Evaluation of botanical pesticides against vegetable insect pests
The research team of the University of the Philippines Visayas (UPV) has formulated botanical pesticides or botanopesticides from Derris elliptica (Tubli), Tinospora rumphii (makabuhay), and Dioscorea hispida (kayos). There were tested in the field and evaluated under greenhouse condition against aphid, whitefly, and fruit borer of pechay, eggplant, green onion, and hot pepper by Penecilla and co-researchers (WVSU). The formulated botanicals in powder and liquid forms were diluted in water at 5 tbsp/L, 10 tbsp/L, 15 tbsp/L, and 20 tbsp/L, before application in the field or greenhouse.
Findings
- Based on field trials, the average yields of the vegetables treated with commercial insecticides and those treated with botanopesticides and those from the control were not significantly different. The plant source of botanopesticide and application rate did not show significant effects. However, the total marketable eggplants were low due to severe fruit borer infestation.
- In the control of aphids and mites, formulations of kayos, makabuhay, and tubli at 20 tbsp/L in powder (40-50 kg/ha) or liquid (80 L/ha) were as effective as the commercial insecticides.
- The effect of liquid natural insecticides at 20 tbsp/L water was comparable with that of commercially prepared insecticide in controlling adult whiteflies within one day of spraying.
- There was no effective insecticide evaluated against eggplant borer and fruit borer. Other control strategies must be pursued.
- At the farm level, the use of natural insecticides in liquid formulation at 80 L/ha is effective against infestations of aphids, mites, and whitefly in vegetables.
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Philippine Council for Agriculture, Forestry and Natural Resources Research
and Development (PCARRD)
©2006