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

VegetablesEnza Zaden Cuts Ribbon For New Florida Vegetable Research Facility
December 18, 2014
Seed company shows off new digs and new varieties at its Myakka City field station. Read More
VegetablesRispens Seeds Highlights Their Latest Vegetable Varieties
December 18, 2014
For more information, contact: Rispens Seeds 1357 Dutch American Way, P.O. Box 310, Beecher, IL 60401 708-946-6560; 888-874-0241; fax: 708-946-6115 Read More
Protected Agriculture2014 Marks The 50th Anniversary Of The Double-Poly Greenhouse [sponsor content]
December 18, 2014
Double-poly greenhouses revolutionized the greenhouse industry back in the 1960s, opening the way for developments that still impact the industry 50 years later. Read More
CitrusSouthwest Florida Citrus Bus Tour Yields Learning Opportunity
December 18, 2014
Find out what Florida Grower editor Frank Giles saw and heard during Peace River Valley Citrus Growers Association's annual outing. Read More
Fruits6 Food Trends For 2015
December 17, 2014
University of Florida experts predict what will be cooking for the upcoming year. Read More
VegetablesReed’s Seeds Showcases Their Latest Vegetable Variety Offerings
December 17, 2014
For more information, contact: Reed’s Seeds 3334 NYS 215 Cortland, NY 13045 607-753-9095; fax: 607-753-9511 rsjackie@twcny.rr.com Read More
CitrusStudy: Florida Citrus Valued At More Than $10 Billion
December 17, 2014
Industry continues to have large impact on the state’s economy. Read More
Apples & PearsNovember Cold May Hurt Washington Orchards
December 17, 2014
But it’s too early to tell if well-below-normal temperatures will increase tree mortality. Read More
NutsAlmond Growers Lose Trees In Storm
December 17, 2014
Last week’s welcome rains in California knocked down trees, especially older ones. Read More
NutsAlmond Conference Draws Record Attendance
December 17, 2014
Nearly 3,000 industry professionals attend 42nd annual event in Sacramento, CA. Read More

The Latest

VegetablesEnza Zaden Cuts Ribbon For New Florida Vegetable Resear…
December 18, 2014
Seed company shows off new digs and new varieties at its Myakka City field station. Read More
VegetablesRispens Seeds Highlights Their Latest Vegetable Varieti…
December 18, 2014
For more information, contact: Rispens Seeds 1357 Dutch American Way, P.O. Box 310, Beecher, IL 60401 708-946-6560; 888-874-0241; fax: 708-946-6115 Read More
Protected Agriculture2014 Marks The 50th Anniversary Of The Double-Poly Gree…
December 18, 2014
Double-poly greenhouses revolutionized the greenhouse industry back in the 1960s, opening the way for developments that still impact the industry 50 years later. Read More
CitrusSouthwest Florida Citrus Bus Tour Yields Learning Oppor…
December 18, 2014
Find out what Florida Grower editor Frank Giles saw and heard during Peace River Valley Citrus Growers Association's annual outing. Read More
Fruits6 Food Trends For 2015
December 17, 2014
University of Florida experts predict what will be cooking for the upcoming year. Read More
VegetablesReed’s Seeds Showcases Their Latest Vegetable Var…
December 17, 2014
For more information, contact: Reed’s Seeds 3334 NYS 215 Cortland, NY 13045 607-753-9095; fax: 607-753-9511 rsjackie@twcny.rr.com Read More
CitrusStudy: Florida Citrus Valued At More Than $10 Billion
December 17, 2014
Industry continues to have large impact on the state’s economy. Read More
Apples & PearsNovember Cold May Hurt Washington Orchards
December 17, 2014
But it’s too early to tell if well-below-normal temperatures will increase tree mortality. Read More
NutsAlmond Growers Lose Trees In Storm
December 17, 2014
Last week’s welcome rains in California knocked down trees, especially older ones. Read More
NutsAlmond Conference Draws Record Attendance
December 17, 2014
Nearly 3,000 industry professionals attend 42nd annual event in Sacramento, CA. Read More
Insect & Disease UpdateManage HLB From The Bottom Up
December 17, 2014
Finding the right balance between the roots and shoots is critical to disease mitigation. Read More
VegetablesVariety Trials 2014: Seedway
December 17, 2014
As part of American Vegetable Grower’s (AVG) 2014 variety trial coverage, we visited Seedway’s seed trial at Spiral Path Organic Farm in Loysville, Read More
OrganicUSDA Proposes Expansion Of Organic Assessment Exemption
December 17, 2014
Action would increase the entities exempt from paying assessments for promotion programs on products certified as “organic” or “100% organic.” Read More
MarketingThe U.S. Potato Board Receives $5 Million In Funding To…
December 17, 2014
The funds will be used to help increase consumption of frozen, dehydrated, chip stock, table stock and seed potatoes around the world. Read More
ProductionNational Vegetable Grafting Symposium To Take Place Jan…
December 17, 2014
The third grafting symposium, Growing New Roots for the Vegetable Industry in the U.S., will be held at the Savannah International Trade and Convention Center in Savannah, GA. Read More
VegetablesOutstanding Seed Co. LLC, Showcases Their Latest Vegeta…
December 16, 2014
For more information, please contact: Outstanding Seed Company, LLC P.O Box 202 Monaca, PA 15061 877-248-4567; fax: 724-775-1644 outstandingseed.com Read More
VegetablesJohnny’s Selected Seeds Showcases Their Latest Ve…
December 16, 2014
For more information, please contact: Johnny’s Selected Seeds 955 Benton Ave. Winslow, ME 04901 877-564-6697; fax: 800-738-6314 johnnyseeds.com Read More
Apples & PearsFour Highlights You May Have Missed At Great Lakes Expo
December 16, 2014
Record-setting crowd sat in on presentations featuring precision orchard management, mechanical berry harvesters, biocontrols, and more. Read More