Pansy Tolerance to Preemergence Herbicides

Abstract

Abstract Three studies were conducted to determine tolerance of pansy cultivars to preemergence applied herbicides. In the first two studies, three cultivars were evaluated for tolerance. In the first study plants were small at the time of treatment [5 cm (2 in) in height]. Herbicides that caused no injury or shoot dry weight (SDW) reduction of ‘Crystal Bowl True Blue’ and ‘Maxim Orange’ were Corral (pendimethalin) and Pennant (metholachlor). With ‘Imperial Antique Shades’, only Pennant 5G caused no injury or SDW reduction. In the second study, with larger transplants [12 to 15 cm (5 to 6 in) in height], the same three pansy cultivars appeared more tolerant of applied herbicides. With ‘Crystal Bowl True Blue’ only Rout 3G and Pendulum 60WDG caused injury and reduced SDW, while with ‘Maxim Orange’ those two plus Ronstar caused injury or SDW reduction. ‘Imperial Antique Shades’ again was the most sensitive cultivar with five herbicides causing injury or SDW reduction. In the third study, two cultivars, ‘Bingo’ and ‘Majestic Giant’, were treated with 11 herbicides. Corral, Treflan, and Factor caused no injury to either cultivar.