ABSTRACT The hardness and pH of the spray water can interfere with the weed control effectiveness with herbicides, but it is not clear the magnitude of this interference, mainly associating different levels of pH and hardness to different glyphosate formulations. This study aimed to evaluate the influence of hardness and pH, in association, of the water used in the application of two glyphosate formulations on the weed control effectiveness. The experiment was conducted in duplicate, in areas with a predominance of Digitaria horizontalis, under a randomized block design with a 4×4×2+1 factorial scheme, composed of four water hardness levels (70, 110, 230, and 430 ppm CaCO3), four pH levels (3.5, 4.5, 5.5, and 6.5), two glyphosate formulations (ammonium salt and potassium salt), and control without application, with four repetitions. The physicochemical characteristics of the spray solutions and the weed control effectiveness were evaluated at 7, 14, and 21 days after application (DAA). The water pH at the studied range did not interfere with the control effectiveness. The increase in hardness reduced the control at 7 DAA, but this difference was not noticed after 21 DAA. Glyphosate ammonium salt promoted higher control of D. horizontalis than that with potassium salt, regardless of water hardness and pH.

Resumo A consolidação em uma área do conhecimento acontece principalmente quando as informações acerca de um determinado fato ou fenômeno são sistematizadas na forma de uma teoria explicativa, capaz de gerar novas hipóteses testáveis. Na biologia da polinização, o teste de diversas hipóteses ecológicas permitiu ampliar o entendimento sobre os processos que originam, mantêm, alteram ou ainda excluem as interações entre plantas e visitantes florais, gerando os padrões observados na natureza. Visando sintetizar esse panorama teórico e oferecer condições para que novas questões relacionadas ao funcionamento de interações de polinização sejam geradas, compilamos aqui um conjunto de 25 hipóteses, ideias e teorias ecológicas que fornecem aporte conceitual para a área. Essas ideias estão relacionadas a aspectos reprodutivos, morfológicos, cognitivos, macroecológicos e de coexistência, de acordo com a especialização das interações entre as plantas e seus polinizadores. Ao apresentarmos essas ideias principais, esperamos promover a utilização de uma abordagem teórico-conceitual explícita no planejamento e desenvolvimento de estudos em biologia da polinização. Concluímos com a expectativa de que essa contribuição direcione os estudos em biologia da polinização no Brasil e contribua para o avanço e internacionalização das pesquisas desenvolvidas no país.

Abstract A particular research area can be significantly improved when information is systematized in explanatory theories able to generate testable hypotheses. In pollination biology, such systematization contributed to several ecological theories and expanded the understanding of the patterns and processes that originated, maintain, or exclude ecological interactions. Here, we compiled a set of 25 ecological ideas that have already received conceptual contribution from pollination biology. These ideas are related to reproduction, morphology, cognition, macroecology and species coexistence. We hope to promote the use of an explicit conceptual and theoretical approach when planning and developing studies in this research field by presenting these main ideas. We conclude that this contribution will boost studies in pollination biology in Brazil and contribute to the advancement and internationalization of such research developed in the country.