Matheron Michael E, Porchas Martin
The University of Arizona, Yuma Agricultural Center, Yuma 85364.
Plant Dis. 2010 Nov;94(11):1323-1328. doi: 10.1094/PDIS-04-10-0296.
Fusarium wilt of lettuce caused by Fusarium oxysporum f. sp. lactucae continues to spread and cause economic losses in Arizona lettuce fields since the initial discovery of the disease in the state in 2001. Studies were initiated to assess the potential of summer soil solarization and flooding as management tools for Fusarium wilt of lettuce in southwestern Arizona production fields. In microplot studies, lettuce plant growth in soil naturally infested with F. oxysporum f. sp. lactucae that was solarized from 2 to 8 weeks was consistently greater than growth in nonsolarized soil. Growth of lettuce in flooded soil containing the pathogen occasionally was significantly higher than in nonflooded soil; however, the effect on plant growth and health was not as consistent as that recorded for solarized soil. In four trials within a field containing F. oxysporum f. sp. lactucae, the incidence of Fusarium wilt on lettuce sown in soil after solarization was reduced from 42 to 91% compared with disease in nonsolarized plots. There was no significant benefit of a 2- over a 1-month solarization period under the conditions of these trials, where the mean soil temperature at a depth of 5 cm during a 1-month solarization period in 2005 and 2006 was 47 and 49°C, respectively. These findings suggest that soil solarization can be an effective tool for management of Fusarium wilt on lettuce, especially when used within an integrated program in conjunction with existing disease management tactics.
自2001年该州首次发现由尖孢镰刀菌莴苣专化型引起的莴苣枯萎病以来，该病继续在亚利桑那州的莴苣田中蔓延并造成经济损失。开展了相关研究，以评估夏季土壤太阳能消毒和淹水作为亚利桑那州西南部生产田莴苣枯萎病管理工具的潜力。在微区试验中，在自然感染尖孢镰刀菌莴苣专化型的土壤中，经2至8周太阳能消毒处理的莴苣植株生长情况始终优于未经太阳能消毒的土壤。在含有病原菌的淹水土壤中，莴苣的生长偶尔显著高于未淹水土壤；然而，对植株生长和健康的影响不如太阳能消毒土壤那样稳定。在一块含有尖孢镰刀菌莴苣专化型的田块进行的四项试验中，与未进行太阳能消毒的地块相比，经太阳能消毒处理的土壤中播种莴苣后枯萎病的发病率从42%降至91%。在这些试验条件下，2个月的太阳能消毒期与1个月的太阳能消毒期相比，没有显著优势，2005年和2006年1个月太阳能消毒期内5厘米深度处的平均土壤温度分别为47°C和49°C。这些研究结果表明，土壤太阳能消毒可以成为管理莴苣枯萎病的有效工具，特别是在与现有病害管理策略结合的综合方案中使用时。
