Friday, March 3, 2017

Warm spring, challenging pruning and cold temperatures ahead



Pruned field of Navaho blackberry, Guilford Co. NC
Yesterday the NC Cooperative Extension County offices in Guilford and Rockingham Counties held a joint blueberry and blackberry pruning demonstration in Guilford County. The pruning demo had been planned in the fall of 2016, with the thought that the first few days of March would be ideal time to prune. That is, plants are transitioning from winter dormancy to spring but buds are not yet swelling or opening. But February 2017 was much warmer than usual, so bud break had already occured on blackberry and blueberry. This is NOT a good time to prune because as you prune, you pull those removed canes through the canopy and you may accidently rub off buds on canes that remain.  The grower was wise and had already pruned all but 3 plants earlier this winter (see picuture above). 

A close up of these canes shows that the buds that are furthest out on the canes are more advanced on some canes (foreground), while other canes had very little bud break (background). The open buds could easily be broken or rubbed off during pruning.

With the predicted lows into the 20's this weekend, there is a potential for damage to flowers in the blackberry buds.  Research has shown that unlike strawberry or blueberry ALL stages of flowers in blackberry are killed when the plant temperature is at 27 F. 


Growers should monitor their fields and record the low temperatures. Check buds the day after the freeze and look to see if there is any damage in the center of the buds. See images below. 
Damaged blackberry bud (photo taken 2014).

Healthy blackberry bud (photo taken 2014).

We have posted lots of information on this site before. Here is a quick link to some of that information.


 




Tuesday, February 14, 2017

Latest Southern Region Small Fruit Newsletter



Here is a link to the latest Small Fruit News. This is an online publication that the Southern Region Small Fruit Consortium posts 4 times a year. Contributions are usually from faculty at one of the participating institutions, NC State University, Clemson University, The University of Arkansas, The University of Georgia, The University of Tennessee and Virginia Polytechnic and State University. 



In this  issue:
NCSU Strawberry Yield Trials 2015-16 
‘Opportunity’ and ‘Enchantment’ Wine Grapes for the Mid-South 
Training Opportunity for Beginning Blackberry Farmers in the Mid-South 
Creating a gentler, more profitable way to harvest blueberries
Take Advantage of the Clemson Fungicide Resistance Profiling Service

Tuesday, January 24, 2017

Caneberry Resource List 2017

Blackberry and Raspberry Resources 2017
For the Southern Region of the US


2016 Southeast Regional Caneberry Production Guide
is available in 2 formats:
1. An online version that includes links to videos http://content.ces.ncsu.edu/southeast-regional-caneberry-production-guide. This is the first NCCES numbered publication to include videos!


2. There is also a PDF version available.  It is 44 pages long and includes all the text, color images and figures that the online version has but no videos. The PDF version that is a smaller file size (3.2 MB) is available at the end of the link above.

Websites
Grower Information Portal:

Caneberry Budgets:
https://rubus.ces.ncsu.edu/rubus-blackberry-and-raspberry-budgets-pricing/
Conventional and Organic budgets                                                                                                                                                            

Southern Region Small Fruits Consortium:
- see “Crops” and “Production Guides” sections
- IPM guides have pest management recommendations.
- Small Fruit News, a quarterly newsletter with timely articles and checklists for chores in blackberry and raspberries

NC Agricultural Chemicals Manual:
-for most recent pesticide recommendations
http://ipm.ncsu.edu/agchem/agchem.html
                 
Berry Diagnostic Tool:
- all berries, including blackberries and raspberries

Blackberries for the Home Garden:

Berry Market Prices
http://www.ncagr.gov/markets/mktnews/fruit.htm

Association Contact list and meetings
North American Raspberry & Blackberry Association (NARBA)
Debby Wechsler, Executive Secretary 


Phone: 919-542-4037

Annual meeting in Jan/Feb various US locations (Williamsburg CA)
Annual regional meeting often with SE Regional Fruit and Veg Conference, Savannah GA (early Jan)

North Carolina Commercial Blackberry and Raspberry Association (NCCBRA)
Annual meeting held each year (Jan/Feb/March) in western NC

SE Regional Fruit and Vegetable Conference
Annual meeting early Jan, ½ day or more dedicated to blackberry and raspberry grower talks

Social Media
Team Rubus Blog:

Team Rubus Twitter
@NCTeamRubus
Facebook Team Rubus

Books/References
Compendium of Raspberry and Blackberry Insects and Diseases
NEW EDITION COMING OUT IN 2017

National Clean Plant Network-Berries

Small Fruit Update –PNW weekly newsletter during growing season.
http://www.nwberryfoundation.org/sfu.html







Friday, January 13, 2017

January Thaw (again)

It's "January thaw" time in North Carolina, the current temperature is 67F (19.4C). So growers and researchers are worried. Will blackberry buds be breaking?

For those of you that were in Savannah last week, both John Clark and I discussed chilling models. John described the Utah Model ( models 5 and 6 below are variations of the Utah model), that assigned partial ceiling units and subtracted units. I discussed a simpler model (model 2) that just accumulated chill units when the temperature was between 32-45 F and the starting date occurred when temperatures were below 28F.  See the tables at the end of this post for all the details.

Based on the data collected so far this winter by the State Climate Office of North Carolina, we have somewhere between 259-420 chilling hours in Raleigh. We usually get around 800 units, because we are well below 800, buds should remain dormant. However, in the western part of the state, chilling units are higher and a lengthy warm spell may stimulate some buds.

Here are some chill units that have accumulated so far around the state.



Location (CRONOS)
Blueberry model
Blackberry model 1
Blackberry model 2
Blackberry model 5
Blackberry model 6
Raleigh (LAKE)
832
406
259
420
375
Salisbury (SALI)
978
788
517
727
612
Lincolnton (KIPJ)
953
692
433
631
537
Hendersonville (BEAR)
NA
923
512
782
627
Castle Hayne (CAST)

315
195
212
171


You can calculate your chilling units near you at this site State Climate Office of North Carolina Model 2  (it also can calculate for stations in  GA, KY, MD, NC, SC, TN , VA, WV).

If you would like me to look up chilling units for other models for your area, send me an email. Gina_Fernandez@ncsu.edu.

http://climate.ncsu.edu/cronos/blackberry


Details of all the chilling models.

NCSU Blueberry Model
Temperature
Units of chilling
< 45°F (7.2 °C)
1
45-55°F (7.2-12.8 °C)
0.5
55-65°F (12.8-18.3 °C)
-0.25
>65°F (18.3 °C)
-1.0
The model begins when it has a positive balance that is not negated by warmer weather. Once 800+ chill hours have accumulated, points are no longer negated for temperatures 55° and above. The model ends February 28 at midnight. 

Blackberry model 1
Temperature
Units of chilling
<44.6°F (7.2°C)
1
Starts when hit 28°F for the first time in the fall.

Blackberry model 2
Temperature
Units of chilling
32-44.6°F (0-7°C)
1
Starts when hit 28°F for the first time in the fall.

Blackberry model 5
Temperature
Units of chilling
32-48.38°F (0-9.1°C)
1
48.5-54.3°F (9.2-12.4 °C)
0.5
54.5-60.6°F (12.5-15.9°C)
0
60.8-64.4°F (16-18°C)
-1
Starts when hit 28°F for the first time in the fall.

Blackberry model 6
Temperature
Units of chilling
34.7-36.3°F (1.5-2.4°C)
.5
36-48°F (2.5-9.1°C)
1.0
48.5-54.3°F (9.2-12.4°C)
.5
54.5-60.6°F (12.5-15.9°C)
0
60.8-64.4°F (16-18°C)
-.5
>66°F >18°C)
-1
Starts when hit 28°F for the first time in the fall.

Utah Chill model
Temperature
Units of chilling
<34.5°F (1.4°C)
0
34.6-36.4°F (1.5 – 2.4°C)
.5
36.5-48.4°F (2.5- 9.1°C)
1.0
48.5-54.4°F (9.2-12.4°C)
0.5
54.5-60.6°F (12.5-15.9°C)
0
60.8-64.4°F (16-18°C)
-.5
>64.5°F (18°C)
-1.0