<b>By ANN HINCH<br>
Assistant Editor</b> </p><p>

LOUISVILLE, Ky. — As one of the world’s largest producers of soybeans, much of Brazil’s farm economy relies on the grain. And since Brazil has been fighting Asian soybean rust (ASR) longer than the United States, much of what U.S. ag experts know relies on research that has been conducted in Brazil.</p><p>
Estimates from AgRural are that Brazil will harvest 62.4 million metric tons of soybeans in 2008. This will surpass the country’s record harvest last year of 58 million metric tons, according to Austeclinio de Farias Neto with the Brazilian Agricultural Research Corp. (EMBRAPA), a cooperative effort of 40 research centers throughout the country.</p><p>
Even so, he said Brazil estimated losses of $2.257 billion to ASR in 2007, including $615 million in ruined crop and more than $1.5 billion in fungicide application costs.</p><p>
Neto, a speaker at the National Soybean Rust Symposium in Louisville last month, said environmental conditions were favorable for rust in late 2006 and into 2007, when excessive rain prevented timely fungicide application. Brazil’s growing season runs from planting in October to harvest between March and May; the country first identified ASR in 2001 and since, he said the fungus has established a presence throughout the country’s growing area in southern and central Brazil.</p><p>
Right now, the Brazilian farmer’s best weapon is a notification network that tells them what to look for and when it’s best to spray. An anti-rust consortium begun in 2004 involves specialists and labs at nearly 100 institutions dedicated to identifying ASR infections and putting the information online so farmers can track its progress, as well as educating them on the benefits of eliminating “volunteer” plants from their soybean fields and on the best times to apply fungicide.</p><p>
“This technology has been successfully provided to the farmers, and the farmers learned how to control the rust,” Neto said.
In addition, he said in 2006 the government began mandating a free host period (FHP) that prohibits the planting of a second annual soybean crop that would go into the country’s winter season. The intention is that if ASR does show up in the first crop late in its season, without a second planting it will have no host and, hopefully, will die out before the next regular planting in October.</p><p>
To this end, Neto said farmers are also encouraged to sow early and plant early-maturing cultivars.</p><p>
So far, the FHP seems to be working for Brazil, though Neto said it would help if neighboring countries Bolivia and Paraguay also mandated a similar no-grow period.</p><p>
He said their governments are looking into the possibility and may institute their own FHPs as early as this year.</p><p>
He also explained the forecast for this growing season involves La Nina-influenced weather, which the U.S. National Oceanic and Atmospheric Administration describes as cooler-than-normal sea surface temperatures in the central and eastern tropical Pacific that often means wetter conditions in tropical land areas.</p><p>
Since ASR thrives best on the combination of heat and moisture, this is of concern to Brazilian growers.</p><p>
A closer threat</p><p>

Closer to the United States is Mexio, which also has problems with ASR.</p><p>
According to Barrera Farias with the Centro Nacional de Referencia Fitosanitaria, soybean production is concentrated in the northern state of Chihuahua (south of New Mexico) and in five states along the mid-Gulf of Mexico eastern coast. Soy production in 2006 was about $19 million.</p><p>
Mexico first identified ASR in October 2005 in two of its coastal states, approximately 10 months after the first U.S. infestation was found in Louisiana. Farias explained it was late in the year, near harvest time, and no damage was recorded. In 2006 and 2007, conditions were not favorable for ASR, again, until harvest.</p><p>
Mexico’s real ASR problems began in January 2007, when the fungus showed up on yam bean plants in a field in Veracruz, located on the southwestern edge of the Gulf. Farias said within only 10-15 days, the field had gone from green and thriving to brown and dead. The season saw a $2 million loss in yam beans in the state, which is the country’s third-largest producer.</p><p>
He believes Mexico will suffer more yam bean losses to ASR in 2008. While Brazil has at least 40 fungicidal products on its market, the Mexican government has authorized fewer than 10. This is likely of concern to nearby U.S. growers, who worry not only about ASR during growing season, but also about how well the fungus can over-winter on other plants in the off-season.</p><p>
Research on dry beans</p><p>

While nobody has found the silver bullet to eradicate ASR, Neto said Brazilian researchers have been conducting greenhouse and field experiments with soybean cultivars and have found some resistance that cuts down on the severity of reddish-brown lesions of ASR (there are also tan lesions). He said the government will likely approve the release of these varieties this year to see how they perform in a practical setting.</p><p>
Talo Pastor-Corrales of the USDA’s Agricultural Research Service, also speaking at the symposium, presented research done on other beans and legumes to see if any would give clues on how to better engineer the soybean to resist ASR. Many types of common dry beans – of which the U.S. is the world’s second-largest producer – were tested.</p><p>
“We know so little about the effect of this pathogen on common beans,” he explained, adding researchers tried isolating different genetic traits to see if any were more resistant to ASR than others, based on the proven resistance of each trait to dry bean rust (a different fungus).</p><p>
Unfortunately, no correlation was proven between resistance to dry bean rust and resistance to ASR; in fact, a certain pinto bean that had no resistance whatsoever to dry bean rust exhibited high resistance to ASR.</p><p>
“You wouldn’t have guessed that,” Pastor-Corrales said.
The only other conclusion was that dry beans, though close in makeup to soybeans, are less susceptible overall to ASR. So, he said, the focus of that research now becomes determining how North American dry beans are so ASR-resistant. He believes continued research will eventually benefit both dry bean and soybean growers.