Abstract

VITORINO, H.S.  and  MARTINS, D. Effect of water stress on the efficiency of herbicides and on the biochemical characteristics of Ipomoea grandifolia. Planta daninha [online]. 2012, vol.30, n.1, pp. 185-191. ISSN 0100-8358.  http://dx.doi.org/10.1590/S0100-83582012000100021.

The objective of this work was to evaluate the efficacy of ALS and PROTOX inhibiting herbicides in the control of Ipomoea grandifolia under two levels of water deficit, as well as to determine the influence of drought on the content of the soluble carbohydrates, protein and free amino acids of the weed. The study was conducted in a greenhouse in a completely randomized design with treatments in a factorial scheme 4 x 2, with four herbicides (fomesafen, lactofen, chlorimuron-ethyl and imazethapyr), and two levels of water deficit (with and without deficit, - 0.5 MPa and -0.01 MPa, respectively). At 7, 14, 21, and 28 days after application, the control was evaluated visually and organic solutes were determined 24, 48, 72 and 96 hours after herbicide application. Except for chlorimuron-ethyl, the herbicides effectively controlled I. grandifolia. The control efficiency of the herbicides was affected by the water deficit condition. The herbicides increased the soluble carbohydrate content, regardless of the water status and reduced the soluble proteins in the I. grandifolia plants, also increasing the concentrations of free amino acids

Keywords : amino acids; carbohydrates; chemical control; stress; proteins.