Agriculture and Environment: Orange Juice
Better Management Practices: Use of Agrochemicals
One strategy used by main citrus growers to reduce their dependence on and use of chemical pesticides has been to incorporate new varieties of oranges that are more disease-resistant.
They also graft more productive varieties onto hardy rootstock. These strategies are viable options for those who want to control some of the more difficult citrus diseases.Japan sets the example
In Japan, one of the most capital-intensive citrus production systems has been developed for satsumas (also called Mandarin oranges). Many satsuma farms are covered entirely by greenhouses.
Even the drain water is collected and pumped back onto the crops. Very few pesticides are used. Since the greenhouses are intermixed with citrus grown in open, existing groves, one barely notices them. In short every effort has been made to close the production system and this has resulted in a very clean, low-input production system that recycles most of its waste and by-products.
While such a system could not be imported whole cloth into many orange producing areas producing bulk juice, it is likely that many specific practices may. For example, catching and recycling water in a water-scarce world will make increasing sense. Likewise, capturing agrochemical inputs in water runoff for reuse makes sense.
Examples of efficient practices in Florida
In Florida, one orchard has reduced spraying from an average of 22 to 24 times per crop to 10. Orchard managers use IPM, the breeding and release of ladybugs, and the incorporation of hursatelia to reduce chemical interventions. Most of these approaches require that producers anticipate and prevent problems rather than following a strategy of trying to catch up with them later.
Employing professional scouters
Consequently, producers must monitor their fields and anticipate issues by paying close attention to warning signals. Increasingly, such farms employ professional scouters to undertake this work. The company reports that professional scouters are more attentive to details and changes than regular employees who are responsible for a number of different activities.
Scouters are kept on retainer and their sole purpose is to visit fields and observe which pests are becoming problems in which areas of the groves. One farm manager reports that through better timing and targeting, he has reduced spray costs by 20-25% with scouting.
The need to create polycultures
A Florida producer suggests that the reduction of pesticide use has resulted from a fundamental change in attitude. Most producers have found that even if they are producing only oranges, they need to be creating polycultures. What this means is that in addition to growing oranges, producers have to create or maintain conditions for beneficial organisms as well as problematic ones.
For this reason, whenever producers are forced to use chemicals such as copper and sulphur compounds, they kill the beneficials, too. The goal is to provide conditions where both beneficial and problematic organisms can exist but in balance. Spraying is an indication that the proper balance has not been maintained.
Effective information gathering
In order to monitor pests and treat them more effectively, producers need information that allows them to make more precise analyses and interventions. One 1,600-hectare (4,000-acre) Florida orange farm, for example, is divided into lots, the smallest of which are 110 acres.
These lots allow managers to trace problems and input use to specific areas and even specific workers. Managers now realise that they need to keep records for even smaller areas so that they can make informed production decisions. With better, targeted data they can see that some areas require more inputs and efforts than their yields justify, and they are beginning to cut down trees in such areas.
Producers prune and manipulate trees to increase production or to reduce the overall cost of production. For example, trees are trimmed around the edges and the top to make picking easier.
"Skirting" trees
In addition, many producers "skirt" trees, a process that consists of trimming the lower branches so that the lowest branches are half a meter from the ground. This allows air to flow into the tree branches which in turn reduces fungus and mould and the necessity to spray to eradicate it.
