The objectives of this research were to determine if adjuvants with water-repellent properties could reduce herbicide retention on foliage, and thereby absorption, of the spray solution and to determine if herbicide activity was maintained with a reduction in herbicide retention. Water-repellent adjuvants, DC 2-1322, DC 1-6184, and DC 772, were evaluated with three herbicides, isoxaflutole, pendimethalin, and flumioxazin, and on three crop species, cabbage, tomato, and wheat. The water repellents DC 2-1322 and DC 772 were ineffective with these herbicides and these crop species. DC 1-6184 effectively reduced spray retention for all three herbicides evaluated, regardless of formulation, on all three species. The efficacy of DC 1-6184 was more evident if the spray application was restricted to the plant foliage. The water-repellent DC 1-6184 has potential to decrease injury while maintaining weed control with certain herbicides.

Nomenclature: Flumioxazin; isoxaflutole; pendimethalin; cabbage, Brassica oleracea L. ‘Megaton F1’; tomato, Lycopersicon esculentum Mill., ‘Sunny hybrid’; wheat, Triticum aestivum L. ‘Harus’.

Additional index words: Retention, surfactant.

Abbreviations: CS, capsule suspension; DAT, days after treatment; EC, emulsifiable concentrate; SC, soluble concentrate; WDG, water-dispersible granule.