The acid lime fruit showed a typical single sigmoidal growth curve and attained ripening stage in about 180 days. Growth of the fruit in terms of its weight was slow till 40 days after set, increased rapidly upto 160 days, followed by a slow phase again, The cytokinin activity in the butanol-soluble fraction and the total cytokinin activity were high immediately after fruit set, intermediate in the middle phase of fruit growth and decreased later. The pattern of relative growth rate of the fruit closely resembled that of its total cytokinin activity. The concentrations of the substances behaving like zeatin riboside (ZR), zeatin (Z), isopentenyl adenosine (iPA) and of the unidentified substance from the butanol-soluble fraction at 280-400 ml elution volume in sephadex LH-20 column chromatography were high soon after fruit set and in the initial stages of fruit development upto 60 days. The initial high cytokinin activity in the fruit is possibly contributing to the enhanced cell division in the first phase of fruit growth.
