INFLUENCE OF SMOKE AND ETHYLENE ON THE FRUITING OF THE PINEAPPLE (ANANAS SATIVUS SHULT)

The use of smoke to force pineapple plants into fruit production is a practical development. No controlled experimental work has been reported of this practice. For this reason it seemed desirable to determine the influence of smoke under controlled conditions. In considering the cause of flowering of the pineapple plant following the treatment of smoke, the primary hypothesis raised was that smoke forces the pineapple plant out of a dormant condition. However it was recognized that some constituents of smoke probably ethylene might effect metabolic changes even though the plants were not in a dormant condition, which changes might conduce to floral development. Both slips and suckers are completely developed plants. The roots at the time of planting are very short. The fact that new leaf development is retarded four to six weeks after planting suggests that slips and suckers are in a state of dormancy. It seemed probable that the use of ethylene on these might bring about an immediate resumption on growth with a consequent shortening of the time for flower production. There also remained the possibility as was realized, of a more pronounced effect of ethylene on fruit production. Accordingly an experiment was devised in which both slips and suckers were exposed to ethylene previous to planting. Such a method, if it proved successful, would obviously be a cheaper and more practical method than the use of smoke under field conditions.