Helicoverpa advances strongly in corn biotechnologies

For at least three seasons, attacks by the Helicoverpa caterpillar on corn biotechnologies, especially those most adopted by farmers, have intensified in strategic areas of agribusiness, including the western regions of Bahia and the state of Maranhão. Reports and studies, recently released, warn of the need to encourage a change in producer behavior, given the increasingly severe damage caused by this pest to off-season and summer corn.

Two consultancies in the country, Evoterra and Multcrop, have been researching and developing new management strategies for more than two years, aiming to minimize, now and in the future, potential damage caused by Helicoverpa to the cereal.

With more than 80 thousand hectares of crops under management, Evoterra serves producers in Maranhão, Piauí and Tocantins. Multcrop covers around 170 thousand hectares in Western Bahia and Piauí. Soon, it will also arrive in Tocantins.

“Around 70% of the 30 thousand hectares of corn assisted by Multcrop between Bahia and Piauí already coexist with Helicoverpa”, highlights Tiago Souza, agronomist, master in herbology and plant protection, founding partner and director of Multcrop.

Director of Evoterra, Octavio Augusto Queiroz, agronomist, specialist in plant protection, master in seed production, reveals that in the last harvest the consultancy once and for all boosted the management of Helicoverpa in corn, “due to the high pressure of the pest , today a real problem.”

‘Biotechnology crash’, losses of R$70 million

Evoterra and Multcrop emphasize the importance of the producer observing the exact moment to apply insecticides to control Helicoverpa in corn. “The timing of spraying is more important than the dose of agrochemical used”, warns Queiroz, from Evoterra. “We carry out integrated pest management and use traps for moths (‘attract and control’)”, he summarizes.

“The target is difficult to control. We validate baculoviruses among the tools recommended to farmers”, continues the expert. “If there are moths in crop traps, there will inevitably be Helicoverpa eggs in the crop.”

As Queiroz notes, successful applications of baculovirus, isolated or associated with chemical insecticides, occur when the corn is in the 'pre-tasseling' stage, that is, while the 'hairs' on the cob have not yet emerged. “So, when it hatches, the caterpillar already enters the cob contaminated and tends to die. This is the crucial point. Applications from R1 (tasseling), in turn, make control much more difficult.”

Tiago Souza, from Multcrop, adds that it is essential today to “review some practices”. “In the Mapitoba region we now have to put a magnifying glass on the corn, thinking about Helicoverpa and Spodoptera”, he says. “The biotechnology crash has become reality, we are losing grain.” According to him, studies show that in the area covered by Multcrop there were recent losses of 4 to 4,5 bags of cereal per hectare, due to the strongest pressure from Helicoverpa.

“In a simple calculation, if there are around 250 thousand hectares of corn in this region, at R$70 per bag, we are talking about R$70 million in losses, this on a small border compared to Goiás, Mato Grosso and Paraná”, he explains. “We are looking for alternatives. We started working with baculoviruses and saw that they resolved well. We will not eliminate the caterpillar with any tool, but with viruses we observed a significant reduction in damage, in the range of 70%.”

Tiago Souza adds that in cotton areas covered by Multcrop, the use of attractants captured more than 70 moths per meter. “This is relevant data. This tool will become more common every day in different cultures, even more so at a time when the industry has a low capacity for innovation in chemical molecules and mechanisms of action.”B