South America Calling

Brazil's Agriculture Ministry Thursday approved the importation of more powerful pesticides in a bid to control the threat posed by the Helicoverpa armigera caterpillar to soybean and cotton crops.

The measure comes in response to Brazilian farmer complaints that the pesticides at their disposal aren't sufficiently effective against the caterpillar, also known as the corn earworm or cotton bollworm, which caused up to $900 million in damage to crops across the northeastern state of Bahia last year and threatens soybean crops in the top-producing Cerrado region this season.

Following a ministerial decree, farmers may now use Emamectin Benzoate, the principle chemical employed against the caterpillar elsewhere but banned in Brazil because of its toxicity.

However, there are restrictions. Before benzoate-based pesticides can be sprayed on soy crops, individual states must declare a state of emergency and have a pest contention plan approved by Embrapa, the federal crop research agency.

Bahia has already declared an emergency and Mato Grosso, Brazil's No. 1 soy state, is preparing its own declaration.

Previously not thought to be present in the Americas, Helicoverpa amigera created havoc in Bahia last season after spraying proved ineffective following a prolonged drought.

The caterpillar has triggered the kind of concern among soybean farmers not seen since the appearance of Asian rust fungus back in 2003.

Just seven weeks into the season, large populations of the caterpillar have already been reported in Mato Grosso and surrounding states.

Nobody knows where it came from but Embrapa is blaming lax farmers for its spread. A lack of respect for fallow periods and no-plant zones as well as the indiscriminate use of chemicals are key contributing factors, the agency said.

Farmers will celebrate the decree but it may take some time before the new pesticides reach them. In the meantime, caterpillar populations continue to grow.

Farmers expect to make two or three extra applications of pesticides to soybeans this season because of the new pest.

Helicoverpa amigera is a formidable foe. In India and China, up to half of all insecticide applications are focused on controlling it.

(AG)

© Copyright 2013 DTN/The Progressive Farmer. All rights reserved.