Varietal reaction of carnation to bud borer, Helicoverpa armigera (Hubner) in relation to plant characters

An experiment was conducted at Regional Research Station, Uttar Banga Krishi Viswavidyalaya, Kalimpong, during the winter seasons of 2008–09 and 2009–10, to study the reaction of twenty one varieties of standard type carnation (Dianthus caryophyllus Linnaeus) to bud borer, Helicoverpa armigera (Hubner) and the influence of varietal characters on the infestation of the pest. The bud borer infestation varied significantly amongst different carnation varieties during peak incidence period of the pest for both the seasons. The mean bud borer infestation ranged from 8.18% in the variety Dover to 17.61% in the variety Charment. Dover, Lavender Lace, Tikar and Madras were the least susceptible varieties showing less than 10% bud infestation. There was significant difference in various vegetative and floral parameters among different varieties of carnation. The bud borer infestation was found to be significantly and positively correlated with the plant height, number of branches per plant and bud/flower number per plant. Anegative correlationwas found between bud borer infestation and thickness of calyx.