Surface tension analysis of fungicidal spray solution and emulsifiable oils in the control of Asian soybean rust

摘要

Emulsifiable oils and adjuvants can provide desirable characteristics to the spray solution when added to fungicides, reducing surface tension and enabling a higher contact between spray solution and plant surface. In this sense, a two-phase study wasdeveloped. The first phase was carried out in the laboratory aiming at analyzing surface tensions of fungicidal spray solutions associated with different emulsifiable oils and adjuvant. The second phase was conducted under field conditions using soybeanplants, on which spray solutions were applied, and the following parameters were analyzed, Asian soybean rust severity, percentage of control, thousand-grain weight, and yield. The yield was correlated to verify the interference that surface tension ofspray solutions could provide to the chemical control of the fungus Phakopsora pachyrhizi. It allowed knowing the interaction between emulsifiable oils and adjuvants with the fungicide, generating information of high relevance, especially for soybean cropg.