Eficácia do herbicida flumioxazin no controle de Euphorbia heterophylla, na aplicação sobre diferentes tipos de palha e simulações de chuva: Controle de Euphorbia heterophylla com flumioxazin

Abstract

In the spread of pre-emergent herbicides on straw, the type and quantity of this material and the physical-chemical characteristics of the herbicides, are decisive in the effectiveness of weed control. The objective of this work was to evaluate the efficacy of the flumioxazin herbicide in the pre-emergence control of the weed Euphorbia heterophylla L., when applied over different straw management and rain simulations. The experimental design was completely randomized, with four replications, organized in a 7x3 factorial scheme, with seven straw managements (without straw; B. ruziziensis with 3t ha-1 and 5t ha-1; B. ruziziensis+Z. mays with 3t ha-1 and 5t ha-1; Z. mays with 3t ha-1 and 5t ha-1) and three amounts of rain (10, 25 and 40mm) and the herbicide flumioxazim(120g ai ha-1). The control evaluation was carried out at 7, 14, 21, 28, 35 and 45 days after emergence(DAE) and at 45 DAE the dry mass of the aerial part. The highest percentages of control occurred in the application of flumioxazin on Brachiaria ruziziensis 3t ha-1 and 5t ha-1 and Zea mays 3t ha-1, with 86.25, 82.08 and 80.41% respectively. The 10 mm rain resulted in the lowest percentage of control of Euphorbia heterophylla. Thus, the type of straw and its quantity interfere in the control effectiveness.