Tu J C
Agriculture and Agri-Food Canada, Greenhouse and Processing Crops Research Centre, Harrow, ON, Canada N0R 1G0.
Meded Rijksuniv Gent Fak Landbouwkd Toegep Biol Wet. 2002;67(2):209-16.
Pythium root rot caused by Pythium aphanidermatum is one of the most important diseases of greenhouse tomatoes. Hydroponic culture exacerbates the problem. Both nutrient film technique (NFT) and recirculating growing systems pose a challenge in the control of this disease, because the pathogen, especially the zoospores, can spread easily in the recirculating solution to the whole growing system. Fortunately, hydroponically grown plants are easier to manipulate than soil grown plants, proper manipulation of root environments can lead to excellent disease control. This paper reports the development of an effective integrated control measure for pythium root rot of tomato by integrating pH, bioagent, and ultra-violet irradiation in a specific manner. This integrated control consists of three operations: a) before transplanting, the UV system is connected to sterilize the recirculating solution using 100 mJcm-2; b) after transplanting, the nutrient solution is delivered at pH 5.0 regime for five weeks followed by adjusting pH to 5.8 to 6.2 regime for one week; and c) bacterial bioagent, such as Pseudomonas is introduced into the root zone at 100 mL per plant at 10(8) bacteria mL-1 or added to the nutrient solution to arrive at 10(6) bacteria mL-1 in the solution. This report also discusses the advantages and limitations of this measure in the control of pythium root rot.
由瓜果腐霉引起的番茄腐霉根腐病是温室番茄最重要的病害之一。水培加剧了这一问题。营养液膜技术（NFT）和循环种植系统在控制这种病害方面都面临挑战，因为病原菌，尤其是游动孢子，能够在循环溶液中轻易传播至整个种植系统。幸运的是，水培植物比土培植物更易于操控，对根系环境进行适当操控可实现出色的病害防控。本文报道了通过以特定方式整合pH值、生物制剂和紫外线照射，开发出一种有效的番茄腐霉根腐病综合防控措施。这种综合防控包括三个操作步骤：a）移栽前，连接紫外线系统，使用100 mJ/cm²对循环溶液进行消毒；b）移栽后，在pH值为5.0的条件下供应营养液五周，随后将pH值调整至5.8至6.2并维持一周；c）将细菌生物制剂，如假单胞菌，以每株100 mL、浓度为10⁸个细菌/mL的量引入根区，或添加到营养液中，使溶液中的细菌浓度达到10⁶个细菌/mL。本报告还讨论了该措施在控制番茄腐霉根腐病方面的优点和局限性。
