Dynamics of Clomazone Formulations Under Different Applications Conditions

ABSTRACT: Maintenance of straw on the soil surface in sugarcane production areas can influence weed occurrence and herbicide dynamics. After application, considerable losses of clomazone can occur as a result of its physicochemical characteristics. For this reason, novel formulations have been developed. In addition to the conventional formulation, microencapsulated formulations are currently available. Thus, the aim of this study was to observe and compare the effect of clomazone formulations under different application conditions. For this purpose, the experiment was carried with 12 treatments in a completely randomized design, with four replications, using clomazone formulations (1,200 g a.i. ha-1), on soils with different moisture levels, in the presence and absence of sugarcane straw, followed or not by rainfall simulation. The treatments were compared by observation of number of emerged plants and phytotoxicity at 7 and 14 DAA, as well shoot dry matter at 14 DAA for Ipomoea nil, Urochloa decumbens and Panicum maximum. In general, the microencapsulated formulation presented a better performance under the less suitable application conditions when compared to the conventional one. However, for the other conditions, both formulations had a similar performance.

摘要：甘蔗种植区保留土壤表面秸秆覆盖，可对杂草发生情况及除草剂的动态行为产生影响。广灭灵（clomazone）因其自身理化特性，在施用后可能发生大量流失。鉴于此，科研人员开发了新型除草剂制剂，目前市场上除常规制剂外，还推出了微囊化制剂。因此，本研究旨在观测并对比不同施药条件下，广灭灵不同制剂的应用效果。为此，本实验采用完全随机设计，设置12个处理组、4次重复，以剂量为1200 g a.i. ha⁻¹（克有效成分每公顷）的广灭灵制剂为供试材料，设置不同土壤湿度水平、是否覆盖甘蔗秸秆，以及施药后是否进行降雨模拟等变量。通过观测施药后7天和14天（DAA，Days After Application，施药后天数）的杂草出苗数与药害程度，以及施药后14天的三种供试杂草——裂叶牵牛（Ipomoea nil）、俯仰臂形草（Urochloa decumbens）和大黍（Panicum maximum）的地上部干物重，对各处理组进行比较分析。总体而言，相较于常规制剂，微囊化制剂在较不适宜的施药条件下表现更优。但在其余施药条件下，两种制剂的应用效果无显著差异。