Potential selectivity of herbicides in pre-and post-emergent linseed (Linum usitatissimum L.)

Linseed is an oilseed crop that is widely used in human and animal feed, as a cover crop in agroecosystems, and for fiber production. To facilitate the management of weeds in the crop, this study aimed to evaluate potential selective herbicides for linseed cultivation applied in pre-planting and incorporation (PPI), pre-emergence (PRE), and early (POST) and late (late POST) post-emergence stages, since there are presently no herbicides registered for use on linseed in Brazil. Therefore, four experiments were conducted in a completely randomized design with four replications, and five (exp. 1), 21 (exp. 2), 26 (exp. 3), and four (exp. 4) treatments. Crop injury and the fresh and dry matter of the plants were evaluated. Experiment 4 was conducted until seed production, and data on the final height, number of capsules, and yield were obtained. The results were characterized by the low selectivity of herbicides during pre-emergence, whether incorporated or not, and indicated 11 herbicides with potential selectivity in post-emergence, whether early or late, namely: bentazon, bentazon + imazamox, clethodim + fenoxaprop, clethodim, flumiclorac, fluazifop, flumioxazin, haloxyfop, nicosulfuron, tembotrione, and tepraloxydim. Linseed is demonstrated to be susceptible to or has low tolerance to various herbicides.