Plant Growth-Promoting Rhizobacteria May Reduce Fusiform Rust Infection in Nursery-Grown Loblolly Pine Seedlings
Authors: S. A. Enebak1; W. A. Carey2
Source: Southern Journal of Applied Forestry, Volume 28, Number 4, November 2004 , pp. 185-188(4)
Abstract:
Fusiform rust caused by Cronartium quercuum f.sp. fusiforme (Hedg. & Hunt ex Cumm.) is the most damaging stem disease of Pinus spp. in the southern United States. Plant-growth-promoting rhizobacteria (PGPR) have induced systemic resistance in many host-pathogen systems. To determine whether rhizobacteria could induce systemic resistance to fusiform rust infection, loblolly pine (Pinus taeda L.) seedlings were evaluated for rust resistance following preemergence seed and post emergence foliar sprays with three bacterial strains. Treated seed was sown in one bare root nursery in Alabama and one in Georgia, and seedlings were examined for size differences and rust galls at the end of one season. Treatment with bacteria at the time of sowing did not affect rust galls or seedling growth at the Alabama nursery but reduced galls and increased seedling growth at the Georgia nursery. Bacterial treatment T4 resulted in significantly fewer galls and strains T4 and SE34 resulted in larger seedlings compared to nontreated controls. This is the first report of a reduction in fusiform rust by plant growth-promoting rhizobacteria and although nursery × treatment interactions exist, the current findings suggest that induced systemic resistance is possible. South. J. Appl. For. 28(4):185–188.Keywords: biological control; Cronartium quercuum f.sp. fusiforme; nursery production; Pinus taeda; PGPR; environmental management; forest; forest management; forest resources; forestry; forestry research; forestry science; natural resources; natural resource management
Document Type: Regular article
Affiliations: 1: School of Forestry and Wildlife Sciences Auburn University 108 M.W. Smith Hall Aurburn AL 36849 Phone: (334) 844-1028;, Fax: (334) 844-1084, Email: enebasa@auburn.edu 2: Auburn University Southern Nursery Management Cooperative Auburn University 108 M.W. Smith Hall AL 36849
