FIGURE 2. Panicle blast severity (mean percentage of panicle branches that were necrotic due to infection by Magnaporthe grisea) of rice varieties planted in monocultures and mixtures.

a, The susceptible, glutinous varieties Huangkenuo and Zinuo. b, The resistant, hybrid varieties Shanyuo22 and Shanyuo63. S98, Shiping County, 1998; S99, Shiping County, 1999; J99, Jianshui County, 1999; open bar, blast severity for a variety grown in monoculture control plots; black bar, blast severity of the same variety when grown in mixed culture plots in the same fields. Error bars are one s.e.m.; n, number of plot means that contribute to individual bars for each of the four combinations of susceptible and resistant variety. All differences between pairs of monoculture and mixture bars are significant at P < 0.01 based on a one-tailed t-test, unless indicated by 0.05 (significant at P < 0.05), 0.10 (significant at P < 0.10) or n.s. (not significant at P = 0.10).