Reap Benefits With Citrus Mechanical Harvesting

A Healthy Harvest

To be competitive in an increasingly global marketplace, Florida citrus growers must reduce harvesting costs. Furthermore, immigration issues may force a substantial decrease in the available numbers of workers to harvest citrus. These concerns pushed the Florida Department of Citrus (FDOC) to re-examine the feasibility of mechanical harvesting for citrus. For the last few years, the FDOC and the University of Florida/Institute of Food and Agricultural Sciences (UF/IFAS) have been supporting harvesting research and evaluating several mechanical harvesting machines and abscission chemicals to increase the efficiency of mechanical harvesting.

Research Disproves Reservations

Despite the substantial cost savings of mechanical harvesting relative to conventional hand harvesting, the adoption of mechanical harvesting has been slower than expected. Many factors contribute to the slow acceptance of mechanical harvesting. One factor is the visible damage to the trees that can include breaking of branches, sloughing of trunk bark, exposing root systems, and noticeable leaf, flower, and young fruit drop. Growers worry that these visible signs of physical damage will have negative effects on tree health and future yields. When healthy, well-managed trees are mechanically harvested, there is no scientific evidence that these injuries negatively reduce tree yields or longevity.

For the last five years, several studies have focused on the physiological effects of mechanical harvesting. Short- and long-term physiological measurements revealed that the water use, growth, and yield of healthy, well-managed and well-prepared citrus trees was not negatively affected by mechanical harvesting — even when mechanically harvested annually for several consecutive years. The removal of healthy leaves by mechanical harvesting has no long-term effect on trees, and in some cases, can even be beneficial to light penetration, growth, and yield. Any visible root damage after shaking does not measurably affect water and nutrient uptake by the root system. In addition, root growth and recovery, return bloom, and water status were similar to that of hand-harvested trees.

Why Move To Mechanical?

The objectives of mechanical harvesting are:

1) To decrease harvesting costs, which implies an increase in  “on-tree” revenues.

2) To increase overall labor productivity, which implies a reduction in the required number of harvest workers.

Many tree and vegetable crops have moved to mechanical harvesting to survive. There is now a general consensus among industry leaders that mechanical harvesting offers the greatest potential to reduce costs and keep the citrus juice industry economically viable. It has been well documented that the major benefit of mechanical harvesting relies on its efficiency and lower costs in comparison with hand harvesting.

Mechanical harvesting during peak bloom in Valencia removes some flowers, but does not diminish fruit set. These trees did not develop any physiological stress as measured by stem water potential or leaf photosynthesis. So long as the diameter of the young green Valencia fruit is less than about 1 inch, mechanical harvesting of Valencias does not reduce yields the following year. Once the young fruitlets exceed this size, however, aggressive trunk or canopy shaking will likely depress the following year’s yield by at least 25%.

The Bottom Line

Except for late-season Valencia with large young fruit, all research studies where citrus trees have been harvested mechanically for many years have shown no reductions in yield or tree health. Currently, work is underway to develop an abscission chemical which could solve the late-season Valencia problem.

Leave a Reply

Featured Stories

All Vegetables Stories >All Fruits Stories >All Nuts Stories >All Citrus Stories >

The Latest

BerriesReal Estate Firm, Wish Farms Strike Large Land Deal
October 1, 2014
$13.8 million transaction includes more than 800 acres acquired from longtime Central Florida produce operation. Read More
VegetablesFind The Right Market For Your Crops
October 1, 2014
Getting to know the demographics of your market is key to maximizing your return on investment. Read More
Insect ControlBagrada Bug And Brown Marmorated Stink Bug Posing Threa…
October 1, 2014
Two species of stink bugs are now posing a serious threat to agricultural production in the Western U.S.: the brown Read More
OrganicResearchers Breeding Organic Tomato Varieties Receive $…
October 1, 2014
Purdue University accepts funding to lead multi-institution research to breed organic varieties that will resist foliar diseases. Read More
Vegetables14 Quality Cabbage Varieties [Slideshow]
October 1, 2014
Browse the slideshow below for information on cabbage varieties from the nation’s leading seed breeders and distributors. Read More
FruitsOrganic And Local Food Economies Receive More Than $52 …
October 1, 2014
Most of the grants were authorized through the 2014 Farm Bill. Read More
Insect ControlMore Than 600,000 Acres Removed From Golden Nematode Re…
October 1, 2014
The potato acreage was taken off the Animal and Plant Health Inspection Service’s list; under 6,000 acres in New York are still considered to be infested. Read More
Crop ProtectionTool Helps Track Insects On The Move At Night
October 1, 2014
Signals collected by the National Weather Service’s Doppler radar network may serve as an early warning system to track corn earworm, a major pest in sweet corn. Read More
NutsNew Walnut Budding, Grafting, and Planting Video Releas…
October 1, 2014
Lake County nurseryman Alex Suchan, who has been grafting trees for two-thirds of a century, is the star. Read More
GenNext GrowersGrowers Need To Be Mindful When Dealing With The Media
October 1, 2014
When being interviewed for a story, preparation is the foundation to help you successfully get your point across. Read More
Citrus Achievement AwardSharing Is Caring When It Comes To Curing Citrus Greeni…
October 1, 2014
Mike Sparks, 2014 Citrus Achievement Award winner, says being open with peers about what's working and not working is crucial in managing HLB. Read More
Florida Ag ExpoKnow How To Knock Back Nematodes
October 1, 2014
The 2014 Florida Ag Expo will provide critical tips in soilborne pest management. Read More
CEU SeriesCEU Series: Vow To Vanquish Weeds Among Vegetables
October 1, 2014
Herbicidal neglect can and will kill your crops. Read More
Insect & Disease UpdateUF Names Interim Director For Citrus Research And Educa…
September 30, 2014
Michael Rogers has been a central figure in Florida’s battle to survive greening. Read More
BerriesPractice Persistence When Battling Botrytis In Blueberr…
September 30, 2014
Cognizance of resistance is key to managing formidable fungus. Read More
CitrusFarming Is Quite The Scary Prospect For Some [Opinion]
September 30, 2014
Florida Grower managing editor Paul Rusnak says economic realities might frighten off future leaders from noble professions. Read More
FruitsNew Suppress Herbicide Gets Green Light From EPA
September 30, 2014
Approval gives organic growers new weed management tool. Read More
BerriesNew Fill-By-Weight Clamshell Filler For Blueberries
September 30, 2014
Lakewood Process Machinery's equipment offers a simplified user interface, minimized drop heights, a new dribble-gate system designed for an increased level of accuracy. Read More