Plant pathogens in recycled irrigation water in commercial plant nurseries and greenhouses: their detection and management

With water conservation and reuse a priority for communities worldwide, recycling irrigation water in commercial plant nurseries and greenhouses is a logical measure. Plant pathogenic microorganisms may be present in the initial water source, or may accrue and disperse from various points throughout the irrigation system, constituting a risk of disease to irrigated plants. The continual recycling of this water is exacerbating this plant disease risk. Accurate and timely detection of plant pathogenic propagules in recycled irrigation water is required to assess disease risk. Both biological and economic thresholds must be established for important plant-pathosystems. Plant pathogens in recycled irrigation water can be managed by a variety of treatment methods that can be arranged in four broad categories: cultural, physical, chemical, and biological. An integrated approach using one or more techniques from each category is likely to be the most effective strategy in combating plant pathogens in recycled irrigation water.