LAUSR

An air layering experiment was conducted at the Division of Floriculture & Landscaping, Indian Agricultural Research Institute, New Delhi during June 2013 to May 2014. Six bougainvillea cultivars which were difficult-to-root along with check as easyto-root cultivars were used in this study with three replications. The difficult-to-root cultivars used were: Dr. H. B. Singh, Red September, Sweet Heart, Refulgens, Thimma, Mahatma Gandhi, whereas Chitra was used as easy-to-root check. The results revealed that almost all cultivars had shown significant differences in rooting percentage, survival percentage, growth, flowering, total carbohydrate and nitrogen concentration percentage. Maximum rooting (92.01) and survival of plants (100.00) were recorded in Chitra, which was easyto-root, whereas good rooting percentage was observed in difficult-to-root cultivars such as Sweet Heart (59.33%), Red September (59.02%), Dr. H. B. Singh (53.66%), Mahatma Gandhi (50.66%) and Refulgens (47.98%). The biochemical investigation of these cultivars showed that the easy-to-root cultivars had higher carbohydrate content (40.58%) and lower nitrogen content (2.24%) compared to the difficult-to-root ones i. e. Refulgens (20.85 and 3.76%) and Mahatma Gandhi (19.25 and 3.88%), respectively. The air layering technique is a good solution for rooting of difficult-to-root cultivars, and is expected to help people/nurserymen who take up on multiplication of bougainvillea.