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.

摘要 激素类除草剂的飘移是农业生产中的一大棘手问题，即便施用量极低，也可能对作用机制敏感的作物造成大幅减产损失。本研究旨在评估空气导入式液压喷头的防控效能，以及LI-700助剂（LI-700）在降低番茄田2,4-滴除草剂（2,4-D）飘移方面的应用价值。试验采用完全随机裂区设计，设置8次重复。主区设置两种除草剂药液处理：仅施用2,4-滴（670 g·ha⁻¹），以及2,4-滴（670 g·ha⁻¹）与LI-700助剂（712.88 g·ha⁻¹）复配的药液；副区设置5种喷头型号：普通扇形喷头（JSF11003）、普通空气导入式扇形喷头（AD-IA11003）、双扇叶空气导入式喷头（AD-IA/D11003）、空气导入式锤形扇形喷头（TTI11003-VP）以及空气导入式空锥喷头（CV-IA10003）。所有处理均在风洞环境下以300 kPa的压力施药。采用激光粒度分析仪，以清水为介质测定各喷头的体积中径、相对幅度以及直径小于150 μm的雾滴占比。结果显示，CV-IA10003与TTI11003-VP型液压喷头在降低2,4-滴除草剂飘移、减轻对番茄植株的危害方面表现突出。向2,4-滴药液中添加LI-700助剂，无论搭配何种喷头型号，均可降低该除草剂的飘移量及其对番茄植株根系的不良影响。但即便采用上述防控技术，仍应避免在番茄田邻近区域施用2,4-滴除草剂。