November 17, 2003
From: @gWorldwide, 18 Nov 2003 via Reuters [edited]

Brazilian growers arm to fight Asian soy rust

Soybean producers across Brazil have armed themselves this season in a battle against possibly the biggest threat to their livelihood -- a virulent strain of Asian soy rust caused by _Phakopsora pachyrhizi_.

"The whole state is worried," said head agronomist Andre Neves Santos at the Moises Sachetti farms in Brazil's No. 1 soy state, Mato Grosso. "I've been to 5 training seminars on how to identify and combat rust fungus in the last few months."

According to the U.S. Department of Agriculture, Brazil will become the world's No. 1 exporter of soy in 2003, displacing the USA.  Experts agree that Brazil's future leadership in soy production will depend on how well it contains Asian rust, the most destructive soybean leaf disease, which reduces yields by up to 80 percent.

Rust first showed up in Paraguay in 2001 and has since spread through Paraguay, Brazil, Bolivia, and parts of Argentina. U.S. producers are terrified at the possibility of the fungus reaching U.S. soy fields.

Of the main soy states affected last season, Mato Grosso suffered the most because growers were caught off-guard, unconvinced it could travel so fast across Brazil's massive 20-million-hectare soy belt.

"95 percent of producers in the state have already purchased all the fungicide they expect to need this season," said Cristina Santos, who added the cost of fungicide and its application would be expensive. Cost estimates of soy experts are around $50 per hectare.

Rust showed up late in the growing cycle last season, reducing yield by 3 million tonnes off the 2002/03 crop, lowering Brazil's output to 52 million tonnes, said Jose Tadashi Yorinori, Brazil's top soy rust expert at the national plant research agency (Embrapa). 

As Brazil enters the peak of a new Sept-Dec planting season, Mato Grosso has already registered its first outbreaks of rust. "It began earlier this year," said Yorinori. He said losses were pronounced in Mato Grosso and Bahia last season because producers didn't identify the rust and spray soon enough. But this is also a particularly virulent strain of rust.

Yorinori said tropical varieties of commercial soy seed that were previously thought to have some rust resistance last season did not have resistance to this virulent strain. Producers will have to rely largely on fungicide until new rust-resistant strains are developed -- but that is likely to take years.

Embrapa has identified one soy variety (BR-134) that is resistant to rust, but it is not adapted to many growing regions in Brazil. Embrapa is working with private sector firms to find and develop more resistant soy varieties.

For now, producers are betting on a tough spraying campaign to hold off the disease.

[Byline:Reese Ewing]