The experiment was conducted at the Farm of Sher-e-Bangl a Agricultural University, Dhaka, Bangladesh, to study the effectiveness of some insecticids against major sucking pests of okra during the period from February to August 2009. BARI Dherosh 1 was used on the experiment. The seeds were collected from Siddique Bazar, Dhaka, Bangladesh. Cowdung (10 t/ha), urea (45 kg/ha), TSP (85 kg/ha) and MP (35 kg/ha) was applied as basal dose at the time of land preparation. The experiment consisted eight management practices viz. T1: Admire 200 SL @ 0.5 ml/L of water, T2: Actara 25 WG @ 1 g/L of water, T3: Neem oil @ 5 ml/L of water, T4: Neem seed kernel extract @ 5 g/L of water, T5: Petroleum oil (sparrow 888 plus) @ 2ml/L of water, T6: Detergent @ 5 ml/L of water, T7: Shobicron 425 EC@ 2 ml/L of water and T8: Control using Randomized Complete Block Design (RCBD) with three replications. All the insecticides used as treatments applied 7 days interval. The size of the each unit plot was 3.0 m × 2.5 m. Seeds were sown in the furrows having a depth of 2-3 cm maintaining 60 cm line to line distance and 50 cm plant to plant distance.
Data were collected on incidence of insect pests, number of healthy fruits, number of infested fruits, fruit infestation in number, weight of healthy fruits, weight of infested fruit, fruit infestation in weight, plant height at harvest, plant diameter at harvest, days for sowing to 1st flowering, days for flowering to attaining marketable sized fruits, fruit length, fruit diameter, number of fruits, individual fruits weight, fruit yield and fruit yield.
Fruit infestation was calculated using following formula
Fruit infestation = (Number of infested fruits ÷ Number of healthy fruits) × 100
Fruit damage was calculated using the following formula:
Fruit damage (%) = (Number of damaged fruits ÷ Total number of fruits) × 100
The data on different parameters as well as yield of okra were statistically analyzed to find out the significant differences among the effects of different management for sucking pest of okra. The mean values of all the characters were calculated and analyses of variance were performed by the ‘F’ (variance ratio) test. The significance of the differences among the mean values of treatment in respect of different parameters was estimated by the Duncan’s Multiple Range Test (DMRT) at 5% level of probability