Drip Irrigation Boosts Pineapple Yields by 21% Over Conventional Sprinklers

An irrigation trial in pineapples at Yeppoon, Qld, has recorded a 21pc lift in production, using a drip irrigation system compared with a conventional overhead irrigation system.

These results, from a trial commenced in 2005 on the Steven's property near Yeppoon, were presented to growers at a field day organised by Fitzroy River and Coastal Catchments and Growcom Water for Profit Field Officer, Marcus McCormick.

Two equal sized and similar production blocks of about a quarter of a hectare each were selected to compare the yield and water efficiency benefits of drip irrigation with an overhead system.

The infield material costs of the drip line worked out at $3,516/ha compared to $1,932/ha for the solid set overhead system - so drip cost more. “However, while the in-paddock costs for the dripline were almost double that of the overhead, installation required less labour," Mr McCormick said. "And the drip system provided significant yield and profit benefits which more than made up for the expense.”

There were also remarkable differences in the volume of irrigation water used, with dripline saving about 50%. Only 0.489ML of water was applied to the drip block throughout the whole of the trial compared with 0.892ML for the overhead block. "We installed an Enviroscan to monitor soil moisture levels and this assisted the Stevens in making appropriate decisions about when to irrigate,” Mr McCormick said.

From this water, an additional 1,042 trays per ha of pineapples were harvested on the drip irrigation block. This represented a 21pc increase in production.

A cost analysis of the trial was conducted using pack-out figures supplied by the Stevens family and average market prices for the first six weeks of 2007 supplied by Tropical Pines. Based on these figures, the extra production from the drip block represented an additional 16pc in returns, after the cost increases for the in-paddock setup of the drip block had been accounted for.

Improved uniformity of fruit quality, sizing and superior growth and vigour of the pineapple plants produced from the drip block were apparent in the trial. Drip irrigation also allowed superior irrigation scheduling. “The beauty of drip irrigation is that the wind does not affect when you can irrigate," Nathan Stevens said at the field day. "At times, we had to wait for up to a month until we could irrigate with the overhead because of the wind,” The trial has attracted a great deal of interest from the pineapple industry.

The trial was the result of a collaborative partnership between the Stevens family, Tropical Pines, Fitzroy River and Coastal Catchments Inc., Growcom’s Water for Profit team, Yeppoon District Co-op., Plastro Asia Pacific, Menkens Irrigation Services and the Fitzroy Basin Association. A second stage of the trial is expected to look at the production benefits associated with using fertigation and chemigation through drip irrigation to manage plant nutrition and health.

Once again, water efficient irrigation systems do not cost.............they really do improve the bottom line while saving water.