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

NutsCalifornia County Passes Ordinance To Protect Walnut Gr…
August 27, 2014
Verification of ownership needed to complete sales of valuable nuts. Read More
NutsAlmond Growers Hit By Russian Import Limits
August 27, 2014
Growers reflect on changes to export market in light of produce ban. Read More
Farm ManagementLeadership And Management Expert To Speak At California…
August 27, 2014
Daniel Goleman will make presentation at California State University-Fresno. Read More
CitrusNational Scientific Summit On Herbicide Resistant Weeds…
August 27, 2014
Topics to be covered include the economics of proactively managing herbicide resistance, education and outreach efforts, and incentives and regulatory initiatives. Read More
FruitsFlorida Organic Group Dedicated To Serving Growers, Com…
August 27, 2014
Education and development programs are plentiful for interested producers. Read More
VegetablesExperimental Herbicide Technology Blasts Weeds In Rows
August 27, 2014
The technology uses an air compressor to spray corncob grit on both sides of a crop, killing young weeds. Read More
Disease ControlFungal Disease Outbreak Hits Pacific Northwest Vegetabl…
August 27, 2014
An outbreak of blackleg, light leaf spot, and white leaf spot can be significant problems in several vegetable crops.   Read More
CitrusClean Water Conundrum: Ditch The Rule Or Ditch The Myth…
August 26, 2014
Regulation inundation causing a rising tide of confusion for farmers. Read More
BerriesMichigan State University Extension Offers Tips To Prev…
August 26, 2014
Humidity, rainy periods conducive to disease development. Read More
FruitsSpotted Wing Drosophila Populations Rising In Michigan
August 26, 2014
Extension researchers advise berry growers on trapping, salt testing to take stock of pest population. Read More
Apples & PearsNorthwest Pear Crop Estimate Revised Upward
August 26, 2014
Washington and Oregon pear growers forecast a larger size crop than that originally estimated. Read More
VegetablesAgrium Acquires A Controlling Interest In Biotech Compa…
August 26, 2014
The company also acquires stake in Agricen Sciences as part of strategic effort to expand their offering of integrated, next-generation plant health technologies. Read More
Insect ControlCover All Angles When Taking On Threecornered Alfalfa H…
August 25, 2014
Learn how to ID, the survival and spread, and management methods for this insect pest. Read More
GrapesEarthquake Shakes Up Napa Wine Industry
August 25, 2014
Sunday’s early morning quake was centered just six miles from the city of Napa. Read More
OrangesNew Orange Pipeline Full Of Juice
August 25, 2014
Industry stakeholders are working on a rapid release model for processed varieties. Read More
CitrusCalifornia Citrus Cleared For Chinese Export
August 25, 2014
New agreement addresses concerns over brown rot. Read More
CitrusConsolidated Citrus Eyes Giant Planned Agricultural, Em…
August 25, 2014
South Florida real estate endeavor includes a 5 million-square-foot industrial park, including 200,000 square feet of retail space and 500 hotel rooms. Read More
Pest ControlManaging Lepidoptera In Tomatoes
August 22, 2014
This video provides information on how to best identify and control Lepidoptera in tomatoes. Read More