Response of Loropetalum chinense var. rubrum ‘Ruby’ to Foliar Applications of Micronutrient Fertilizers and Miticide

Abstract

Abstract Loropetalum chinense (also called Chinese Fringebush or Chinese Witch Hazel) is commonly used in the Florida landscapes. However, in recent years, there have been increasing reports and complaints of unexplained decline throughout Central Florida. The objective of this study was to evaluate the growth and quality response of declining L. chinense plants to foliar micronutrient and miticide applications. L. chinense ‘Ruby’ plants exhibiting significant decline symptoms were treated with eight foliar fertilizer treatments (High Cu, Low Cu, Kocide® 2000 [copper hydroxide], B, Mn, Zn, and Peters S.T.E.M.) and half of the plants also received two treatments of GardenTech Sevin Concentrate Bug Killer® (carbaryl, 22.5% AI). Plant growth was not influenced by miticide or fertilizer treatments. However, plants sprayed with Cu (i.e., Cu high, Cu low, and Kocide) had quality ratings, at 4 and 8 weeks after treatment, that were significantly higher than plants treated with other foliar fertilizers. Additionally, results indicated that there was no fertilizer treatment effect on mite populations. Failure of the miticide to enhance plant quality ratings, suggested that eriophyid mites were not associated with decline symptoms. The quality of declining landscape plantings of L. chinense ‘Ruby’ can be improved with the application of foliar Cu sprays.