02576nas a2200277 4500008004100000022001400041245012600055210006900181260002900250300001600279490000700295520170800302653003202010653002602042653001602068653002402084100001302108700001702121700001302138700002702151700001902178700001402197700001702211700001502228856005502243 2011 eng d a1365-305900aPotential for eradication of the exotic plant pathogens Phytophthora kernoviae and Phytophthora ramorum during composting0 aPotential for eradication of the exotic plant pathogens Phytopht bBlackwell Publishing Ltd a1077–10850 v603 a

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.

10aPhytophthora pseudosyringae10aRhododendron ponticum10atemperature10aVaccinium myrtillus1 aNoble, R1 aBlackburn, J1 aThorp, G1 aDobrovin-Pennington, A1 aPietravalle, S1 aKerins, G1 aAllnutt, T R1 aHenry, C M uhttp://dx.doi.org/10.1111/j.1365-3059.2011.02476.x