Bill Castle
By Bill Castle
University of Florida professor emeritus
Paul Genho, a former manager of the Deseret Ranch in Osceola County, spoke about soils and food at a Florida land conference in 2015.** He noted that 90 percent of the world’s food production occurred on only four soil types: Mollisols, Alfisols, Ultisols and Oxisols. A goodly proportion of those soil types form U.S. farmland. They gain additional importance when considering that, although these soils exist elsewhere in the world, many of those places do not have regular rainfall.
As the world continues to add millions to the planet’s population on a daily basis, food must be produced somewhere by farmers. There are parallels to this story in Florida citriculture. Among the four soils types, only Alfisols are particularly important in growing citrus. Furthermore, producing citrus may not be seen as being in the same category as wheat, corn, rice and soybeans. Nevertheless, citrus is a part of the fruit and vegetable food group considered important in our diet. Therefore, where might our industry be going?
Florida’s population also continues to grow. It would be a shame if our best soils for crops and citrus were lost to development. Fortunately, population growth is relatively slow in the major counties where citrus is grown. Traditional citrus land remains available, and there are plenty of abandoned groves.
HIGHER-DENSITY GROVES
The major threat to our future is not loss of land, but huanglongbing (HLB). One response to HLB that our industry is exploring is keeping production up by growing more fruit on less land via higher-density (HD) groves. Such groves have been talked about for decades, but there is little long-term commercial experience — thus, limited validation of expectations. In fact, most growers who planted more trees per acre in the past wished they hadn’t after about eight years because of declining production, and that was in the absence of HLB.
Today’s prospects and incentives for HD groves are different. HLB may shorten grove life, but that is exactly why learning how to produce citrus in HD groves is more appealing than before. My colleagues, together with growers, have become much better at managing tree nutrition and water requirements. There are many more rootstock options for at least planting modern-density groves at 8 feet by 20 feet or HD groves at 360 or more trees per acre.
HD groves make sense, but they need to be carefully planned and managed in order to avoid exceeding (abusing) their biological and economic limits. HD is not just more trees per acre using traditional cultural designs, practices and varieties. The Florida citrus industry can learn from other HD cropping systems such as with apples and olives, as well as applying lessons from the Florida experience.
FRESH VS. JUICE
Will the balance between fresh fruit and juice fruit production change? Maintaining our current processing capacity requires millions of boxes of fruit. More intensively designed and operated production systems may prove to be well-suited to raising juice fruit and especially suited to fresh fruit culture. One advantage of HD groves for fresh fruit is that they are affordable to establish and operate on a small or large scale.
Also entering the fresh fruit arena are newer production systems like CUPS (citrus undercover production systems). Partly for these reasons, I see the share of fresh fruit increasing. Why can’t there be 25,000 acres of fresh fruit production in the near future? There used to be more than 50,000 acres; now there are just 14,077 specialty fruit acres. Sounds to me like there should be some dialog on this topic!
The current interest in new scions and rootstocks and new production systems is having an impact on the need for early-on, reliable data to allow better-than-normal decisions to be made. The citrus-breeding programs in Florida are regularly providing new rootstocks and scions for evaluation under normal and Fast Track options. A systematic approach to gathering and compiling data after planting is essential. The same would apply to planting designs as growers venture forth with new ideas.
Exciting and challenging times are our future with new grove designs; planting at higher densities like 8 feet by 20 feet or 272 trees/acre, or more; over-the-row cultural operations and harvesting; and some of the best varieties and rootstocks ever available to our industry. It behooves us to take full advantage of this future and see that there is a system in place to gather the information and data needed to support such a future, a matter of high importance. Do you agree?
*Special thanks to more than a dozen growers and industry representatives whose comments added perspective and improved this letter.
**Contact Bill Castle (bcastle@ufl.edu) for a link to the full story.
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