Uniconazole effect on growth and chlorophyll content of pyracantha, photinia, and dwarf Burford holly

Abstract

Pyracantha, photinia, and dwarf Burford holly were treated with a uniconazole medium drench at 0, 0.5, 1.0, or 3.0 mg · container⁻¹ a.i. or a foliar application at the following rates: pyracantha at 0, 50, 100, or 150 mg · L⁻¹ a.i.; photinia at 0, 25, 50, or 100 mg · L⁻¹ a.i.; and holly at 1, 10, 25, or 50 mg · L⁻¹ a.i. Height, width, leaf area per plant, and dry weights of all species decreased as uniconazole drench rate increased. Foliar applications were less effective than drenches in pyracantha and photinia, and holly did not respond to the foliar treatment. Chlorophyll content of pyracantha increased with rate in both application methods. Leaf N, P, and Zn increased in pyracantha and photinia with increasing medium drench rate, but only P was increased in holly. Zn also increased in pyracantha and photinia with foliar applications, but only N in photinia and P in pyracantha increased with increasing uniconazole foliar application rates.