Table 2.

Contingency tables of strain identity versus nodule size class after accounting for differences among plants.

strain	rank	large	small	medium
(a) strains LB16-1 versus LA11-1
LB16-1	good	10	8
LA11-1	poor	8	25
${\chi }_1^2=5.00$, p<0.03
(b) strains LA17-1 versus LA11-1
LA17-1	meda	11	6	12
LA11-1	poor	0	8	18
${\chi }_2^2=12.36$, p<0.002
(c) strains LB16-1 versus LA17-1
LB16-1	good	6	2
LA17-1	meda	6	17
${\chi }_1^2=5.99$, p<0.02

^amed, mediocre.