November 9, 2005


Early Asian rust puts Argentina's soy at risk


Argentine soybean farmers could have more trouble with Asian rust this season than they have in previous years, a plant specialist said Tuesday.


The pathogen linked to Asian rust, a fast-flying fungal disease that can severely crimp yields, is spreading in the key soybean-producing provinces of Entre Rios and Santa Fe, according to recent data from Senasa, Argentina's animal-and food-health agency.


Asian rust appeared in at least 10 Argentine provinces last season. However, the disease caused almost no damage because it appeared late in the growing cycle, after crops had already passed through the most important growing stages.


For the 2004-05 harvest, Asian rust did not appear until March, which is when the harvest normally begins. However, this season the disease was found many months before planting even began. It was found in several provinces as early as June.


"We're in a more risky situation than we were a year ago," said Daniel Ploper, a plant pathologist and director of an experimental research station in Tucuman Province. "It seems like each year this disease becomes more of a regular problem."


Asian rust has been detected in around 38 places in eight provinces, according to Senasa.


The rust pathogens survived Argentina's winter and managed to spread among volunteer crops throughout the country earlier this year, Ploper said. Volunteer soybeans are crops that grow accidentally between seasons where farmers did not intend to plant them.


Argentine soybeans are usually sown October through January and harvested between March and July. Soybeans grown between those months are normally volunteer beans.


As of Saturday, farmers had planted 17.1 percent of the 2005-06 soybean crop, lifting the pace of planting from about 15.5 percent a year earlier, according to the Buenos Aires Cereals Exchange.


The exchange expects farmers to plant a record 15.6 million hectares of soy this season, up 6.3 percent from the previous year.


Asian rust can thrive only when environmental conditions are favourable. The disease requires humidity and moderate temperatures. A prolonged drought last year in Brazil, where rust has caused serious damage in recent years, prevented it from spreading into Argentina.


However, climatic conditions could be more favourable for the disease this season.


"There is a difference from last year," Ploper said. "This winter has been more humid. There was rain in May, June and July. If we are dry in January and February, we shouldn't have problems. But the forecasts are calling for normal, not dry weather during those months. One really never knows about the climate or what will happen."


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