%0 Journal Article %J Plant Pathology %D 2011 %T Potential for eradication of the exotic plant pathogens Phytophthora kernoviae and Phytophthora ramorum during composting %A Noble, R. %A Blackburn, J. %A Thorp, G. %A Dobrovin-Pennington, A. %A Pietravalle, S. %A Kerins, G. %A Allnutt, T. R. %A Henry, C. M. %K Phytophthora pseudosyringae %K Rhododendron ponticum %K temperature %K Vaccinium myrtillus %X

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°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°C in flasks, it survived on leaves exposed to a mean temperature of 40·9°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 >=41·9°C (32·8°C for P. kernoviae) or for 10 days at >=31·8°C (25·9°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°C or for 10 days at 35°C were <3%, for an average initial infection level of leaves of 59·2%. 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°C, when all culture results were negative.

%B Plant Pathology %I Blackwell Publishing Ltd %V 60 %P 1077–1085 %G eng %U http://dx.doi.org/10.1111/j.1365-3059.2011.02476.x %R 10.1111/j.1365-3059.2011.02476.x