International Maize and Wheat Improvement Center (CIMMYT), Addis Ababa, Ethiopia.
CIMMYT, Texcoco, Mexico.
PLoS One. 2019 Jul 31;14(7):e0219327. doi: 10.1371/journal.pone.0219327. eCollection 2019.
Crops are variously susceptible to biotic stresses-something expected to increase under climate change. In the case of staple crops, this potentially undermines household and national food security. We examine recent wheat rust epidemics and smallholders' coping mechanisms in Ethiopia as a case study. Wheat is a major food crop in Ethiopia widely grown by smallholders. In 2010/11 a yellow rust epidemic affected over one-third of the national wheat area. Two waves of nationally representative household level panel data collected for the preceding wheat season (2009/10) and three years after (2013/14) the occurrence of the epidemic allow us to analyze the different coping mechanisms farmers used in response. Apart from using fungicides as ex-post coping mechanism, increasing wheat area under yellow rust resistant varieties, increasing diversity of wheat varieties grown, or a combination of these strategies were the main ex-ante coping mechanisms farmers had taken in reducing the potential effects of rust re-occurrence. Large-scale dis-adoption of highly susceptible varieties and replacement with new, rust resistant varieties was observed subsequent to the 2010/11 epidemic. Multinomial logistic regression models were used to identify the key factors associated with smallholder ex-ante coping strategies. Household characteristics, level of specialization in wheat and access to improved wheat seed were the major factors that explained observed choices. There was 29-41% yield advantage in increasing wheat area to the new, resistant varieties even under normal seasons with minimum rust occurrence in the field. Continuous varietal development in responding to emerging new rust races and supporting the deployment of newly released resistant varieties could help smallholders in dealing with rust challenges and maintaining improved yields in the rust-prone environments of Ethiopia. Given the global importance of both wheat and yellow rust and climate change dynamics study findings have relevance to other regions.
作物易受生物胁迫的影响，而这种情况预计会随着气候变化而增加。对于主要作物来说，这可能会破坏家庭和国家的粮食安全。我们以埃塞俄比亚最近的小麦锈病流行和小农应对机制为例进行研究。小麦是埃塞俄比亚的一种主要粮食作物，广泛由小农种植。2010/11 年，一场黄锈病疫情影响了全国三分之一以上的小麦种植面积。在疫情发生前的一个小麦种植季（2009/10 年）和三年后（2013/14 年）收集了两波具有全国代表性的农户层面面板数据，使我们能够分析农民在应对疫情时采用的不同应对机制。除了使用杀菌剂作为事后应对机制外，种植更多黄锈病抗性品种的小麦、增加种植的小麦品种多样性，或者综合运用这些策略，是农民为减少锈病再次发生的潜在影响而采取的主要事前应对机制。在 2010/11 年疫情之后，大规模淘汰高度易感品种，并代之以新的抗锈品种。随后观察到大量淘汰高度易感品种，代之以新的抗锈品种。采用多项逻辑回归模型来确定与小农事前应对策略相关的关键因素。农户特征、对小麦的专业化程度以及获得改良小麦种子的情况是解释所观察到的选择的主要因素。即使在田间锈病发生最少的正常季节，将小麦种植面积增加到新的抗锈品种也能带来 29-41%的产量优势。为应对新出现的锈病新菌株而不断进行品种开发，并支持新发布的抗性品种的部署，这将有助于埃塞俄比亚的小农应对锈病挑战并保持在锈病多发环境中的改良产量。鉴于小麦和黄锈病的全球重要性以及气候变化动态研究结果与其他地区有关。
