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.
BMSB adults as well as second and third instar nymphs were found feeding on fruit (mostly peaches and nectarines). If BMSB nymphs are spotted, the control treatment is needed immediately. While adult BMSB can continuously move in and out from any orchard, BMSB nymphs are resident pests and will continue feeding (and damaging fruit) for a consecutive 4 to 6 weeks. During the last week Japanese beetles (JB) were observed feeding in orchards located in southern Pennsylvania. Materials recommended for the control of brown marmorated stink bug should also provide effective control of JB.
Brown marmorated stink bug movement away from overwintering shelters is finally completed. BMSB adults are observed feeding on stone and pome fruit. The first egg masses and second instar nymphs were found during our weekly orchard observations. If BMSB nymphs are spotted, a control treatment is needed immediately. First generation codling moth (CM) flight continues in all areas across Pennsylvania. If pheromone trap captures indicate strong continuous CM flight, third applications of control materials will be needed. The second or third treatment of insecticides for the control of codling moth should also effectively control tufted apple bud moth (TABM) larvae. No Oriental fruit moth (OFM) control is required at this time.
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.
With an alumni base of 600 strong, The Pennsylvania Rural-Urban Leadership Program (RULE) still has room to grow. Leadership is all over the map and it’s certainly in your part of Pennsylvania.
During this past week, relatively high numbers of adults (for this time of the season) were observed feeding on stone and pome fruit. The first egg masses and young nymphs were also found. If BMSB nymphs are spotted, a control treatment is needed immediately. Codling moth (CM) adults continue first generation flight in all areas of Pennsylvania. The second treatment of insecticides for the control of codling moth should also effectively control early tufted apple bud moth (TABM) larvae.
Have you ever looked for training materials to build the knowledge and confidence of your farm market personnel? Penn State Extension now offers on-line training for farm professionals that handle, process, or merchandise fresh market produce.
Update on the strawberry virus situation in Pennsylvania. Last month, I had written an article regarding two strawberry viruses (strawberry mottle virus, and strawberry mild yellow edge virus) that could be present in strawberry plug plants grown by mid-Atlantic nurseries (and others in the East) that had obtained runner tips from a Canadian supplier. The concerns were that the viruses could spread to otherwise healthy plants if aphids (the vectors of these particular viruses) were present; that the presence of the viruses would affect growers' plans to carry over plantings; and that if both viruses were present in the same plants, vigor and yields would be affected. At the time the article was written, we weren't sure how widespread the problem was in Pennsylvania.
Update on the current status of spotted wing drosophila, a species of fruit fly, that is problematic because the tiny larvae of this pest can be present in the fruit when it is harvested.
As a Pennsylvania grower of fresh vegetables and fruits, you have worked hard to learn about and adopt GAPs (Good Agricultural Practices) on your farm and in your packing house. Now that we are moving into peak marketing season, remember those farm food safety concepts when selling your produce at farm and farmers markets. Food safety practices that extend from farm to fork can help prevent foodborne illness outbreaks.
Adams County young growers were featured in the Gettysburg Times and Country Folks Grower.
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.
The tables below present weekly adult moth captures in pheromone traps and degree day comparisons 2008 to 2013.
As during previous years, the Penn State Fruit Research and Extension website located at: http://agsci.psu.edu/frec is again providing the information related to seasonal observations on insects and diseases (http://agsci.psu.edu/frec/growing-season-information).
Brown marmorated stink bug (BMSB) is continuing its movement away from overwintering shelters and feeding on multiple species of plants, most likely not inside orchards.
A critical time to control the second generation of pear psylla is during the first week of hatch of the young nymphs and then a repeat application should be made 12 to 14 days later.
The 2013 spring weather conditions created a fortunate pattern for combining effective management options for some of our most important fruit pests—codling moth (CM), tufted apple bud moth (TABM) and obliquebanded leafroller (OBLR).
Many growers applied chemical thinners during the week of 5/13 to 5/18, and the effects of these applications are just becoming apparent. The forecast for our region calls for temperatures in the high 80s to low 90s for Wednesday through Sunday, with lows in the mid-60s throughout that time. Under high temperatures, all thinning chemistries are more effective than when temperatures are more moderate.
Carbohydrate balances for the most part are positive across the state indicating the potential for trees to be less responsive to chemical thinner applications. (The exception is up along Lake Erie). IMPORTANT: Plant growth regulator label precautions supersede recommendations from thinning models when temperatures approach 90 degrees or higher.
The first treatment to control codling moth is needed early during the week of May 27th (around 250 DD50, 5 percent CM egg hatch on May 27th). If hand applied mating disruption materials (Isomate® or CheckMate® products) are planned for the control of CM, Oriental Fruit Moth (OFM), dogwood borer, peach tree borer and lesser peach tree borer, the dispensers should be already placed in the orchards. First generation Oriental fruit moth flight is winding down across the state. Plum curculio (PC) adults will need to be controlled for at least another week. Brown marmorated stink bug (BMSB) is continuing its movement away from overwintering shelters and feeding on multiple species of plants, most likely not inside orchards. All pheromone traps for monitoring fruit insect pests should already be placed in orchards.