Effect of herbicides and doses on short- and long- term Eleusine tristachya control

BRUNORI, A.; PURICELLI, E

WEED RESEARCH

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2019

0043-1737

Eleusine tristachya has been recently reported in Argentina as a problematic weed that can occur at high densities in spring and summer in fallows and in maize and soyabeans. The reason for E. tristachya populations increase is that once the weed is established, it is difficult to eliminate as it produces a high number of seeds and plant regrowth occurs after herbicide treatments. The aim of this study was to determine the effect of herbicides (glyphosate, haloxyfop-methyl and clethodim) on short- (biomass 30 days after treatment -30 DAT-) and long- (tiller number and height and seed production ?regrowth at 330 DAT-) term control of E. tristachya biotypes applied at the seedling, vegetative, and reproductive stage. Data fitted to a log-logistic model. Short-term control, can be achieved with low doses (ED50 and ED90) at the seedling- and vegetative stages for all herbicides considered. Instead, for the reproductive stage, ED90 values showed a three to six-fold- (glyphosate), six- to fifty-two- fold (haloxyfop-methyl), and five- to thirteen- (clethodim) increase of the parameter. Long- term control at the recommended dose or lower is not acceptable at the reproductive stage as tiller regrowth and seed production occurred with all herbicides. Consequently, control of E. tristachya early in the growing season is adequate in the growing season of the application and can also prevent infestations by tiller regrowth the following year. A management program based on the combination of glyphosate with post-emergence graminicides applied at early stages will be effective to control future infestations.