February 25, 2011

Researchers Surveying Extent of Mad Soybeans II in Brazil

Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.

Researchers from Embrapa and the federal government are in the state of Tocantins in northern Brazil conducting a survey with the goal of identifying how widespread the anomaly called Mad Soybeans II is within the state. They are going to survey all the soybean producers in three municipalities of the state to determine if the anomaly may be connected with common management practices employed in the region. Researchers have already combed the region trying to identify if the anomaly is caused by insect attack or if it is an unknown fungal or viral diseases. Thus far, no single cause has been identified.

The anomaly was first identified in the state in 2006 during field surveys monitoring the spread of soybean rust and nematode infestations.

The anomaly occurs during vegetation development of the soybean plant resulting in abnormal high amounts of flower and pod abortion, impeded pod formation, deformed leaves and pods, and it causes the plant to remain green and not to mature normally. The presence of green plants makes harvesting the field very difficult. The anomaly appears to be more common in the hotter and wetter regions of soybean production in Brazil in northern, northeastern, and west central regions of the country.

The inconsistency of the anomaly has frustrated attempts by scientists to identify a single cause. As a result, researchers are asking all Brazilian soybean producers to report any abnormalities in their soybean fields in an attempt to document the extent of the anomaly.

In severe infestations, yield losses can be very significant, but the occurrence of the anomaly thus far during the 2010/11 growing season has been less widespread than in previous years