Effect of bee attractants on activity of stingless bee, Tetragonula “nr.” pagdeni, and its significance in pollination of coriander

Abstract

Coriander (Coriandrum sativum L.) is an important seed spice crop that depends largely on insectmediated pollination for optimum seed production. A field experiment was conducted at Devihosur, Karnataka, to evaluate the efficacy of different bee attractants in enhancing pollination by stingless bees (Tetragonula “nr” pagdeni) and improving coriander productivity. Seven treatments comprising jaggery (15%), jaggery + lime juice (15%), enriched jaggery (15%), ocimum oil (0.1%), menthol oil (0.1%), ajwain oil (0.1%), and an untreated control were evaluated in a randomized design. Among the treatments, ocimum oil (0.1%) recorded the highest seed yield (14.46 q ha-¹), followed by jaggery (15%) (12.91 q ha-¹), both of which were significantly superior to the untreated control (9.15 q ha-¹). The higher seed yield obtained with ocimum oil was associated with increased stingless bee visitation, resulting in improved
pollination efficiency. Enhanced pollination also positively influenced seed quality, with ocimum oil recording the highest seed germination (82.67%), seedling length (12.23 cm), seedling vigour index (1011), and seedling dry weight (0.013 mg) compared with the control. Although ocimum oil produced the maximum yield and superior seed quality, jaggery (15%) resulted in the highest benefit ratio owing to its low input cost. The findings demonstrate that bee attractants can effectively enhance stingless bee activity and coriander productivity, with ocimum oil being the most effective for maximizing yield and seed quality, while jaggery (15%) offers a simple, economical, and farmer-friendly option for profitable coriander seed production.