“Adjusting the preparation procedure to obtain a homogeneous solution can lead to better application results, and may reduce, during the crop cycle, one or even more applications.”
Marcelo da Costa Ferreira is an agronomist and PhD in agronomy from the Faculty of Agrarian and Veterinary Sciences of the Universidade Estadual Paulista – Unesp, Campus of Jaboticabal, with a post-doc internship in the United Kingdom, and coordinator of the Center for the Study and Development of Application Technology – (NEDTA – Núcleo de Estudo e Desenvolvimento da Tecnologia de Aplicação).
Ferreira is a professor of technology for the application of phytosanitary products at Unesp in Jaboticabal, carrying out research on the preparation of mixtures, droplets formation, drift from spraying and depositing the mixture on targets.
AgriBrasilis – What is pesticide application technology and what is its importance?
Marcelo Ferreira – The technology for the application of phytosanitary products is defined by the use of scientific knowledge for the correct placement of these products on the target, in the necessary quantity, when and if necessary, economically and with minimal contamination of the ecosystem. Application technology is of great importance to the agribusiness economy. It involves the maintenance of production, since it is responsible for the transfer of biologically active products to the phytophagous organisms that cause damage to the crops.
If the application technology is done in the wrong way, there will be no good control of phytosanitary targets, and the losses for agricultural production will be consolidated. There will also be the loss of the investment itself for phytosanitary treatments, which involves the acquisition of products, the cost of sprayers and operators.
In Brazil, around US$ 14 billion are sold in phytosanitary products alone. An application with a lower-than-expected control result means a considerable loss of money (productivity + products + man-machine time). Some side effects should also be considered, such as the perpetuation and even the increase of organisms in the area, which will continue to cause damage to crops in successive seasons. There will still be possible environmental damage, as the product was applied without “hitting the target”, this implies that the product went to some area outside the target. Whether soil, air, or water, positioning the product in other areas will have a greater impact than would be acceptable for a successful application.
Considering that there is currently pressure from the European Community, included in the Green Deal, to reduce the use and risk of plant protection products by 50% by 2030, application technology has its importance even more evident.
AgriBrasilis – What factors affect the application of pesticides? How can you control these factors to optimize field operations?
Marcelo Ferreira – Agricultural production is complex, as it depends on factors such as soil quality and weather, which are very dynamic over time. These factors influence from the growth of crops to the occurrence of biological targets. The selection of items that will compose a given application is equally dynamic and individualized.
The selection of products, adjuvants and application equipment, the spray preparation procedures, the working speed, the spray nozzles, the pressure used to produce the drops, will influence the coverage and the spray deposit in the crops, which will be influenced by the size and stage of development of the crop, the climate and the proper care with the calibrations of the sprayers.
The good selection of droplet size (spray tip model, working pressure and use of adjuvants) is essential to obtain the best results in a spray.
Even today there are few professionals really prepared to understand these factors and properly decide on how the application should be. Resorting to professionals with recognized background in the area is a good indication.
AgriBrasilis – How is it possible to save on products through application technology?
Marcelo Ferreira – A good preparation of the spraying mixture can already be a way to save money. In the field, it is very common to verify problems of incompatibilities between products in the sprayer reservoirs. These incompatibilities show us that the products are being altered in their physical-chemical composition. This means that some of the active ingredients have been lost and will not result in target control.
It is often found that products become encrusted in the tank, piping and filters of the sprayer. If the products didn’t even come out of the sprayer, what or how much of what went into the tank was applied? Therefore, the dosages that reach the crops are lower than expected, resulting in possible control failures.
Adjusting the preparation procedure to obtain a homogeneous solution may imply a better application result, being able to reduce, during the culture cycle, one or even more applications, given the best control. Therefore, the good technology used should mean a more rational use of resources, making phytosanitary treatment more economical.
AgriBrasilis – How did application technology advance in Brazil? What is the level of adoption among farmers?
Marcelo Ferreira – This is a complex question, since there are many “Brazils” within Brazil. We have highly developed equipment and techniques available for use, but the range is not balanced for all agriculture.
It is a sociological problem that needs a public approach. Therefore, this requires a segmented approach, which would give some doctoral theses. So, I think we can leave the answer to this question for a few years from now.
AgriBrasilis – What are adjuvants for? What types are there and for what purposes?
Marcelo Ferreira – Adjuvants are used for many things. The most common function is to reduce the surface tension, which acts from the formation of droplets to the absorption of the products, passing through the interaction with the targets.
It is a subject that is far from being fully understood. Even the functional definitions are undergoing an expert review, in order to propose a consensus on the role of adjuvants.
There is a specific event, which is the “Workshop on Adjuvants in Phytosanitary Spraying Liquid”. The next edition will be held in August 2023 in the city of Ribeirão Preto, State of São Paulo, for which I open the invitation to those interested in this topic, for an update on the latest on adjuvants.
AgriBrasilis – It is very common among farmers to mix pesticides in the spray solution. Are these tank mixes safe?
Marcelo Ferreira – If the mixtures are made considering good agricultural practices, they can be safe, yes. Naturally, it will depend on the guidance of a competent professional to indicate what, how much and how to proceed. Once well recommended, well oriented and well performed, they can be safe.