Author
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EAYRE, CYNTHIA |
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Submitted to: APS Net Plant Pathology Online
Publication Type: Abstract Only Publication Acceptance Date: 3/13/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Crown gall, caused by "i"Agrobacterium tumefaciens"/i", is a serious problem in walnut and Prunus orchards and nurseries. Trees shipped from nurseries with out galls may carry bacterial populations, and the bacteria can be spread during transit to the orchard. Galling may also occur due to "i"A. tumefaciens"/i" populations that are already present in the orchard soil. The effect of galls on yield is not clear. Galls may be visible on the trunk of the tree at the soil line, or may be completely under the soil, and not visible until the tree is removed to replace the orchard. Preliminary work by others suggests that there is a significant yield reduction in galled walnut trees. Current recommendations are to remove visible galls with a hatchet and use a blowtorch to kill bacteria and plant tissue at the margin of the excised gall. Incidence of crown gall in nurseries varies from year to year and within fields, suggesting some natural control is occurring. Bacteriophages of "i"A. tumefaciens"/i" were readily isolated from walnut nursery and orchard soils and water in puddles in orchards and nurseries. Host range tests were performed, and efficacy tests initiated. |
