2019 年 2019 巻 66 号 p. 95-99
The sugar beet cyst nematode, Heterodera schachtii Schmidt, is an economically important pest of sugar beet (Beta vulgaris L.), and the nematodes occurrence had not been confirmed in Japan. However, in September 2017, H. schachtii was detected on roots of Brassica sp. cultivated in a field in Hara Village, Nagano Prefecture, Central Japan. The host plant range of H. schachtii is broad including crops of Brassica, Beta, Rheum and Spinacia spp. The impact of H. schachtii spread is of immeasurable importance in Nagano Prefecture because it is a production area specialized in Brassica crops. Since April 2018, emergency measures to eradicate H. schachtii and to prevent its spread have been implemented with application of lime nitrogen and multiple treatments of fumigants. As one of the measures to prevent recurrence of H. schachtii, the difference in control effects among various nematicides should be examined. In this paper, we report the control effects of nematicides registered on crops mainly produced in the H. schachtii outbreak area. We found that soil fumigants were generally effective. Non-fumigants, which were easy to handle and applied just before planting or seeding also had some control effects although not as highly effective as the fumigants.