Potential Economic Value of Abscission Citrus Mechanical Harvesting Field Day & Workshop Immokalee, FL April 18, 2007 Fritz Roka University of Florida - SWFREC Primary focus of this field day is on abscission – the loosening of the fruit detachment force – and its anticipated effect on mechanical harvesting. One specific compound, CMNP, is working its way through the EPA registration process. Between $7 and $11 million dollars will be spent in the registration process alone. Another $300 to $400,000 of state dollars are being spent annually through the Citrus Initiative to screen for other abscission compounds and to develop a management strategy for CMNP. In addition to these dollars are the University of Florida salaries of the faculty and staff who are working on this project. While significant resources are being spent to develop and register an abscission compound, there is strong evidence suggesting economic benefits that will more than offset the development and registration costs. The purpose of this presentation is to underscore the potential economic benefits we expect from an effective abscission compound. The lack of an effective abscission compound is the single biggest hurdle standing in the way of mechanical harvesting from becoming the dominate and a more cost efficient harvesting method.

MH Goal: lower “net” harvest costs Hand Harvest in: Pick & Roadside ($/bx): Florida $1.60 - $2.00 / bx Sao Paulo, BR $.50 - $.75 /bx Goal of any mechanical harvesting system is to reduce “net” harvest costs. In the short-term, we will evaluate the economic success of a MH system against the current costs of hand harvesting crews. Over the long-term, MH systems must reduce costs to become more in-line with its greatest citrus competitor – Brazil. By measuring “net” costs, we account for all changes that will have to occur as the industry shifts from hand crews to mechanical harvesting systems. That is, the savings in harvest costs must be great enough to offset any increases in costs either to grove production or juice processing operations.

CCSC TSC $250K (?) Two systems – Continuous Canopy Shake & Catch (CCSC) and Trunk Shake & Catch (TSC) – have been the dominate systems in FL citrus to date. Larger growers are taking the initiative and choosing CCSC because of its higher capacity and perception that it does less damage to the trees. CCSC systems cost ~$1 million per set. TSC systems cost ~$250,000, but none have been officially sold. $1M+

Canopy Shaker with Pick-up A third system involves a tractor-drawn Canopy Shaker (CS) that puts fruit on the ground. Such a system will evolve quickly if a “pick-up” machine is perfected. This system is well suited to small growers and can accommodate non-uniform grove conditions. The high capital investment required by mechanical harvesting systems creates some inflexibility not found among hand harvest crews. In other words, with a mechanical system some costs are going to incurred even if no harvesting occurs. The economic potential of mechanical harvesting, however, resides with economies of scale. As the equipment more effectively utilized, the unit cost of harvesting can be driven down. Machine harvest Flexibility NO Scale Economies YES

Lower Cost through Higher Capacity Harvested Boxes/Season = BX/HR * HR/Day * Day/Season Economies of scale achieved through increased capacity. Increasing harvested boxes per season with a given amount of investment in a mechanical harvesting system can be achieved in one or in combination of 3 ways. Increasing Bx/Hr, Hr/Day, and Day/Season. Lets examine how abscission can influence each of these pathways.

Abscission Impact (BX/HR) Faster harvest speed Higher recovery percentage (?) Based on some preliminary data, we believe that abscission will allow equipment to increase harvest speeds by at least 25% without sacrificing fruit removal efficiencies. Important to note that faster harvest speeds are only an economic benefit if there are sufficient trailers allocated to the site. We are exploring a working hypothesis that abscission may improve overall fruit recovery. Without abscission and in prepared trees, trunk and canopy shakers can catch 90% of the available crop in the tree. Abscission should facilitate fruit removal and thereby lessen “fruit-slinging”, allowing fruit to drop straight down onto the catch frame. To date, we do not have data to support this contention, but more field trials are being planned and the higher recovery may be achieve through better machine operation with abscission.

Abscission Impact (HR/Day) ~Less machine force, ~Fewer breakdowns, ~Increased runtime % Runtime is the percent of time that the system is “actively” harvesting fruit. Runtime decreases with breakdowns. Since abscission loosens the fruit, less machine force will be necessary, and thereby lessen the likelihood of machine wear and breakdown.

Abscission Impact (Day/Season) Access to entire Valencia acreage Earlier start date (i.e. October) More acreage if grower perceives less damage. The biggest impact on mechanical harvesting from abscission is the ability to harvest through out the Valencia season. Without abscission, MH systems have to shut down once the immature fruitlets reach 1” in diameter. The shaking forces required to remove mature fruit begins to significantly impact the green, immature Valencia fruitlets once the fruitlets grow larger than 1’ in diameter. With abscission and the selective loosening of just the mature fruit, shaking forces can be sufficiently lowered. This mature fruit is removed without significant losses of next year’s Valencia fruitlets. With abscission, MH equipment can operate at least 4, if not 6, additional weeks. Because abscission loosens the mature fruit and less machine energy is required, we expect to see less cosmetic damage to the trees from MH with abscission. With less visible damage, more growers may be willing to commit their acreage to MH – further increasing overall equipment efficiencies.

The Multiplicative Effect $1.60 When two, or even three, factors are enhanced the impact on scale economies becomes multiplicative. Shifting from the blue to green line may be achieved by operating in more productive blocks and increasing harvest speed. As we extend the harvesting season and increase the number of acres that are MH, units costs can be cut in half, (~$1.35 to less than $.60 per box). If abscission allows equipment to harvest more loads per day and extend the season by at least 400 hours and the resulting drop in unit harvesting costs is 50 cents, then the value of abscission is 50 cents multiplied by the total number of boxes harvested – including all the boxes harvested during the early and mid season. Why? – because abscission fundamentally changed the entire cost structure of mechanical harvesting.