Table 6.

Maize yield response to inoculation, relative to control plots, based on 2005–11 field trails comprising large (n = 369) and small (n = 92) sampling plots

Large plots			Small plots
Yield level (t/ha)	n	% Increase (±s.e.)	Yield increase (t/ha ± s.e.)	n	% Increase (±s.e.)	Yield increase (t/ha ± s.e.)
Low <6·3	21	6·5 ± 1·2	0·34 ± 0·112		–	–
Medium (6·3–12·6)	264	3·4 ± 0·36	0·32 ± 0·031	66	2·2 ± 0·48	0·19 ± 0·048
High >12·6	54	2·6 ± 0·72	0·35 ± 0·070	26	0·8 ± 0·76	0·12 ± 0·077
P-value (Prob > F)		0·018	0·939		0·145	0·407