2008 年 62 巻 1 号 p. 15-19
Big-vein disease occurs on lettuce worldwide in temperate regions. The causal agent is transmitted from diseased to healthy plants by zoospores of the lettuce root-infecting fungus Olpidium brassicae. To enhance the suppressive effect of soil solarization on the occurrence of lettuce big-vein disease, various supplementary materials were applied to soils before solarization. All the supplementary materials tested, i.e., methionine (40 kg/10 a), urea polymer (200 kg/10 a), and calcium cyanamide (100 kg/10 a), enhanced the suppressive effect of solarization, especially, calcium cyanamide showed the highest prevention value.