<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hong, C. X.</style></author><author><style face="normal" font="default" size="100%">Marston, C. D.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Crown rot of Abies balsamea var. phanerolepis caused by Phytophthora cactorum in Virginia</style></title><secondary-title><style face="normal" font="default" size="100%">Plant Disease</style></secondary-title><short-title><style face="normal" font="default" size="100%">Plant Disease</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2005</style></year><pub-dates><date><style  face="normal" font="default" size="100%">04/2005</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">  http://dx.doi.org/10.1094/PD-89-0433B </style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">89</style></volume><pages><style face="normal" font="default" size="100%">433 - 433</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;In early July 2004, a severe crown rot of Canaan fir (&lt;em&gt;Abies balsamea&lt;/em&gt; var. &lt;em&gt;phanerolepis&lt;/em&gt; Fern.) was reported to the Virginia Cooperative Extension, Frederick County Office, and subsequently to the Virginia Tech Disease Clinic in Virginia Beach. One thousand five-year-old Canaan fir transplants (approximately 11 mm in caliper and 31 cm high) had been purchased from a tree nursery in Oregon and planted in the field in Frederick County, VA, in April of 2004. The field site had not been cultivated for 4 years after an apple orchard had been removed in 2000. By mid-May, needle browning had become serious, affecting the lower crown first. By August, transplants had suffered 40% mortality. Basal stems of affected plants were obviously discolored. Root and basal stem samples from several infected plants were then cultured on PARP-V8 agar on three different dates. &lt;em&gt;Phytophthora&lt;/em&gt; sp. isolates were recovered from all stem samples but none from the roots. These isolates produced a large number of papillate sporangia that were caducous with short pedicels. Abundant oogonia with paragynous antheridia formed oospores directly on isolation plates within 7 days. The isolates were keyed as &lt;em&gt;P. cactorum&lt;/em&gt; (2). This identification was confirmed using a single-strand-conformation polymorphism analysis of ribosomal DNA internal transcribed spacer (ITS)-1 (4). It appears that the source of inoculum was &lt;em&gt;P. cactorum&lt;/em&gt; associated with the previous apple crop, since Canaan fir from the same transplant lot planted in a nearby field without a history of apples remained healthy. &lt;em&gt;P. cactorum&lt;/em&gt; has been reported to cause root rot of noble fir (&lt;em&gt;A. procera&lt;/em&gt; Rhedo), Pacific silver fir (&lt;em&gt;A. amabilis&lt;/em&gt; (Dougl.) Forbes), and Shasta red fir (&lt;em&gt;A. magnifica&lt;/em&gt; var. &lt;em&gt;shastensis&lt;/em&gt; Lemm.) in the Pacific Northwest (3). It has also caused crown rot of Fraser fir (&lt;em&gt;A. fraseri&lt;/em&gt; (Pursh) Poir.), noble fir, white fir (&lt;em&gt;A. concolor&lt;/em&gt; (Gord. &amp;amp; Glend.) Lindl.), and balsam fir (&lt;em&gt;A. balsamea&lt;/em&gt; (L.) Mill.) in Michigan (1). To our knowledge, this is the first report of &lt;em&gt;P. cactorum&lt;/em&gt; attacking Canaan fir. Canaan fir currently is a recommended Christmas tree species for areas where Fraser fir does not do well due to root rot caused by &lt;em&gt;Phytophthora cinnamomi&lt;/em&gt;. This study suggests that such a recommendation must be used with caution. Growing Canaan fir trees in &lt;em&gt;P. cactorum&lt;/em&gt;-infested soil could result in devastating crop losses as reported in this note.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">4</style></issue></record></records></xml>