Phytotoxicity of Bedding Plants Resulting from Applications of Knoxout 2Fm, Pennsylvania, 1980

Knoxout 2FM was evaluated for phytotoxicity on 8 types of bedding plants. The experiment was conducted on raised greenhouse benches. Treatments were replicated 4 times (exception ‘Red Star’ marigold only 3 replicates) for each type of plant in a randomized complete block design. Each replicate consisted of one plant transplanted in a 4 x 4 inch square pot filled with pro-mix. Foliar sprays were applied May 2 to the point of runoff with a hand-held compressed air sprayer. Knoxout 2FM was used at 2 rates: 1% (7.8 lb ai/100 gal) and 2% (15.6 lb al/100 gal). Five treatments were observed: treatment 1, one application of 1% spray; treatment 2, two applications of 1% spray; treatment 3, one application of 2% spray; treatment 4, two applications of 2% spray; and treatment 5, control. Plants were retreated at a 7 day interval (temperatures 75°F and 76°F, respectively). All plants were inspected for phytotoxicity on days 7, 14, 21, and 28 following the first application. They were evaluated for overall appearance of the plant compared to an untreated check on a scale of: 0 = no damage, 1 = slight, 2 = moderate, and 3=severe.