Phytohormones and induction of plant-stress tolerance and defense genes by seed and foliar inoculation with Azospirillum brasilense cells and metabolites promote maize growth

AMB Express

Table 2 Effects of inoculation with Azospirillum brasilense strains Ab-V5 and Ab-V6 applied via seeds (seed inoculation, SI, at sowing) or by foliar application (inoculation by leaf spray, ILS, at the V2.5 stage) and of application of their metabolites (MLS) at the V2.5 stage on the chlorophyll content (CC), plant height (PH), culm diameter (CD) and shoot dry weight (SDW) of maize plants (DKB330 VT PRO2)

Treatment	CC (µg cm⁻²)	PH (cm)	CD (mm)	SDW (g pl⁻¹)
T1: non-inoculated control	4.45 e^a	57.33 a	12.22^ns	3.24 c
T2: SI Ab-V5	5.03 e	57.00 a	13.46	4.56 ab
T3: SI Ab-V6	7.00 d	63.60 a	13.35	5.71 a
T4: SI Ab-V5 + Ab-V6	8.51 c	59.17 a	12.84	4.85 ab
T5: ILS Ab-V5	6.80 d	58.40 a	13.23	4.84 ab
T6: ILS Ab-V6	8.04 c	63.00 a	12.74	4.67 ab
T7: ILS Ab-V5 + Ab-V6	7.07 d	59.67 a	12.97	4.67 ab
T8: MLS Ab-V5	7.08 d	65.40 a	12.16	4.15 bc
T9: MLS Ab-V6	9.30 b	60.50 a	12.49	5.39 ab
T10: MLS Ab-V5 + Ab-V6	10.80 a	64.67 a	13.34	5.57 a
p value	<0.0001	0.03915	0.2609	<0.0001
CV (%)	10.11	8.50	8.69	13.81

All treatments received the equivalent of 60 kg of N ha⁻¹ at sowing, plants were grown under greenhouse conditions and harvested at 30 days after transplanting
^aMeans (six replicates) followed by the same letter on the same column are not statistically different according to the Tukey’s test (p ≤ 0.05); ^ns statistically non-significant