Emergence and Control of Rottboelia spp. in Different Months in Sugarcane Cultivation¹

Emergência e Controle de Rottboelia spp. em Diferentes Meses na Cultura da Cana-de-Açúcar

ABSTRACT

This study aimed to evaluate the control of Rottboelia spp. with the formulated mixture diuron + hexazinone + sulfometuron-methyl and the emergence of this weed in the months of April, May, June, July, August, September, October and November 2012 in sugarcane cultivation, cultivar RB867515. The experimental design consisted of randomized blocks, with treatments in a 4 x 4 factorial arrangement with four replicates for the months of April to November. The emergence tests used a randomized block design, in a 8 x 5 split plot arrangement with four replicates. The analyzed factors were the rates of the formulated mixture (diuron + hexazinone + sulfometuron-methyl), which consisted of: 1,809.00 + 510.00 + 43.50 g ha^-1 (T2); 1,507.50 + 425.00 + 36.25 g ha^-1 (T3) and 1,386.90 + 391.00 + 33.35 g ha^-1 (T4), in addition to the control (T1) without application. Controls over 80.00% were found for the application performed in the month of November in evaluations at 30 and 60 DAA, regardless of the rate in use. All treatments were selective for the sugarcane cultivar RB867515. The tests conducted in the months of August, September, October and November showed the highest population density.

Keywords:
R. exaltata; rates; effectiveness; Saccharum spp