Herbicide selectivity in safflower crop

Abstract

Safflower (Carthamus tinctorius L.) is an annual oleaginous plant that presents high potential in Brazilian agriculture. The chemical control of weeds in the crop is essential to avoid damage and protect productive potential. The objective of this study was to evaluate the selectivity of herbicides applied in pre-planting incorporated (PPI), pre-planting (PRE) and post-emergence (POST) of the safflower crop. For all, three experiments were installed in greenhouse with a completely randomized design with five replications. The herbicides evaluated for application in PPI (Experiment I) were: diclosulam, metribuzin, pendimethalin and trifluralin; for the application in PRE (Experiment II) the herbicides were: 2,4-D, ametryn + clomazone, atrazine, carfentrazone, carfentrazone + sulfrentrazone, clomazone, diclosulam, flumioxazin, imazethapyr, isoxaflutole, lactofen, mesotrione, metribuzin, metsulfuron - ametryn + clomazone, atrazine, bentazon, bentazon + imazamox, carfentrazone, chlorimuron, clethodim + fenoxaprop, clethodim, clodinafop, were used for the application in POST (Experiment III) , floroxypyr, fluazifop + fomesafen, fluazifop-P, flumiclorac-pentyl, flumioxazin, fluroxypyr, fomesafen, foramsulfuron + iodosulfuron, haloxyfop, imazethapyr, iodosulfuron, lactofen, mesotrione, nicosulfuron, tembotrione and tepraloxydim), compared to the control without herbicide application . The crop phytotoxicity was evaluated at 7, 14, 21 and 28 days after application (DAA), using the percentage scale from 0 to 100, with fresh and dry mass obtained at 35 DAA. The data was submitted to analysis of variance and the means were compared by the Tukey test (p≤0.05). Trifluralin herbicide is selective to the safflower crop in PPI and PRE aplications, while cletodim, fluazifop-p-butyl and haloxyfop-p-methyl are selective for application in POST.