Cambodia. These wasps proved successful in eradicating large numbers of mealybugs that caused a cassava blight in much of sub-Saharan Africa during the 1980s.

“We’re hopeful that Cambodian authorities will take appropriate action to give permission to bring [the wasps] in or bring them in themselves,” Macgregor said, adding that this measure needs to be implemented as quickly as possible.

“The main thing is that the solution isn’t held up by bureaucracy, because cassava mealybugs don’t wait for bureaucracy,” he said.

Khem Chenda, director of the department of administrative affairs for the Ministry of Agriculture, said last June that Cambodia had roughly 3.7 million tonnes of cassava under cultivation.

Minister of Agriculture Chan Sarun could not be reached for comment Tuesday.

No comments: