ARS | Publication request: ALTERNATIVE BIOLOGICAL AMENDMENTS: EFFECTS ON SOIL BIOLOGY AND SOILBORNE DISEASES

Submitted to: Northeast Potato Technology Forum Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 15, 2005
Publication Date: March 15, 2005
Citation: Larkin, R.P. 2005. Alternative biological amendments: effects on soil biology and soilborne diseases. Northeast Potato Technology Forum Abstracts. pages 43-44

Technical Abstract: A variety of biological amendments, including commercial biocontrol organisms, microbial inoculants, and biostimulants, were evaluated in greenhouse and field tests for efficacy in controlling soilborne diseases of potato. The commercial biocontrol agents Bacillus subtilis (Bsub), Burkhoderia cepacia (Bcep), Trichoderma virens (Tvir), and Trichoderma harzianum (Tharz), all significantly reduced stem canker and all but Tharz reduced black scurf, caused by Rhizoctonia solani. Bsub and Tvir also increased total and marketable tuber yield over multiple field seasons. Some treatments, including vitazyme, Effective microororganisms (EM-1), and foliar-applied compost tea (FCT) produced no significant effects on soilborne diseases, tuber quality, or tuber yields. In other cases, significant effects and trends, indicating reduced disease and increased yield, were observed for mycorrhizae (AMF) and soil-applied compost tea (SCT) treatments, but these effects were not consistent. When used in conjunction with different 2-yr rotations, some treatments (such as SCT and a Microbial Mixture) showed significant disease control in some rotations, but not in others. Alternative biological amendments that effectively manipulate soil microbial communities, resulting in reduced soilborne disease and increased tuber yields, could play an important role in potato disease management strategies, but more research is needed to determine the most effective treatments; the degree, extent, and duration of efficacy; and economical means of implementation.