N. K. Dutta
Entomology Division, Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh
S. N. Alam
Entomology Division, Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh
M. Mahmudunnabi
Entomology Division, Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh
M. R. Amin
Department of Entomology, Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU), Gazipur, Bangladesh
Y. J. Kwon
School of Applied Biosciences, Kyungpook National University, Daegu, Korea
Hemipteroid insects, Insecticides, Predator, Solanum melongina.
The field laboratory of the Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh
Pest Management
Insecticide, Brinjal
Study site and climatic conditions
The study was conducted in the field laboratory of the Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh (25°25′N, 89°5′E) during September 2014 to March 2015. The mean annual maximum and minimum temperatures, relative humidity, and rainfall in this area were 36.0°C and 12.7°C, 65.8%, and 237.6 cm, respectively.
Cultivation of the egg plant
The eggplant seedlings (variety BARI Begun-8) were collected from the Horticulture Research Center of BARI and transplanted in the field with an area of 5.5 m × 4.0 m. The experimental design was randomized complete block. The spaces between blocks and between plots were 0.5 m and 1.0 m, respectively. Seedlings were planted on 5th September 2014 in rows. Each plot contained 1 row with 5 plants separated by 60 cm. A total of 75 plants were grown in 15 rows. The manures and fertilizers were applied according to the recommended doses of the BARI. M ulching, weeding and irrigation were done whenever necessary, and the shoot and fruit borer Leucinodes orbonalis Guenee (Pyralidae: Lepidoptera) was controlled mechanically.
Monitoring of the pests and application of the treatments
After transplanting, the plants were monitored weekly to observe the abundance and infestations of the sucking insects (aphid, jassid, white fly and thrips). The newly introduced insecticides Python 20 SL (Nitenpyrum), Plenum 50WG (Pymetrozin), Polo 500 SC (Diafenthiuron) and Admire 200 SL (Imidacloprid) were applied with concentrations of 1mL/L, 0.5g /L, 1mL/L and 0.5mL/L water after the infestation had occurred. An untreated control observation was made with spraying water. Each of the treatment was applied in three plots and each plot indicated a replication. All the treatments were sprayed four times at fortnightly interval with a hand sprayer.
Collection of pest and predator population data
Insect population abundance on the eggplants was recorded one day before spraying and, 3 and 7 days after spraying. The numbers of sucking insects (aphid, jassid, white fly and thrips) and lady bird beetles were recorded from the middle plant of each row during early morning. Five leaves were observed from different heights of each plant to record the population (both nymphs and adults) of the sucking pests, while total number of lady bird beetles present on the plant was also recorded. It is noted that two species of lady bird beetles (Menochilus sexmaculatus Fab. and Micraspis discolor Fab.) were abundant but data were taken together. The observed population reductions of the pests and predator were corrected according to Abbott (1925).
Pt = (Po - Pc/100 - Pc) x 100
Where, Pt = Corrected population, Po = Observed population, Pc = Control population.
Statistical analysis
Data were analyzed by analysis of variance using SPSS (IBM SPSS statistics 21, Georgia, USA) software and means were separated by Duncan’s Multiple Range Test (DMRT).
Bangladesh J. Agril. Res. 42(1): 35-42, March 2017 ISSN 0258-7122 (Print), 2408-8293 (Online)
Journal