WVU Extension Service: The Orchard Monitor: Committed to the Integration of Orchard Management Practices
April 25, 2005

Upcoming Events


Pheromone Trap Counts Plant Pathology Horticulture



April 26, 7:00 p.m. - Spring In-depth Fruit Meeting at the Alson Smith Research and Extension Center, Winchester, Va. Dr. Mike Orzolek from Penn State University will discuss "High Tunnel Production of Sweet Cherries".  Nic Ellis, Ph.D. student at the Penn State University Fruit Research and Extension Center, will discuss "Effects of Apple and Peach Host Crops on Dispersal of Oriental Fruit Moth".  For more information contact Cyndi Marston at 540-665-5699 or at cmarston@vt.edu.

April 28,  6:00 p.m.
- Tree Fruit Grower Twilight Dinner and Meeting at Gourmet Central (in Hampshire Industrial Park), Romney, W. Va.  Following dinner, WVU Extension Specialists will discuss horticultural issues, weed management, and use of new chemistries for insect and disease management.  For more information contact the Hampshire County Extension Office at 304-822-5013.

May 2 & 3 - West Virginia Farmland Protection Workshop at Canaan Valley Resorts.  Workshop is free, but registration must be received by April 15.  Canaan Valley State Park is offering a package deal which includes lodging the night of May 2, dinner May 2 and breakfast May 3 for $101.  For more information and to register contact Debbie Hovatter at Canaan Valley Institute (800-922-3601 or Debbie.hovatter@canaanvi.org).

May 3, 6:00 p.m. - Tree Fruit Grower Twilight Dinner and Meeting at National Fruit Products Co., Inc., Gerrardstown, W. Va.  To reach the meeting site, take exit 5 (Inwood) off I-81 and travel Route 51 West (towards Gerrardstown) for 1.5 miles to Goldmiller Road.  Turn left onto Goldmiller Road and travel 500 ft to the entrance on the right.  Following dinner, seasonal updates will be provided by Extension Specialists from the WVU Kearneysville Tree Fruit Research and Education Center, and a tour will be provided by David Cosby and staff.  For more information contact the WVU KTFREC at 304-876-6353.


Most apple varieties will be in various degrees of bloom when you receive this newsletter.  Since some varieties will reach petal fall before the next newsletter, those blocks should be inspected within the next two weeks to determine which pests will require control.  Petal fall is a very important stage for insect management because it provides the last opportunity to control some prebloom pests to minimize injury, and numerous other pests can be controlled for the first time at this stage.  Action taken, or not taken, at petal fall can have a significant impact on the success of the overall pest management program.

Rosy apple aphid can cause significant indirect injury to apple fruit in the early posbloom period in orchards where prebloom control was not effective.  As aphids feed within curled leaf clusters, their saliva is translocated to nearby fruits which causes them to remain small and become deformed and unmarketable.  Many orchards experienced substantial fruit injury from rosy apple aphid in 2003.  Conduct a thorough inspection of apple orchards for this insect prior to the petal fall spray application.  Make a 3-minute examination of 5-10 trees per block and count the number of fruit clusters showing curled leaves with live aphids.  Pay particular attention to the center region of trees.  Also, inspect root suckers around the trunk for colonies which could disperse later into the tree canopy.  Apply Provado, Actara, Assail or Calypso at petal fall if an average of one or more infested fruit clusters per tree are found.
Rosy apple aphid fruit injury
European apple sawfly injury on young fruit

European apple sawfly injury on older fruit

European apple sawfly is a localized problem that has increased in some orchards over the past few years.  Adults begin emerging from the soil at pink and females deposit eggs in the calyx end of young fruit from bloom through petal fall. Tunneling by the hatching larva creates a large circular russeted scar that originates from the calyx.  The larva will typically leave the first fruit and tunnel to the core of a second fruit, consuming most of the flesh.  Frass (excrement) will protrude from these injured fruits which will later fall from the tree.  Where white visual traps have been used for adult monitoring, petal fall control is justified if the accumulated  prebloom and bloom capture reaches 3 or more per trap.  Where traps have not been used, control is recommended if fruit injury was  observed last year.  Early petal fall timing usually provides effective control.  Where injury was severe last year, a bloom application is recommended.  Avaunt, Assail and Calypso may be used during bloom as long as bees are not foraging during application and sprays have sufficient time to dry before bees become active.  Petal fall options include these materials, or azinphos-methyl (Guthion), Imidan, Sevin, or Actara. European apple sawfly larva in fruit
Plum curculio adult

Plum curculio is an important direct pest of both apple and peach, causing injury to developing fruit in the early postbloom period.  Adult beetles, which overwinter in hedgerows, trashy fields and woods, usually begin moving into orchards during the bloom stage.  Maximum activity occurs when  temperatures reach 70F and above.  The primary injury results from egg-laying, consisting of a crescent-shaped scar on the fruit surface.  In apples that remain on   the   tree,   most   larvae   do   not  complete development as they are crushed by the expanding fruit.  Larvae successfully complete development in peaches and fallen apples.  Typically, most of the injury from this insect has occurred in apple blocks of mixed cultivars with a wide range in bloom periods.  Injury usually occurs on the earlier blooming varieties while waiting for the later blooming varieties to reach petal fall.  Recommended control options in peach include pyrethroids (Ambush, Asana, Pounce, Proaxis, Warrior), azinphos-methyl (Guthion), Imidan, Actara and Surround. In apple,  recommended options include azinphos-methyl (Guthion), Imidan, Avaunt, Assail, Calypso, Actara, and Surround.

Plum curculio fresh egg-laying injury

Oriental fruit moth adults were first captured in pheromone traps two weeks ago, and biofix was set on April 11 at the WVU KTFREC.  Using a base temperature of 45F and upper temperature of 90F, degree days (DD) should be accumulated from biofix in order to properly time spray applications.  Pheromone traps should be monitored on a weekly basis to determine if control is needed.  Control of the first generation is justified where the pheromone trap capture exceeds 15 moths/trap/week in peach and 30 moths/trap/week in apple.  In peach, an application of pyrethroid, azinphosmethyl (Guthion), or Imidan is recommended at 170-195 DD (10-15% egg hatch).  A second application at 350-375 DD (55-60% egg hatch) may be needed if pest density is high.  In apple, control with an application of Assail or Calypso at 250-275 DD (25-30% egg hatch), or Avaunt, azinphosmethyl (Guthion) or Imidan at 350-375 DD, (55-60% egg hatch).  Application timing for these materials will normally occur near petal fall. 

Through April 24, 131 DD (6% egg hatch) have accumulated since biofix at the WVU KTFREC.

Oriental fruit moth adult

Green peach aphid typically overwinters in this area as wingless females in protected places on the tree and in ground debris.  Aphid feeding on flower parts or on the underside of leaves is usually first observed during the late bloom to petal fall stage.  Infestations are often first detected on leaf clusters attached to the trunk or scaffold limbs in the lower part of the tree.  Feeding on leaves causes them to curl, become yellow, and drop prematurely from the tree.  Feeding on fruit may result in distortion, cracking and drop, especially on nectarine.  Provado and Actara are the most effective treatments and are recommended for control if more than an average of one colony per tree is found.

Pheromone traps should be installed at this time for monitoring codling moth emergence, and at the beginning of May for emergence of tufted apple bud moth, lesser peachtree borer, and dogwood borer.

Green peach aphid colony


March 21 0            
March 28 3 0            
April 4 17 9 0            
April 11 73 720 3            
April 18 51 896 42            
April 25 34 1372 186            

RBLR = Redbanded leafroller; STLM = Spotted tentiform leafminer; OFM = Oriental fruit moth; CM = Codling moth; TABM = Tufted apple bud moth; DWB = Dogwood borer; LPTB = Lesser peach tree borer; PTB = Peach tree borer; AM = Apple maggot.


Apple scab. We recorded our second apple scab infection period of the season last week on April 22 - 23 for 33 hours at 52 F. In addition to apple scab, during the period from tight cluster through second cover your selection of disease management options should include materials with activity against powdery mildew and the rust diseases. Good choices include the sterol-inhibiting fungicides (Nova, Rubigan, or Procure combined with a protectant) or the strobilurin fungicides (Flint or Sovran).

Table 1. Dates and conditions for apple scab infection periods at the WVU - KTFREC, 2005.

No. Date 2005 Hours/ degrees F
1. April 7 - 8 14 hr/58 F
2. April 22 - 23 33 hr/52 F

Fire blight. Conditions favorable for fire blight occurred on April 20th, if wetting occurred on the 19th or 20th. The long range weather forecast predicts cooler temperatures for the next several days, which should reduce the risk for fire blight infections. See our "Current Conditions" Web page for details that are updated at least three times weekly.

Streptomycin reminders: For best blossom blight control, apply Streptomycin just before an anticipated infection, then re-apply it in 4 days if high risk conditions persist. High risk occurs with any combination of three out of the following four criteria: 1) blossoms open, 2) bacteria present on blossom surface, 3) average temperature for the day of 60 F, and 4) sufficient moisture in the form of rain or dew. Note that infection of susceptible cultivars is very likely to occur if all four of these criteria are satisfied. Streptomycin applied after infection can provide acceptable control, however the level of control that is achieved declines with time and declines more rapidly as temperature increases.

Avoid alternate-row-middle programs for fire blight control. If this method is used and if infection conditions occur after the first half spray, follow immediately with the second half spray of streptomycin. Do not exceed 3 - 4 antibiotic sprays per year in order to minimize the chance that the fire blight bacterium will develop resistance to streptomycin. Make blossom treatments strictly on whether an infection is expected or has occurred, not on how severe that event might be.

Peach scab and Rusty spot: The shuck split - shuck fall stage is the time to initiate fungicide applications for managing these diseases on peaches and nectarines. Follow instructions in the 2005 Spray Bulletin for the selection of spray materials for these diseases. For scab control, remember that Bravo is highly effective but is not labeled for applications after the shuck fall stage. Control of rusty spot will be facilitated by adequate control of powdery mildew in adjacent apple orchards.


Boron. As we move to the petal fall stage of fruit development it is time to apply Boron if you have experienced internal corking problems.  Foliar sprays are the easiest method of application, however soil applications have been shown to increase calcium levels in leaf tissues and have been associated with yield increases when tests have indicated a boron deficiency.

Generally, a single application of 3 to 4 pounds per acre of Solubor at petal fall or first cover will maintain Boron levels.  Soil applications are usually 1.5 to 2.5 pounds of actual Boron per acre per year.  Growers are urged to use leaf analyses and soil tests to determine optimum rates and method of application to achieve the greatest impact.

Note:  Do not premix Boron with Calcium Chloride in a small volume of water because Boron will generally precipitate out.  (See pages 135 and 136 of the 2005 Spray Bulletin for more information.)

April Apple Holdings Up 36 Percent from 2004

April 18, 2005. March movement of fresh and processing apples of 20.5 million bushels was up 18 percent from movement in 2004 and 5 percent above the five-year average for March movement, according to the U.S. Apple Association's (USApple) nationwide survey of apple storage facilities. The strong movement is attributed to greater supplies of fresh apples and continued strong demand this season.

Movement of fresh apples from regular and Controlled Atmosphere (CA) storage of 13.1 million bushels during March was 21 percent higher than the March 2004 movement and 5 percent higher than the five-year average for March movement.

Movement of fresh-market apples from CA storage during March was 12.5 million bushels, 24 percent higher than the same time last year, and up 8 percent from the five-year March average.

March movement of processing apples of 7.4 million bushels was 14 percent above 2004 movement and 5 percent higher than the five-year average for March movement.

April 1 U.S. Holdings. Total U.S. holdings of fresh and processing apples on April 1 were 67.8 million bushels, a 36 percent increase from holdings on April 1, 2004 and 21 percent higher than the five-year average of 56.2 million bushels.

April 1 U.S. fresh holdings of 45 million bushels were 41 percent above last year and 22 percent above the five-year average.

Holdings of fresh-market and processing apples in CA storage on April 1 were 61.7 million bushels, a 36 percent increase from April 1, 2004, and 20 percent higher than the five-year average. Fresh CA holdings on April 1 were 37 percent higher than holdings on April 1, 2004, and 18 percent above the five-year average for holdings on that date.

Total processing apple holdings as of April 1 were 22.8 million bushels, 27 percent higher than on April 1, 2004, and 19 percent above the five-year average for that date.

Regional Fresh Apple Holdings.  On a regional basis, fresh holdings on April 1 in the Northeast were 3.6 million bushels, a 6 percent decrease from holdings on April 1, 2004, but 11 percent higher than the five-year average for that date. Southeast April 1, 2005, fresh holdings were 38 percent lower than on April 1, 2004, and 37 percent below the five-year average for that date.

In the Midwest, April 1 fresh holdings were 1.8 million bushels, down 25 percent as compared to holdings on April 1, 2004, and 10 percent lower than the five-year average. Fresh market apples in storage in the Southwest on April 1 totaled 90,346 bushels, a 402 percent increase compared to that date in 2004. However, Southwest holdings were 21 percent lower than the five-year average.

Northwest April 1 fresh holdings were 39.5 million bushels, 55 percent higher than on April 1, 2004, and 25 percent above the five-year average for that date.

Fresh Holdings by Variety.  On a varietal basis, April 1 fresh-market Red Delicious holdings were 18.5 million bushels, a 40 percent increase from that date in 2004, but 1 percent less than the five-year average.

Fresh Golden Delicious holdings of 7.2 million bushels were up 61 percent from holdings on April 1, 2004, and 19 percent higher than the five-year average for that date.

Fresh Granny Smith holdings of 5.3 million bushels on April 1 were up 39 percent from holdings on April 1, 2004, and 57 percent above the five-year average for that date.

McIntosh holdings on April 1 were 1 million bushels, up 8 percent from holdings on April 1, 2004, and up 37 percent from the five-year average.

Fresh Fuji holdings of 5.1 million bushels on April 1 were up 64 percent compared to last year's holdings on that date, and increased 65 percent as compared to the five-year average.

Fresh Gala holdings on April 1 were 2.5 million bushels, up 58 percent from April 1, 2004, levels and 137 percent greater than the five-year average.

Fresh Empire holdings were 842,720 million bushels, a 34 percent decrease from April 1, 2004, levels and 17 percent below the five-year average. 

Source:  The Fruit Grower News, April 2005 online edition. 

The Squeeze is On - Not Just in Apple Juice

Every orchard and every firm in the apple business needs to have a strategy for dealing with the charge from China. For growers, that probably doesn't mean planting more Fuji apple trees.

Right now, China's strong suit - and its weakness - is relying heavily on one product - large, autumn-harvested Fuji apples.

Desmond O'Rourke, the agricultural economist who founded Belrose, Inc., a Pullman, Wash., firm specializing in apple market analysis, spoke about the Chinese challenge to members of the Washington State Horticultural Association in December.

"Beating the Chinese product in the marketplace presents challenges," he said. "In the case of apple juice concentrate, which is a relatively fungible commodity, it will be difficult to beat the Chinese on price.

"In contrast, the fresh apple market offers marketers many opportunities to differentiate their production on the basis of variety, size, region of origin, seasonality, production methods (such as organic), third-party standards, delivery methods, pre- and after-sales services, etc.

"The fresh market also offers opportunities for differentiation through the use of branding, promotion, creation of status or exclusivity, greater responsiveness to retailer or consumer concerns or other extrinsic qualities," he said. "The consumer market in the developed world is likely to continue to splinter and to yield many opportunities for product differentiation."

O'Rourke does not expect the Chinese challenge to go away, or even weaken. 

"At one time or another," he said, "we have become concerned about rising threats from France, Poland, Turkey, Chile and South Africa. However, no country has thrust its way on the world scene so rapidly, so forcefully and on such a scale as has China. The Chinese assault on world apple markets shows no sign of slowing down in the near future."

Chinese production began to soar in about 1990, he said. Then a smaller producer than the United States, with 234 million boxes, by 2000 its production was four times as large as U.S. production. With an annual output of 1.1 billion boxes, its production was larger than all of Europe combined. Today, China produces one-third of the world's apples.

China became an exporter "by default," O'Rourke said. Even with 1.3 billion people, production grew so rapidly per capita that availability rose from half the world average in 1991 to twice the world average in 1999. Chinese apple growers flooded their domestic market, drove down the price and turned outward to relieve the price pressure.

Annual exports of both fresh apples and concentrated apple juice (CAJ) soared. Even with U.S. anti-dumping actions against CAJ imports, Chinese apple exports bounced back. This year, China will surpass both France and the United States to become the largest exporter of fresh apples.

Will Chinese exports continue to grow? O'Rourke said the capacity is there. Even without more trees, Chinese production could grow by another third by 2010 as growers use better methods and increase yields.

The Chinese are also adopting technology such as cold and CA storage and sorting and packing systems that will elevate the quality of Chinese apples and help them compete in global markets.

"It appears likely that Chinese exports of fresh apples and CAJ will continue to grow rapidly in the next few years," O'Rourke said.

They could, in fact, become important world suppliers of applesauce and other fruit beverages.

Strategies used against the Chinese in the past probably won't work. Blocking Chinese product on sanitary or phytosanitary grounds will become more difficult because China, as a member of the World Trade Organization, is both improving quality control and gaining negotiating clout.

For American growers, the option is to "differentiate their product."

For large organizations like major retailers, another option is, "invest in China" and buy more Chinese apples. They will increasingly look to China for cheap, quality product, since China has a third of the world's apples and half its pears.

The Chinese need the investment money, O'Rourke said. The downside of that strategy is that China remains a non-market economy, and its commercial system "involves many pitfalls."

For American growers facing marketers who source product globally, the Chinese economic system may also be their ally.

Source:  The Fruit Grower News, April 2005. 

USDA to Buy up to 78 Million Pounds of Apple Products 

April 22, 2005. USDA plans to purchase up to 78 million pounds of apples and apple products to be donated to child nutrition and other domestic food assistance programs, according to an announcement made April 21 by Agriculture Secretary Mike Johanns.

"This purchase will provide our federal food program recipients with tasty and nutritious products," Johanns said.

Since the beginning of the current fiscal year, which began Oct. 1, 2004, USDA has purchased 52.4 million pounds of apples and apple products, including fresh apples, canned and frozen apple slices, apple juice and applesauce. USDA purchased 64.2 million pounds of apples and apple products in FY 2004 and 83.8 million pounds in FY 2003.

For more information, visit www.usda.gov.

Source:  The Fruit Grower News, April 2005 online edition.


Trade and brand names are used only for the purpose of information, and the West Virginia University Extension Service does not guarantee nor warrant the standard of the product, nor does it imply approval of the product to the exclusion of others which may also be suitable. The West Virginia University Extension service assumes no responsibility in the use of hazardous chemicals.

Individuals requesting an accommodation at a meeting because of a disability should contact one of the Extension Specialists at the WVU Kearneysville Tree Fruit Research and Education Center at 304-876-6353 at least five days prior to the event.

Helping you put knowledge to work

P. O. BOX 609
PHONE:  304-876-6353
FAX:  304-876-6034
WEB:  www.caf.wvu.edu/kearneysville

The West Virginia University Cooperative Extension Service, U.S. Department of Agriculture, West Virginia County
Boards of Education and County Commissions Cooperating.  Equal Opportunity / Affirmative Action Institution

Top of PageWVU Extension ServiceWest Virginia University