Category Archives: General interest

A Review of the 2013 Growing Season

At the annual Cumberland-Shenandoah Fruit Workers Conference in Winchester,  researchers and extension personnel from each of the attending states prepares a review of the past growing season. These reports are published in the Conference Proceedings, but we thought that a broader audience might also be interested in our assessment of the 2013 growing season. Please contact us if you have any additional thoughts or comments.

 

Call of the States – Virginia

Horticulture- Greg Peck

The 2013 growing season was marked with abundant rains in May, June, and July and relatively cool conditions from mid-August through to the end of harvest. Spring conditions were generally favorable for planting, and many acres of new orchard have been established in Virginia over the past year. On April 22 and May 15 there were light spring frosts in the Winchester area. Additionally, there was cool weather with reduced honeybee flight when many fruit trees were flowering. With the exception of russetted fruit in some low-lying areas, neither the peach or apple crops appeared to be significantly negatively affected by the frosts. In fact, many growers reported having fewer superficial blemishes and russets than would be expected from the cool humid conditions. However, the sweet cherry crop in Winchester, as well as many other locations in the mid-Atlantic displayed severe fruit drop due to these environmental factors, as well as potentially low light levels that occurred prior to pit hardening. Amongst the tree-fruit crops in Virginia, sweet cherries once again proved to be the most disappointing. In general, apple fruit set was more than adequate and most growers had a full crop.

Growers throughout the Commonwealth reported above average yields for both peaches and apples. Indeed, it would not be surprising if Virginia’s statewide apple yields in 2013 were greater than from any year in the past decade, if not longer. Indeed, many growers had difficulty sourcing sufficient labor and towards the end of harvest enough bins into which to pick their crop. However, excellent crop conditions were also reported in Pennsylvania, New York, Michigan, and elsewhere in the Eastern US, so prices were lower than grower expectations. In addition to the abundant yields, fruit size, color, and overall quality were quite good.

 

Entomology- Chris Bergh

Oriental Fruit Moth biofix was April 11, Codling Moth on May 2; both within historical norms since 2000. Cool wet weather following biofix resulted in slow Degree Day accumulation. There was very low internal worm pressure in 2013; was this effects of weather? Cool spring also resulted in prolonged activity of Plum Curculio and injury well into the summer. There was an unusual instance of lots of pansy spot on some apple varieties throughout central and northern VA and extending further north. Also foliar injury: Western Flower Thrips and/or soybean thrips.

Brown Marmorated Stink Bug (BMSB) populations were very high by late summer, based on captures in traps. Ideal growing conditions maintained lush condition of wild hosts, prompting the question,” Did BMSB stay longer on them? (considering the huge amount of vegetative growth on peach).” BMSB injury at harvest managed quite well in most orchards in which targeted sprays used. Many growers are now using Alternate Row Middle sprays. There were examples of high levels of BMSB injury to late-season apples when BMSB was not targeted as in processing blocks. San Jose Scale is an increasing concern behind BMSB programs. Mites continue not to be an issue. The biggest secondary pest concern is late-season Woolly Apple Aphid outbreaks; Diazinon worked very well, but not Movento, Provado or Closer. There was Issue with Diazinon restrictions on fruit for baby food; Also there was a potential issue with compatibility between diazinon and captan.

 

Pathology- Keith Yoder

2013 was an “average” disease year in the Winchester area, but with progressively heavier pressure farther south. There was no apple scab infection period in the Winchester area until Apr 17. Scab lesions from April 17 were present by May 6, and then heavier secondary occurred May 6-24. Sterol inhibiting fungicide resistance and QoI resistance, confirmed in 2012, are being dealt with in the Winchester area. Cedar-apple rust spores were released as early as April 12 and discharge continued into June; but for the most part, susceptible blossoms escaped quince rust infection. Our test treatments in 2013 again bore out the value of following likely cedar rust infection periods with an SI fungicide for after-infection control. In 2013, mildew conidia were available April 11 a week ahead of scab infection, and we had 42 dry weather “mildew infection days” from April 11-June 14. Summer rains prolonged growth and the length of shoot susceptibility, and secondary mildew infection was common on susceptible varieties. In spite of some earlier indications, some (Maryblyt) predicted fire blight days fell short of the requirements for infection and most infection events occurred mostly only on late bloom.

For purposes of predicting development of the sooty blotch and flyspeck (SBFS) fungal complex, we started wetting hour accumulation from May 13, and by July 1, and had reached the 250-wetting hour threshold for specific treatment against the SBFS fungal complex, about five weeks later than last year. Leaf spot problems on Golden Delicious in the Winchester area were primarily necrotic leaf blotch, not the Glomerella leaf spot which suddenly became prominent in late August 2012. The late season was not conducive to rot development in the Winchester area; however, with heavy rainfall in southern VA and western NC, Glomerella was again a problem in those areas in 2013. Some samples of rot spots from those areas developed into bitter rot and some were white (Bot) rot.

Grape disease development followed a similar pattern, with generally heavier disease pressure by wet weather diseases farther south into Virginia.

Cost Share Program for Planting Hard Cider Apple Cultivars by Greg Peck

A Specialty Crop Block Grant from the Virginia Department of Agricultural and Consumer Services was awarded to the Nelson County Economic Development Office to increase the volume of hard cider apples grown in Virginia. Grant awards are for a maximum of $3,000.

Please contact Maureen Kelley, Nelson County, info@nelsoncounty.org or 434-263-7015 if you have any questions about this program.

Click the below link to download the application form as a Word Document.

VACiderAppleCostShareGrant

Program Timeline:

January 1 – Announce Program

January 31 – Applications Accepted

February 15 – Announce Awards

May 30 – Deadline for submitting reimbursement request

A review of the 2012 Growing Season by Drs. Peck, Bergh, Pfeiffer, and Yoder

At the annual Cumberland-Shenandoah Fruit Workers Conference in Winchester, the researchers and extension personnel from each of the attending states prepares a review of the past growing season. These reports are published in the Conference Proceedings, but we thought that a broader audience might also be interested in our assessment of the 2012 growing season. Please contact us if you have any additional thoughts or comments. Greg

Call of the States – Virginia

Horticulture

The 2012 growing season began with unseasonable warm temperatures in February and March, which caused fruit-tree bud break to be nearly four weeks ahead of the long-term average. The early bud break led to an early bloom, which lengthened the period when flowers and fruits were susceptible to freezes. Interestingly, trees in the northern Shenandoah Valley were blooming at the same time as trees in Central Virginia; in most years there is a two-week difference. Likewise, many apple, cherry, and peach trees had overlapping bloom. Several frosts damaged blooming fruit trees in Virginia, particularly peaches and cherries, with the most damaging frost occurring on the morning of March 27. Many king bloom in apple were also lost to the frost. But, Virginia growers were spared the colder temperatures that severely reduced the tree fruit crops in North Carolina in late March, and in New York and Michigan in late April. Cool temperatures stretched out the remainder of the bloom period. The frost and prolonged bloom made fruit thinning strategies more challenging.

The fruit producing regions of Virginia were also spared the droughts that devastated farmers in many other parts of the country. However, high winds from the June 29 Derecho storm damaged some orchards in both Central Virginia and Northern Shenandoah Valley orchards. The massive Hurricane Sandy (October 29) that caused widespread flooding in the northeast arrived after most of the Virginia apple crop was already harvested, so damage was minimal and mostly from toppled trees. The early bloom meant that tree-fruit crops were harvested 10-14 days earlier than usual, but this was not problematic since crop losses in other states meant that fruit was in high demand. The USApple crop forecast that was released in August predicted little change in the 2012 apple crop compared to the five-year average. Despite losing many king bloom in apple, fruit size was satisfactory, likely because of adequate rainfall in the latter half of the growing season. I would say that most growers were happy with the yields, quality, and prices that they received for their fruit this year.

Entomology

Warm temperatures in March translated to the earliest biofix dates for oriental fruit moth (OFM) (March 20) and codling moth (CM) (April 14) recorded since 2000.  OFM and CM biofix occurred 10 and 9 days earlier, respectively, than the previous earliest in 2002 and 2008, respectively. Cooler weather in April resulted in tufted apple budmoth biofix on April 29, which tied the previous earliest record in 2000 and was only a few days earlier than average. Cool, wet weather following petal-fall resulted in a prolonged period of plum curculio movement into orchards. There were not significant issues with OFM and CM in fruit at harvest and leafroller populations remained at the very low levels seen in recent years. The overwintering population of adult brown marmorated stink bug (BMSB) was smaller than in recent years, due to an unknown source of mortality late in the 2011 season. This translated to relatively low BMSB pressure early in the growing season. BMSB populations rebounded during the summer and large numbers of adults seeking overwintering sites were recorded from late September through about mid-October; the first mass movement to overwintering sites occurred on September 21. BMSB injury to peaches and nectarines at harvest was relatively light, likely due to the combined effects of more targeted sprays, lighter pressure early in the season, and an early harvest that reduced the duration of fruit exposure to some extent.  This was also noted in early and mid-season apple varieties. Late season varieties were exposed to the last generation of BMSB in September and October; injury levels in those varieties at harvest varied considerably among blocks, likely according largely to differences in management programs. In general, BMSB management programs did not incite spider mite or San Jose scale populations. However, woolly apple aphid outbreaks in August and September were more common than is typical. Following its first detection in Virginia in 2011, spotted wing drosophila posed a severe challenge to berry growers throughout the 2012 growing season.  Some caneberry plantings experienced 100% berry infestation.  Blueberries and wine grapes were also affected.

 Pathology

Apple scab: We had “normal” scab development in spite of the early 2012 season. Critical primary infection periods occurred Mar 19-20 and Mar 24-25 and scab lesions appeared Apr 13. This led to severe secondary (also primary) infections Apr 18-19 and 21-23. Getting proper spray coverage through several weeks in April was a challenge because of persistent windy and rainy conditions. Nine later secondary infection periods occurred in May.  Apparent widespread emergence of QoI (strobilurin) resistance presents an important problem for scab management in Frederick County.

Rusts: An unusual development with cedar rust infection was heavy infection on flower cluster leaves (from Mar 24-25) as well as the mid-shoot positions (from May 5-15). For the most part, fruit escaped quince rust infection because wetting periods were too cool for infection while the blossoms were most susceptible.

Powdery mildew: This year we had 44 dry weather “mildew infection days” between Mar 19.and May 31. Summer rains prolonged the length of shoot susceptibility with more likelihood of bud infection, overwintering, and a recurrent problem next year.

Fire blight: Although there were several opportunities for blossom blight infection from Mar 24-Apr 20, there were more numerous reports of fire blight from areas east of the Blue Ridge and the Roanoke area south where bloom was open earlier than in the Winchester area. Some pear shoot symptoms were evident in central VA as early as Apr 3, from infection in mid-March.

Summer diseases: We passed the 250-wetting hour sooty blotch/flyspeck threshold by May 25, four weeks ahead of last year, and the second earliest date for reaching this predictive threshold on record since 1994. Sooty blotch was observed in non-treated trees at our AREC June 13, and this confirmed the validity of using Apr 8 as the unusually early petal fall date and Apr 18 as the date for starting wetting hour accumulation.