FIGURE 1. Planting arrangements in rice variety mixture and monoculture survey plots in 1999 and patterned after those used by farmers in Yunnan Province.
From the following article:
Genetic diversity and disease control in rice
Youyong Zhu, Hairu Chen, Jinghua Fan, Yunyue Wang, Yan Li, Jianbing Chen, JinXiang Fan, Shisheng Yang, Lingping Hu, Hei Leung, Tom W. Mew, Paul S. Teng, Zonghua Wang and Christopher C. Mundt
Nature 406, 718-722(17 August 2000)
doi:10.1038/35021046
Each symbol represents a hill of susceptible (O) or resistant (X) rice. Distances between hills within rows were 15 cm for glutinous monocultures, 30 cm for hybrid monocultures and 30 cm for mixtures. Spacings and arrangements were the same in 1998, except that the distance between rows of glutinous rice in monoculture was 13 cm.