Response of bio-fertilizers and NPK levels on the growth and yield of garlic in north western Himalayas

Garlic is the second most widely used cultivated Allium after onion and has long been recognized all over the world as valuable spice for foods and a popular remedy for various ailments and physiological disorders. Indiscriminate use of synthetic fertilizers imparts reduced nutritive value and sensory parameters, whereas integration of organic amendments and microbial inoculants reduces the NPK doses and improves the soil health and plant nutrient availability resulting in higher crop yields besides being environmentally safe. On farm trials were conducted during rabi seasons of 2009 and 2010 to study the effect of biofertilizers (Azotobacter and PSB) in combination with four levels of NPK fertilizers (0, 50, 75 & 100% NPK) on growth and yield of garlic cv. ‘GHC-1’ in Kullu district of Himachal Pradesh. The application of bio-fertilizers either alone or in combination resulted in significant improvement in plant height, number of cloves/bulb, mean bulb weight and bulb yield and benefit cost ratio. The increased bulb yield was to the tune of 20.44%, 15.67% and 10.43% with the combination of bio-fertilizers (Azotobacter + PSB), PSB and Azotobacter, respectively over un-inoculated control. The application of NPK fertilizers significantly increased all the growth and yield parameters along with bulb yield with each incremental level of NPK. The interaction effects showed that bulb yield and benefit cost ratio increased in a linear manner with the application of bio-inoculants integrated with increasing levels of NPK fertilizers. The highest yield (188 q/ha) was recorded when the plots were supplemented with 100% NPK + clove treatment of both the inoculants. Furthermore, it was observed that the garlic yield (187 q/ha) obtained with the application of 75% NPK +Azotobacter +PSB was at par with that of recommended NPK (100%), thus resulting in net saving of 25% NPK fertilizers with maximum benefit cost ratio (4.05).