Brazil will have to develop its own biological control model

Strategies for using natural agents to combat crop pests must be adapted to the characteristics of tropical agriculture, experts say.

By Elton Alisson  |  Agência FAPESP – Just as it has done in agriculture, where it has become one of the world’s leading producers by developing native technologies and adapting temperate cropping systems to the tropics, Brazil will also have to develop its own biological control model.

This is one of the main conclusions reached by researchers who participated in a workshop on “Challenges of Research on Biological Control in Agriculture in São Paulo State,” held on February 29 in FAPESP’s auditorium.

Representatives of universities, research institutions and companies that are developing biological control techniques to combat agricultural pests discussed the main advances achieved in São Paulo and other regions of Brazil in the use of natural enemies of organisms that attack forests, crops and other plants.

“We need to develop a biological control model that suits the characteristics of Brazilian agriculture, which is highly dynamic and involves uninterrupted growing of crops in very large areas as well as constant production of new plant varieties and frequent emergence of pests,” said workshop chair José Roberto Postali Parra in opening the event. Parra is Full Professor in the Department of Entomology & Acarology of the University of São Paulo’s Luiz de Queiroz College of Agriculture (ESALQ-USP).

According to Parra, Brazilian research and development in the field of biological control has made strides in recent years. There is now a reasonable critical mass in knowledge of macroorganisms such as insects, mites and ticks as well as microorganisms such as bacteria, viruses, protozoa and nematodes, which are part of Brazil’s biodiversity and can be used to control a range of crop pests.

The progress has mainly been made possible by breeding techniques that enable large numbers of insects to be produced on a plantation to reduce the target pest population more quickly.

In contrast to countries such as the Netherlands, where biological control is applied almost exclusively in greenhouses, in Brazil, it is applied in open areas. Nevertheless, Brazil’s programs are comparable with the best in the world, under conditions that differ from those of other countries and with fewer natural enemies being marketed by companies.

One reason for these differences is the widespread use of agrochemicals to control pests in Brazilian agriculture. This has caused severe biological imbalances, including the appearance of secondary pests as well as contamination of soil and water.

Spending on agrochemicals totaled R$12 billion in 2014, up from R$9.7 billion in 2012. Insecticides alone accounted for R$4.6 billion of the 2014 total.

According to Parra, the use of agrochemicals has risen 172% in the last 12 years, compared with 90% growth in the rest of the world. “A lot of insecticide is used in Brazil, much of it based on molecules other countries have banned,” he said.

“Agrochemicals can be used as long as they’re selective, so that they kill the pest but not its natural enemies. The active principles should also be rotated. Otherwise, the organisms they’re supposed to control will become resistant to them.”

High development costs and the growing challenges of synthesizing molecules for the production of insecticides are the main reasons for the increasing recourse to biological control in Brazil and elsewhere.

Data presented by Parra show that synthesizing a new molecule for an insecticide can cost approximately US$250 million. It costs US$125 million to develop a genetically modified pest-resistant or pest-tolerant cultivar. Breeding an insect for biological control costs between US$2 million and US$10 million.

“The use of biological control in Brazil and worldwide has been stimulated by the high cost of developing molecules for insecticides, added to the increasing pressure from society to stop using agrochemicals and the realization that GM crops can’t solve the agricultural pest problem,” Parra said.

“But biological control can’t be used in isolation, and it isn’t the only solution for pest control. It must be a component of integrated pest management. In fact, it can and should be used in association with insecticides, as long as these are rationally applied, as well as with GM crops and other pest control methods.”

The use of biological control is growing 15-20% per year worldwide, and turnover in the sector has reached US$17 billion.

Disseminating biological control

According to Parra, biological control is mainly used in Brazil to combat pests that attack sugarcane plantations. For example, Cotesia flavipes, a wasp produced by 20 biofactories, is used in more than 3 million hectares to combat the sugarcane borer Diatraea saccharalis.

“This is the right time to disseminate the use of biological control in Brazil, especially since the 2013 appearance of Helicoverpa armigera, a caterpillar that attacks several crops, including soybeans, corn and cotton. It’s very hard to control this pest using agrochemicals,” he said.

Microorganisms and macroorganisms for biological control are currently marketed by 26 firms and 21 firms, respectively, according to Parra, but these would be insufficient if demand from farmers for biological control were to rise abruptly.

“If everyone decided to use biological control at once, there wouldn’t be enough supply, so we need to increase the number of biofactories,” he said.

Potential beneficiaries

São Paulo State Secretary for Agriculture Arnaldo Jardim and FAPESP President José Goldemberg took part in the opening of the event.

Jardim said that 82% of São Paulo State’s agricultural production comes from small producers, who are potential beneficiaries of biological control technologies as an alternative to agrochemicals.

“We don’t demonize agrochemicals because we see them as necessary to productivity, but their use can be reduced, better disciplined, and partly replaced by solutions like biological control,” Arnaldo stressed.

Goldemberg offered an analogy between the need to support research on biological control in Brazil to tackle future challenges in agriculture and the recent emergency campaign to combat Zika virus.

“FAPESP’s support for projects linked to VGDN, the Viral Genetic Diversity Network, between 2000 and 2007, for example, has made it possible today to set up the Zika Network swiftly to address the challenges presented by the rise in cases of viral transmission in Brazil,” Goldemberg said.