Corn stunting has a research network in Paraná

Representatives of entities dedicated to agricultural research are meeting in Londrina to formalize and discuss partnership details with the aim of carrying out studies on the corn stunting complex. The meeting began this Wednesday morning (26/04), at the headquarters of IDR-Paraná (Instituto de Desenvolvimento Rural do Paraná — Iapar-Emater), and continues this Thursday (27/04), ending at noon.

“Our objective here is to integrate the network’s partners and funders, establish integration strategies and, also, mechanisms to disseminate the results of the research that will be carried out to the academic community and, mainly, to producers”, stated the research director and innovation from IDR-Paraná, Vania Moda Cirino.

In addition to IDR-Paraná, Adapar (Paraná Agricultural Defense Agency), UEL (Londrina State University), Uenp (Northern Paraná State University), UEPG (Ponta Grossa State University), Unicentro ( Central-West State University), UTFPR (Federal Technological University of Paraná), UniCesumar, Embrapa Milho e Sorgo, Embrapa Cerrados and the cooperatives Coamo, Cocamar, Copacol and Integrada.

“Stunting is a new problem and the technological strategy is to be developed so that we learn to live with it and overcome it. Look for tolerant cultivars or, at the very least, find the best management”, said the secretary of agriculture and supply, Norberto Anacleto Ortigara, in a videoconference speech.

The cooperation involves twelve agronomic research projects, covering the evaluation — in the field and in a controlled environment — of the tolerance of corn cultivars available on the market, the monitoring of corn leafhopper populations and their control with synthetic insecticides. and biological.

Also participating via videoconference, the secretary of science, technology and higher education, Aldo Nelson Bona, highlighted the importance of using the collaboration strategy between institutions as a strategy. “Everything good we have in terms of technological assets must be increasingly connected with the demands of society. In this partnership, government, academia and society work together to solve everyday problems through knowledge,” he said.

The planned investment is R$ 3,8 million, resources coming from the Araucária Foundation — an entity that supports scientific and technological development linked to Seti (Secretariat of Science, Technology and Higher Education of Paraná) — and Senar-PR (National Service of Rural Learning). The duration of the projects is three years.

The problem

The disease involves an insect, the corn leafhopper (Dalbulus maidis), which transmits the stripe virus and the bacteria phytoplasma and spiroplasma, also known as molicutes. For this reason, technicians call it the stunting complex.

The leafhopper becomes infected by sucking the sap from infected plants and transmits the pathogens when it feeds again on healthy crops. It can fly within a radius of 30 kilometers, but, transported by air currents, it can reach greater distances.

Plant infection occurs in the period from emergence to approximately 35 days, although the symptoms — red or yellow spots on the edges of the leaves or in the shape of stripes (which reveals the presence of the virus) and little plant development — are manifested. with the crop already in the bolting and grain formation phase.

Ivan Bordin, a researcher at IDR-Paraná responsible for coordinating the cooperative work, explains that estimating losses caused exclusively by the disease is a complex task. “There are other diseases and the climate issue involved. But, in the last harvest, we observed cases of producers who used highly susceptible cultivars sown at an unfavorable time and lost 100% of the harvest”, he points out.

The stunt complex was first detected in western Paraná around 20 years ago, in sporadic and localized occurrences. From 2017 onwards, reports of its presence in crops began to increase.

In the 2019-2020 harvest, Adapar extensionists and technicians carried out collections of plants, leafhoppers and tigueras in different producing regions of the State, and the IDR-Paraná confirmed the presence of the stripe virus and phytoplasma and spiroplasma bacteria.

To date, the main recommendations for dealing with the disease are the use of tolerant cultivars and constant inspections in the period from plant emergence to the eight-leaf stage, with the aim of evaluating the presence of the leafhopper and the need for its removal. control with chemical or biological insecticides.

It is also recommended to use treated seeds and simultaneous sowing in the same region to avoid the so-called “green bridge”, which is the existence of crops at different stages of development and, therefore, supplying food and encouraging the migration of leafhoppers. and the restart of the crop contamination cycle.

Eliminating tigueras, or raccoon plants, from the land is important to interrupt the leafhopper and pathogen cycle.

research network

The cooperative project takes place within the scope of the Paraná Network for Agricultural Research and Applied Training, created by Seab (Secretary of Agriculture and Supply) and Seti with the aim of structuring intelligence networks and promoting shared agricultural research work in Paraná.

Presence

Participating in the meeting, for IDR-Paraná, are Rafael Fuentes Llanillo, Altair Sebastião Dorigo and Cristovon Videira Ripol, respectively integration director, business director and regional manager in Londrina; Luiz Márcio Spinosa, director of science, technology and innovation at Fundação Araucária and Débora Grimm, technical director at Senar-PR, as well as researchers and representatives from all entities involved in the new research network.