Author
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GROTH, E - UNIVERSITY OF WISCONSIN |
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HIRANO, S - UNIVERSITY OF WISCONSIN |
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BAKER, L - UNIVERSITY OF WISCONSIN |
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Upper, Christen |
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Submitted to: American Phytopathological Society
Publication Type: Abstract Only Publication Acceptance Date: 8/27/1995 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Field experiments were conducted to examine the role of immigration in the development of populations of P. syringae (Ps) on snap bean leaves. Immigration was monitored continuously for 14 days by exposing petri dishes containing a medium selective for Ps. Deposition plates were exposed for 2 hr (day) or 4 hr (night) at each of 52 sites in a 90 m x 200 m bean field. When summed over the 14 days, the number of Ps detected on the deposition plates when the leaves were wet with dew (0200 to 0800) was roughly twice that found when the leaves were dry (0800 to 1600) and aerosol deposition was expected (Lindemann & Upper, Appl. Enivron. Microbiol. 50:1229-1232, 1985). It was not uncommon to find 10 to 100 colonies of Ps distributed nonrandomly on the deposition plates exposed during the early morning hours. The patterns were suggestive of insects tracking across the plates. Of 47 insects trapped in petri plates shortly after sunrise, 67.5% were found to harbor Ps on their surfaces. The majority were flies of the genus Delia and potato leafhoppers (Empoasca fabae). Thus, insects may play an important role in dispersal of Ps when leaves are wet with dew. |
