Figure 3. Agricultural area in study area and disease occurrence.

Each grid cell is 500 × 500 m. (A) agricultural area in Tsumagoi village, (B) occurrence of Verticillium wilt of cabbage in grid cells Base maps, including grid map, and distribution data of agricultural area were obtained from Fundamental Geospatial Data (Geographical Survey Institute; http://www.gsi.go.jp/kiban/, accessed on 6 January 2016) and National Land Numerical Information download service (Ministry of Land, Infrastructure, Transport and Tourism, http://nlftp.mlit.go.jp/ksj/, accessed on 6 January 2016), respectively.