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.