THE EFFECT OF PLANT SIZE AND SPRAY VOLUME ON THE EFFICACY OF AVIGLYCINE IN THE INHIBITION OF NATURAL FLOWERING OF 'QUEEN' PINEAPPLE (ANANAS COMOSUS) IN SOUTH AFRICA
Ninety percent of South Africas fresh market pineapples are produced in Hluhluwe and consists of the Queen cultivar. Managing the crop to produce pineapples all year round is achieved by planting the correct size of planting material at a certain planting time and manipulating the harvesting date by the artificial induction of flowering while applying standard cultivation practices for nutrition and crop protection. Natural induction of flowering is a severe problem for the pineapple grower and can result in serious losses. In Northern Kwazulu Natal, natural flowering occurs during the winter months (May-August), yielding an over-production of fruit in December/January with consequently lower market prices. It affects crop management, increases harvesting cost due to multiple harvesting actions and can affect fruit quality. The main environmental factors responsible for natural flower induction are photoperiod (short days) and low temperatures but radiation and water supply can also play a role. The susceptibility of the pineapple plant to natural flowering is related to the age and the size of the plant. Aviglycine, an ethylene biosynthesis inhibitor, proved to control natural flowering to less than 2% at 100 mg L-1 applied in a spray volume of 1500 L/ha every fortnight. These application rates are costly and a series of trials were conducted to evaluate more cost effective application rates. The effect of plant size and planting time on the efficacy of treatments were also evaluated. It was found that by increasing the spray volume from 1500 to 3000 L/ha, and not increasing the amount of Aviglycine to apply a specific concentration of product (mg L-1), the dosage per hectare could be reduced. Plant size is also critical and therefore plantings made between November and January should be planted with smaller plants for Aviglycine treatments to be effective.
Rabie, E.C., Mbatha, B.W. and Tustin, H.A. (2013). THE EFFECT OF PLANT SIZE AND SPRAY VOLUME ON THE EFFICACY OF AVIGLYCINE IN THE INHIBITION OF NATURAL FLOWERING OF 'QUEEN' PINEAPPLE (ANANAS COMOSUS) IN SOUTH AFRICA. Acta Hortic. 1007, 837-848
natural flower induction, minimum temperature, photoperiod, Retain®