Lauren Maine Santos Menandro

New agronomic practices are emerging in the green cane system to utilize sugarcane (Saccharum officinarum L.) straw for energy cogeneration, which necessitates its removal from the soil surface. This study has three main objectives: (1) evaluate the population dynamics and composition of Jamaican crabgrass (Digitaria horizontalis Willd.) and large crabgrass [Digitaria sanguinalis (L.) Scop.] under different sugarcane straw amounts, with and without herbicide treatment; (2) assess the development of sugarcane under different straw amounts; and (3) determine the amount of sugarcane straw that should be kept on the soil surface after harvest to ensure that it does not compromise the chemical control for Digitaria spp. in ratoon cane in a green cane system. We conducted this research at two experimental sites, one at the beginning and the other during the middle of the harvest season, over a span of 2 yr. Our primary treatments consisted of different amounts of sugarcane straw after harvest on the soil surface (0, 5, 10, and 15 Mg ha⁻¹), while secondary treatments included the herbicide application (sulfentrazone + tebuthiuron for the beginning of harvest season and isoxaflutole + tebuthiuron for the middle of harvest season). The Digitaria spp. exhibited higher density (four times more) and dry matter (two times more) in scenarios with a lower sugarcane straw amount (5 Mg ha⁻¹) on the soil surface and no herbicide application. However, a higher straw amount (15 Mg ha⁻¹) contributed to reduced Digitaria spp. infestation and to improved sugarcane yield. According to this research, it is essential to maintain at least 10 Mg ha⁻¹ of sugarcane straw on the soil surface and remove only 5 Mg ha⁻¹ for energy cogeneration.

Background A new agronomic management is used in sugarcane fields, due to the removal of part of the layer of straw on the soil surface for the cogeneration of energy, culminating in variable amounts of straw. Objective The objective was to evaluate the population dynamics of weeds in different scenarios of straw removal; to evaluate the weed control and selectivity of sugarcane; to determine the amount of sugarcane straw that must remain in the soil to facilitate weed control [...] Abstract Background A new agronomic management is used in sugarcane fields, due to the removal of part of the layer of straw on the soil surface for the cogeneration of energy, culminating in variable amounts of straw. Objective The objective was to evaluate the population dynamics of weeds in different scenarios of straw removal; to evaluate the weed control and selectivity of sugarcane; to determine the amount of sugarcane straw that must remain in the soil to facilitate weed control