Optimizing Plant Health and Pest Management of Lagerstroemia spp. in Commercial Production and Landscape Situations in the Southeastern United States: A Review

摘要

Lagerstroemia is a genus of plants comprised of deciduous shrubs or small trees native to China southward into Southeast Asia. L. indica, the oldest and most widespread species in cultivation in the United States, has been cultivated as an ornamental for centuries and was introduced to the Southeastern U.S. over 175 years ago. Much has been disseminated on the culture and commercial production of crapemyrtle species and cultivars; including plant forms and function, adaptability to macro and micro environment, growth and floral characteristics, and commercial production and landscape culture and maintenance. Since the introduction of L. indica in the United States, L. fauriei, L. subcostata and L. limii have also been introduced. However, since the mid 1970s, interspecific hybrids between L. indica x L. fauriei comprise the majority of new cultivar introductions. Breeding efforts have resulted in 133 commercially available cultivars as of December 2011 that include cultivars with ever improving form and flowering, new flower colors, ornamental bark, ornamental foliage, and disease tolerance. However, there is a wide range among cultivars of tolerance to key pests and diseases such as powdery mildew, Cercospora leaf spot, flea beetle and Japanese beetle. A large number of pests and plant pathogens also negatively affect crapemyrtle health including granulate ambrosia beetle, crapemyrtle aphid, bark scale, bacterial leaf spot, sooty mold and soil-borne root and crown diseases. This review focuses on crapemyrtle culture, in both commercial and landscape settings, with an emphasis on optimizing plant health through the discussion of major abiotic and biotic stressors and cultivar variation in tolerance to these stressors.