Von holding up in the wet weather

Von July 5, 2013

Von July 17, 2013

Last week we received a phone call from a large and long time blackberry grower here in NC. He has a 10 plant test plot of 'Von' and is comparing it to the 'Navajo', 'Ouachita' and 'Nachez' varieties from Arkansas. The extremely wet weather this summer has allowed him to make comparisons that we (NCSU) have not had the opportunity to make up to this time. The most important comparison is with 'Navajo' because it has a very similar harvest season to 'Von'. What the grower  found is that 'Von' has much greater tolerance to wet weather (superior firmness) under these conditions compared to the three Arkansas varieties.

Black Raspberry Research Project Video

In this video, Christine Bradish gives us a peek at what she is doing this summer in the field at the Sandhills Research Station in Jackson Springs, NC.
http://www.black-raspberries.com/#!field-update-videos/c1rq7

Managing blackberry harvest and health in the midst of a rainy and cool season UPDATED 7/11/13

In light of the wet weather and the forecast of more wet weather and a possible tropical storm next week, I asked for some recommendations from Specialists around the region. Here they are, I will update as more come in and and welcome comments.


Dr. Carl Crozier, Soil Science, NC State University

Nitrogen management could be even more unpredictable than usual. Depending on timing of N, the nature of the soil profile, and the crop management (including mulching) system; excess water may have enhanced deeper N movement and/or N runoff or denitrification losses, and an elevated water table may have restricted crop rooting. Plant tissue analysis could be useful in assessing crop status.


Dr. Gina Fernandez, Horticulture, NC State University

Yesterday, I was at a blackberry farm in eastern NC.  They were using a radar app (My Radar) to help determine when rain was coming. They were dodging rain showers the entire time, and with the help of the app they could determine if they should run a load of fruit into the packing shed, unload and by the time they were unloaded the shower had passed. There are several other apps that can pinpoint your location, so see what works best for your farm.

Another observation was that they said they would pick the fruit as long as the rain is not dripping off from the ends of the fruit. They also were covering the clamshells in the field with a layer of plastic to keep the rain out of the clamshell off the berries.

When you are tipping the primocanes, the smaller the diameter of the cane at pinching will minimize the  potential for cane blight infection. If you have to use a pruners, a fungicide  should be applied soon after the canes were cut. For more information see http://teamrubus.blogspot.com/2012/06/blackberry-tipping.html

Be sure to remove spent canes as soon as the fruit is harvested. Good air movement will be important to minimize disease pressure.

Dr. Penny Perkins, Post Harvest Handling NC State University

We're finding the (rotating arm) trellis is helping greatly with fruit quality in this rain.  I see a lot less 'bleed out' as rain sits far less on the fruit.  What the eastern NC grower is doing is very similar to what we're doing-dodging showers.  We're finding that the droplets from the wet fruit condense on the top (inside) of the clamshells, which for us is not a problem since we transfer to pints later.  I would think that placing clamshells in the cooler then turning on fans to move air would help more than anything to evaporate the condensation.

Although these high rainfall years are unusual, the trellis is proving itself to be a huge asset in boosting berry quality (less soft, less bleaching, less sour fruit, and much better fungicide contact on fruit itself).


Dr. Hannah Burrack, Entomology, NC State University

SWD is the greatest insect concern because rain limits both the ability to apply insecticides as well as their residual activity. I put a post on the strawberry portal this year discussing this issue:
http://strawberries.ces.ncsu.edu/2013/05/swd_in_rain/

In blackberries, Mustang Max has shown some decent residual activity following rain, so that would be the material I'd use if I anticipated a rainy week ahead. Delegate might be another option, but we have less information on its rain fastness.

Also important is good sanitation after rain. Fruit that is on the overripe side has been exposed to SWD longer and at greater risk of infestation. Overripe fruit is also softer, making it potentially more attractive to SWD. This fruit should be removed before harvest so that it doesn't make it into a clamshell.

Dr. Phil Brannen, Plant Pathology University of Georgia

Tell them to review the IPM spray guide at www.smallfruits.org.  http://www.smallfruits.org/SmallFruitsRegGuide/Guides/2012/2012BrambleSprayGuide.pdf

Botrytis is the primary driver of their spray program at this point, but leaf spots and cane diseases will increase with this weather.  Without knowing more, I would suggest Switch for the next couple of applications.  We are observing substantial resistance development with other Botryticides, but at least one component of Switch will work.  They should send Botrytis samples to Clemson University for resistance profiling.  This will help them to better address which fungicides are active for the remainder of the season.  Turnaround is 72 hours.

Dr. Guido Schnabel, Plant Pathology,  Clemson University

Yes, we are able to process botrytis samples and screen for sensityvity to 7 classes of fungicides. (see previous blog post: http://teamrubus.blogspot.com/2013/04/monitoring-of-fungicide-resistance.html

Gray mold in caneberries

Gray mold in Ouachita blackberries. July 2, 2012. North Carolina.

Cultural Practices for Gray Mold Control in Brambles*

Temperatures in June were well below normal and now we are getting above normal amounts of rain. These are ideal conditions for a disease called gray mold. So even though this disease is not usually a problem here in NC, gray mold is showing up in the blackberry plantings. Following from an article that appeared in the Summer 2013 issue of the BRAMBLE, this information is useful for both blackberry and raspberry plantings.

Cultural practices are the major means of control for several important bramble diseases, including gray mold. The following practices should be carefully considered and implemented whenever possible in the disease management program.

• Avoid Excessive Fertilization: Base fertility on soil and foliar analysis. Avoid use of excessive fertilizer, especially nitrogen.
• Control Weeds In and Around the Planting: Weeds in the planting prevent air circulation and result in fruit and foliage staying wet for longer periods. Controlling wild brambles (which are weeds) near the planting is also important because they can serve as a reservoir for several important diseases and insect pests.
• Practice Sanitation (Removal of Overwintering Inoculum): Pruning out all old fruited canes and any diseased new canes (primocanes) immediately after harvest and removing them from the planting breaks the disease cycle and greatly reduces the inoculum.
• Manage the plant population and canopy to increase air circulation and exposure to sunlight: Ideally, rows for red raspberries should not be over 2 feet wide and contain about 3 or 4 canes per square foot. Specialized trellis designs for Rubus spp. can further improve air circulation and increase exposure to sunlight, as well as increase harvest efficiency. Trickle irrigation, (vs. overhead sprinkler irrigation), greatlyreduces wetting of foliage. Removing young fruiting shoots (before 4 inches long) from the lower 20 inches of canes will remove fruit that might become soiled.
• Adjust Production Practices to Prevent Plant Injury and Infection: Many plant pathogens take advantage of wounds in order to penetrate and infect the plant. Using sharp pruning tools will help minimize damage to canes during pruning operations. Prune only when necessary (avoid cosmetic pruning of primocanes) and avoid pruning during periods when plants are wet or immediately before wet weather is forecast. Provide proper cane support through trellising or otherwise tying the canes to in avoiding abrasions from sharp spines and wind whipping of plants during windy conditions. Proper spacing between rows and the use of the proper size equipment will also prevent plant damage.
• For chemical control options see the SRSFC IPM guide, pg 24 (and 15) http://www.smallfruits.org/SmallFruitsRegGuide/Guides/2013/2013BrambleSprayGuide6_17_2013.pdf

*Copied from the Bramble Newsletter, which was edited – because of space limitations – from a much longer article by Mike Ellis & Mizuho Nita, Ohio State

University. See the full article at www.fruit.cornell.edu/nybn/newslettpdfs/2013/nybn1205a.pdf.