Author
Bock, Clive | |
PARKER, PAUL - USDA-APHIS | |
GOTTWALD, TIMOTHY |
Submitted to: Phytopathology
Publication Type: Abstract Only Publication Acceptance Date: 9/9/2003 Publication Date: 6/1/2004 Citation: Bock, C.H., Parker, P., Gottwald, T.R. 2004. The effect of wind speed on dispersal of bacteria from canker-infected citrus trees. Phytopathology. 94:S9. Interpretive Summary: Technical Abstract: The effect of wind speed on dispersal of citrus canker (Xanthomonas axonopodis pv citri) was investigated. Wind was simulated with an electric fan to produce winds of 0 [control], 4, 6 and 15 ms-1 at the canopy face. Spray generated by nozzles was used to simulate rain, and was fed into the wind 1 m upwind of (and directed at) the inoculum source. Samples were taken using panel (at 1, 2, 3 and 5 m) and funnel samplers (at 0, 1 and 2 m) downwind from the inoculum source. Bacteria were deposited at all distances, but most were deposited 1 m downwind (86% of the sample at 1 m vs <1 % at 5 m). Greater wind speed increased the quantity of bacteria deposited at all distances. At 1 m downwind and no wind, 6,168 bacteria were deposited on the panels, but at 15 ms-1 over 320,700 were deposited. The concentration of bacteria rose from 9 to 138 ml-1, respectively. The results show that greater wind speed increases the quantity of bacteria dispersed. The effect of wind speed on dispersal of X. axonopodis pv citri) is relevant where storms with strong winds can increase wind blown inoculum (as in Florida). |