Competitive pear orchards
Precocious, dwarfing rootstocks are critical.
OSU technician Janet Turner demonstrates how the Horner pear rootstock selections that are being evaluated at Hood River vary tremendously in size.
An analysis of the cost of producing fresh pears in a standard medium-density orchard illustrates the urgency of adopting more efficient and profitable systems for growing pears, reports Dr. Clark Seavert, agricultural economist with Oregon State University.
The analysis shows that in a standard pear orchard, with 272 trees per acre, production costs average $222 per bin, compared with a likely return of $150 per bin. The analysis assumes that production begins in year four with three bins of fruit per acre, peaking at 40 bins in year nine. Such an orchard planted now would never recoup the investment, Seavert calculates.
Growers often look at the cash flow, and fail to take into account the cost of establishing the orchard, he said. "If you borrowed all the dollars, you would have to have at least 8.5 or 9 percent return on investment, otherwise, you're subsidizing the orchard."
Seavert figures that the return on investment over the 20-year life of a traditional orchard is about 7 percent, but that can be increased to 8.5 percent by harvesting the crop a year earlier. Early cropping is critical in a high-density planting because of the high cost of trees.
Seavert further calculates that a grower can increase the return on investment to 11.5 percent by producing targeted fruit (pears in the sizes and grades that return the most). The return on investment can increase to 19.5 percent if the grower also increases the packable yield by 50 percent.
OSU's Mid-Columbia Agricultural Research and Extension Center at Hood River has an experimental pear block that demonstrates what Seavert calls the Competitive Orchard System. It is designed to generate a 15-percent return on investment to the grower by lowering costs and boosting returns.
Seavert said production costs of $222 per bin are unacceptable today. As costs increase, growers have to move beyond the standard orchard with three-dimensional trees and plant more --efficient and profitable systems.
"We have to do something now, and do these things as quick as we can, because there are a lot of people around the world growing pears cheaper than we can, and when you look at the energy used and carbon footprints, we have to be much more efficient in what we're doing," he told growers at a summer field day. "If you're not in the top 30 percent of the growers in the world, you're going to have a hard time making it."
The Competitive Orchard System block was planted in 2006. Trees are spaced four feet apart with 12 feet between rows (a total of 907 trees per acre) and are trained on a vertical trellis with the goal of creating a flat fruiting wall, rather than a three-dimensional canopy.
Three different types of material were used: finished nursery trees; rootstocks --budded in place; and bench-grafted rootstocks.
Technician Janet Turner said the bench-grafted trees are producing nice, weak wood, and she thinks the vigor is better balanced than in the budded rootstocks, which have not branched well. Next year, she will notch the trees and apply Promalin (gibberellic acid and cytokinins) to encourage them to produce weak branches.
Tom Auvil, research horticulturist with the Washington Tree Fruit Research Commission, who is involved in the trial, said the finished nursery trees grew very well, and most were 11 feet tall by the summer of the second growing season. "Our challenge, though, with the finished trees, is dealing with the larger limbs. In these very formal training systems, the planting material may have a pretty big influence on our ability to establish and maintain these thin canopies."
The limbs are tied to the wires, rather than being headed or spread, so that the trees will produce fruit as quickly as possible. Auvil said the limbs are tied down to the wires, rather than tied up, to create better light distribution between the wires. If limbs are tied up to the wire, they tend to be stronger and develop more upright suckers, he said. One of the keys to the system is to quickly remove upright shoots growing from limbs that have been trained to the wire.
The varieties in the block are Bartlett, Bosc, d'Anjou, Comice, Black's Pride, and an unnamed variety, and they're on 17 different rootstocks. Some trees bore a few pears this season, and Turner expects the planting will generate its first crop in 2008. She hopes fruiting will slow down tree growth.
Seavert said finding a precocious, dwarfing rootstock for pears is critical to the success of the Competitive Orchard System, which must produce a crop of 15 bins per acre of target fruit in the third year and reach full production of 50 bins per acre by year six. If that can be achieved, the establishment costs of $12,300 per acre can be recouped by year five.
Seavert defines "target fruit" as pears that pack out 90 percent U.S. No. 1, 6 percent Fancy, and 4 percent culls. The pears also need to be in the size ranges that bring the best returns, with 25 percent of the fruit being size 70, 50 percent size 80, and 25 percent size 90.
Under this scenario, growers can expect to receive returns of $300 per bin, while costs at maturity will be reduced to $78 a bin in because of increased efficiencies and the --ability to pay off the establishment costs early in the life of the orchard, Seavert said.
The system lends itself to mechanical harvesting and, ultimately, robotic harvesting, but, in the meantime, growers should find it more efficient for hand pickers, Turner said, as all the fruit is within easy reach. Pruning and training can be done from a platform.
Rootstocks in the trial include: Pyrodwarf; Old Home by Farmingdale 97, 87, 69, and 11; FI 12, 14, and 15 and Fox 11 from Italy; Q 29857, 29858, and 29859 from Kazakhstan; 517-9 and 708-13 from East Malling, United Kingdom; Horner 4 from Oregon; Pyriam and P.2535 from France; and Betulaefolia 2291.