Keinath Anthony P
Clemson University, Coastal Research and Education Center, Charleston, SC 29414-5329.
Plant Dis. 2008 Aug;92(8):1223-1228. doi: 10.1094/PDIS-92-8-1223.
The crowns of muskmelon (Cucumis melo subsp. melo) plants are susceptible to cankers caused by the fungal pathogen Didymella bryoniae. The objective of this study was to compare the length of time D. bryoniae survived in infested crowns that were buried or left on the soil surface. Dried crowns with cankers were buried 12.5 cm deep, placed on the soil surface, or placed on top of raised beds covered with white-on-black polyethylene mulch from July 2002 to June 2003, December 2003 to October 2004, July 2004 to November 2005, and November 2005 to November 2007. At regular intervals, crowns or crown debris were retrieved, washed, cut into pieces, and cultured on semiselective medium to recover D. bryoniae. D. bryoniae was not recovered from crowns buried 35 and 45 weeks in 2003 and 2004 but was recovered from 2.5% of crowns buried 66 weeks in 2005. In contrast, D. bryoniae was recovered after 48, 45, 66, and 103 weeks from 66, 6.3, 2.5, and 10% of crowns on the soil surface in 2003, 2004, 2005, and 2007, respectively. D. bryoniae also was recovered after 66 and 103 weeks from 12.5 and 8% of crowns on mulched beds in 2005 and 2007. In two additional experiments, the pathogen was recovered from 15.0 and 20.1% of infested muskmelon debris left in place for 42 and 38 weeks on polyethylene-mulched beds. To reduce the time D. bryoniae survives after a cucurbit crop, crop debris should be incorporated into soil promptly after harvest.
甜瓜（黄瓜变种甜瓜）植株的顶部易受真菌病原体黄瓜壳二孢引起的溃疡病影响。本研究的目的是比较黄瓜壳二孢在埋于地下或留在土壤表面的受侵染顶部存活的时间长度。2002年7月至2003年6月、2003年12月至2004年10月、2004年7月至2005年11月以及2005年11月至2007年11月期间，将带有溃疡病的干燥顶部埋入地下12.5厘米深处、放置在土壤表面或放置在覆盖黑白相间聚乙烯地膜的高畦顶部。定期取回顶部或顶部碎片，清洗后切成小块，在半选择性培养基上培养以分离出黄瓜壳二孢。2003年和2004年埋入地下35周和45周的顶部未分离出黄瓜壳二孢，但2005年埋入地下66周的顶部中有2.5%分离出了该病菌。相比之下，2003年、2004年、2005年和2007年分别从土壤表面66%、6.3%、2.5%和10%的顶部中在48周、45周、66周和103周后分离出了黄瓜壳二孢。2005年和2007年分别从覆盖地膜的高畦上12.5%和8%的顶部中在66周和103周后也分离出了黄瓜壳二孢。在另外两个实验中，在聚乙烯地膜覆盖的高畦上放置42周和38周的受侵染甜瓜碎片中，分别有15.0%和20.1%分离出了该病原体。为了缩短葫芦科作物收获后黄瓜壳二孢的存活时间，收获后应及时将作物残茬埋入土壤中。
