Effect of growth retardants on growth and flowering of bougainvillea (Bougainvillea spectabilis) cv. Shubra

The present investigation to study the effect of growth regulators on growth and flowering of bougainvillea (Bougainvillea spectabilis) was carried out in the Division of Floriculture and Landscaping, IARI, New Delhi during 2012-13. The experiment was laid out in completely randomized block design with 11 treatments, 4 replications and 4 plants per replication. The bougainvilleas were planted in 10 inches pots in the month of July and were pruned back to a uniform height of 10+2 inches. The growth regulators, viz. maleic hydrazide, B-9 and paclobutrazol were applied in the form of foliar spray or drench and were compared with control (Distilled water) and the data were recorded for vegetative and flowering traits. Over a period of 14 weeks, it was observed that there was a significant reduction in plant height, plant spread, intemode distance and shoot length with the application of maleic hydrazide followed by drenching with paclobutrazol. Maximum shoot diameter, maximum number of structural branches and maximum flower index was observed when plants were either sprayed or drenched with paclobutrazol.