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Table 2 Population densities of Tetranychus urticae (N) on hydroponic cucumber and effectiveness of biopesticides

From: Efficiency of botanical pesticides against some pests infesting hydroponic cucumber, cultivated under greenhouse conditions

Treatments Before spray After 24 h After 72 h After 168 h After 336 h
N CPD (%) EF (%) N CPD (%) EF (%) N CPD (%) EF (%) N CPD (%) EF (%)
Matrine 28.6a 11.3a − 60.4 76 23.0a − 19.7 62 8.0a − 72.0 69 2.3a − 91.8 88
Spintoram 26.3a 25.3a − 3.7 41 27.6ab 5.0 53 6.3a − 75.9 78 2.3a − 91.1 86
Azadirachtin 30.0a 25.0a − 16.6 47 13.6a − 54.4 79 22.0b − 26.6 31 14.6b − 51.1 31
Custard apple 33.3a 33.3a − 1.0 33 6.0a − 82.0 91 3.3a − 90.0 89 2.6a − 92.0 85
Control 40.3a 67.6b 67.7   88.3b 119   45.6c 13.2   55.0c 36.3  
Significance level F = 0.61; df = 4; P ≥ 0.05 F = 19.6; df = 4; P ≤ 0.01    F = 5.52; df = 4; P ≤ 0.01    F = 95.9; df = 4; P ≤ 0.01    F = 12.5; df = 4; P ≤ 0.01   
  1. The mean number (N) of mites/leaf (30 leaves per plot); within a column, the means pursued by the same letter are not significantly different (Tukey’s HSD test, α = 0.05)
  2. CPD (%) change in population density, EF (%) percent efficacy (Henderson-Tilton formula)