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 Be vigilant and scout for apple scab! Photo: K. Peter, Penn State
May 26, 2017

Diseases for the fruit grower radar and their management strategies are discussed as we wrap up May and begin June.

Too late to manage peach leaf curl when symptoms are present. Photo: K. Peter, Penn State
May 26, 2017

Peach leaf curl has caught many folks off guard this year. Tips for preventing the disease next season are discussed.

Conditions are favorable for fire blight spread: be alert! Photo: K. Peter, Penn State
May 19, 2017

Beware of fire blight and bacterial spot conditions! Ideal conditions have been present for bacterial diseases to be problematic. Growers are encouraged to scout for fire blight.

Protect any trees still in bloom: Fire blight conditions ideal April 29 through May 2. (Photo: K. Peter)
April 28, 2017

Conditions are optimal for fire blight, apple scab, and rust infections. Growers are encouraged to keep trees protected. Other diseases for the fruit grower radar are also discussed.

Be proactive about fire blight management: Let’s not repeat 2014. (Photo: B. Lehman)
April 21, 2017

Conditions are favorable for fire blight and apple scab. Additional tools for the fire blight management toolbox are discussed.

Control for fire blight and apple scab is critical during bloom. (Photo: K. Peter)
April 17, 2017

Bloom is well underway in parts of PA and MD. Fire blight and scab disease conditions are in full force now. Growers are encouraged to protect trees.

Growers need to be on alert for apple scab infection period this week. (Photo: K. Peter)
March 28, 2017

Due to the presence of green tip on early varieties of apples combined with rain and mild temperatures occurring this week, we are in our first apple scab infection period for 2017.

March 10, 2017

Penn State Extension held nine regional educational meetings for commercial tree fruit growers this winter.

Dormant copper sprays are encouraged to help keep diseases in check. (Photo: K. Peter)
March 10, 2017

Consider applying dormant sprays soon to manage fungal and bacterial diseases this season.

March 7, 2017

The updated Penn State Extension Spray Record-Keeping Spreadsheet for apples, pears, peaches, and cherries is now available from Penn State Extension.

Copper sprays need to be applied prior to bud swell to manage peach leaf curl. (Photo: K. Peter)
March 3, 2017

Depending on your location, the warm weather over the last few weeks may have pushed some fruit trees along. For disease management, consider applying dormant copper and urea sprays soon.

Moldy core in Red Delicious. (Photo: K. Peter)
January 20, 2017

Moldy core is characterized by the growth of fungus mycelium within the apple fruit seed cavity, without penetration into the flesh of the fruit.

G.935 is replant tolerant, but is susceptible to some latent viruses, highlighting the importance of choosing rootstocks that best fit your own unique orchard conditions. Photo by Rob Crassweller
December 27, 2016

I spent most of the summer writing a review paper on apple rootstocks and came across quite a bit of information that might be of interest to commercial fruit growers.

A declining tree with bark removed from graft union to show necrosis. Note numerous rootstock suckers. (Photo: K. Peter)
December 5, 2016

There is a mystery surrounding rapid apple decline/sudden apple decline of young, dwarf apple trees. For the last several years, there have been many reports in Pennsylvania and, most recently, in the Northeast and states south about unusual sudden decline of young, dwarf apple trees.

Be sure to remove cankers from trees when pruning. (Photo: K. Peter)
December 5, 2016

Sanitation is the best offense for disease management, especially when it comes to canker removal.

Take care of fallen scabby leaves to prevent scab infection in 2017. (Photo: K. Peter)
October 28, 2016

Growers can get a jump on disease management for the 2017 season this fall. This month’s article will be a review of tips to manage apple scab, peach leaf curl, and cherry leaf spot.

Bitter rot spores on the surface of the lesion arranged in a concentric ring. (Photo: K. Peter)
September 30, 2016

There have been many reports of bitter rot on apple while fruit are being harvested. With Mother Nature recently dumping a ton of rain, which will have washed off any plant protection materials, growers are encouraged to apply protectants to apple varieties that have yet to be harvested. Tips for identification and late season management are discussed.

If ripe fruit are not kept cold, Rhizopus rot can take over very quickly. (Photo: K. Peter)
August 26, 2016

Management strategies are discussed for mitigating the postharvest disease Rhizopus rot on peaches and nectarines.

Protect your fruit: bitter rot on apple can wreak havoc in the orchard. (Photo: K. Peter)
August 26, 2016

A review of managing pre- and postharvest apple fruit rots is discussed. Alternative rot management strategies are included.

Protect peaches and nectarines from brown rot (Photo: K. Peter).
July 29, 2016

With peach season in full swing, a review of management strategies for controlling brown rot is discussed.

Bacterial spot on peach leaves still needs to be managed despite no fruit on the tree. (Photo: K. Peter)
July 1, 2016

The latest information that growers need to know for apple scab, fire blight, sooty blotch and flyspeck, rots, bacterial spot, and cherry leaf spot.

The PSU Tree Fruit Path Lab is in need of 2016 fire blight samples. (Photo: K. Peter)
July 1, 2016

The Tree Fruit Pathology Lab at FREC is seeking fire blight samples again this season from around the state of Pennsylvania in commercial orchards and home landscapes for evaluation for antibiotic-resistant strains of the bacteria and other projects. If you have fire blight present in your orchard/yard, please contact Dr. Kari Peter for instructions for sampling.

Orange rust stunting black raspberry plant. Note the “spindly” elongated shoots. Photo credit: Mike Ellis
July 1, 2016

We all get a little rusty as we get older, but one thing that we don’t want to see getting rusty is our brambles. There are several rust diseases that affect brambles. I’m just going to focus on orange rust, which is the most important rust disease in the northeast. We are definitely seeing a bit of orange rust this year, with the cool wet springs. You’ll see this disease on blackberries, black raspberries and purple raspberries. Orange rust does not affect red raspberries.

Photo 1. Brown marmorated stink bug hatched eggs, first instar and freshly molted second instar nymphs. Photo: Greg Krawczyk
June 17, 2016

We continue to observe a strong presence of codling moth adults in pheromone traps placed in commercial apple orchards. Despite the codling moth developmental model suggesting the end of the codling moth egg hatch period (95% eggs hatched by June 25), the presence of moths in the traps in the next few weeks still warrants extended management activities.

MyIPM-NED app: disease management for apples, pears, cherries, and cranberries at your fingertips.
June 3, 2016

A new smartphone application, called MyIPM-NED, was developed to promote integrated disease management for apples, pears, cherries, and cranberries and is available for free for Android and iOS devices. These apps are also able to be used on tablets, as well.

The release of overwintering apple scab spores will be peaking soon: protect your trees. Photo: K. Peter
April 29, 2016

After a dry April, rain has crept into the forecast making conditions ideal for apple scab, fire blight, and cherry leaf spot. Other diseases to keep an eye for management are powdery mildew and bacterial spot. For those who had their stone fruit crop frozen out in April, disease management is still needed. Disease infection periods are being posted for regions in Pennsylvania and Maryland.

Botrytis cinerea sporulation on a ripe strawberry.  Scott Bauer, USDA Agricultural Research Service, Bugwood.org
April 29, 2016

Strawberries are blooming, the rain is falling and it’s warming into the 60’s and 70’s—and as a plant pathologist, all I see is Botrytis spores dancing about the farm. We have already started to see Botrytis popping up on stem tissue and flower petals. Scouting for the pathogen in your fields will help inform you whether you need to spray.

Oriental fruit moth larva(e) (Grapholita molesta). Photo: Clemson University, USDA Cooperative Extension Slide Series, Bugwood.org
April 22, 2016

Unusually warm weather in March, despite relatively colder conditions in early April, pushed the development of most insect pests well ahead of a routine timetable.

Gala at tight cluster. Photo: K. Peter
April 5, 2016

The recent winter-like conditions do not kill scab spores and the spores continue to further mature and release. If the weather forecast comes to fruition, an apple scab infection event is predicted for April 7. If your trees have green tissue, recommendations for dealing with scab while managing cold injury are discussed.

Network for Environment and Weather Applications (NEWA)
April 1, 2016

All current conditions point to an early spring and tree fruit bloom. At Rock Springs we had first bloom on Methley plums and pink on peaches on Friday March 25th. Last year we observed the same growth stage on April 29th!

A thermometer that records the maximum and minimum temperature is extremely useful for determining degree hours.
April 1, 2016

This article will help you manually determine infection periods for certain diseases (scab, fire blight, cherry leaf spot). Also included is a table listing coppers available to manage bacterial spot during cover sprays.

April 1, 2016

Since 1980 weather patterns such as rainfall quantity and duration, temperature and extreme weather events have become increasingly erratic.

Aprovia is a new fungicide to help in the apple scab fight. (Photo: K. Peter)
April 1, 2016

Aprovia is a new fungicide (SDHI, FRAC group 7) available for pome fruit disease management. Due to crop safety concerns, BASF will be cancelling the pome fruit registration for Vivando.

Green tip peeking through saying, “Be sure to protect me from apple scab!” Photo: K. Peter
March 15, 2016

Due to the presence of green tip on early varieties of apples combined with rain the last several days plus forecasted for the next two, we are in our first apple scab infection period for 2016. Protection is needed for vulnerable green tissue; a copper spray will be useful for trees not at green tip.

March 9, 2016: No green tip yet on Gala…but it will be soon! Photo: K. Peter
March 10, 2016

The first scab spores of the season have been detected; however, there is no scab infection risk until green tissue is present and there is an infection period. Since trees are pushing due to the warm weather the last several days, now is a good time to apply dormant copper sprays to manage diseases.

Riesling vines that show severe dieback due to winter kill. Photo: Bryan Hed
January 21, 2016

The past two winters have ramped up concerns about crown gall in Pennsylvania and other parts of the Northeast. Wine grape growers are discovering, many for the first time, the horrors of this disease and the extent of the damage it can cause in their vineyards. While there is reason for great concern, I would like to start out by saying that research efforts are generating extensive information on management of this disease, and there are new solutions from research in the pipeline.

January 15, 2016

When it comes to managing fire blight, the first line of defense is good sanitation, which is removing the overwintering source for the bacteria: cankers. Understanding what a canker is, being able to identify them in orchard, the importance of removal, and pruning strategies are discussed.

Cold-injured primary blackberry bud (left) and uninjured secondary bud (right).  Photo credit: Fumi Takeda, USDA-ARS-AFRS
January 13, 2016

Although the earth is warming as a whole as a result of climate change, the weather is also becoming more variable resulting in early-winter cold snaps, winter thaws followed by extreme cold events, and early spring bloom followed by frosts.

Different stages of infection of bitter rot on Honey Crisp.
October 30, 2015

Growers can get a jump on fungal and bacterial disease management for the 2016 season this fall. A review of tips to manage apple scab, fire blight, peach leaf curl, cherry leaf spot, bacterial canker, and fungal fruit rots are discussed.

October 29, 2015

The Penn State Extension Horticulture, Start Farming, and Pesticide Education Teams have produced three new videos on integrated pest management practices for sustainable establishment and management of apple orchards.

Be sure to protect your fruit from rots: bitter rot on Red Delicious. (Photo credit: K. Peter)
August 24, 2015

The biggest disease concern this time of year is keeping fruit free of rots as they are nearing the home stretch of the season. The recent bouts of rain and prolonged warm weather are ideal conditions for fruit rot issues.

Brown rot can cause shoot blight. (Photo: K. Peter)
July 31, 2015

With peach season in full swing, a review of management strategies for controlling brown rot is discussed.

Bacterial spot on peach fruit. Photo by S. Bardsley.
July 30, 2015

There has been much confusion this season being able to tell the difference between bacterial spot disease and copper injury. This article will describe symptoms in detail, as well as offer guidance to avoid the pitfalls of using copper for disease control.

July 29, 2015

Make sure you know where apple scab overwinters, how to monitor and when it is most likely to appear. Penn State Tree Fruit Plant Pathologist Kari Peter provides some key points..

Alternaria rot on cherry: velvety dark green to black lesions. (Photo: K. Peter)
July 15, 2015

The extremely wet weather over the last month has triggered rot issues in both sweet and tart cherries. As a result of the volume of fungal spores flying around and the persistent warm wet conditions, peach and nectarine growers need to be on high alert as we are nearing the home stretch for harvest. Vigilant rot management strategies are critical this year to prevent brown rot (and other rots) during preharvest and postharvest. Management options, including organic strategies, are discussed. Conditions continue to be favorable for bacterial spot, necessitating shorter spray intervals for disease management.

Anthracnose is diagnosed by the sunken black lesions on the fruit, with little black dots
July 12, 2015

Anthracnose (also called ripe rot) in blueberry, has been quite severe this year, especially in highly susceptible varieties such as Bluecrop, Bluetta, and Blueray.

June 26, 2015

Thanks to one of our growers we have been advised of a formula error in our spreadsheet.

The Penn State Tree Fruit Pathology Lab is seeking fire blight samples from Pennsylvania. (Photo: K. Peter).
June 26, 2015

The Tree Fruit Pathology Lab at FREC is seeking fire blight samples from around the state of Pennsylvania found in commercial orchards and home landscapes for evaluation for antibiotic-resistant strains of the bacteria and other projects.

Yellow poplar weevil is not known to cause any injuries to fruit or fruit trees. Photo provided by B. Boyer
June 26, 2015

The beginning of July usually marks a switch in our approach to control common insect pests in orchards.

Leftover fire blight cankers in trees wreaking havoc in the orchard. (Photo: K. Peter)
June 25, 2015

Primary apple scab is finally over as of mid-June. Conditions have been ideal for canker blight: leftover fire blight cankers continue to grow and bacteria move within the tree to growing areas causing shoot blight. Conditions have been favorable lately for bacterial spot on peaches.

Shoot blight resulting from bacteria moving within the tree from overwintering cankers to growing shoots. (Photo: K. Peter)
June 16, 2015

Conditions have been optimal for canker blight: leftover fire blight cankers continue to grow and bacteria move within the tree to growing areas causing shoot blight. Shoot blight is also occurring to those who experienced blossom blight, as well. Leafhoppers are active and will cause wounds in growing shoot tips, creating entry points for bacteria to enter. Pruning blighted areas and managing insects are the best methods for control.

June 2, 2015

Primary scab infection is still occurring and this week will prove to be another critical period for disease management. Fire blight infections are popping up in the region and more could be expected as a result of the weather conditions. Scouting is a must this week; however, do not prune during wet weather. Conditions are also favorable for cedar apple rust, cherry leaf spot, and bacterial spot infections.

Fire blight in July, 2014.
May 29, 2015

The primary infection period for apple scab continues, although available spore numbers are decreasing. Growers should be scouting for fire blight infection thanks to the ideal conditions we have been experiencing throughout the month. In light of the hail some growers experienced this week, a reminder that diseases still need to be managed despite a damaged or minimal crop during the season. Going into June, growers need to be mindful about controlling for sooty blotch and flyspeck soon.

May 29, 2015

Based on weather station data, we had only low risk fruit rot events in both Pennsylvania and Maryland up until mid-May, when several warm rains soaked the region, leading to two to three dispersal events. There are likely more to come, which means that throughout the region, there is an increased risk leading up to harvest of strawberries, and bloom time for many fruit crops. Protection of these highly susceptible flowers and fruits is critical.

May 27, 2015

A band of strong storms blew through Pennsylvania and Maryland this afternoon. If you experienced hail, apply streptomycin to apple and pear trees within 24 hrs of the hail event to prevent trauma blight. More heavy thunderstorms are in the forecast until early Thursday. Please be on alert.

May 21, 2015

The rain occurring today could have the potential to produce an apple scab infection event if adequate leaf wetness hours are achieved. Growers are encouraged to monitor conditions in their orchards and spray accordingly to protect for apple scab. In addition, be mindful of rust: the cedar galls have made their appearance, making spores available to cause infection in apple trees.

Infected king bloom oozing bacteria (Photo: K.Peter).
May 15, 2015

If the rain in the forecast comes to fruition this weekend, be prepared for a major apple scab infection period for the region. Growers in northern PA still in bloom need to be vigilant for fire blight conditions this weekend and next week. Although many are past bloom in the region, we experienced fire blight conditions from May 5 – May 12 and growers should begin to scout for infections during the coming week. Be on alert for powdery mildew infections, thanks to the dry weather lately. Control measures are needed to manage bacterial spot on stone fruit.

May 4, 2015

A weather system moving East will be bringing rain Tuesday into Wednesday. At the same time we are experiencing the peak period for dispersal of mature scab spores. The predictive models indicate May 5 - 6, 2015 will be a scab infection period. Growers need to protect trees to prevent scab infection during this critical period.

May 3, 2015

All predictive models indicate a high risk for fire blight infection this week due to the high temperature, humidity, and chance of rain showers in the forecast. Growers should begin protecting blossoms with streptomycin on Monday. More strep applications will be needed as infection conditions persist.

April 29, 2015

Rain is in the forecast for Thursday and Friday. As a result, the prediction models indicate this will be a scab infection period -- and a big one since we’re reaching peak maturity with spore release. This weather will also be ideal for cedar apple rust infection. Growers are encouraged to have trees protected before the rain occurs. In addition, growers need to be on alert for next week since fire blight models indicate the week of May 4 may be an infection period.

Protect tart cherries during bloom to prevent cherry leaf spot infection.
April 24, 2015

May is the battleground month for disease management: growers need to be on alert for apple scab, fire blight, powdery mildew, rust, cherry leaf spot, brown rot, and bacterial spot infection conditions. Disease infection periods are now being posted for regions in Pennsylvania and Maryland.

Dr. Cassandra Swett, Grape and Small Fruit Pathologist
April 23, 2015

Dr. Cassandra Swett started at University of Maryland, College Park as the new grape and small fruit pathologist in May 2014, with a split research and extension appointment. Her primary functions are to develop basic and applied information that improves management of grape and small fruit diseases, provide a resource to extension specialists and educators, and communicate information on disease management to producers.

April 23, 2015

Real time disease updates are now available for berry growers. "Follow" on line or via your smart phone!

Left: gray mold; right: anthracnose fruit rot.
April 23, 2015

The strawberry bloom has begun and it’s time for fruit rot protection. Our two main targets for bloom time protection of strawberries are gray mold/ Botrytis fruit rot (Botrytis cinerea), and, if you are growing susceptible varieties like Chandler, anthracnose fruit rot (Colletotrichum acutatum).

Gala at tight cluster: lots of green tissue available to become infected with overwintering scab spores. (Photo: K. Peter)
April 20, 2015

Scab infection period today, April 20, 2015, and predicted through Thursday. Rain most likely washed off all protection that was applied prior to the rain overnight and early this morning. Growers are encouraged to spray their trees to prevent scab infection. For growers in Maryland experiencing bloom, a streptomycin spray to protect open blossoms from fire blight is warranted.

Stone fruit blossoms are susceptible to brown rot during warm wet weather (photo: K. Peter)
April 17, 2015

We’re experiencing a scab infection period April 17. Warm, wet weather also is a threat for stone fruit blossoms that are open. Fungicides needed today to protect against scab and blossom blight caused by brown rot.

Gala at green tip (K. Peter)
April 9, 2015

If not already completed, copper sprays are encouraged for fungal and bacterial disease control. Apple scab primary infection has kicked off this week.

Blossom Blight. Photo by K. Peter
March 27, 2015

The who, what, why, when, where, how and how much of everything you need to know about fire blight and its management in preparation for the 2015 season.

Early apple scab lesions.  K. Peter.
March 6, 2015

Dormant season urea and copper sprays are recommended for decreasing available populations of apple scab spores and fire blight bacteria in the orchard for the 2015 season.

March 6, 2015

Organic fruit growing in the Mid-Atlantic Region can be successful and profitable with careful study and planning. There are natural features in the Mid-Atlantic region that offer nearly ideal conditions for growing high quality organic fruit. Also, the market in this area for locally grown organic fruit far exceeds the current production capacity of existing organic fruit farms.

January 16, 2015

The Penn State Tree Fruit Pathology Program has established a Twitter account to be another tool for folks to receive updates, information, and interesting pictures. Please start following!

Examples of Nectria infecting twigs, branches, and pruning wounds.
January 16, 2015

As folks are pruning their apple trees, the presence of the Nectria fungus is being reported. A weak fungus that attacks already compromised trees, growers are encouraged to prune out symptomatic tissue from trees to limit spread of the disease.

October 31, 2014

To reduce apple scab risk for next season, growers are encouraged to spray a fall application of urea as close to leaf drop as possible. Prune out fire blight strikes now while they are still visible on the tree to prevent cankers from overwintering. For those battling bacterial canker, copper applications are recommended since autumn is an optimal time for high bacterial populations. Additional disease management strategies are also discussed.

August 28, 2014

The fungi causing fruit rots can be quite stealth since spores will land on the fruit and cause symptoms after the fruit have been in storage. We have had excellent conditions for fruit rots this month with frequent rain and stretches of warm weather.

Necrotic leaf blotch, which is a physiological disorder and not a disease, has been manifesting throughout the area and is predominantly seen on the leaves of Golden Delicious, as well as those cultivars with Golden Delicious as a parent.
July 25, 2014

Management is discussed for controlling the physiological disorder necrotic leaf blotch, which is being reported throughout the area. Managing late season bacterial spot and rot diseases on stone fruit is also discussed. Disease infection periods to date for apple scab, fire blight, cedar apple rust and cherry leaf spot are included to help growers determine where control failures may have occurred this season.

Great year for disease on stone fruit: cherry leaf spot, bacterial spot, and cherry powdery mildew.
June 23, 2014

Conditions so far this season have been excellent for many stone and pome fruit diseases. Sooty blotch/flyspeck treatment threshold has been reached and disease control is encouraged. In addition to SBFS, management strategies are covered for fire blight, apple scab, fruit rots, bacterial spot, cherry leaf spot, and powdery mildew.

Bacterial spot on peach fruit. Photo by S. Bardsley.
June 23, 2014

I suppose I do not have to tell you that bacterial spot is a difficult disease to manage.

June 23, 2014

A toll-free hotline is available for growers in the region to receive seasonal updates about pest and pest management information. Laminated copies of the fungicide resistance management guidelines for scab, powdery mildew, brown rot, and peach scab are available for anyone who didn’t receive a copy during the spring twilight meetings this year.

Apple scab primary lesions producing spores
June 17, 2014

The primary infection period for apple scab is over. If growers are experiencing apple scab at this time, control measures will be needed throughout the remainder of the growing season to keep the disease in check. An option for fire blight management is also discussed.

2014: The Year of Fire Blight (photo courtesy of B. Lehman)
June 13, 2014

Fire blight is being reported throughout Pennsylvania and Maryland. Management strategies are discussed for dealing with active fire blight infections.

Golf ball sized hail (from NOAA)
May 23, 2014

Storms occurring on May 22, 2014 in the eastern part of Pennsylvania produced hail, which was capable of causing damage to fruit trees. Growers in affected areas will want to consider applying a streptomycin spray within 24 hrs of the hail event to protect trees from fire blight.

Cedar apple rust.
May 16, 2014

The weather during May 2014 has provided excellent conditions favorable for disease. Disease control recommendations are covered for fire blight, apple scab, powdery mildew, rust, and bacterial spot on stone fruit. This is an updated version of the Disease Update posted on May 14, 2014.

Bacterial ooze from fire blight infection.
May 14, 2014

Fire blight risk remains high through the week. When applying streptomycin, it is effective for 24 hrs before and 24 hrs after a rain event. Apple scab spore dispersal is peaking, and with the predicted rain events this week, we are in for a very rough, serious infection period. There is potential for secondary spread if fungicide protection earlier this year was less than adequate. The humid conditions are also optimal for mildew and rust infections.

Left - fireblight strike; right - fire blight ooze.
May 8, 2014

The apple blossoms are open and conditions are soon to be optimal for fire blight infection. Keep an eye on the weather for favorable temperatures and moisture since forecasts indicate May 9th to 12th (and possibly beyond) to be an infection period. Blossoms need to be protected.

April 28, 2014

Apple scab spores continue to rapidly mature and be released. With the expected rainfall accumulations predicted for tonight to Wednesday night to be at least three inches, the stage could be set for a severe apple scab infection period. Growers are encouraged to apply a spray prior to rainfall, particularly to susceptible cultivars and areas known for high scab inoculum.

Dull, olive green areas visible on the undersides of leaves are the first evidence of apple scab.
April 25, 2014

Early season apple disease management is primarily directed at controlling scab.

April 21, 2014

Apple scab spores continue to rapidly mature and discharge. Rain and thunderstorms are forecasted for Tuesday, April 22, 2014, and combined with temperatures in the upper 60s to low 70s, these are once again great conditions for scab infection. Apple cultivars with green tissue need to be protected.

April 15, 2014

Apple scab spores are rapidly maturing and beginning to discharge. Combined with the rain and temperatures in the 60s, these are great conditions for scab infection. Early season apple cultivars with green tissue need to be protected.

April 10, 2014

If not already completed, copper sprays are encouraged for fungal and bacterial disease control. Scab spores have not yet been released. Excellent resources are available for growers for resistance management this season.

March 28, 2014

There is a need to figure out novel disease management strategies necessary for staying one step ahead of postharvest decay pathogens. Evaluating wild apples for resistance to postharvest diseases, understanding fungi causing decay in storage, and finding alternatives for controlling rots are briefly discussed.

March 28, 2014

As you begin thinking about your IPM scouting program for the new season, consider the value of field guide for proper identification of orchard pests and beneficials. The Tree Fruit Field Guide to Insect, Mite, and Disease Pests and Natural Enemies of Eastern North America includes 500 color photos, actual size drawings of pests, over 20 pages of diagnostic keys.

February 14, 2014

The Orchard Spray Record-Keeping Spreadsheet has been updated and is available at the Penn State Tree Fruit Production website (http://extension.psu.edu/plants/tree-fruit). New features include the addition of FRAC codes and pages for supplying additional information required by processors.

January 24, 2014

A must-have investment for folks in the tree fruit business is the recently released Compendium of Apple and Pear Diseases and Pests, Second Edition. The first edition was published in 1990 and the second edition has evolved to be nearly double in size. My one word review of the second edition: awesome.

Apple scab spores for next season.
October 25, 2013

To reduce apple scab risk for next season, growers are encouraged to spray a fall application of urea as close to leaf drop as possible. Additional disease management strategies are also discussed.

Left to right:  Blue mold on apple; gray mold on apple; diseased fruit with debris in the bin - what not to do.
August 23, 2013

General management techniques for reducing postharvest fruit rots are important considerations as we approach harvest season. Growers are encouraged to use the infection periods posted as a tool to understand disease issues encountered in the orchard during this season.

Concentric circle pattern typical of bitter rot.
July 26, 2013

The weather conditions during the last several weeks have provided excellent conditions for bitter rot. Growers are encouraged to monitor their orchards and apply fungicides on a 10- to 14-day interval until harvest for effective disease control. The latest infection periods have been posted.

June 28, 2013

Sooty blotch/flyspeck infection period is underway and growers are encouraged to apply a cover spray. The latest infection periods have been posted, which include sooty blotch/flyspeck.

The number of oxytetracycline applications influenced the sensitivity of Xap isolates at higher oxytetracycline concentrations (right) but not at lower concentrations (left).
June 27, 2013

Bacterial spot of stone fruit (caused by Xanthomonas arboricola pv. pruni [Xap]) remains the most important bacterial disease of peach and nectarine in the eastern United States. We conducted a study in 2012 to monitor and identify populations of bacteria in stone fruit orchards, including bacteria resistant to the antibiotic oxytetracycline and to determine the current levels of oxytetracycline sensitivity in Xap populations. Of the 237 isolates tested, 99% and 81% grew in media amended with 5 and 10 mg/L oxytetracycline, respectively, while 25% and 22% of isolates grew in media amended with 15 and 20 mg/L and greater of oxytetracycline, respectively. Prudent use of this antibiotic is advised to prevent the loss of sensitivity.

Apple scab observed in a plant pathology research planting at the Penn State Fruit Research and Extension Center
June 12, 2013

The primary infection period for apple scab is nearing an end. Scab sources are still being sought in the region for fungicide resistance studies. Included is a thank you note to the attendees of the Spring Meetings.

Various disease symptoms are showing up in orchards.  This season was ideal for Peach Leaf Curl (shown here on peach leaves)).
May 31, 2013

Peach leaf curl is occurring throughout the region; effective control measures occur after leaf drop in the fall. Weather conditions are still excellent for fire blight; growers are encouraged to keep young, newly planted blooming trees protected. Apple scab sources are being sought in the region for fungicide resistance studies.