Qualidade da água para preparo de calda herbicida no controle de capim amargoso (Digitaria insularis)

Abstract

Brazil has a great prominence in world agricultural production, especially with regard to commodities such as soybeans (Glycine max) and corn (Zea mays), due to the technologies employed in production. The phytosanitary management is of great importance, because all the actions taken before and after planting will reflect in productivity. Many times this technology is used incorrectly, not achieving satisfactory management, which may be linked to the quality of water application. The objective of this study was to identify if the origin of the water has an influence in the control of bittergrass related to three different active ingredients and more pH reducer. The work was conducted on the property of José Carlos Pontes, located in Capitão Leônidas Marques - PR. Three water sources were used in the treatments: artesian well water, water mine and river water. Three active principles of different classes belonging to the ACCase group (Cletodim, Haloxifop-P-methyl and Quizalofop-P-ethyl) were also used. Thus, the experimental design used was randomized block design (BAD) in a trifactorial scheme containing three repetitions plus control, where the plots were planted in pots containing 800 ml of substrate, obtaining a total of 57 plots. The application occurred in the tillage with a D20 knapsack sprayer, where the doses of Clethodin were 0.825 L/ha, Haloxyfop 0.290 L/ha and Quizalofop 2.0 L/ha. Ori-Min mineral oil was used in all herbicide treatments at a dose of 0.413 L/ha, as well as the pH reducer Aquaxis Full 0.085 L/ha. Control evaluations occurred at 7, 14, 21, 28 days after application. It was possible to observe interference in the decrease in efficiency of the products when well water was used, which may be related to the amount of carbonates present in the water, while river or mine water showed satisfactory control for all active principles.