Climatic parameters

Modality

Percentage of responses

Transition

(n = 114)¹

Northeast

(n = 121)¹

Northwest

(n = 116)¹

Total

(N = 351)¹

Amount of rainfall (precipitation or annual rainfall)

Effect on the growth and yield of yams

81.6

86.8

78.4

82.3

Has no or very little effect on yam growth and yield

18.4

13.2

21.6

17.7

Length of the rainy season

Effect on the growth and yield of yams

90.4

92.6

88.6

90.6

Has no or very little effect on yam growth and yield

9.6

7.4

11.2

9.4

Rainfall distribution during the rainy season

Effect on the growth and yield of yams

90.4

99.2

84.5

91.5

Has no or very little effect on yam growth and yield

9.6

0.8

15.5

8.5

Duration of the dry season

Effect on the growth and yield of yams

71.9

91.7

83.6

82.6

Has no or very little effect on yam growth and yield

28.1

8.3

16.4

17.4

Temperature

Effect on the growth and yield of yams

77.2

95.9

81

84.9

Has no or very little effect on yam growth and yield

22.8

4.1

19

15.1

Insolation

Effect on the growth and

yield of yams

77.2

93.4

79.3

83.5

Has no or very little effect on yam growth and yield

22.8

6.6

20.7

16.5

Harmattan

Effect on the growth and yield of yams

62.3

57.9

39.7

53.3

Has no or very little effect on yam growth and yield

37.7

42.1

60.3

46.7

The wind

Effect on the growth and yield of yams

11.4

13.2

10.3

11.7

Has no or very little effect on yam growth and yield

88.6

86.8

89.7

88.3