Growth and Flowering of Lagerstroemia in Response to Pinching, Photoperiod, and Fertilization

Abstract

Three experiments were conducted using Lagerstroemia `Victor' and `Zuni', one on pinching, another on photoperiod, and the third with fertilizer rates. Liners were potted with either one or three liners per container. In the pinching experiment, treatments were 0, 1, 2, 3, or 4 pinches at 0, 2, 4, or 6 weeks after planting. In the photoperiod experiment the plants were exposed to 0, 4, 8, or 12 weeks of short days before being moved to long days. In the fertilizer experiment the plants were fertilized at 0, 200, 400, 600, or 800 mg.L-1 nitrogen from 20-10-20 liquid feed and 0 or 6 g per container of 15-11-13 slow-release fertilizer. For both `Victor' and `Zuni', three liners per container resulted in plants that were wider and shorter than those with only one liner. Neither timing nor number of pinches significantly affected plant size. Short days prevented vegetative growth and floral development in both cultivars. `Victor' grew and flowered best after receiving 8 weeks of short days before moving to long days. `Zuni' grew and flowered best when moved directly to long days after potting. Both `Victor' and `Zuni' grew best when receiving either 200 mg·L-1 or 6 g of slow-release fertilizer.