December 20, 2013
Brazil Farmers Advised to Monitor Corn Earworm on Weekly Basis
Brazilian scientists and farmers have confirmed the presence of the corn earworm (Helicoverpa armigera) all across Brazil from the northern production regions of Maranhao to the southernmost state of Rio Grande do Sul. Groups of scientists from Embrapa have been conducting seminars for agronomists and technicians across the country instructing them on the best practices to control the new pest.
They are recommending that farmers adopt the Integrated Pest Management approach that relies on cultural practices, natural enemies, and chemicals to control the insect. They are also highly recommending that farmers don't panic and start applying insecticides indiscriminately in an effort to control the insect even though it may have not reached populations that surpass the economic threshold.
Farmers are advised to actively monitoring their fields for the presence of the corn earworm at least once a week. The life cycle of the insect is very short, so it could get out of hand if not monitored every week. Active monitoring also aids in determining the number of caterpillars and their size which is important in determining the correct control methods. Control measures are recommended once the caterpillar populations reach 2-4 per square meter in soybean fields.
Close monitoring of the insect is practically important when soybeans are setting pods and filling pods because the insect can bore into the pods making control measures more difficult.
Even though this new pest has caught most of the attention this growing in Brazil, farmers are also being advised to not forget about the number one disease that affects soybeans which is soybean rust. The last several weeks have been very rainy across central Brazil which is idea for the spread of soybean rust.