Control Efficacy of an Endophytic Bacillus amyloliquefaciens Strain BZ6-1 against Peanut Bacterial Wilt, Ralstonia solanacearum

Table 2

(a) Experimental factors and their levels for orthogonal projects. (b) Application of orthogonal L16 (4⁵) to investigating effects of three factors on OD and IZD of BZ6-1. (c) Variance analysis for optimized culture conditions of strain BZ6-1.

(a)

Levels	pH	DO (rpm)	Temperature (°C)
1	5.5	180	20
2	6.5	200	25
3	7.5	220	30
4	8.5	240	35

Note: levels 1–4 represent concentration levels of each factor.

(b)

Trial number	pH	DO (rpm)	Temperature (°C)	IZD (mm)	OD600
1	1	1	1	24.2±0.4^e	0.67±0.06^d
2	1	2	2	27.6±0.3^d	0.98±0.08^c
3	1	3	3	26.4±0.6^de	0.86±0.04^cd
4	1	4	4	24.8±0.2^e	0.65±0.05^d
5	2	1	2	30.5±0.5^b	1.23±0.06^bc
6	2	2	1	32.5±0.3^a	1.47±0.03^a
7	2	3	4	31.3±0.5^b	1.28±0.04^b
8	2	4	3	30.8±0.2^b	1.22±0.05^bc
9	3	1	3	26.6±0.6^d	0.85±0.06^cd
10	3	2	4	26.8±0.5^d	0.88±0.08^cd
11	3	3	1	25.5±0.3^e	0.76±0.04^d
12	3	4	2	28.7±0.5^cd	1.06±0.05^c
13	4	1	4	26.8±0.6^d	0.89±0.03^cd
14	4	2	3	23.5±0.4^f	0.56±0.05^e
15	4	3	2	25.8±0.3^e	0.78±0.04^d
16	4	4	1	22.4±0.5^f	0.45±0.07^e
𝐾1	25.750	27.025	26.150
𝐾2	31.250	27.600	28.150
𝐾3	26.900	27.250	26.825
𝐾4	24.625	26.675	27.425
𝑅	6.650	0.925	2.000

Note: values are means ± standard deviations. The same letters mean no significant difference at 𝑃<0.05.

(c)

Variance sources	Sum of deviation squares	Df	𝐹 value	Significance
pH	103.69	2	4.052	^∗𝑃<0.05
DO	2.19	2	0.086
Temperature	0.68	2	0.261
Error	127.94	8	0.086