PHYSIOLOGICAL STUDIES ON FLOWERING OF PINEAPPLE IN RESPONSE TO CHEMICALS AND ENVIRONMENT
The present investigation was undertaken to elucidate the changes in relation to flowering as influenced by the treatment with ethrel, acetylene and NAA at different seasons of the year. In this experiment 50 ml solution of ethrel (100 ppm), calcium carbide (2 per cent) and NAA (20 ppm) was applied at the core of plant of cv. Kew on 15 June, October and January, 1980–1981, when the age of the plant was 335 days. Treatment with ethrel and calcium carbide in June caused appearance of inflorescence within 30 days, application in October delayed the emergence up to 58 and 60 days in case of calcium carbide and ethrel, respectively. Treatment in January resulted in flowering in about 50 days. The application of NAA at different seasons markedly affected the response to flowering and the time was reduced from 260 days to 62 days from June to January application. Treatment with calcium carbide, ethrel or NAA in February caused flowering in about 28 days. Treatment with chemicals in general showed a reduction in the percentage of flowering from June to January. Anatomical studies of shoot apices revealed that initiation to flowering started in 15 to 25 days after treatment by chemicals. Shoot apices from plants treated with ethrel and calcium carbide showed an increase in total nitrogen at the first (5 days) or second stage (15 days) after treatment. Application of ethrel and calcium carbide caused a greater release of ethylene irrespective of the time of treatment compared to control plants. The shoot apices treated with ethrel, calcium carbide and NAA mainly contained growth inhibitors at 5 days after treatment. An increase in growth promoting substances was found at 15 days while at 25 days after treatment the concentration of endogenous inhibitor again increased.
Das Biswas, S., Dhua, R.S., Mitra, S.K. and Bose, T.K. (1983). PHYSIOLOGICAL STUDIES ON FLOWERING OF PINEAPPLE IN RESPONSE TO CHEMICALS AND ENVIRONMENT. Acta Hortic. 137, 231-242