Pears Are Like Apples: So Why Aren t We Growing Them in High Density

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1 Pears Are Like Apples: So Why Aren t We Growing Them in High Density The Challenges with Pears Slow to begin production (Plant pears for your heirs) Low Mature Yields - Apples have higher yields thus most growers choose to plant apples. Poor fruit set Fire blight Pear Psylla Modest or Low Prices Terence Robinson Dept. of Horticulture, Cornell University, Geneva, NY USA Solutions for the Production Problems of Pears Higher tree densities Better rootstocks New varieties with fire blight resistance or new varieties for high priced market niches Adoption of apple tree management Improvement of fruit set and thinning i Most High Density Pear Orchards use Quince Rootstocks The Challenges with Quince Rootstocks in NY Quince is susceptible to cold damage in some years in New York State. Quince is susceptible to pear decline and fire blight Most pear orchards are not irrigated What is the optimum planting density? 2 trees/acre 4 trees/acre 1

2 The Variety Dilemma: Traditional Varieties or New Fire blight Resistant Varieities Traditional Varieties:,, Anjou, Comice, Seckel Fire Blight resistant varieties: i Harrow Varieties - Harrow Crisp, Harrow Sweet, Sundown USDA varieties Magness, Potomac, Blakes Pride, Sunrise, Shennandoah, Gem NY Pear Systems Trial A 4 acre field trial was planted at Geneva, NY in Varieties (,, Taylors Gold Comice, Concorde). 5 Rootstocks (seedling,,,, Pyro 2-33, Quince A) 4 training systems were used ranging in density from 242-2,178 trees/acre. Tree Den. Spacing Initial Heading System (trees/acre) (ft) Height (inches) Central Leader x Vertical Axis x Tall Spindle 98 4 X 12 6 Super Spindle x 1 6 Traditional Central Leader Spacing 1X18 Conduit support pole but no trellis Leader headed each year Branches tied down to 45 in third year. Vertical Axis Spacing 6 X 14 Conduit support pole and single wire trellis. Leader headed at planting. Branches tied down to 9 at end of second year. Large branches removed with a bevel cut. Tall Spindle Spacing 4 X 12 Conduit support pole and single wire trellis Leader not headed at planting. Branches tied down below horizontal (135 ) at the end of the second year. Super Spindle Spacing 2 X 1 Leader not headed at planting. Branches tied to trellis wire in first and second year. Large branches removed with a bevel cut. Fruitful branches shortened to fit into space. 2

3 Effect of Planting Density and Rootstock on Tree Size Trunk X-Sect. Area (cm 2 ) Pyro 2-33 Quince A Effect of Training System on Yield /Tree Yield (kg/tree) 5 45 Central Leader (598 trees/ha) Vertical Axis (1283 trees/ha) 4 Tall Spindle (2244 trees/ha) 35 Super Spindle (5382 trees/ha) Year Trunk X-Sect. Area (cm 2 ) Pyro 2-33 Yield (kg/tree) 5 Central Leader (598 trees/ha) 45 Vertical Axis (1283 trees/ha) 4 Tall Spindle (2244 trees/ha) Super Spindle (5382 trees/ha) Year Effect of Training System on Yield /Ha Yield (t/ha) Central Leader (598 trees/ha) Vertical Axis (1283 trees/ha) Tall Spindle (2244 trees/ha) Super Spindle (5382 trees/ha) Effect of Training System and Rootstock on Cumulative Yield /Ha Cumulative Yield (t/ha) Pyro 2-33 Quince A Year Yield (t/ha) Central Leader (598 trees/ha) Vertical Axis (1283 trees/ha) Tall Spindle (2244 trees/ha) Super Spindle (5382 trees/ha) Cumulative Yield (t/ha) Pyro Year Effect of Planting Density and Rootstock on Light Interception (1:1 ratio of tree height to between row width) 8 (%) Light Interception Effect of Planting Density and Rootstock on Cumulative Yield Efficiency Cum. Yield Eff. (kg/cm 2 TCA) Cum. Yield Eff. (kg/cm 2 TCA) Series Pyro 2-33 Quince A Pyro

4 Effect of Planting Density and Rootstock on Average Fruit Size Av. Fruit Size (g) Av. Fruit Size (g) Pyro 2-33 Quince A Pyro Effect of Rootstock and Cultivar on Tree Survival al (%) Tree Surviva Pyro2-33 Quince Taylors Gold Rootstock Options Pyrus communis OHF 97, 87, 69, 4, 217, 513 BP1, 3 Pryodwarf, Pyro 2-33 Horner Pyrus calleryana Pyrus betulafolia Cydonia oblonga (Quinces) Quince A Quince C Quince BA29 Quince Sydo Quince Eline Option 1: Tall Spindle Tree Density ~12 trees/acre Spacing: 3 ft X 12 ft Rootstock: OHF 87, Pyro 2-33 Trellis: Three or four wire trellis with 12 posts Pruning: Leader not headed at planting, then branch renewal (remove branches larger than ¾ inch diameter. Feathered tree Branches tied down below horizontal (135 ) early in the second year. Plant Growth Regulators and/or trunk ringing to induce cropping in the second and third years. Option 2: Bi-Axis, Tri-axis Planting Density: 98 trees/acre Spacing: 4 ft X 12 ft Rootstocks: OHF 87, Pyro 2-33, Trellis: 4 wires with 12 ft posts 2 stem tree from nursery Short fruiting branches without limb bending. Renewal pruning to eliminate larger branches (>3/4 inch) Short pruning (cutting back fruiting branches to a spur 4

5 Option 3: Quad Axis in a V Tree density: 185 trees/acre Spacing: 2 ft X 12 ft Rootstocks: OHF 87, Pyro 2-33, Trellis: A low V-trellis with 3 wires per side 4 stem trees from the nursery 2 stems on each side of the V- trellis with bamboo training sticks Short fruiting branches and spurs. Eliminate branches Short pruning (cutting back fruiting branches to a spur Option 4: Super Spindle Tree density: 2-4 trees/acre Spacing: 18 inches X 1 ft Rootstocks: OHF 87, Pyro 2-33, Quince C, Quince A Trellis: 4 wire Eliminate branches Short pruning (cutting back fruiting branches to a spur 5

6 Key New Management Strategies for Pear No heading of the leader at planting Tying down branches in year 1 or 2 Renewal pruning (no permanent branch structure) Root pruning Trunk Ringing Growth thregulators Option 5: V-Tall Spindle Pruning or branch bending with Pear Traditional pear management uses pruning to manage pear branches when planted on Quince rootstocks With Pyrus rootstocks limb bending is useful to induce cropping and manage branch vigor In apple it is common to tie down branches With Pear it is common to stub back branches Branch Renewal or Permanent Branches Permanent branch structure is common on wide spaced central leader trees Branch renewal is critical to management of high density pear orchards Simple and Inexpensive Platforms $25, $12,5 6

7 Root pruning to control Vigor Trunk Ringing to induce Flowering Mechanical Summer Pruning to Reduce Labor Cost Growth Regulators Maxcel for Chemical Thinning(1-15ppm) Promalin to improve set ReTain to improve set GA3, 4+7 to improve set after a frost Prohexadione-Ca to improve set (risk of reduced return bloom) Fall foliar Urea (2-4%) to improve fruit set Boron in pink bud stage to improve fruit set NAA during the summer to improve return bloom Harvest Mechanization Harvest labor represents 1/3 of the annual labor costs Harvest labor is becoming increasingly more expensive and less a Harvest with a multi-level platforms Pear scuffing is a problem with conveyer belt machines The Wafler platform or the bandid Express that have hand movement of the fruit to the bin have less scuffing. Also ladders are a liability Labor can be reduced 3-4% in a pear orchard 7

8 Preliminary estimates of harvest assist machine performance, cost per bin and labor savings per bin Number Bins Acres/ Bins/ Cost of Cost/bin Labor Machine of Pickers per Day Season Season Machine harvested Savings/bin Human w Ladder ~$12.5 $.4 $ Platforms (Blosi) ~$6, $ 3.9 $6.25 DBR ~$15, $ 9.76 $6.25 Picker Tec ~$25, $16.27 $6.25 Pluck-O-Trac ~$8, $ 3.47 $6.25 Argiles ~$125, $ 5.1 $6.25 Bandit Xpress ~$5, $ 3.25 $6.25 Wafler ~$5, $ 2.4 $6.25 The possibility of reducing labor costs by combining the Tall Spindle system with partial mechanization Traditional CL Trees Tall Spindle Trees Labor Inputs (1 bu/ac with ladders) (15 bu/ac with machines) Dormant Pruning 5 hours/acre 2 hours/acre Tree Training 1 hours/acre 1 hours/acre Hand Thinning 6 hours/acre 3 hours/acre Summer Pruning 4 hours/acre 1 hour/acre Total Pre-harvest 16 hours/acre 61 hours/acre Harvest 75 hours/acre 7 hours/acre (6 bins/person/day) (1 bins/person/day) Total annual labor input = 235 hours/acre 131 hours/acre Conclusions You can reduce tree size of trees on Pyrus rootstocks by planting high tree densities. (The highest density systems had trees about 6% the size of the lowest density system after 8 years). You can increase yields by planting high tree densities. (The Super Spindle was 5 times as productive as the traditional Central Leader system which was the least productive). OHF 87 or Pyro 2-33 are both good rootstock options for high density pear orchards Increasing tree density resulted in smaller fruit size. (Thining and irrigation will be essential to manage fruit size) Apple management strategies can improve early yield. (Tying limbs down, using PGR s to increase flowering and fruit set) Apple tree pruning can help with long term canopy management. (Limb renewal pruning, root pruning, ringing or growth regulators) The best option with Pyrus rootstocks appears to be the Tall Spindle (3X12 feet) or Bi-axis Tall Spindle (4X12 feet) Fire blight resistant varieties offer an opportunity for pear growers. Questions? Thank you for your attention 8