Bio-Efficacy of Granular Insecticides against White Grub (Holotrichia consenguinea Blanch) in Tulip (Tulipa gesneriana L) under Temperate Condition of Kashmir

The field trial was conducted during 2018-19 and 2020-21 at Urban Technology Park, Habak, Sher-e- Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar (UT of Jammu and Kashmir) to evaluate the bio-efficacy of various insecticides viz., Clothiandin 50% WDG @ 300 g a.i./ ha, Thiamethoxam 25% WG@ 80 g a.i./ ha, Imidacloprid + Fipronil 80% WDG @ 300 g a.i./ha and Imidacloprid 70% WG@ 300 g a.i./ ha against white grubs infesting tulip. The required amount of insecticides was applied in furrows by incorporating with pulverized soil before sowing of the tulip bulbs. Experimental results indicated that all the insecticidal treatments were significantly superior in respect of per cent reduction of bulb damage in both weight and number basis as well as reducing the number of grubs per square meter over the untreated control. However, the plots treated with Imidacloprid + Fipronil 80% WDG @ 300 g a.i./ha recorded lowest per cent of tuber damage (6.64 and 4.78 % both in weight and number basis) as well as least number of grubs (0.96/m2) resulting in a marked increase in bulb yield of 220.78kg/500m2. On the other hand, untreated control recorded lowest bulb yield (125.50kg/500m2) with a very high levels of infestation (73.74% and 67.43% based on weight and number, respectively) of bulb caused by the grubs. The economics of various treatments revealed that the height net gain was procured in Imidacloprid + Fipronil 80 % WDG @ 300 g a.i./ha that registered maximum B.C. ratio (1.57) followed by Imidacloprid 70 % WG @ 300 g a.i./ha (1.42).On the basis of efficacy of various treatments and economics, Imidacloprid + Fipronil 80 % WDG @ 300 g a.i./ha was superior for effective and economical management of white grub in tulip crop.