www.IndianJournals.com Members Copy, Not for Commercial Sale Downloaded From IP - 14.139.52.4 on dated 2-Jul-2016 Effects of Salicylic acid (SA) and Azospirillum on growth and bulb yield of Onion (Allium cepa L.) cv. Agrifound Light Red Sunil Prajapati*, P.K. Jain and Akhilesh Tiwari Department of Horticulture, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur-482004 (Madhya Pradesh), India *Corresponding author: prajapatisunil4960@gmail.com Paper No. 454 Received: 16 Dec 2015 Accepted: 22 June 2016 Abstract The present investigation was carried out during Rabi season of 2014-2015 and laid out in a Randomized Block Design with three replications at Vegetable Research Farm, Department of Horticulture, J.N. Krishi Vishwa Vidyalaya, Jabalpur (Madhya Pradesh).The experimental material for the study was comprised of 18 novel treatments combination of Salicylic acid (SA) and Azospirillum to estimate the best treatment combination in Rabi onion under particular region. The growth parameters under present investigation noted under T 17 recorded maximum plant height (cm) at 30, 60, 90,120 DAT (33.28 cm), (37.58 cm), (45.22 cm) and (48.46 cm) respectively, length of leaves (cm) at 30 DAT (32.57 cm), 60 DAT (36.29 cm) under (T 17 ) and T 11 (41.75 cm) at 60 DAT and T 12 (44.15 cm) at 120 DAT respectively, maximum number of leaf at 30 DAT (8.09) in T 14, 60,90 DAT (12.99,17.92) in T 17 and at 120 DAT (19.37) in T 11 respectively, neck thickness (mm) at 120 DAT (13.71 mm) under T 11, dry weight of leaf (g) at 120 DAT (3.92 g). The yield parameters also reported best under T 17 as average weight of bulb (88.07g), equatorial diameter (67.38mm), polar diameter (60.37mm), double bulb(2.38%)T 11 , bolting per cent lowest (1.18%), A, B and C grade bulb (on weight basis) (37.22%)T 5 , (65.09%) and (34.19%) respectively, bulb yield polt 1 (14.77kg), marketable bulb yield (26.28t/ha.) T 13 , total bulb yield estimated in T 16 (30.47 t/ha). T 11 recorded highest gross monitory return (` 450705/ha), net return (` 385020/ha) and beneit cost ratio 5.86. Highlights • Eighteen novel treatment combinations of Salicylic acid (SA) and Azospirillum to estimate best treatment combination for growth, yield, storage life of onion. • The application of Salicylic acid @250 mg lit. -1 30, 45& 60 DAT with Azospirillum @5 kg ha -1 at 60 DAT enhance the growth and yield of onion. • The treatment T 11 Salicylic acid (250 mg lit. -1 ) at 30 DAS, 30,45,60DAT+ Azospirillum (5 kg ha -1 ) at 30 DAT fetched highest gross monitory return (` 450705/ha), net return (` 385020/ha) and beneit cost ratio 5.86. Keywords: Onion ( Allium cepa L.), Salicylic acid, Azospirillum, onion bulb yield International Journal of Agriculture, Environment and Biotechnology Citation: IJAEB: 9(3): 393-402, June 2016 DOI Number: 10.5958/2230-732X.2016.00051.6 ©2016 New Delhi Publishers. All rights reserved HORTICULTURE Onion (Allium cepa L.) is one of the most important bulb crops. It is an indispensable item in every kitchen used as salad, culinary purpose for lavoring as spice in pickles, sauce and vegetable. In India, it is cultivated as annual crop for bulb production and as biennial crop for seed production. Onion is an export-oriented crop earning valuable foreign exchange for the country.In India, Maharashtra is one of the leading state in the cultivation of onion, occupied area of 382.0 (000’ ha) with production of 5638.0 (000’ ha) and its productivity is 14.76 t/ha, as compared to Madhya Pradesh which occupies