Plugs of Zinnia elegans Jacq. `California Giant' and Tagetes erecta L. `Golden Climax' and `Grange Lady' were treated with foliar sprays of uniconazole solutions at 0, 5, 25, or 50 mg·liter-1 (spray volume = 120 ml·m-2). Ten days later individual plants were transplanted to OS-liter pots for evaluation of subsequent growth and flowering. All uniconazole treatments reduced height 10 days after application; the extent of reduction depended on uniconazole spray concentration. With zinnia, only the 50-mg·liter-1 foliar spray caused undesirable stunting for at least 1 month after transplanting. None of the uniconazole treatments affected time to anthesis for zinnia. With both marigold cultivars, all uniconazole treatments reduced growth the 2 weeks following transplanting. The highest concentration reduced marigold shoot growth during this period to 25% to 30% of untreated controls. Between 2 and 4 weeks after transplanting growth of all uniconazole-treated marigolds recovered to levels similar to the control. Time to anthesis was increased by the 50 mg·liter-1 treatment for both marigold cultivars. These results suggest that foliar sprays of uniconazole at 5 to 25 mg·liter-1 can control plug height during production without adversely affecting subsequent growth and flowering. with both zinnia and marigold, a single GA3 foliar spray of 100 mg·liter-1 at transplanting partially reversed the adverse post-production effects of the 50 mg·liter-1 uniconazole foliar spray.
If the inline PDF is not rendering correctly, you can download the PDF file here.