北茎溃疡

Diaporthe caulivora
(原Diaporthe phaseolorumvar。caulivora)
北方溃疡病是一种经济关注疾病，2014年首次在纽约被发现和证实。自最初的确认以来，它被发现在纽约的许多大豆产区相当广泛，尽管目前仅在中等低发病率。病原体在被感染的大豆残渣上生存，感染发生在营养生长阶段，但症状直到生殖阶段才出现。叶面症状包括脉间褪绿，然后是坏死，这与其他土传疾病的叶面症状难以区分，包括突然死亡综合征和棕色茎腐病。死叶仍然附着在茎上。最初，小的红褐色病变出现，通常靠近下部茎节，扩展成独特的“溃疡病”，中心轻微凹陷，灰褐色，边缘微红。大的溃疡病可以完全缠绕茎干。茎纵向分裂可能会揭开一个褐色变色的维管组织和髓,经常低茎上的节点附近更为明显,类似于什么是观察棕色的茎腐病。该病减少种子的数量和规模生产,并可能导致产量损失高达50%的严重传染病。值得注意的是，茎腐烂有两种形式;1)北生溃疡病，2)南生溃疡病。南方的茎溃疡病尚未在纽约被鉴定。 Each disease is caused by a different pathogen, and controlled by separate resistance genes. Because northern stem canker was dismissed as a disease of minor importance in the 1950s, most seed companies do not provide disease ratings specific for northern stem canker in their catalogs. Most ‘stem canker’ ratings in commercial seed catalogs are for southern stem canker, a disease of great importance to many soybean production areas of the U.S., but have no relevance to northern stem canker resistance. Foliar fungicide applications for management have shown inconsistent results, and may not be cost effective. Tillage practices to bury infected residues and rotation with non-host crops, including small grains or corn, are recommended for highly infested fields if varieties with resistance specific to northern stem canker are not available.

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相关资源

• 北茎溃疡病:纽约大豆生产商的新挑战-康奈尔农田作物博客文章
• 全州出现大豆土传病害-康奈尔农田作物博客文章
• 北茎溃疡病的首次报道Diaporthe caulivora在纽约的大豆-APS期刊2015年7月,
• 纽约州疾病调查-按疾病和县分类的疾病调查中发现的疾病地点。