Javier Veloso: «Biocontrol does not replace phytosanitary products, but it is key to reducing their environmental impact»

At the Plant Physiology Laboratory at the Higher Polytechnic School of Engineering on the Campus Terra, Javier Veloso is working toward a goal that closely affects the future of agriculture: protecting crops sustainably, reducing environmental impact, and ensuring food security.

Specializing in the study of the interaction between plants and pathogens, the researcher from the Biodiversity and Applied Botany Group is committed to alternative methods to chemical plant protection products and to the application of new biotechnological tools that pave the way for more environmentally friendly production.

Veloso, who spent part of his career at the prestigious University of Wageningen—a world leader in plant health—is now conducting research in Lugo on beneficial fungal strains and natural metabolites that can curb destructive pathogens such as Botrytis, Phytophthora, and Monilinia. His work combines basic science and practical application to provide Galician farmers with effective, safe, and economically viable tools.

In this interview, he reflects on the impact of climate change on the emergence of new plant diseases, the role of biocontrol as a complementary strategy to traditional phytosanitary products, and the importance of training the next generation of researchers to understand and care for the balance between production and nature. His message is clear: «The study of the countryside is the study of the natural environment that gives us life; we need to look at it more closely».

-Your main line of research focuses on sustainable pest control and plant-pathogen interaction. What motivated you to specialize in this field, which is so crucial for the primary sector?

-Mainly two reasons. The first is that the primary sector is an important economic activity in Galicia, and current European regulations are having a major impact on its practice.

This impact is due to the increasingly restrictive use of plant protection products, which affect the natural environment, making alternative control methods increasingly necessary.

The second reason is more personal. Since I was a child, I have been in contact with the countryside in rural Galicia. Since then, I have been concerned about caring for the natural environment, which we are lucky to enjoy in Galicia.

-During your doctoral thesis, you studied the interactions between Padrón peppers and various pathogens and proposed two promising methodologies for their sustainable control. What is the current status of this research?

-We are currently working on both methodologies. The first, the use of secondary metabolites from the plants themselves, is showing good results, but we need more effective methods for large-scale production.

The second methodology, the use of biocontrol agents —specifically beneficial fungal strains —involves working with different species, including Fusarium and Penicillium.

We are currently developing different product approaches to enable these organisms to remain viable for extended periods and retain their protective capacity.

-You did a postdoctoral fellowship at Wageningen University, in the world's leading laboratory for the study of Botrytis cinerea. What lessons or experiences would you highlight from that period, and how do they influence your work today?

-Botrytis cinerea is a pathogen with a major economic impact worldwide, and many groups are working on the development of effective control methods.

Furthermore, because of its importance, this pathogen is used as a model for studying other pathogens with similar infection mechanisms. Wageningen is a center of excellence in crop research, from genetic improvement to plant-pathogen interaction studies.

During my postdoctoral stay at the host laboratory, I was fortunate to join the world's leading group in the study of Botrytis.

In addition to the most cutting-edge research techniques, I had the opportunity to interact with several world-renowned research groups, with whom I continue to collaborate today.

These interactions with other research groups are extremely important for carrying out high-quality research.

-In your studies, you worked with high-impact pathogens such as Botrytis, Verticillium, Fusarium, Phytophthora, and Monilinia. What common challenges do they present, and what are the most relevant differences you observed between them?

-All these pathogens are very difficult to control due to their virulence and ubiquity. Vascular pathogens such as Verticillium, Fusarium, and Phytophthora invade their hosts through the roots and colonize the vascular bundles, causing varying degrees of dryness and rot.

These pathogens are more difficult to detect in the field because their mycelium is not visible in plants with early infection. In the case of Botrytis or Monilinia, the aerial parts —leaves, stems, and fruits — are usually affected, and their typical symptoms include rotting of these organs, which become visibly covered with the fungus's mycelium.

Due to these differences in infection mechanisms, control methods must be adapted to each pathogen. Of the methods mentioned above, the use of secondary metabolites has a better effect on pathogens in the aerial parts, as they come into direct contact with the fumigant.

However, the use of biocontrol agents, such as beneficial fungal strains of Fusarium and Penicillium, is more effective against root pathogens such as Verticillium or Phytophthora.

-You recently published an article in Plant Pathology on the influence of light on Monilinia fructigena infection in nectarines. What practical implications might these findings have for disease management in fruit trees?

-Monilinia is an important post-harvest pathogen that affects the economic viability of fruit during storage before and after distribution to points of sale.

These fruits may contain small amounts of the pathogen that are not detected in the field and that develop during storage.

Reducing the pathogen's virulence depends on environmental factors, such as lighting conditions. It is known that Botrytis infection depends on light conditions and the fungus's circadian rhythm. In this research, we observed that some Monilinia species are less virulent in light conditions than in darkness.

This knowledge may enable the design of more effective storage protocols to reduce the impact of this pathogen.

-The use of biological biocontrol agents is one of the lines of research that arouses the most interest in your group. Do you think these methods will replace chemical pesticides in the near future, or will they coexist as complementary strategies?

-Biocontrol is a strategy that is currently being successfully implemented to control various pathogens and pests.

However, these methods always complement other control mechanisms, such as chemical pesticides. Biocontrol is a highly specialized method that also depends on suitable environmental conditions.

Therefore, it needs to be complemented with more generic methods that do not require specific environmental conditions for their application. Biocontrol reduces the amount of chemical pesticides used, thereby reducing their environmental impact.

However, it is unlikely that they will replace them completely. As in finance, the smartest approach is to diversify to ensure benefits.

The use of diverse methodologies within integrated management is the most effective way to reduce the impact of pathogens on crops.

-You have also participated in genomics and transcriptomics studies to understand better the mechanisms of action of pathogens and biocontrol agents. How do these “omic” technologies contribute to research in plant pathology?

-These technologies are of great importance in advancing our knowledge of diseases and in designing new control strategies to combat them.

For example, in the genomic study of the Fusarium biocontrol strain, they led to the identification of several genes important for biocontrol, which we subsequently used to identify new biocontrol strains.

In the case of the genomic study of the Botrytis pathogen, it allowed us to identify the most important genetic components of its virulence, opening the door to designing strategies to minimize or inhibit its expression and thus reduce its virulence, as in the aforementioned work on light regulation.

-In addition to your research work, you are a professor at the Higher Polytechnic School of Engineering. How do you integrate your scientific experience into teaching students at Campus Terra?

-Knowledge transfer is a fundamental role for a researcher. This transfer can take place in different ways, in the classroom, at outreach events, or in specialized work such as scientific articles.

In the classroom, I try to incorporate the study of leading scientific publications in my field and connect them to the subject matter so that students encounter these scientific innovations and learn to interpret and apply them.

I also participate in events outside the classroom, such as “Pint of Science,” an international event we are fortunate to have organized in the city of Lugo, which attracts students curious about the research being done on their campus.

At these outreach events, it is important to demonstrate the impact on society and the applicability of this knowledge to an important sector, such as the primary sector.

-Climate change is altering the environmental conditions that favor or limit the development of plant pathogens. How is plant health research preparing for this scenario?

-Climate change is a fundamental challenge for the primary sector, especially in Spain. Changes in temperature and humidity greatly affect the virulence of crop diseases.

We are currently studying the impact of climate change on the incidence of pathogens in peaches.

Preliminary data indicate the emergence of new pathogens adapted to hot, dry climates. This succession of pathogens could mean that current disease-control protocols for these and other crops will need to be adapted.

The study of these changes is urgent, as the primary sector is already being greatly affected by climate change.

-Finally, what message would you like to convey to students and young researchers who want to pursue a scientific career in the field of plant biology and crop protection?

-This field of research is of great importance to society. Primary production is a strategic sector as it enables food independence and self-sufficiency. Plant health faces major challenges in the future, including climate change and the need to adapt to sustainable production.

Research in this field requires multidisciplinary knowledge ranging from molecular biology to basic management techniques. In short, studying this field means examining the natural environment around us, and I encourage you to take a closer look.