South America Calling
Alastair Stewart South America Correspondent

Tuesday 12/17/13

Heavy Rain Puts Brazil on Asian Soy Rust Alert

A hot, wet December was just what the soybean crop in Brazil's top-producing center-west region needed. And that's what it is getting.

But the humid conditions are also promoting the spread of the deadly Asian rust fungus

The first confirmed cases among commercial crops were reported in Mato Grosso and Goias at the start of the month and instances are now expected to multiply quickly as the crop hits the later stages of development.

In total, Brazil has registered 47 cases so far this season, up from 27 at the same stage last year. So far, many of the cases are in voluntary plants.

Now the task is to control the fungus

"We know from 10 years' experience that we can limit the impact of rust. But farmers have to monitor crops closely to treat before it takes hold," said Luiz Nery Ribas, technical director at the Mato Grosso Soybean and Corn Growers Association (Aprosoja).

The rust fungus, or Phakopsora pachyrhizi, causes lesions on the leaves of soybean plants, which impede the formation of the bean and can result in massive yield losses. In more extreme cases, the fungus can kill the plant.

It is virtually impossible to prevent rust's arrival as the fungal spores are carried on the wind. However, it can be controlled by fungicide.

In 2012-13, rust cut yields by as much as 10% in Mato Grosso, according to the Mato Grosso Agricultural Research Foundation (Famato-MT).

The concern among researchers is that farmers will not be as diligent in monitoring for rust as in the past because they are so worried about a new threat -- the Helicoverpa amigera caterpillar, or corn earworm, which devastated crops in Bahia last year and has spread across Brazil's farm belt.

"We want to make sure that producers don't forget about rust, which is potentially much more dangerous," said Ivan Pedro, a Famato researcher.

Especially as while the rainy conditions are conducive for rust, they increase the efficiency of pesticide in tackling corn earworms.

The cost of controlling rust, and other pests and diseases, has risen this year.

At the start of December, chemical costs for soybean crops in Mato Grosso were, on average, 22% higher than last year, although many farmers bought earlier in 2013 when prices were lower, according to the Mato Grosso Agricultural Economics Institute (Imea).

Mato Grosso farmers will apply fungicide an average of three times this year, according to Aprosoja, although the number varies greatly from farm to farm.

"Farmers who monitor hard and act quickly as the first sign of rust will end up spraying less," said Aprosoja's Ribas.

Brazilian soybean planting is now virtually complete with approximately 60% of the crops in the germination phase, 25% in the flowering phase and 7% in pod filling.

Alastair Stewart can be reached at


Posted at 2:33PM CST 12/17/13 by Alastair Stewart
Post a Blog Comment:
Your Comment:
DTN reserves the right to delete comments posted to any of our blogs and forums, for reasons including profanity, libel, irrelevant personal attacks and advertisements.
Blog Home Pages
September  2015
      1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30         
Subscribe to South America Calling RSS
Recent Blog Posts
  • Upturn in Brazilian Fertilizer Demand
  • Brazilian Fertilizer Sales Stable in July
  • Floods Threaten Argentine Wheat Crop
  • Argentine Farmers Plant Defensively
  • Brazil 2015-16 Cotton Area to be Lowest in 13 Years
  • Brazil's Crisis and Forex
  • Brazilian Soy Industry Nervous About Chinese Moves
  • Brazil Focuses on Integration
  • Brazil's Corn Market Sees Busy July
  • Brazil to Plant More Soy In 2015-16
  • Brazil Intacta Royalty Controversy
  • Brazil's Soy Industry Raises Soybean Export View
  • Brazilian Chicken Exports Strong
  • Brazilian Soy Rust Threat
  • Argentine Farmers Must Declare Soy Seed Origin
  • Argentina to Plant Less Wheat
  • Brazil To Set New Corn Export Record In 2015
  • The Debate Over Brazilian Soybean Area
  • Brazilian Farmers to Use Less Fertilizer In 2015-16
  • Brazil Second-Crop Corn Forecasts Rise