Habitat manipulation strategies for sustainable management of mustard aphid

A field experiment was conducted at Tokowbari Farm, AAU-ZRS, Shillongani, during 2020–21 to 2022–23 to evaluate theeffect of habitat manipulation on the management of mustard aphid (Lipaphis erysimi). The pooled data over three yearsrevealed that the lowest mustard aphid population (25.08 and 15.98 aphids/plant) was recorded in the mustard + corianderintercrop, followed by mustard + fennel (38.84 and 25.77 aphids/plant) and mustard + chickpea (41.87 and 29.68 aphids/plant) during flowering and siliquae formation stages, respectively. Similarly, the highest population of coccinellids (2.22beetles/plant) was observed in mustard + coriander, followed by mustard + fennel (2.01 beetles/plant) and mustard +chickpea (2.00 beetles/plant). Mustard-fennel intercrop recorded a significantly higher yield (677.44 kg/ha mustard +172.89 kg/ha fennel) compared to sole mustard (586.89 kg/ha) and intercrops with chickpea (660.44 kg/ha mustard +156.00 kg/ha chickpea) and coriander (702.11 kg/ha mustard + 171.78 kg/ha coriander). The yield of sole mustard and itsintercrops with chickpea and coriander were statistically at par. The highest benefit-cost ratio (BCR) of 2.43 was observedin mustard-fennel intercrop, followed by mustard-coriander (2.10), mustard-chickpea (1.75), and sole mustard (1.69).These findings suggest that intercropping mustard with fennel or coriander can effectively manage mustard aphidswhile enhancing natural enemy populations and economic returns