Table 4 Cumulative mortality of Sitophilus zeamais adult induced by Plectranthus glandulosus leaf powder, Hymenocardia acida wood ash and their binary combinations under fluctuating laboratory conditions (temp. = 22.76 ± 2.02 °C; r.h. = 69.87 ± 9.93%)

1 day

0

0.00 ± 0.00^aA

0.00 ± 0.00^cA

0.00 ± 0.00^cA

0.00 ± 0.00^cA

0.00 ± 0.00^bA

–

5

3.82 ± 2.41^aB

2.50 ± 1.44^bcB

8.75 ± 3.15^bcAB

11.25 ± 1.25^bAB

21.25 ± 5.91^abA

5.14*

10

6.25 ± 2.39^aB

5.00 ± 8.75^abB

22.50 ± 4.33^abAB

20.00 ± 2.04^bAB

28.75 ± 6.57^aA

5.64*

20

7.50 ± 2.50^aB

8.75 ± 1.25^aB

25.00 ± 6.12^abAB

20.00 ± 3.54^bAB

36.25 ± 9.44^aA

6.82*

40

16.25 ± 5.91^aAB

12.50 ± 1.44^aB

36.25 ± 5.54^aAB

36.25 ± 5.54^aAB

41.25 ± 8.51^aA

5.04*

F _{(4; 15)}

2.48 ^ns

19.66**

15.83***

40.80***

11.68**

3 days

0

0.00 ± 0.00^cA

0.00 ± 0.00^cA

0.00 ± 0.00^cA

0.00 ± 0.00^bA

0.00 ± 0.00^bA

–

5

6.25 ± 3.15^bcB

21.08 ± 3.73^bAB

22.90 ± 7.37^bAB

37.04 ± 4.39^aA

25.06 ± 4.10^aA

6.09*

10

11.38 ± 3.13^abB

24.57 ± 1.99^abAB

42.17 ± 7.18^abA

40.92 ± 4.17^aA

38.82 ± 7.98^aA

6.24*

20

17.83 ± 4.97^aB

33.66 ± 2.01^aAB

44.42 ± 5.58^abA

46.81 ± 7.31^aA

40.07 ± 7.87^aAB

3.95*

40

21.58 ± 3.87^aB

37.41 ± 4.63^aAB

57.57 ± 5.84^aA

56.45 ± 6.18^aA

52.83 ± 7.85^aA

7.02*

F _{(4; 15)}

12.10***

66.26***

28.53***

40.77***

22.16***

7 days

0

0.00 ± 0.00^cA

0.00 ± 0.00^bA

0.00 ± 0.00^bA

0.00 ± 0.00^dA

0.00 ± 0.00^bA

–

5

7.77 ± 2.59^bB

63.55 ± 12.84^aA

36.55 ± 10.94^aAB

43.71 ± 3.25^cAB

36.92 ± 3.14^aAB

5.89*

10

14.15 ± 3.21^abB

72.69 ± 8.58^aA

53.15 ± 9.47^aA

58.92 ± 1.35^bA

49.27 ± 5.36^aA

10.59***

20

20.59 ± 3.70^abB

77.96 ± 8.65^aA

57.16 ± 9.11^aA

69.72 ± 5.31^aA

49.42 ± 6.99^aA

11.63***

40

28.16 ± 4.73^aC

87.11 ± 4.91^aA

68.35 ± 4.40^aAB

76.76 ± 1.02^aA

56.14 ± 3.97^aB

27.67***

F _{(4; 15)}

16.00***

18.27***

21.54***

202.13***

57.03***

14 days

0

0.00 ± 0.00^dA

0.00 ± 0.00^bA

0.00 ± 0.00^cA

0.00 ± 0.00^cA

0.00 ± 0.00^cA

–

5

19.54 ± 2.63^cB

69.08 ± 10.78^aA

68.13 ± 10.30^bA

63.16 ± 5.27^bA

56.07 ± 3.93^bA

7.87**

10

33.82 ± 3.52^bB

82.60 ± 7.91^aA

82.09 ± 3.59^abA

80.92 ± 4.61^aA

66.89 ± 5.78^abA

15.27***

20

40.33 ± 4.12^bC

90.64 ± 6.23^aA

93.13 ± 1.41^aA

82.17 ± 2.71^aAB

72.44 ± 4.13^abB

27.04***

40

57.24 ± 2.71^aC

94.66 ± 3.72^aA

94.59 ± 2.15^aA

90.42 ± 1.35^aAB

80.85 ± 1.45^aA

47.34***

F _{(4; 15)}

106.53***

26.03***

65.27***

105.05***

122.33***