Reduction in the spray drift of 2,4-D in tomato using hydraulic nozzles with air induction and LI-700 adjuvant

Abstract

The drift of hormonal effect herbicides is a major problem for agriculture, because, even in small amounts, it may cause high losses in crops with plants that are sensitive to their action mechanism. This study aimed to evaluate the efficiency of hydraulic spray nozzles with air induction, as well as the use of the LI-700 adjuvant, in the reduction of the 2,4-D herbicide drift, in tomato crop. A complete randomized split-plot experimental design, with eight replications, was used. Two herbicide solutions were assigned in the plots (with or without the use of adjuvant) [2,4-D (670 g ha-1) and 2,4-D (670 g ha-1) + LI-700 (712.88 g ha-1)], and, in the subplots, five nozzle models [simple fan (JSF11003), simple fan with air induction (AD-IA11003), dual fan with air induction (AD-IA/D11003), simple hammer fan with air induction (TTI11003-VP) and empty cone with air induction (CV-IA10003). The treatments were applied in a wind tunnel, under a pressure of 300 kPa. In a laser analyzer, applying only water, the volumetric median diameter, the relative amplitude and the percentage of drops with diameter lower than 150 µm were measured for all nozzle models. The CV-IA10003 and TTI11003-VP hydraulic nozzles outstand by reducing the 2,4-D herbicide drift and decreasing the damage to tomato plants. The addition of the LI-700 adjuvant to the 2,4-D syrup, independently of the nozzle model, reduces the drift of this herbicide and its effects on the tomato plant root. However, even when adopting these technologies, the application of the 2,4-D herbicide near the tomato crop should be avoided.

Tecnologia de aplicação com o uso de diferentes adjuvantes na cultura da soja

“…Differences begin to occur in the middle third of the canopy (Table 3), in which the adjuvant LI700® again demonstrates the highest relative dispersion associated with the highest number of drops that resulted in the highest VMD, again classifying the droplets as ultra coarse. In the assessment of the quality of application with four different types of nozzle, applying a solution with LI700®, GODINHO JUNIOR et al (2018) point a decrease in the risk of drift, thus avoiding losses to the environment. Such circumstances are related to the droplet size, the higher droplet density, and volume of deposited solution, which probably generated a higher droplet coverage rate in the leaf mass, which also corroborates the research of CUNHA & PERES (2010).…”

“…In this way, in the middle third, droplets were above coarse, which requires care in the application and corroborates MOTA & ANTUNIASSI (2013), in which study the use of adjuvants increases the volume median diameter during spraying, which requires knowledge in the preparation of the solution, as droplet size and density are related to the poisoning of the plant. In greater droplets, GODINHO JUNIOR et al (2018) have found poisoning of the plant, which requires a decrease in the dose of the product.…”

Relationship of contact angle of spray solution on leaf surfaces with weed control

“…The adjuvant Lecithin is a mixture of phosphatidylcholine and propionic acid, commonly used to decrease drift, due to the presence of propionic acid also causes a reduction in the pH of the spray solution. In a study carried out with the herbicide 2,4-D, it was found that the addition of this adjuvant, regardless of the tip model used, reduced the herbicide drift by 4.9% 32 .…”

Use of Remotely Piloted Aircrafts for the Application of Plant Protection Products

“…The drift of active ingredients is one of the main problems in their application in agricultural areas (Godinho Júnior et al, 2018). This can be succinctly defined as the process of the physical movement of droplets out of the application area (Wang et al, 2020 b).…”