Bangladesh is rich in plant biodiversity. This research in botanical pesticides has a good scope of study to find out different indigenous plants of Bangladesh to produce an eco-friendly plant-based pesticide for sustainable aphid management in bean field. This study was conducted at Rajshahi University to find out the suitable botanical pesticides for eco-friendly pest control in bean field.
2.1. Collection of Botanicals Ten plants were collected from the campus of University of Rajshahi, Bangladesh. After collection, fresh plant parts were washed in running tap water and air dried in the shade for one week at room temperature.
2.2. Preparation of Land for Bean Cultivation The experimental land was first opened with a country plough. Ploughed soil is then brought into desirable final tilth condition by five operations of pouching followed by laddering. The stubbles of the crops and uprooted weeds were removed from the field and the land was properly leveled for planting of beans.
2.3. Experimental Plot Preparation The field experiment was conducted at IES Botanical Pesticides Research Field of University of Rajshahi. To support the plant growth cow-dung, Triple Super Phosphate (TSP), Murate of Potash (MP) and Urea fertilizers were applied. The whole amount of fertilizers was used as the basal dose during pit preparation. Then, the seeds were planted in the experimental plot. The plot was irrigated with tap-water when necessary.
2.4. Preparation of Botanical Pesticides for Spray Plant parts were dried at room temperature for seven days before grinding or cutting into small pieces. About 100 gm of grinding or cutting leaves, stems, outer cover of fruits and seeds were dissolved in one liter of water. These samples were kept in water for three days. Then solutions were filtered with plastic filter. The filtrated water extract was kept in plastic bottles. The water extracts was kept in refrigerator until use.
2.5. Spraying Method Botanicals pesticides were sprayed on experimental field twice a week with the help of sprayer. One control treatment of without botanical pesticide was maintained in this experiment where only water was sprayed.
2.6. Pest Damage Counting The pest damaged was monitored every day and the damages were counted every 3-day in a week. The number of plants damaged, leaves damaged and the number of leaves perforation was also recorded.
2.7. Data Collection from the Experimental Bean Field The following data were collected from experimental bean field: • Plants length (cm) • Total leaves • Number of leaves damaged by insects • Number of perforation • Aphid affected plant’s length (cm) • Total number of branches • Number of total flowering branches • Bean productions (number & weight).
2.8. Statistical Analysis of Data The observed values were statistically analyzed by RCBD. Mean values were adjusted by one way ANOVA and the significant leaves were tested by Duncan’s Multiple Range Test (Duncan, 1951) (P < 0.05) using standard software.