Authors: M. A. Latif, N.
Akhter* and M. S. Islam
*Corresponding
author, Email: nurmohalsau@yahoo.com
Abstract
The experiment
was conducted at the Farm of Sher-e-Bangla Agricultural University,
Sher-e-Bangla Nagar, Dhaka, Bangladesh to evaluate the effect of sowing dates and
lentil (Lens culinaris Medikus)
varieties on incidence of insect pests and their predators during the period
from October 2008 to April 2009. The experiment comprised two factors, viz.,
Factor A: Sowing date (4 levels) S1: Sowing on 06 November, S2:
Sowing on 16 November, S3: Sowing on 26 November and S4:
Sowing on 06 December; Factor B: Variety (4 levels) V1: BARI
Masur-3, V2: BARI Masur-4, V3: BARI Masur-5 and V4:
BARI Masur-6. Incidence of insect pests was recorded for the entire cropping
season. Aphid and whitefly were found as major insect pests; and spider and
lady bird beetle were predators of these pests. Considering sowing date, the
lowest number of aphid, whitefly, spider and lady bird beetle (4.07, 1.89, 2.00
and 2.69, respectively) was recorded from S3 while the highest
number (5.48, 2.28, 2.57 and 4.46) was found from S4. On the other
hand, the minimum number of aphid, whitefly, spider and lady bird beetle (4.56,
2.03, 2.36 and 3.97) was recorded from the variety V4 while the
highest number of insect pests (5.74, 2.37, 2.31 and 4.41) was found from variety
V1. The lowest number aphid and whitefly (3.67 and 1.80,
respectively) was obtained from S3V3 combination and the
highest number of aphid and whitefly (6.93 and 2.70, respectively) were
recorded from S1V1 combination. BARI Masur-5 sowing on 26
November was the best combination having lowest incidence of aphid and
whitefly.
Key words: Aphid, Whitefly, Spider, Ladybird
beetle, Lentil, Sowing date and Variety.
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