Evaluation of Bacillus Strains for Plant Growth Promotion and Predictability of Efficacy by In Vitro Physiological Traits

Table 2

Promotion of corn shoot and root growth by twelve Bacillus strains in three greenhouse pot experiments.

Strain	% increase compared to control^w									GSF (%)^x
	Shoot height			Shoot fresh weight			Root fresh weight
	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3
Bacillus acidiceler R228	7	42	28	7	118	66	−11	155	92	44
B. megaterium R181	19	45	28	40	140	59	36	121	132	78
B. megaterium R232	17	45	12	24	144	32	—6	107	173	44
B. pumilus R174	13	41	7	30	126	24	—3	117	91	33
B. pumilus R183	12	40	28	33	103	62	0	122	12	44
B. pumilus R190	—	38	13	—	77	32	—	93	104	50
B. safensis R173	3	44	15	−15	137	51	−14	167	222	56
B. safensis R176	—	34	20	—	111	42	—	124	110	83
B. simplex R180	—	41	30	—	118	68	—	112	206	100
Lysinibacillus fusiformis R198	5	47	17	6	122	33	−25	135	147	56
Paenibacillus cineris R177	9	51	20	20	155	42	3	168	−8	67
P. graminis R200	—	54	18	—	215	37	—	203	75	67

^wPercentage increase of a growth variable by bacterial treatment compared to the control. ^xGSF = growth stimulation frequency; frequency at which a strain increased growth (at 95% confidence level) in all measurements across trials. Significant difference between treatment and control () according to Dunnett’s test. — = no data because strain was not tested.