A simple format for reporting methods used in nutritional studies: Application with loropetalum response to fertilizer rates

Abstract

Loropetalum (L. chinense) cv ‘Blush’, ‘Burgundy’, and ‘Pizzazz’ were grown for 16 months using different rates and application schedules of a 17–7–12 slow‐release fertilizer. Rates were45,68,or 91 g pot¹, each applied once in the Spring, or as a split application, half in the Spring, and half in the Fall. A simple format for reporting fertility, methodology used in tissue sampling, and analytical methodology was developed and used. Fertilizer treatments did not affect significantly growth and color ratings 4 and 12 months after potting (p>0.30). ‘Burgundy’ was significantly the fastest growing cultivar. Yet, all plants from all treatments and cultivars were of commercial quality 12 months after potting. Foliar nutrient content was significantly affected by fertilization treatment for most of the essential elements (p<0.03), but not by cultivar (p>0.10). However, differences due to fertilizer treatments were of limited practical importance as they did not follow the trends in fertilizer rates. Based on these results, sufficiency ranges (% for macronutrients and ppm for micronutrients) were proposed for Loropetalum when the plant‐part sampled was the healthy leaves from the terminal 10 to 15 cm of 4 to 6 branches, without any woody tissue: 1.10<N<2.30; 0.10<P<0.30; 0.50<K<1.00; 0.70<Ca<1.50; 0.10<Mg<0.20,5<B<20; 5<Cu<10;20<Fe<80; 10<Mn<40; and10<Zn<40.