Buddleia davidii Franch. ‘Royal Red’ (butterfly-bush) was treated with different rates of Cutless (flurprimidol) in two experiments. Growth index, and inflorescence number and index decreased with increasing rates of Cutless. Foliage of treated plants was darker green than that of control plants. Growth inhibition persisted for at least 120 days when plants were treated with rates of 125 to 2000 ppm, but not when treated with 62.5 ppm Cutless. Shoot length measured after the following spring flush was similar among treatments, indicating similar plant vigor.
2Professors of Horticulture.