Table 5 Variation of the effectiveness of bacterial treatments against foliar wilting, root canker, black dot and vascular discoloration severities on potato cv. Spunta plants depending on cropping seasons

Foliar wilting severity (0–5)

Late season

3.82 a^c+

2.90 c

3.40 b

2.80 c

2.70 c

3.45 ab

3.60 ab

3.24 b

Extra-early season

3.07 a

1.43 c

2.17 b

2.03 b

2.10 b

1.33 c

1.53 c

1.95 c

Season

5.00 a

4.87 ab

4.93 a

4.73 b

5.00 a

5.00 a

5.00 a

4.93 a

Average^b*

3.96 a

3.07 d

3.50 b

3.19 cd

3.27 bcd

3.26 bcd

3.38 bc

Rhizoctonia root canker severity (0–5)

Late season

1.73 a

1.28 c

1.33 bc

1.58 ab

1.31 bc

1.64 a

1.86 a

1.53 b

Extra-early season

1.52 a

1.18 b

1.25 ab

1.49 a

1.08 b

1.16 b

1.19 b

1.27 c

Season

1.93 a

1.85 a

1.76 a

1.65 a

2.16 a

1.74 a

1.84 a

1.85 a

Average

1.73 a

1.43 c

1.45 bc

1.57 abc

1.52 bc

1.51 bc

1.63 ab

Black dot severity (0–4)

Late season

2.51 a

2.13 ab

2.36 a

1.59 c

1.78 bc

2.49 a

2.26 a

2.16 b

Extra-early season

1.77 a

0.90 b

0.88 b

0.80 b

1.07 b

0.90 b

0.84 b

1.02 c

Season

2.77 a

2.79 a

2.74 a

1.68 b

2.31 a

2.43 a

2.75 a

2.50 a

Average

2.35 a

1.94 bc

1.99 b

1.36 d

1.72 c

1.94 bc

1.95 bc

Relative vascular discoloration extent (%)

Late season

58.01 a

17.83 b

14.69 b

12.29 b

19.77 b

24.79 b

25.71 b

24.73 c

Extra-early season

68.84 a

20.54 c

51.62 ab

39.41 bc

35.25 bc

29.56 c

29.02 c

39.18 b

Season

83.93 a

50.37 b

87.08 a

55.54 b

63.10 b

66.55 ab

61.56 b

66.88 a

Average

70.26 a

29.58 c

51.13 b

35.74 c

39.37 c

40.30 c

38.76 c