Pineapple growth and nutrition over a plant crop cycle in south-eastern Queensland. 1. Root development and general growth features

Abstract

The morphological and growth features of a monthly sampling study on a standard commercial planting are described. A spring planting of the Cayenne variety was used and the sampling terminated at the green fruit stage.
The numbers of major roots, their length measurements and the dry weights of the whole root systems are recorded. The general development of the root systems is described.
Root growth was continuous over the cold winter months while soil moisture was adequate. The weight of the recovered roots decreased considerably during the dry spring months and nematode damage was also apparent. Recovery occurred after the first rains in October.
It is suggested that the use of raised beds may limit the longevity of the root system.
Leaves and stems also continued growth through the winter months up until the onset of dry conditions. Recovery after the October rains was associated with the development of fruit and reproductive parts.
The wide degree of variability in both growth and physiological age of the sampled plants commencing about July was interpreted as indicating very strong interplant competition.
Tissue moisture contents in terms of the water:dry-matter ratio were followed for all plant parts except the roots. Stem W /D ratios produced a well-defined peak of 7 .3 in February and this foreshadowed a long period of accumulation of food reserves for the remainder of the sampled growth cycle.