Regulation of fruit size and maturity in pineapple

Abstract

In spite of spectacular achievement obtained In controlling flowering In pineapple by the application of ethrel In recent times, uniformity In fruit size In large pineapple plantings, even under uniform cultural and manurlal schedules, is seldom achieved in Kerala. Both 1n plant crop and especially in rations, a considerable percentage of fruits fall below standard. Regulation of fruit size and maturity will help to Increase the fruit size as well as to extend the period of harvest. The present Investigations were carried out In the Department of Pomology, College of Horticulture, Vellanlkkara from 1988 to 1980 to study the effect of different concentrations of NAA (0, SO, 100, 200 and 300 ppm) at different stages of application (at Inflorescence emergence, one month after Inflorescence emergence, two months after Inflorescence emergence, three months after 1nfIorescenee emergence and four months after Inflorescence emergence) on the size, maturity and quality of fruits and also to assess the best time of application of NAA, on pineapple variety. ‘Kew’. Uniform flowering was Induced by giving a combination treatment of 25 ppm ethrel, 2 per cent urea and 0.04 per cent CaCO3. Considering the quality parameters like T.S.S., acidity and total sugars, the period between 132 and 135 days after Inflorescence emergence appeared to be the best time of harvest of pineapple fruits. Application of NAA was found to Increase the fruit size the maximum being effected by 300 ppm NAA applied one month after Inflorescence emergence.200 ppm NAA applied at the same stage and 300 ppm applied at Inflorescence emergence and two months after Inflorescence emergence had a similar effect. Maximum delay in fruit maturity was observed by the application of 300 ppm NAA followed by 200 ppm NAA. There was significant Increase In fruit size 1n different leaf groups when 300 ppm NAA was applied one month after Inflorescence emergence. The reduction in fruit size associated with lower leaf number could thus be improved by the application of NAA.