Insect larvae residue is capable of controlling tomato diseases

Incorporation of Tenebrio molitor larval residue into the soil promotes plant growth and development and increases the amount of nutrients

02.04.2024 | 14:41 (UTC -3)
Christina Tordin
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A team of scientists from the Federal University of Lavras (UFLA) and Embrapa identified that the residue from commercial production of larvae Tenebrius molitor, an insect commonly used in animal feed, has a suppressive effect on two important agricultural pathogens: the fungus Fusarium oxysporum and the nematode Meloidogyne incognita.

Laboratory experiments evaluated the effects of these residues on the germination of spores and the growth of Fusarium oxysporum breed 3. Scientists also evaluated effects on hatching, mobility and mortality of juveniles of Meloidogyne incognita. The results revealed a significant reduction in the germination of fungal spores, reaching up to 84%, and an impressive reduction in nematode hatching, reaching 97%.

Furthermore, the pioneering study revealed that the incorporation and incubation of larvae residue Tenebrius molitor to the soil promotes plant growth and development by increasing the amount of nutrients available. The work also showed that it is not toxic to plants, that is, it does not cause phytotoxicity. Furthermore, the residue contains a beneficial microbiota that produces essential substances for the healthy development of plants. One of the components found in the residue is chitin, a polymer that brings several benefits to agriculture.

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UFLA researcher João Pedro Gondim highlights the importance of the study. "Research has scientifically and technically demonstrated the advantages of using waste Tenebrius molitor, not only for insect biofactories and users of the residue, but also for producers and professionals in the agricultural sector. We observed a significant increase in the aerial and root biomass of plants and highlighted the mechanisms of action that suppress populations of these pathogens."

Pathogens cause billions in losses to agriculture

The pathogens in question, such as the fungus Fusarium oxysporum and nematodes of the genus Meloidogyne, represent a constant threat to farmers, resulting in considerable economic losses and significant challenges to food security. It is estimated that these pathogens cause losses reaching billions of dollars annually worldwide.

In Brazil, there is an estimate that losses resulting from the action of nematodes are R$65 billion per year, mainly due to the intense exploitation of the soil and the sequence of crops susceptible to these phytopathogens. Therefore, the research results indicate a potential effective and sustainable solution to minimize these problems.

Tests under controlled conditions also demonstrated a suppressive effect of the residue on Fusarium wilt in tomato. A significant reduction of 18% in disease severity was observed, and a surprising increase in plant development of up to 328%.

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Furthermore, tests were carried out under field conditions to investigate the effects of applying the residue to the soil on the nematode population and the productivity of tomato plants. The results of these experiments demonstrated a notable reduction in the nematode population, reaching 88%, and a substantial increase in plant fruit productivity, reaching 163%.

The research also involved additional experiments to evaluate the contribution of volatile compounds to the residue's antifungal and nematicidal activity and to better understand the mechanisms involved in its biological action.

“The results of these experiments provided valuable insights into the potential of larval waste Tenebrius molitor in the control of diseases that affect agricultural crops, providing a solid basis for the results and conclusions presented in the study”, says Embrapa Meio Ambiente researcher Wagner Bettiol.

Bettiol reports that the results offer promising insight into the potential of larvae residue Tenebrius molitor as an effective tool in controlling tomato diseases and other agricultural crops. Furthermore, the approach represents a significant advance in the field of sustainable agriculture and could play a crucial role in ensuring global food security, according to the researcher.

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This study has the potential to guarantee greater returns from commercial production of tenebrio molitor, as it will add value to the waste generated in the production of this important animal protein, comments the scientist. Furthermore, informs the researcher, there is a prospect that products will be made available if companies in the sector see potential in the Brazilian market.

Mosaic Biosciences March 2024