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

Farm ManagementIndustry Organizations Sound Off On President’s Immigration Plan
November 21, 2014
Agriculture is not given the attention it so sorely deserves when it comes to the immigration debate. Read More
Insect ControlDon’t Turn Your Back On Striped Blister Beetles
November 21, 2014
Learn how to ID, the survival and spread, as well as management methods of this vegetable pest. Read More
CitrusRamped-Up Predatory Mite Production To Benefit Growers
November 21, 2014
Biologics company Beneficial Insectary now rearing two species in its California facility. Read More
NutsArizona Pistachio And Pecan Growers Benefiting From High Prices
November 21, 2014
Pecan production alone is expected to double in the next 10 years. Read More
Apples & PearsOn The Road With The International Fruit Tree Association Study Tour To Italy Part 2 [Slideshow]
November 21, 2014
Attention to detail is evident in the production of high quality feathered apple trees at GRIBA’s nursery. Read More
Fruits2014 California Winegrape Harvest: Outstanding
November 21, 2014
It’s the earliest crop of the decade, but still a third in a string of great vintages. Read More
FruitsFetzer Vineyards Pioneers Zero Waste
November 21, 2014
Company achieves top sustainability certification by diverting 98% of its waste from the landfill. Read More
VegetablesFormer Harris Seeds Co. CEO, Per Jensen, Passes At 85
November 21, 2014
A passion for plants defined longtime industry influencer. Read More
GrapesPerfect Storm Hurts New York Concord Grape Growers
November 21, 2014
More than 10,000 tons of juice grapes are abandoned because of too much production and no market. Read More
FruitsClassic Turkey Day Dinner Costing Consumers More This Year
November 20, 2014
Despite increase, a family of 10 can still get stuffed for less than $50. Read More

The Latest

Farm ManagementIndustry Organizations Sound Off On President’s Immig…
November 21, 2014
Agriculture is not given the attention it so sorely deserves when it comes to the immigration debate. Read More
Insect ControlDon’t Turn Your Back On Striped Blister Beetles
November 21, 2014
Learn how to ID, the survival and spread, as well as management methods of this vegetable pest. Read More
CitrusRamped-Up Predatory Mite Production To Benefit Growers
November 21, 2014
Biologics company Beneficial Insectary now rearing two species in its California facility. Read More
NutsArizona Pistachio And Pecan Growers Benefiting From Hig…
November 21, 2014
Pecan production alone is expected to double in the next 10 years. Read More
Apples & PearsOn The Road With The International Fruit Tree Associati…
November 21, 2014
Attention to detail is evident in the production of high quality feathered apple trees at GRIBA’s nursery. Read More
Fruits2014 California Winegrape Harvest: Outstanding
November 21, 2014
It’s the earliest crop of the decade, but still a third in a string of great vintages. Read More
FruitsFetzer Vineyards Pioneers Zero Waste
November 21, 2014
Company achieves top sustainability certification by diverting 98% of its waste from the landfill. Read More
VegetablesFormer Harris Seeds Co. CEO, Per Jensen, Passes At 85
November 21, 2014
A passion for plants defined longtime industry influencer. Read More
GrapesPerfect Storm Hurts New York Concord Grape Growers
November 21, 2014
More than 10,000 tons of juice grapes are abandoned because of too much production and no market. Read More
FruitsClassic Turkey Day Dinner Costing Consumers More This Y…
November 20, 2014
Despite increase, a family of 10 can still get stuffed for less than $50. Read More
Insect ControlFlorida Vegetable Growers Gain Access To New Nematicide
November 20, 2014
Methyl bromide alternative Nimitz approved for use on tomatoes, peppers, okra, eggplant, cucumber, watermelon, cantaloupe, and squash. Read More
EquipmentHighlights From EIMA International In Italy [Slideshow]
November 19, 2014
The 2014 edition of the International Agricultural and Gardening Machinery Exhibition (EIMA) boasted a record number of attendees from 124 countries. Read More
Farm ManagementVegetableGrowerConnect Delivers Results For Growers And…
November 19, 2014
Suppliers and growers got down to business in San Diego discussing current needs, solutions, and ways to increase efficiencies on the farm. Browse this slideshow for VegetableGrowerConnect highlights. Read More
FruitsFixing Farm Labor Woes Worth The Extra Effort [Opinion]
November 19, 2014
40th annual Ag Labor Relations Forum encourages outreach and action. Read More
BerriesPackaging Company’s Campaign To Benefit Future Organi…
November 19, 2014
Sambrailo Packaging of Watsonville, CA, has partnered with California Certified Organic Farmers and will donate a portion of the sales of clamshells made from plastic bottles. Read More
Apples & PearsOn The Road With The International Fruit Tree Associati…
November 19, 2014
Win Cowgill of Rutgers University details a trip through the one of the most concentrated fruit growing areas in the world, the South Tyrol region of Italy. Read More
IrrigationAlmond Grower Honored For Water Efficiency
November 18, 2014
Ongoing drought highlights the efforts of third-generation Madera County grower Tom Rogers. Read More
CitrusWomen’s Impact On Agriculture Impressive [Opinion…
November 18, 2014
Florida Agriculture Commissioner Adam Putnam says the long-term sustainability of farming depends on our youth. Read More