Table 2. Effect of plant extracts and synthetic insecticides on mean (±SE) percentage reduction of Plutella xylostella numbers and Brevicoryne brassicae infestation score (0 = absent to 5 = large continuous colonies) in field cage experiments at Kumasi, Ghana.

Treatment	P. xylostella	B. brassicae
A. conyzoides	100 ± 0.00 a	0.17 ± 0.17b
C. odorata	100 ± 0.00 a	0.17 ± 0.17b
S. nodiflora	93 ± 0.06a	0.00 ± 0.00 b
C. frutescens	93 ± 0.06 a	0.33 ± 0.33b
N. tabacum	93 ± 0.06 a	0.00 ± 0.00 b
C. sophera	66 ± 0.17ab	0.00 ± 0.00b
J. curcas	66 ± 0.08ab	0.00 ± 0.00 b
R. communis	85 ± 0.07 a	0.00 ± 0.00 b
O. gratissimum	89 ± 0.05a	0.17 ± 0.017b
Lambda super®	51 ± 0.11 b	2.33 ± 0.37 a
Attack®	100 ± 0.00a	0.00 ± 0.00 b
0.1% detergent solution	21 ± 0.11 c	2.33 ± 0.60a
Tap water	6 ± 0.06 c	3.00 ± 0.50 a

Means within the same column with different letters are significantly (P < 0.05) different from each other