HOST PREFERENCE AND DAMAGE OF CHEWING AND SUCKING INSECT PESTS OF STEM AMARANTH AND THEIR ECO-FRIENDLY MANAGEMENT

Abstract

The experiment was conducted at the research field, Sher-e-Bangla Agricultural University, Dhaka during the period of March 2016 to September 2016. Stem amaranth variety BARI datha 1 (V1) and BARI datha 2 (V2) were used as test crop in this experiment and consists of 6 treatments as Mechanical method + Cultural method at 7 days interval, Spraying of soap water @ 1.0 g detergent/L of water, Apply wood ash @ as per required with mixing inert materials (2:1), Spraying of neem oil @ 2.0 mg/L of water with mixing 10 ml detergent, Spraying of neem leaves extracts @ 20 gm/L of water at 7 days interval and untreated control. The experiment was laid out in Factorial Randomized Complete Block Design (RCBD) having two factors with three replications. Results showed, percent infestation due to grasshopper, green leaf eating caterpillar and amaranth stem weevil were decreased more in V2T4 (71.71); in V2T3 (77.51) and in V2T4 (83.69) treatments respectively; whereas less in V2T1 treatment (25.42, 59.45 and 22.83, respectively for those insects) compared to untreated control. But incase of leaf miner, percentage of infestation was decreased more in V1T4 (87.70) and less in V2T1 (49.92) compared to untreated control. Percent of infestation due to stink bug, jassid, white fly and aphid were decreased more in V1T4 treatment (77.51, 82.46, 84.60 and 87.70), respectively; whereas and less percent of infestation due to stink bug in V1T2 (55.27); jassid in V1T1 (52.26); white fly in V2T1 (50.64) and aphid in V2T1 (49.92) compared to untreated control. The highest plant height was observed both in V1T4 (109.50 cm) and V2T4 (108.47): on the other hand the lowest was in V1T0 (70.86 cm). The highest yield was observed both in V1T4 (36.56 t ha-1) and V2T4 (34.57 t ha-1): whereas the lowest was in V2T0 (21.78 t ha-1). At last it was observed that, infestation was more in both varieties in untreated control (T0) treatment but BARI datha-2 (V2T0) more infested than BARI datha-1 (V1T0). But yield was calculated more in both varieties in T4 treatment but BARI datha-1 (V1T4) given more yield than BARI datha-2 (V2T4).