Jan 29, 2010
White Mold Is An Emerging Concern In Brazilian Soybeans
Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.
Brazilian scientists from Embrapa are launching a new initiative to identify ways to control a disease that American soybean farmers are very familiar with - white mold. Over the last five years, the disease has become a significant problem on soybeans, edible beans, and cotton especially in the states of Goias, Minas Gerais, and Bahia. This fungal diseases, which is caused by the organism Sclerotinia, can affect more than 200 different types of plants.
The infected soybeans usually develop symptoms after flowering when the plant has fully developed. The disease attacks the vascular system of the plant and interrupts the transport of nutrients within the plant. In advanced stages of infection, the stem of the plant takes on a white moldy look. In cases of severe infestations, yield losses of more than 30% can occur. The disease is spread in the soil that clings to machinery when it is moved from field to field. Planting infected soybean seed can also spread the disease. The disease can lay dormant in the soil for up to 12 years before the right environmental conditions can trigger an infestation.
Farmers and scientists in Brazil have been trying to develop different methods to control the disease, but with limited success. Various fungicide combinations have proven to be ineffective. U.S. farmers have found out that the best way to control the disease is through crop rotations and planting soybean varieties that demonstrate more tolerance to the disease.
In recent years, a number of new soybean diseases and pests such as soybean rust, nematodes, leaf eating worms, and white mold have appeared in Brazilian soybean fields. One of the problems in Brazil is that the tropical climate allows these organisms to easily survive between growing seasons. The other big concern in Brazil is the monocrop nature of soybean production. Most of Brazil's soybean are not rotated to other crops, which encourages a rapid buildup of diseases and pests.
Similar concerns are developing in Argentina as well where the soybean acreage is now 9 to10 times greater than the corn acreage. Argentina is turning into a virtual one-crop country of soybean production, which too will encourage a rapid buildup of diseases and pests.