Selectivity of Herbicide Associations with Chemical Protector in the Treatment of Sweet Sorghum Hybrid Seeds

Abstract

-Sweet sorghum culture is an alternative to sugar and ethanol production. With the aim of evaluating herbicide tank-mix selectivity associated or not to sweet sorghum seed treatment with naphthalic anhydride, two experiments with ESX5200 and EJX7C5110 hybrids were performed in red oxisol (clayey) field conditions, in the municipality of Campo Mourão, Paraná state. A randomized block design was used, with 4 x 2 factorial scheme, with four replications. The first factor represented three herbicide associations and a control sample without herbicide, and the second factor was constituted by the absence or presence of seed treatment with naphthalic anhydride (5.0 g kg -1 ). Herbicide treatments were tank-mixes of atrazine + S-metolachor (2,640 + 480 g ha 1 ) (pre-emergence); atrazine + S-metolachlor + isoxaflutole (2,640 + 480 + 11.25 g ha -1 ) (pre-emergence) and atrazine + S-metolachlor (1,500 + 384 g ha -1 ) (post-emergence). The following characteristics were evaluated: intoxication, plant height, stalk diameter, number of internodes per stalk and plant density, performed 60 days after emergence (DAE); stalk yield and Brix, were evaluated on day 85 DAE. Atrazine + S-metolachlor tank-mix applied in pre or post-emergence did not affect growth, development, yield and stalk quality of the ESX5200 and EJX7C5110 sweet sorghum hybrids. Sweet sorghum seed treatment with naphthalic anhydride provided partial protection against the action of atrazine + s-metolachlor + isoxaflutole tank-mixes, being more evident for the ESX5200 hybrid. Keywords

Selectivity of Herbicides Applied Alone and in Tank Mixtures to Sweet Sorghum in Post-Emergence

“…at 35 days after emergence (Maciel et al, 2017), similar to the results found for the hybrid N31G2091 used in this study. Although the results are similar, differential tolerance to herbicides may occur due to genetic variations in the hybrids, affecting herbicide absorption, translocation and metabolism (Bunting et al, 2004;Galon et al, 2016).…”

Weed chemical control in grain sorghum at the steppe zone of Ukraine

“…One of the main factors limiting the increase in sorghum productivity is weed vegetation. The spreading of weeds has become threatening and the issue of weed control is extremely relevant (Pimentel et al, 2019;Maciel et al, 2017;Machado et al, 2016). It should be noted that at the beginning of the growing season sorghum grows slowly.…”