SELECTIVITY OF LINURON HERBICIDE FOR CARROT WHEN SPRAYED IN POST-EMERGENCE

ABSTRACT Among the herbicides registered for carrot crop in Brazil, linuron is the most used one, according to horticulturists. However, there are few reports in the literature on its selectivity for the carrot plants. Therefore, the aim of this work is to study the selectivity of linuron herbicide for growing carrots, influenced by genotype, product dosing, and plant development phase at the time of application. This work included four experiments, one in greenhouse, and three in the field, in area of commercial carrot production. In the greenhouse, the experimental design was completely randomized in factorial scheme 4 x 2 x 3, with four replications. Linuron, at doses 0, 225, 450 and 675 g a.i. ha-1 was sprayed in plants with 1 and 2-3 true leaves of cultivars Brasilia, Kuronan and Verano. In the field, two experiments were carried out, one with the cultivar Verano and the other with BRS Planalto. In three experiments, the experimental design was a randomized block in factorial 2 x 5, with four replications. Verano or BRS Planalto plants were sprayed, in two stages of development (1 and 3 true leaves for Verano, and 1 and 2 true leaves for BRS Planalto), with 0, 225, 450, 675 and 990 g a.i. ha-1 of linuron. Post-emergence herbicide linuron was selective for growing carrots, regardless of cultivar, product dosage and plant development stage at the time of application.

摘要：据园艺从业者统计，在巴西登记用于胡萝卜作物的除草剂中，利谷隆（linuron）是应用最为广泛的品种。然而，目前相关文献中关于其对胡萝卜植株选择性的研究报道甚少。为此，本研究旨在探究基因型、药剂剂量以及施药时植株生长阶段对胡萝卜生长期利谷隆除草剂选择性的影响。本研究共开展4组试验：1组设于温室，3组设于商业化胡萝卜生产田块。温室试验采用4×2×3因子完全随机设计，设置4次重复；供试品种为Brasilia、Kuronan与Verano，分别在植株长出1片真叶和2~3片真叶时，喷施0、225、450、675克有效成分/公顷（g a.i. ha⁻¹）的利谷隆药液。田间试验共设3组，其中2组分别以Verano、BRS Planalto品种为试材，剩余1组沿用相同试验框架；其余3组试验采用2×5因子随机区组设计，设置4次重复。分别在两个生长阶段对Verano和BRS Planalto植株施药：Verano品种的施药时期为1片真叶期和3片真叶期，BRS Planalto品种的施药时期为1片真叶期和2片真叶期；施用的利谷隆浓度梯度为0、225、450、675、990克有效成分/公顷。研究结果表明，无论供试品种、药剂剂量以及施药时植株生长阶段如何，苗后除草剂利谷隆对生长期胡萝卜均具有选择性。