Pineapple Field Establishment Using Slips

Slips are side-shoots or fruit with large crowns that grow from buds on the pineapple (Ananas comosus L.) peduncle. The slips are widely used for pineapple vegetative propagation when crowns are left attached to the fruit that is marketed. There is a difference between the two most popular low-acid pineapple hybrids grown roots when planted compared with 'Pineapple Research Institute 73-114' (MD2). The slow rooting of 73-50 leads to slow field establishment and can extend the crop cycle. Our objective was to determine the cause of this reduced rooting and evaluate treatments to increase the rooting rate. Rooting trials in moist, coarse vermiculite showed that larger slips and green slips with red hues also had a greater number of roots compared with smaller slips and green or yellow slips. Delaying harvesting of the slips after the fruit were harvested also resulted in a greater number of roots. Treatments including components frequently used for rooting cuttings did not significantly increase root numbers. An exception was a tendency for slips treated with potassium nitrate to have greater rooting during some tests. We present data that support the conclusion that the poor root development is associated with the mechanical impedance of the root from the tightly affixed basal leaf bracts. Removal of the lower ten bracts can lead to greater root numbers. When the slip with the bracts removed was tightly wrapped in plastic wrap and masking tape, rooting was reduced. The sizing and selection of slips that are green with a red hue and collected as late as possible after fruit harvest had the best rooting response.