1. Citrus Mechanical Harvesting -Realizing the Potential
Presentation to the FDOC Citrus Commissioners
Lakeland, FL
November 16, 2005
Fritz Roka
UF/IFAS - SWFREC
Previous MH program was active from 1960s into the early 1980s.
Two important features of the original MH program:
USDA/ARS and UF/IFAS were the lead agencies. Focus on building machines, developing new technology.
Fear of labor shortage was a primary motivator for the original program.
Labor shortage never materialized, in large part because of the devastating freezes of the 1980s.
Original MH harvesting program ground to a halt with no viable commercial systems in place. Trunk shakers with ground pick-up machines were developed. The abscission compound CMNP was identified and formulated into the product known as “Release.” Several toxicology studies were done on CMNP, as well as, treatment trials, but the chemical was never taken to the EPA for registration.
Citrus mechanical harvesting program reborn in 1994/95.
Dr. Galen Brown was hired as the DOC’s Harvesting Administrator and helped formulate the vision behind the new program.
Important features of the new program:
DOC was the lead agency with grower taxes supporting the effort.
Focus on working with existing equipment manufacturers.
Reduction of harvest costs (I.e. the Brazilian cost factor) became the over arching reason for MH, not just insuring against labor availability shortages.
Purpose of this presentation:
Summarize harvesting systems currently in the field
Lay out a “roadmap” to capture all the potential savings from MH.

2. Today
Hand harvest, pick & roadside
$ $1.60 /bx
Machine harvest, shake & catch
$ $1.35, includes gleaning (98% in the trailer)
$60 – 125 /ac savings
During 2004/05, nearly 25,000 acres were mechanically harvested. Most (80%) of the acreage was done in southwest Florida.
Growers in southwest Florida pay hand crews between $1.50 and $1.60/bx to pick and roadside fruit for processing. Per box costs increase with smaller yields and as the harvest season progresses into late May and June.
On those same groves that are “properly” prepared, mechanical systems that shake & catch fruit are charging between $1.30 and $1.35 /bx.
Prices include GLEANING which means 98% of the available fruit makes it into the trailer.
Properly prepared trees mean that the trees have been pruned to 18” of clear trunk and skirted to 30” at the drip line.
Assuming between 400 and 500 bx/ac, harvest costs are reduced by ~$100/ac

3. Trunk-Shake & Catch Shaker, receiver, goat 3 people/set 5-12 sec shake
95% removal
Skirt & prune trees
10 years ago, the DOC Citrus Research Advisory Council was wrestling with the question of whether mechanical harvesting was technically feasible. In other words: Can you shake an orange tree strong enough to remove the mature fruit without killing the tree?
10 years later, the answer to that question is YES.
Three types of mechanical harvesting systems were in use during the season.
First system is called the “trunk-shake & catch” (TSC) system.
One TSC system includes three pieces of equipment – shaker, receiver, and a goat.
The shaker’s clamp grabs the trunk of a tree and whips the tree for between 5-12 secs.
The receiver positions opposite the shaker on the bed side of a tree row. Falling fruit is deflected onto the catch frame and a conveyer moves fruit to a trailing cart. The cart collects between boxes before off-loading to a goat.
Grove preparation is necessary for this system to work effectively. Clear trunk for the shaker clamp and skirting for efficient operation of the catch frame.

4. Continuous Canopy-Shake & Catch
2 Shakers, 2-4 goats
4-6 people/set
½ - 1¼ mph
95% removal
Skirt & prune trees
A second system is called the “continuous-canopy shake & catch” system.
Six-foot tines work within the canopy of the tree to knock off mature fruit
Two shaking units work across a row depositing fruit into goats that follow behind the harvesting machines.
The harvesters travel continuously at between half to 1.5 MPH. With an extra set of goats, the harvesters do not have to stop while one set of goats delivers fruit to the bulk road trailer.
Like the TSC system, trees need to be skirted and lower scaffold limbs pruned.
TSC and CCSC are running primarily in SWFla because grove configurations are conducive for efficient operation.
Long rows
Uniform tree configurations
Biggest potential cost savings will come from systems that catch fruit as they are removed.
Both TSC and CCSC systems harvesting WITHOUT the aid of abscission compounds.

5. Avg. Performance Statistics
Early-Mid Season
TSC
Coe
CCSC
Oxbo
Removal % 95
Recovery 87 90
Speed
Tree/hr
200
361
Productivity
Bx/hr 96
103
Evidence of commercial performance:
Statistics compiled over a 5-year period from a variety of grove conditions that typify SWFla.
Removal and recovery a function of machine design – not much change since 1999/00 – removal and recovery %s have not changed much.
Speed and labor productivity influenced by management of the system personnel – harvesting companies learning how to “incentivize” harvesting crews.
CCSC and TSC very similar with respect to removal and recovery. Much of the data came from similar tree and grove conditions.
CCSC faster than TSC, but when crew size factored in overall labor productivity about the same. TSC set uses 2.5 to 3 people. CCSC uses 6.
Statistics based on IFAS field observations NOT overall performance. That is, season-wide performance has not been evaluated.
Performance will vary with grove conditions – skirted & pruned trees allow efficient operation of catch frames; higher yielding trees increase machine through put.
Performance statistics provide evidence that existing systems will work
Statistics compiled from 1999 – 2004.

6. Tractor-drawn Canopy-Shaker
1 Shaker w/ Tractor
15-30 hand crew
½ - 1¼ mph
95% removal
No need to skirt or prune trees
The third system is a tractor-drawn canopy shaker. The shaking action is very similar to the CCSC system, but fruit falls to the ground. A hand crew is employed to pick-up the harvested fruit. The harvester is a single unit, therefore it has to travel up one side of the tree and then travel back down the other tree side.
This system works very well in “unprepared” grove situations. I.E. good fruit removal without skirting.
This system has greater potential to work in non-uniform grove conditions because the operator can adjust the depth of penetration of the tines.
Productivity of pick up crew is doubled over a traditional hand harvesting crew.
Work is underway to develop a “pick-up” machine. If successful, a pick up machine should eliminate the need for the “pick-up” labor. Overall performance of this system would improve.
Processors are concerned about food safety consequences from fruit that is picked-up off the ground. Research is underway to examine bacteria loads and implications on processing when fruit is allowed to hit the ground.
Efficient performance of a pick-up machine will likely require that trees are at least skirted.
Pick-up machine under development

7. Impediments to Adoption
Plentiful harvest labor (prior )
Cost of grove prep
Concern for tree productivity/health
Grower insistence for Gleaning
The “Late Season” Problem
Excess capacity of existing systems
Savings not big enough yet
If the machines work and growers save ~$100 per acre, why were there <25,000 MH during ? More importantly, why is the rate of MH adoption relatively slow?
The answers to the above questions can NOT be dismissed as grower apathy or resistance to change. There are real impediments currently in place that are holding back widespread MH adoption. Recognizing those impediments should help us focus on future efforts to develop MH systems as viable, commercial alternatives to hand harvesting.
Seven (7) impediments too widespread MH adoption have been identified (perhaps there are more):
Some impediments are beyond the control of growers or even the industry
Abundant labor masks the real need for MH (I.e. harvest cost reduction).
Poor markets - low prices, hard to encourage growers to invest more money into preparing groves for MH. In some cases a grove/block has to be replanted for MH systems to work effectively.
Some impediments are a function of education.
Good data emerging that MH does NOT adversely affect tree health and long-term productivity. There remains a need to continue research addressing tree health and mortality concerns. But with each passing year of experience, the more confident we can become.
Gleaning is expensive and raises the price of a “packaged” deal. Proposal: separate harvesting price into machine cost and separate cost for gleaning. That forces a grower to consider whether gleaning is finanically worthwhile.
The most serious impediments need to be solved through research and development
The “late-Season” problem – ability to harvest the entire Valencia crop – till July 1 if need be.
Utilizing existing machine capacity and further increasing system harvesting capacity
Harvesting logistics – implications of trailer allocations; shifting of the harvest season
Machine improvements – increase recovery percentage to point where gleaning becomes less of a consideration.
The final impediment (#7) is that for some growers the cost savings between hand and machine systems is not large enough. If growers have a lingering concern over tree health, then the cost differential has to account for some level of “insurance” against tree damage concerns.
Goal of MH program: develop systems that reduce “NET” harvest costs.
Unfortunately, the industry currently seems to be caught in a “Catch_22”
Catch 22 ( or the circular argument):
Grower adoption depends on (machine price).
Machine price depends on (harvesting capacity).
Harvesting Capacity depends on (grower adoption).
Another concern bucking against private investment are the sizable capital requirements for surmounting the major impediments (for example, equipment development and abscission registration). If public dollars can be invested to eliminate the impediments, hopefully, the price or cost savings from MH will begin to attract a sufficient number of growers to adopt MH. Once the “momentum” toward adoption starts, the market will take over and drive the rest of the adoption effort.
Criteria for public investment: increase – push to the limit – machine capacity. As machine capacity expands, harvesting price to the grower will fall.

8. Multiplicative impacts
Push machine capacity
BX/HR better groves
* HR/DAY more trailers
* DAY/YEAR abscission
= BOXES/YEAR
Multiplicative impacts
How do we break the “Catch-22” cycle? EXPAND and UTILIZE MACHINE CAPACITY.
Recognize how we can push the capacity of existing machines.
BX/HR = allowing equipment to work in higher yielding blocks. Same machine and operator time to run through a 600 bx/ac block as a 200 bx/ac block.
HR/DAY = having a sufficient number of trailers on hand to allow equipment to operate at least 8 hrs/day.
DAY/YEAR =
Sufficient trailers to operate at least 5, if not 6 days per week through out the season
Growers committing more acreage.
Abscission extending the season
Important: if we can increase 2, if not all 3 factors, there will be a multiplicative effect on BOXES/YEAR.
As BOXES/YEAR increase per machine set, $/bx to harvest goes down.

9. Roadmap for MH Industry Commitment More - Better Acreage Growers
More - Better Equipment
Manufacturers
Trailer Allocations
Processors
Abscission Registration
DOC
Abscission Mgmt Plan
IFAS
Education
Ultimate success of MH will depend on a coordinated, industry wide commitment.
This is not to say that there should a “czar” for MH.
Instead, We need to recognized and acknowledged is that EACH sector of the industry has to play an important role. If one sector falls down, or is not committed to the end goal, the industry’s evolution toward MH is in jeopardy.
Ultimately, the private sector will, as it should, take over the drive the evolution of MH.
However, there are impediments that require sustained “public” investment
Industry Commitment

10. Feasible with Commitment
75¢ - 5 years
Feasible with Commitment
DOC has setup a “balanced score card” to evaluate its spending initiatives. For MH, the scorecard has been reported in terms of acreage.
Acreage is important, but it is not the end goal.
NET cost of harvesting is the metric by which to judge MH advances. Furthermore, it is a metric that will vary by individual grower.
I.E. Grower price will be a function of specific block conditions and grower’s willingness and/or ability to change those conditions to conform with efficient use of MH equipment.
Time is money.
The longer the industry delays the adoption of MH, through the collective actions of individual growers, the longer it will take to achieve the cost reductions that we believe are feasible.