Rain and winds moved through Pennsylvania from west to east on Sunday. Monday and Tuesday were cloudy and cool across much of the state. For those wanting to apply thinners weather conditions for thinning based upon SkyBit do not look promising for the remainder of the week.
Bloom is well underway for apples and pears. Be alert since this is a susceptible time for fire blight when conditions are favorable. Primary scab infection is still an issue. Dry weather diseases can still be problematic.
Dinotefuran received a time limited supplemental label for use on peach and nectarine trees, valid until Aug 31, 2015. Calypso 4F received an additional registration for use on stone fruit. The label for all products containing chlorpyrifos allows for only a single application of this ingredient-containing products per season, either as a dormant application or as a trunk application. Endosulfan remains registered for use on pears only until July 31, 2013 and on apples until July 2015.
Although the April weather continued the mix of cold and very warm days, insect development seems to be following a much more normal pattern than during the previous few years. While the biofix dates (first sustained moth flight detected by pheromone traps) for redbanded leafroller and spotted tentiform leafminer were a few days later than usual, April 6 and April 9 respectively, the biofix for Oriental fruit moth was established on the same day as during three other years in the last ten (April 17). As of April 26, we still have not yet established the biofixes for codling moth or tufted apple bud moth.
While the monitoring practices for our common pest species are relatively well defined, monitoring for the newly introduced pest species can be more challenging. A good example of such a challenge is exemplified by our effort to develop an effective monitoring system for brown marmorated stink bug (BMSB).
Monitoring insect pests continues to be one of the pillars of integrated pest management in Pennsylvania orchards. During the last fifteen years, the use of insect sex pheromone traps transformed from an intriguing tool used by researchers into a common pest management practice utilized by many growers.
While fruit bud development is later than last year, there is still the potential for freeze injury to flowers. There were some clear, cold nights this past weekend.
Two strawberry viruses, in combination, are causing problems for Eastern strawberry growers. The viruses (strawberry mottle virus, abbreviated SMoV; and strawberry mild yellow edge virus, abbreviated SMYEV) have now been discovered in Pennsylvania, and growers are advised to check plants propagated from runner tips obtained from Nova Scotia.
Apple bud stages range from green tip in the Lake Erie region of Pennsylvania to a few blossoms opening in Lancaster County. Peach bloom stages range from pink bud in State College to petal fall in Lancaster County.
Be on alert for early season disease development: We have optimal conditions for brown rot (blossom blight) on stone fruit and growers are encouraged to apply fungicides during this critical period. This also continues to be a critical period for controlling primary apple scab infection.
Green tip is here and the next ten days are forecasted to be ideal conditions for apple scab infection. Growers are encouraged to apply protectant fungicides during this critical period.
A new generation of specialty crop growers is building coalitions to develop innovative approaches for meeting future growing and marketing challenges. Participate as much or as little as you want, but get to know other young producers, university extension workers and industry members in your field.
A Northeast Environment and Weather Association program is being introduced this spring to include the Cornell MaluSim carbohydrate model based upon data collected from a grower’s location and compiled by a specific weather instrument.
My goal as the new plant pathologist at the Penn State Fruit Research and Extension Center is to provide timely disease updates and management strategies for tree fruit growers throughout the season through Fruit Times newsletters and timely email updates.
In 2012, the Massachusetts Audubon Society published an Invasive Plant Pest Alert on hardy kiwifruit, Actinidia arguta, also called "tara vine", strongly urging people not to grow or propagate this plant. The apparently rampant growth of vines had been documented at three particular locations. These sites stand in marked contrast to observations of the behavior of commercial and research plantings in PA, OR, MN, NY, ME and many other locations, where planted specimens have stayed in place and seedlings have extremely rarely germinated from fallen berries.
If you wish to review recommendations provided at your local winter tree fruit educational meeting or the Mid-Atlantic Fruit and Vegetable Convention, you may now find the speakers' slides on line!
Proper calibration is a must to make sure pesticide applications get to the target at the proper rate. The Penn State Pesticide Education Program purchased a calibration unit that enables us to collect the output from each nozzle. With the collected information, we troubleshoot any problems like worn or plugged nozzles or broken or wrong whirl plates. The end result is a calibrated sprayer ready to go for the growing season. Growers may sign up to have their sprayers calibrated at the Penn State Pesticide Education website.
For growers in the mid-Atlantic states, GMO vegetable varieties are no longer future products in the pipeline. GMOs such as B.t. sweet corn and virus resistant summer squash are here now, and more varieties are coming soon. Growers need to understand what GMOs (genetically modified organisms) are, and how their customers and others may perceive them, in order to make informed decisions about whether or not to grow them, and how to talk to their customers about them.
Last year, several of us planted demonstration plots of an assortment of day-neutral varieties in PA, MD, and WV. Varieties included some from the U.C. Davis breeding program (Portola, San Andreas, and Monterey), and a variety from Lassen Canyon Nursery (Sweet Anne).
While many of you have already started on your winter pruning, some of you from more northern or central areas may not have begun due to snow cover and cold weather. Below is an excellent article by Mario Sazo and Terrence Robinson. The article primarily deals with orchards that lost their crop and the potential for the trees to have a heavy bloom. Their thoughts revolve around trying to accomplish some crop reduction via pruning to reduce the dependency on post bloom chemical thinning. They have some good ideas if you are in a similar situation, but I would like to add some comments as they pertain to Pennsylvania.