Tweaking Around Tubing

John Paul comes from a family with a history of tinkering with how citrus production works and creating new ways to increase efficiency since groves were first put in during the early 1900s. The grove founder and family progenitor, A.G. Smith, even traded a downtown Wauchula city block for a pump, which was used for the first flood style irrigation system in Central Florida.

With that same sense of discover, Paul put on his thinking cap to develop alternative ways for weed control in his grove. The candidate he liked was an inter-row cultivator to remove weeds. But, an obstacle to this was to figure out a way to relocate or remove polyethylene tubing and emitter assembles used for irrigation.
Paul is trying one method to tweak irrigation in his Wauchula grove where the polyethylene tubing is supported 36 inches off the ground with a galvanized cable. The emitter is not a stake assembly, but a vertical hanging emitter that is inverted. “I really like this approach,” he says. “We are gathering data to prove the efficacy and ease of maintenance over time. Tree farmers currently utilize irrigation systems in this manner. Of course, their rows are as close as six feet apart, but with high margins, they have been able to justify the expense. In citrus, our rows are currently 20 to 25 feet apart with a potential to be as close as 12 feet apart in high-density plantings. This system also will limit emitter clogging and ant and critter damage, an additional savings to the grower.”

The second approach, which is being tested in the family’s LaBelle grove, is subsurface irrigation/drainage. In this trial, large diameter corrugated pipes are installed as mains and sub-mains. The distribution points are corrugated pipes, smaller in diameter than the mains, which are wrapped in mesh socks. Water is introduced into the corrugated mains for irrigation and released for drainage. “The method doesn’t require any above-ground polyethylene tubing, so it’s natural for mechanical inter-row cultivation,” Paul says.
The final alternative is a hybrid of residential and agricultural systems. The emitter would be a gear rotor installed in the center of the bed. “I saw this as being more applicable in the high-density plantings that are on the horizon,” he says. “The installation would be similar to the old solid set irrigation. The emitter is a gear rotor at ground level and not an impact sprinkler 20 feet off the ground. However, the higher operating pressures may make this form of irrigation cost prohibitive to many.”

Paul believes these options are viable depending on soil type, growing region, and tree density. In order to make an educated decision regarding these innovations, citrus growers will have to weigh the costs of maintenance for the irrigation system and the inter-row cultivator against the savings realized through the use of contact herbicide and the efficiency of new approaches over time.