Asian Pear Production Field Performance of Asian Pear Cultivars in the Hot, Humid Conditions of the Mid-Atlantic Region of the United States CS Walsh, JM Harshman, M Newell, A Wallis, GR Welsh and A Barton-Williams University of Maryland College Park, MD USA
Asian pear production Three Major Limitations Limit Pear Production in the Eastern USA 1. Lack of precocity and productivity 2. Fire Blight disease, caused by the bacterium Erwinia amylovora 3. Quince Rootstock is not winter hardy
Flemish Beauty Pear Pears of New York, 1921 At one time Flemish Beauty was a leading commercial variety in pear regions of eastern America, but problems with the scab fungus and resulting blighted trees were too great.
Asian Pear Trials Asian Pear Trials in Maryland 1. 1985 Planting tested 7 cultivars as pollenizers for Magness pear 2. 1989 Southeastern Zonal Trial with 13 cultivars set at each location 3. 1990 Cultivar and Rootstock Trial 4. 2002 Certified Organic Apple and Pear Orchard 5. 2010 Replicated Regional Trial
Asian pear production Can Asian Pears Overcome these Limitations? What are their horticultural characteristics? How about field tolerance to fire blight and other pests?
Asian pear production Asian Pears are precocious. Trees frequently flower in the year after planting, and can crop heavily in the second or third leaf. Due to their heavy bloom, trees are more likely to crop even when there is a late-spring frost.
A Flowers are borne on spurs and laterals Flower thinning by hand or MaxCell is commonly used to produce the required large-sized, sweet fruit
Tree vigor and precocity Trees grow vigorously, but since they are precocious, productive, and easily pruned, they can be maintained in a 3m by 5 m spacing. Without heavy hand thinning, trees overfruit, and limbs will break out.
Asian Pear Yields, WyeREC Variety Yield (kg per tree) 1992 1993 1994 1995 Shinseiki 20.7 10.9 19.8 13.2 Hosui 30.5 24.5 30.7 13.9 20th Century 22.6 9.7 24.3 6.0 Tsu Li 1.1 15.7 29.1 15.0
Hosui trees planted 3 x 5 m Taken in early-august, sixth leaf which was the fourth year of cropping
Asian pear production Can Asian Pears Overcome these Limitations? What are their horticultural characteristics? How about field tolerance to fire blight and other pests?
Fire Blight Symptoms 1. Necrotic Foliage (Blossom Blight) 2. Shepherd s Crook (Shoot Blight) 3. Hail Damage (Trauma Blight)
Asian Pear Evaluation Fire Blight August Hailstorm, Blight Inoculation Trees rated the following June for damage using a 1 to 5 scale: Full canopy, healthy foliage 5 Full canopy, pale foliage 4 > Half the canopy remaining 3 < Half the canopy remaining 2 Dead tree 1
Asian Pear Production Field-Tolerant Pears Shin Li (CA hybrid) Daisu Li (CA hybrid) Shinsui Olympic (Korean) Magness (USDA) 1985 1989 Fire Blight Rating ---- 4.5 ---- 4.4 ---- 4.2 ---- 4.0 4.0 ----
Asian Pear Production Partial Tolerance Magness 1985 1989 Fire Blight Rating 4.0 ---- Chojuro Niitaka Okusanichi Shinseiki Shinsei Shinko 3.6 3.2 3.4 3.4 3.2 ---- 2.5 3.2 ---- 3.1 ---- 3.1
Asian Pear Production Least Tolerant Magness 1985 1989 Fire Blight Rating 4.0 ---- Hosui Choju Kosui Seigyoku Ya Li T se Li ---- 2.7 ---- 2.3 ---- 2.2 2.2 ---- ---- 1.6 1.6 ----
Asian Pear Production Why do we frequently see untreated Asian pear orchards escape infection, when adjacent Gala and Fuji trees have >10 strikes per tree? 1. Bloom usually occurs prior to the GDH triggers in the MaryBlyt model. 2. Insect tolerance decreases likelihood of disease transmission
TRANSITIONAL ORGANIC IPM PROGRAM Yield and quality similar in Asian pear from organic and conventional plots. Producing clean organic apples was far more difficult in the same trial
Organic vs IPM YIELD DATA Blue = IPM Red = Organic Olympic and Atago Asian pear yields were similar under both systems Organic Yields in Apple were less than Apple produced under IPM Significant Interactions: Enterprise, Fuji and Ni itaka
Asian Pear Production Cultivar and species differences in response to copper and sulfur used in the organic schedule likely caused the interactions we observed. Pears tolerate sulfur, apples do not. Disease-resistant apples appeared to be particularly sensitive to sulfur.
Asian Pear Production Despite the potential for organic production using a Sulfur/Surround schedule, US growers have been slow to begin planting Asian pears To address this, we organized a replicated regional trial in 2010
Replicated Asian Pear Trial in the Eastern USA 1. Belchertown, MA 2. Highland, NY 3. Hunterdon, NJ 4. State College, PA 5. Queenstown, MD 6. Kearneysville, WV 7. Urbana-Champaign, IL 8. Raleigh, NC 9. Auburn, AL
Replicated Asian Pear Trial Locations Preliminary results at Queenstown MD Some Asian pear cultivars succumbed to fire blight, but many cultivars like Olympic showed 100% survival Tree survival data were predictable from the ratings made a decade earlier following an August hailstorm
Replicated Asian Pear Trial Locations Preliminary results in MD After the fifth leaf, only 40% of the European pear trees were still alive Except.. Potomac a Blight-tolerant USDA release. Reminiscent of Magness, they are vigorous and unprecocious.
Replicated Asian Pear Trial Locations Preliminary results at Queenstown MD Some Asian pear cultivars like Ya Li succumbed to fire blight, but many cultivars including Olympic showed 100% survival Tree survival data to blossom blight at Wye paralleled the ratings made a decade earlier following an August hailstorm at Keedysville
Replicated Asian Pear Trial Locations How do they taste? Taste testing was conducted in early- October, 2013 and again in 2014 Asian pears were popular with both Asians and non-asians
Replicated Asian Pear Trial 2014 Taste Testing Cultivar Firm (kg) SSC () Buy %? Olympic 5.2 14.9 87 Yoinashi 4.5 14.3 80 Ya Li 4.8 11.5 72 Hosui 4.4 12.4 63 Kosui 5.1 13.3 63 Atago 5.5 11.6 56 Shinko 6.4 12.4 45 Isiiwasi 4.7 12.4 44
Yoinashi November, 2014
Olympic November, 2014
Replicated Asian Pear Trial Locations 2014 - Internal breakdown in Olympic? We saw a significant amount of internal browning (breakdown). Oddly, it did not affect fruit flavor but the fruit could not be sold. This was tentatively attributed to the dry, sunny weather in September, and unusually slow maturation of the fruit that delayed harvest.
Asian Pear Production Thanks now to the sponsors of this project. Harry Hughes Center for AgroEcology The Maryland Agricultural Experiment Station s Competitive Grants Program