By Hamilton Humberto Ramos; Viviane Corrêa Aguiar; Ana Flávia Villa; Ianara Aparecida Mariano
(The authors are adjuvant researchers at the Engineer and Automation Center of the Agronomic Institute of Campinas, a body of the Department of Agriculture and Supply of the state of Sao Paulo, located in the city of Jundiai.)
Adjuvant is an important step towards improving the effectiveness or reducing the cost of phytosanitary treatment in modern agriculture. For years, there has been a discussion on whether such products should or should not be “related” in the Agrotoxic Law (Law No. 7802/89 regulated by Decree No. 4704/02) in Brazil, and because of this, they had to undergo the same procedure of registration as the products in the category in which they are submitted.
Hamilton Humberto Ramos
The products classified as adjuvants were registered in doubt. This discussion ended with the publication of Act No. 104 on November 20, 2017, by the Ministry of Agriculture, Livestock, and Supply (Mapa), which cancels the registration of registered products exclusively, such as adjuvants, “given that there is no mandatory registration in Law No. 7802 and Decree No. 4074.” Although correct, this attitude is also reckless.
By definition, an adjuvant “is any substance or composition without phytosanitary properties, except the water that is added in the preparation of agrochemicals, to ease the application, increase its effectiveness and reduce risks.” This way, if it does “not have phytosanitary properties” and is developed to be “added in an agrotoxic* preparation” by itself, it does not exercise any control and, therefore, it is not agrotoxic. On the other hand, to “ease the application, increase its effectiveness or reduce risks,” it interferes with the characteristics of the syrup (a mixture of agrotoxic with water), which can alter important aspects of the spraying. This interference can be positive or negative on the spraying procedure, the effectiveness of the product and also the safety of the worker, the environment or the food. For example, an adjuvant can alter the superficial tension and/or the viscosity of each spraying. Changing such characteristics, it will interfere in factors such as the size of the drops, spreading and evaporation speed, interfering with technology and the safety of the application. If the adjuvant increases the size of the drops, it can reduce the drift, which is a positive point; however, it can also reduce the size of the drops, elevating the drift and increasing the risk for workers and environmental contamination.
The higher spreading, on the other hand, can be an excellent resource for the reduction of water volume used on spraying, without the loss of effectiveness and significant reduction in cost. However, some adjuvants can increase the wet surface by the same drop up to 30 times. In this situation, drops that initially would not coalesce start to coalesce over the target, increasing the running, reducing the amount of product over the plant and consequently, the effectiveness of phytosanitary treatment, taking it to productivity loss or necessitating more spraying per crop season. Finally, the reduction of speed evaporation can also be an important factor, as well as economic. It can elevate the period of sprayers’ use due to climate conditions, as well as affect the safety and effectiveness factors. If the drops evaporate before reaching the target, they could cause environmental contamination and increase the amount of product over it. A reverse effect will be observed, however, in the case that the adjuvant, even having other positive functionalities, increases the water boiling speed. Therefore, the knowledge of functional characteristics of an adjuvant can limit its use and even alter the form of regulation and sprayer use conditions.
If the adjuvants are not fit as “agrotoxic or related”, they also cannot be “free sale products, without the necessity of any authorization by Mapa,” such as specified in Item 5 of Act No. 104. As a solution, being registered again as agrotoxic would not be a viable alternative, if the effectiveness required in the registration procedure does not translate the functionality of adjuvants. So, if not a registration, the adjuvants need at least a regulation. Initiatives in this sense were taken in the past by the Brazilian Association of Generic Pesticides and by Mapa, but an effective result is yet to achieved. Basic functionalities need to be scientifically analyzed to serve as technical parameters for recommendation and use. As there are no norms, national or international, for tests and classifications of such functionalities, joint action is needed between Mapa, the National Health Surveillance Agency (Anvisa), the Brazilian Institute of Natural Environment and Renewable Natural Resources (Ibama), makers, users, and researchers, along with a Commission of Studies of the Brazilian Association of Technical Norms (ABNT), to develop Brazilian norms. If this is not done quickly, the losses in agriculture, for the farmer, the worker and the environment can be significant.
*The term agrotoxic is used in Latin America to refer to toxic chemical pesticides.