@article {PPA:PPA2476, title = {Potential for eradication of the exotic plant pathogens Phytophthora kernoviae and Phytophthora ramorum during composting}, journal = {Plant Pathology}, volume = {60}, number = {6}, year = {2011}, pages = {1077{\textendash}1085}, publisher = {Blackwell Publishing Ltd}, abstract = {

Temperature and exposure time effects on Phytophthora kernoviae and Phytophthora ramorum viability were examined in flasks of compost and in a large-scale composting system containing plant waste. Cellophane, rhododendron leaf and peat-based inoculum of P. kernoviae and P. ramorum isolates were used in flasks; naturally infected leaves were inserted into a large-scale system. Exposures of 5 and 10 days respectively at a mean temperature of 35{\textdegree}C in flask and large-scale composts reduced P. kernoviae and P. ramorum inocula to below detection limits using semi-selective culturing. Although P. ramorum was undetectable after a 1-day exposure of inoculum to compost at 40{\textdegree}C in flasks, it survived on leaves exposed to a mean temperature of 40{\textperiodcentered}9{\textdegree}C for 5 days in a large-scale composting system. No survival of P. ramorum was detected after exposure of infected leaves for 5 days to a mean temperature of \>=41{\textperiodcentered}9{\textdegree}C (32{\textperiodcentered}8{\textdegree}C for P. kernoviae) or for 10 days at \>=31{\textperiodcentered}8{\textdegree}C (25{\textperiodcentered}9{\textdegree}C for Phytophthora pseudosyringae on infected bilberry stems) in large-scale systems. Fitted survival probabilities of P. ramorum on infected leaves exposed in a large-scale system for 5 days at 45{\textdegree}C or for 10 days at 35{\textdegree}C were \<3\%, for an average initial infection level of leaves of 59{\textperiodcentered}2\%. RNA quantification to measure viability was shown to be unreliable in environments that favour RNA preservation: high levels of ITS1 RNA were recovered from P. kernoviae- and P. ramorum-infected leaves exposed to composting plant wastes at \>53{\textdegree}C, when all culture results were negative.

}, keywords = {Phytophthora pseudosyringae, Rhododendron ponticum, temperature, Vaccinium myrtillus}, issn = {1365-3059}, doi = {10.1111/j.1365-3059.2011.02476.x}, url = {http://dx.doi.org/10.1111/j.1365-3059.2011.02476.x}, author = {Noble, R. and Blackburn, J. and Thorp, G. and Dobrovin-Pennington, A. and Pietravalle, S. and Kerins, G. and Allnutt, T. R. and Henry, C. M.} }