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Brazilian growers facing more sprays for Asian soybean rust

Cid Ricardo Dos Reis isn't sure what to wish for. The soybeans on the 35,000-hectare (86,000 acres) farming operation he manages in the state of Mato Grosso could use a good rain.

But rain could also spur the development of more Asian soybean rust in the fields in this area of north central Brazil. The field that Ricardo is standing in has already received two applications of a fungicide for the disease.

“This field is a test area so it will not be treated again,” Ricardo says through an interpreter to a group of chemical company representatives, farm supply dealers and consultants from the United States. “If it was a commercial field, we would probably make one more application.”

His dilemma appears to be a common one in Mato Grosso where farmers reportedly are having to make more fungicide applications for Asian soybean rust than they did in 2003/04. (The growing seasons are reversed in South America.)

“Some growers in Mato Grosso are having to spray three times and are not getting very good control,” says Claudio Ramos, sales manager for Hokko Do Brazil, a Japanese-owned chemical company. “In Parana (in southern Brazil) where it is cooler and drier, farmers are making only one application.”

In December and January, in the middle of the wet season in Mato Grosso's portion of Brazil's Cerrados area, growers received 35 days of rain. Asian soybean rust, which is highly dependent on moisture and temperature, has exploded, especially in fields where growers were late in treating.

Much of the area in southeast Mato Grosso had not received a rain in 15 days when the group from the United States visited Fazenda Filadelfia, the farm that Ricardo manages, on Feb. 15.

The visitors from Valent USA Corp. and from farm supply dealerships in several soybean-producing states saw fields that had been defoliated prematurely by Asian soybean rust. In most cases, the fields were test fields that were treated late on purpose or not at all.

“In some areas this year the disease is very strong,” said Ramos. “In others, it's not so strong. We're not exactly sure why this is and why it is much stronger this year than last.”

The prospect of having to make a third and, in some cases, a fourth application for Asian soybean rust is not very appealing to Brazil's soybean farmers, who are having to deal with the double whammy of low soybean prices and unfavorable exchange rates (3.8 reals to the dollar).

“Last year we had good prices for most of our crops,” says Melhem Naim Charafeddime, director of Grupo Monica, a large family operation near Rondonopolis in southeast Mato Grosso. “This year, none of them is profitable.”

Melhem, who oversees an operation of 21,000 hectares (52,000 acres), including 17,000 hectares of soybeans and 4,000 hectares of cotton, says that when the exchange rate was 3.4 reals to the dollar last year, “it wasn't so bad. But 3.8 reals to the dollar is terrible.”

Ramos, who oversees sales of Hokko's products such as Select herbicide and Eminent fungicide, said the decision to make a third fungicide application can be a difficult one.

“Many of these farmers don't have the money to make a third application, but they've already put most of the inputs into the crop,” he said. “They can't afford to not protect the crop until maturity.”

Currently, crop advisers in Brazil say that farmers should try to protect their soybeans through the R-7 or pod-fill stage. They generally recommend spraying a fungicide when 5 percent of the leaves sampled from 100 plants selected at random show at least two lesions per square centimeter.

But growers appear to be leaning more toward spraying fungicides when their soybeans reach the R-1 or R-2 stage and again at R-5.1, especially on the larger farms in Mato Grosso. They may also spray in the vegetative stage if the disease becomes severe enough.

The farm that Ricardo manages near Campo Verde is part of an operation that grows 85,000 hectares (210,000 acres) of soybeans and 34,000 hectares (84,000 acres) of cotton spread over central and southern Mato Grosso.

The operation, owned by Erai Sheffer, is reportedly the second largest in Brazil. The largest is owned by Sheffer's cousin, Blairo Maggi, who also is the governor of Mato Grosso. Maggi's holdings reportedly include 140,000 hectares (346,000 acres) of soybeans, 40,000 hectares (98,000 acres) of corn and 11,000 hectares (27,000 acres) of cotton.

The Maggi family moved to Mato Grosso from Parana in southern Brazil in the 1970s and began clearing the stubby trees and grasslands created by the Cerrados region's savannah climate. In the intervening years, Mato Gross has become Brazil's largest soybean producing region.

Maggi, who is sometimes mentioned as a future candidate for president of Brazil, led a public-private partnership that opened a barge channel on the Madeira River from northern Mato Grosso to the Amazon River in the 1990s. Maggi is now working on much-needed improvements on the roads in Mato Grosso.

The staggering size of the operations is one of the reasons Brazilian farmers appear to be leaning toward making an initial fungicide application at the R-1 stage if soybean rust is discovered in their area.

“In Mato Grosso, we have a number of 5,000-hectare to 10,000-hectare growers, and it's difficult to cover all of the area,” says Yukio Arai, president of Hokko do Brazil. “When the disease first hit in Brazil three years ago, everyone was scared because growers faced severe losses.”

Fildelfia Farm's Ricardo says he has not been able to keep up with the demand for spraying with the airplane assigned to his farm operation near Campo Verde this year. Instead, the operation contracted with a private flying service to provide additional aircraft.

“Before we had soybean rust we were making an average of 1.5 applications for other diseases,” he said. “After rust arrived, we've been averaging at least 2 applications. This season two applications have not been enough — it's more like 2.5.”

Farmers like Ricardo say they prefer ground applications because they believe they can get more fungicide down into the plant canopy where the disease is more likely to be found.

Filadelfia farm owns several large self-propelled ground sprayers, but the ground rigs can't handle the wet soils from the rains like those that fell in January.

“This year we had too much rain, and the tractors would have been stuck in the fields,” says Ricardo. “Besides, soybean rust is very fast. You can't wait for ground spraying and hope to control it.”

Ricardo says the soybeans in the fields at the Filadelfia farm headquarters need protection from soybean rust for another 25 days. “If the weather stays dry, we may be finished spraying. If it starts raining, we probably will do one more application.”

Although the soybeans in farm's fields looked relative healthy, appearances can be deceiving with soybean rust.

“If you come back here next week, the lower part of the plant could be defoliated if the if not treated when soybean rust is present,” said Marcos Scarellis, a representative of Isagro Brazil. “Normally, this field would have been treated six days ago, but, as dry as it is, the rust will slow down.”

Brazilian researchers, aided by companies like Hokko, are working on other tools to help growers determine when conditions are favorable for soybean rust. One of those, called the Radar Project, uses a weather station that monitors leaf wetness, temperature, humidity and rainfall.

Measurements are collected in a data logger attached to the monitors and down-loaded to a PC. Researchers are analyzing this year's data to see if they can develop an early-warning system for soybean rust.

One of the Project Radar stations, which cost about $7,000 each, is installed in corner of one of Ricardo's fields.

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