Monday, December 19, 2011

Thursday, December 15, 2011

Raspberry Seed Morphology

Each year I have an undergraduate student work in my program. Usually they help with crossing in the spring and do another small project of their own. Last year, Lauren M. took on a project looking very closely at raspberry seed size and shape. The inspiration for this project was some work done at the USDA-ARS Germplasm Repository and Oregon State University. In 2010, they published a manual on a way to identify blackberry cultivars by looking at thier seed size and shape. Here is a link to that work:;jsessionid=4D8C98C55C3539681A5FF1FA7446EFFE?sequence=1

Lauren spent many hours cleaning and photographing seeds of 16 different raspberry and blackberry cultivars. Here are a couple examples of what she found. Once you start looking closely, you can see how different two varieties can look. We are using this as one way to catalog our breeding material.

Thanks Lauren!

Wednesday, December 7, 2011

Blackberry Budget Update 2011

Sample worksheet gives you an idea of the cost of producing, harvesting and marketing blackberries in North Carolina. It includes worksheets for machinery, materials, yields, labor, production costs and returns. An in-depth financial analysis and overview of the operation is given based on the numbers you plug in.

Friday, December 2, 2011

Meridian AGree Newsfeed

This is the week of spreading information for this blog. Today, I want to share a newsfeed that I have found very interesting. For instance, I found it useful to see what how the 2012 (secret) Farm Bill was evolving. You can sign up and get a daily digest of ag. related news stories arrive in your email inbox every morning. 

To access the Meridian AGree NewsFeed, go to this site and sign up. 

Monday, November 28, 2011

Social media workshops

If you are reading this, I might be I am preaching to the choir. However, this message is worth spreading around.  I was sent this notice about a series of workshops that show you how to use social media on your farm. These workshops  are being conducted by the Carolina Farm Stewardship Association throughout NC in 2012.  See insert below for more information:

Social Media for Farmers

Want to harness the power of Facebook, Twitter and YouTube to reach new customers and grow your farm business?

You won’t want to miss this all-day hands-on workshop designed especially for farmers and taught by social media experts, Johanna Kramer (@durhamfoodie) and Cary and Grace Kanoy (GeoCore Films).

You will leave this workshop with a fully-functioning Facebook and Twitter page (or upgrade your existing pages), the skills to shoot your own short farm video using your cell phone, camera, or iPad, and the training to take better farm photos. Includes lunch. 

Cost: $10

All workshops will be held from 9:00-4:00 PM.
January 24 - Guilford County

January 31 - Watauga County

February 1 - Gaston County

February 16 - Lenoir County

March 6 - Buncombe County

August 16 - Chatham County

August TBA - Forsyth County

Call 919-542-2402, Email or 

On the web at CFSA's online store

These workshops are funded by a grant from the Golden LEAF Foundation and presented in partnership with the Center for Environmental Farming Systems, 10% Campaign, Food Corps, NC Cooperative Extension, and Know Your Farms.

Tuesday, November 22, 2011

Slide Share: Blackberry presentation by Dr. John Clark

For those of you unable to travel to conferences, this site has links to many berry talks given in all parts of the US. For example:

Blackberry presentation by John Clark at the Virginia State Berry Conference in 2011

Wednesday, November 16, 2011

North American Bramble Growers Call for Proposals

Attention Small Fruit Researchers

The North American Bramble Growers Research Foundation (NABG RF) is seeking proposals for the 2012 funding cycle. This year there are specific items that have been identified as important issues to growers. Please feel free to pass this along to your small fruit colleagues.

We have revised the submission process, so I hope it is easier to submit a proposal. If you have any questions, feel free to contact me, Proposals are due Dec 15, 2011. 

Here is a link to the website:

The North American Bramble Growers Research Foundation (NABG RF) is the research branch of the North American Raspberry and Blackberry Association (NARBA). 

Wednesday, November 9, 2011

Small Fruit Agent Training in NC

For the past two days, 24 agents from NC, SC, AR, TN, GA and VA attended a 2 day organic small fruit agent training session sponsored by the Southern Region Small Fruit Consortium (SRSFC). The SRSFC consists of  Clemson University, the University of Georgia, North Carolina State University, the University of Tennessee, Virginia Tech and the University of Arkansas.  The SRSFC was formed to help disseminate small fruit expertise and information throughout the region. One of the key functions of the Consortium is to hold agent trainings based on aspects of small fruit production. A list of the past agent trainings can be found at:

Yesterday, we had a classroom session that started with a general overview of organic production and certification.  Then a series of one hour sessions on strawberry, blueberry, caneberries, and grape organic production were presented.  There was a similar training in 2005, and most of what was presented was standard practices that help minimize pest pressure and general use of cover crops and composts. Although there are still many unknowns, there were many science based recommendations that will help agents help growers produce berries organically. Today we had a tour of the Vollmer Farm in Bunn NC. John Vollmer is the patriarch of this farm. John was one of the first farmers in the area to produce organic strawberries, and has since added blueberries and blackberries. Agents were able to see organic challenges and practices at this farm.

So, those of you in the states that are a part of the SRSFC should have agents that are better equipped to help you grow organic berries.

The picture above was taken today at the Vollmer Farm. Dr. Gerard Krewer, a retired Horticulture Extension Specialist at UGA, now a current organic blueberry grower shared his experience and expertise with the group.

Wednesday, November 2, 2011

Freeze ends blackberry harvest

We have a trial of primocane-fruiting blackberry selections at the Upper Mountain Research Station in Laurel Springs, NC. One set of plants are grown outside and another set are under a multibay high tunnel. Normally Laurel Springs gets its first frost in the first week of October, however this year, it did not occur until last week. 

On October 17, Absalom, my assistant,  took a picture of a developing fruit cluster (photo on left). The fruit was green and there were a couple of flower buds.  He took a photo again of the same plant and same flower cluster  on October 24 (photo on right). The night before, temperatures had dropped to 22 F in the open field and almost as cold in the tunnels. All the green fruit had turned brown and the flowers had turned black in the centers.

We are conducting a few tests, but our initial thoughts are that both the chlorophyll and phenologics ozidized as a result of exposure to freezing temperatures. This is what happens to grape berries in the fall that are hit by cold before they are harvested.

The tunnels did provide some protection, but not enough to save the crop. We estimate that we lost 70-80 of our potential yield. We will be reporting on this more this winter at grower meetings. 

Wednesday, October 26, 2011

NPR story about raspberries in NC!

Julie Zickefoose is a commentator on NPR.  This year she planted some raspberries and is now waiting for the fruit next year. Click on the link below to hear or read her full story.

Wednesday, October 19, 2011

ISHS HIgh Tunnel Symposium

I am attending the ISHS High Tunnel Symposium in State College, PA. Yesterday we toured the high tunnels at the Penn State University Center for Plasticulture. They have 39 single bay high tunnels at this one location. They grow a wide range of crops, including some very nice looking ginger, lettuce, louffa sponge, okra, pimiento and various hot peppers, edible squash flowers,  and lots of brassica crops at this time of the year.

However, the highlight of my day was seeing primocane-fruiting blackberry and raspberry trials in tunnels. Normally central PA will get a killing frost in the first week of Ocotober. However, Kathy Demchak, the Small Fruit Extension Specialist showed us a tunnel with several numbered selections of primocane-fruiting blackberry, and they all were still producing flowers and fruit in mid October. We also saw a trial of 'Heritage' and 'Nantahala', two late varieties of raspberry that were full of fruit. We were able to sample both of these varieties and I am very pleased to report that everyone agreed that 'Nantahala's flavor was exceptional.

Friday, October 14, 2011

Another grant! Red raspberry breeding this time.

A team of scientists from across the US and part of Canada have been funded by USDA-NIFA’s Specialty Crop Research Initiative to plan a breeding roadmap for US red raspberry cultivars. The roadmap will include developing a ranking system for existing and future cultivars in public breeding programs and identifying coordinated research steps to develop usable markers for resistance to certain pests, important horticultural traits and flavor characteristics sought by consumers. Together, this team will describe methods to address stumbling blocks existing within publically funded red raspberry breeding programs that are holding back increases in industry productivity and profitability. This $49,506 planning grant began on September 1, 2011. In order to collect stakeholder input, advisory boards will be recruited and public workshops will be offered.

Wednesday, October 12, 2011

Thursday, October 6, 2011

Specialty Crop Grant Awarded

The USDA just announced its 2011 Specialty Crop awards. We were one of the lucky ones, our grant "Partner with North Carolina State University to develop high quality raspberry cultivars that can be grown in the southern United States and are suitable for both local sales and commercial shipping" was funded. To see what else was funded go to:

Tuesday, October 4, 2011

Newsletter from Southern Region Small Fruit Consortium

Here is a link to the most recent issue the Small Fruit News, a quarterly publication from the Southern Region Small Fruit Consortium. There are several articles of interest for blackberry and raspberry growers, including an article on blackberry flavor written by Dr. John Clark, blackberry breeder from the University of Arkansas.

Monday, October 3, 2011

Louie Schwartzberg: The hidden beauty of pollination | Video on

This is an amazing video. The entire video is stunning, however, I like the shots at 4:52 (bees hovering), 4:57 (raspberry flower and fruit) and 5:00 (ripening strawberry). My students will be seeing this next semester when I teach HS 422, Small Fruit Production.

Louie Schwartzberg: The hidden beauty of pollination | Video on

Friday, September 23, 2011

A List of Blackberry and Raspberry Resources

compiled by
Gina E. Fernandez

NC MarketReady Growers Information Portals:
- section for blackberries/raspberries. SIGN UP FOR THE RSS feed!

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 

NC Small Fruit, Specialty Crop and Tobacco IPM Information:
Fruit/Nut Disease Information Notes:
- links to information on diseases of blueberries, muscadines, and strawberries

Berry Diagnostic Tool: 
- blackberries and raspberries 

Blackberries for the Home Garden:

List of Nurseries licensed to sell Univ Arkansas blackberries

List of nurseries licensed to sell ‘Nantahala’ red raspberry

2009 Nursery Guide for Berry & Small Fruit Crops: Brambles

Team Rubus Blog:

Team Rubus Twitter

Team Rubus

Monday, September 19, 2011

Can raspberries be picked pink for fresh markets?

By Penelope Perkins-Veazie, Plants for Human Health Institute, North Carolina State University and Gina Fernandez, Department of Horticultural Science NC State University

Raspberries are the most perishable of the temperate fruit crops. If you set them on your kitchen counter, you can watch the mold grow within 24 hours. This fruit’s delicate nature is due to its fragile structure, where drupelets are connected together by only a few trichomes (fruit hairs), no cuticle is present, and gray mold (Botrytis cinerea) can set up spores during bloom and produce fuzzy gray fruit as the berries are ripening.

While raspberry fruit mostly produce ethylene from the fruit calyx (the part of the fruit that remains on the plant), there is a small amount of ethylene, the fruit ripening hormone, present in many varieties. This actually can pose an advantage for fruit growers producing raspberries in the warmer parts of the season. Fruit at the pink or even pink-yellow stage will often detach from the calyx with minimal tugging.

We initiated a small test in 2010 to investigate the ability of raspberries to attain full ripeness if harvested unripe. These fruit were harvested in August and September from plants grown in high tunnels at the Upper Mountain Research Station, Laurel Springs, NC. Temperatures within the tunnels were above 85°F for approximately four hours per day. Unripe and ripe raspberries were picked at weekly intervals for the tests, over a three-week period, and one to two clamshells per cultivar and ripeness were used for the study. 

Raspberries were picked into halfpint clamshells and transported at 5°C in refrigerated ice chests (Kooltron) to Kannapolis, and held at 39 °F for six days. Subsamples were removed at day 0 to check firmness, color, sugars, and acidity. Subjective ratings were taken after storage by checking each berry for softness, leak, and mold. The overall color of the fruit within the clamshell was determined subjectively as 0 (light red) to 3 (dark purple red). Percent saleable fruit was determined by using the relationship of color to percent (where rating of 0 was 100% saleable to 3 was 0% saleable).

Surprisingly, even fruit picked considerably unripe (yellow-pink) achieved full color, soluble solids content, acidity, and flavor (tasted at random) after six days storage (Table 1). The biggest disadvantage of picking unripe berries was a depression in berry size of 4% to 20%, depending on variety and relative ripeness at harvest. What was clear from ratings was that fruit picked pink was much firmer and less leaky than berries picked at the normal commercial fresh market ripe stage (Table 2). The amount of moldy berries was slight (less than 10%), due to a rigorous fungicide spray program and the protective effect of the tunnels from moisture and wind.

We hoped that berries varieties known to turn dark red after storage, such as Joan J, would be less fully red if picked pink prior to storage. In fact, we found that color could not be slowed enough, with fruit reaching full color as soon as 2 days at 39° F after harvest. Figure 1 illustrates the change in color of ‘Culivar’ in ripe and unripe berries at 0, 5 and 10 days after harvest.

Flavonoids are compounds are compounds  that are associated with health benefits, and higher levels in fruit are good. Flavonoids in raspberry include the anthocyanins that give raspberries much of their red color, along with other colorless phenolic compounds. In raspberries picked before full ripeness, flavonoid content was decreased by 5-15% after storage. The slight loss in flavonoids in the less ripe fruit was madeup in the better appearance and firmness of the raspberries.

Harvesting raspberries at the pink stage is possible. We did not observe significant problems with composition and flavor, and early picking improves the number of marketable fruit. However, harvesting less ripe fruit is likely dependent on air temperature (detaching raspberries is difficult in cool weather), and will require more attention and training of pickers during harvest than pulling off fully ripe berries. Although we did not determine optimal temperatures for picking unripe berries in this study, the ability of raspberries to fully color up and soften may depend greatly on having a production environment where temperatures are at 75° F for at least four hours.

Table 1.  Comparison of raspberry fruit harvested unripe (pink) or ripe (red)
before and after storage at 4C, averaged for Joan J, Nantahala, Caroline
   Total phenolics
(mg/kg gallic acid equivalents)
   Total anthocyanin
(mg/kg cyan-3-glucoside equivalents)
   FRAP (Ferric reducing antioxidant potential)
(umol/g trolox equivalents)
   Soluble solids content (%)

   Titratable acidity (%)

Means separated within column and days 0,6 using student's t-test, P<5%.

Table 2.  Comparison of raspberries picked unripe (pink) or ripe (red) after storage at 4C for 6 days

%Leaky berries

  Autumn Britten
Means separated within column among cultivars, by letter (P<5%) using REGWQ.

The original version of this article (including photos) appears in Autumn 2011 issue of "The Bramble."  To access this article, you must be a member of the North American Raspberry and Blackberry Association. To become a member to: and click on Membership in the left purple panel. 

Monday, September 12, 2011

Fall Caneberry Field Work 2011

Blackberry and Raspberry (Caneberry/Bramble) Field Work for Fall 2011
Gina Fernandez, Small Fruit Specialist, North Carolina State University

Plant growth and development
Primocanes continue to grow, but slow down
Flower buds start to form
Primocane leaves senesce late fall

Primocane fruit harvest continues until frost

Pruning and trellising
Spent floricanes should be removed asap
Optimal time to prune is after the coldest part of the season is over. However pruning can start in late fall if plantings are large (late winter for smaller plantings)
Start trellis repairs after plants have defoliated

Weed management
Many summer weed problems can be best managed in the fall and winter using preemergent herbicides. Determine what weeds have been or could be a problem in your area. Check with your states agricultural chemical manual and local extension agent for the best-labeled chemicals to control these weeds.

Insect and disease scouting
Continue scouting for insects and diseases.
Remove damaged canes as soon as possible to lessen the impact of the pest.
Check the Southern Regional Bramble integrated Management Guide for recommendations.
Also check out Hannah Burrack’s blog.  She posts timely information on insects of interest.

Growers in warmer areas (e.g. extreme southeastern NC) can plant in December.  Preparations for winter planting should have already been made. If you have questions about winter planting please contact me at the above email address.
Prepare list of cultivars for next year’s new plantings. Find lists of nurseries at

Take soil tests to determine fertility needs for spring plantings.
Non-nitrogenous fertilizers are best applied in the fall to established plantings.
If soil is bare, plant an overwintering cover crop (e.g. rye) to build organic matter and slow soil erosion.

Marketing and miscellaneous
Order containers for next season
Make contacts for selling fruit next season

Make plans to attend Grower meetings! Blackberries and raspberries are part or all of these programs.
The 2012 North American Raspberry & Blackberry Conference will be January 16-18, 2012 in Sandusky, Ohio, in association w/Ohio Produce Growers and Marketers Association.
Caneberry session at the 2012 GA Fruit and Vegetable conference in Savannah GA. Jan 5-7, 2012

Southern Region Integrated Bramble Management Guide and the Southeast Regional Bramble Production Guide:

Blackberry and Raspberry Grower Information Portal:

My Social Media links:
Twitter: @NCTeamRubus
Facebook : Team Rubus

Friday, September 9, 2011

Flooded berry fields

This article is provided courtesy of Cornell University. Although it was written for flooding situations in the northeast, some information may be useful for parts of NC as well.

Steve Reiners and Marvin Pritts
Dept. of Horticulture
Cornell University

Record-breaking rains in the East have left many berry growers with unmarketable crops.  What had been shaping up to be a decent season for fall raspberries and dayneutral strawberries has quickly turned into a bad situation. 


There are two types of flooding.  The first is more typical and occurs after a heavy downpour when fields become saturated and water pools on the soil surface.  This type of flooding can reduce yields and even kill plants but usually will not result in contamination of produce with human pathogens.  The second type of flooding is more severe and unfortunately occurred with the recent storm. This occurs due to runoff from stream/river overflows will more likely be contaminated with human pathogens, as well as chemicals. Unless you are absolutely sure that flooding is not from streams and surface water, do not use berries that were covered with flood water.


How long a crop can live once it is flooded and what may be the effect on yield? Berry crops can tolerate a great deal of flooding when they are dormant, but when actively growing in summer, flooding for any length of time can be detrimental. This time of year is particularly bad because plants are preparing to make flower buds for next year, and stress can compromise this process. If plant roots were under water for more than 48 hours, expect next year’s crop to be compromised as well.

Plants previously flooded may develop an off-green or yellowish color.  These plants are suffering from a complex of nutrient deficiencies, nitrogen, phosphorus, potassium and perhaps others, even though the soil contains adequate amounts. But the main deficient element is oxygen. Plant roots need oxygen to take up nutrients and water to utilize the photosynthate from the tops and to grow. With the heavy rains we have had, soils are saturated; that is, nearly all of the pore space is filled with water, leaving little room for air. Ideally, for good root growth 50 percent of the pore space should be filled with air. As soils drain, air is drawn into the soil, but when it rains, the water forces the air out of the pores. As is obvious to all, what is needed now is several rain-free days so the soils can drain and draw in air to stimulate root growth and help disperse toxic compounds that accumulate when plants lack oxygen.  Once the plant roots get adequate oxygen they will begin to grow and take up the nutrients present in the soil. Anything that can be done to remove surface water will be helpful.

Many plant diseases will be much worse following flooding rains (e.g. Phytophthora and Botrytis), so closely monitor crops and manage these diseases. Phytophthora spores are spread under flooded conditions, so chemical treatment may be warranted in susceptible crops (e.g. red raspberries and strawberries).

(Thanks to Steve Rieners and Marvin Pritts at Cornell University for sharing this with us.) 

Tuesday, September 6, 2011

New Publication

Dr. Ramรณn Molina-Bravo, was a PhD student that worked with myself and Dr. Bryon Sosinski at NCSU. Dr. Molina-Bravo just published an article that details a study that he conducted as part of his research. In a nutshell, he was able to identify several plants in a population of seedlings that had higher chlorophyll fluorescence, a trait that is associated with heat tolerance. We are using those individuals in our breeding program to see if they will survive the heat in additional locations and we will be using them in crosses in the near future.  Congrats Ramon! Here is a link to that article. doi:10.1016/j.scienta.2011.07.022

Thursday, September 1, 2011

Caneberry Workshop

The Caneberry Workshop was a great success. We had over 60 participants, most were from North Carolina, but some even came from Illinois, Virginia and Kentucky! One of the goals of the workshop was to generate interest in growing caneberries in this part of the state. I think we succeeded in generating interest, I am hopeful that we will see some production in this area in the future.

The workshop featured work being done at the station by Drs. Hannah Burrack, Penny Perkins-Veazie and myself. (NB - this may have been the first workshop lead by all female NCSU faculty in history!) Dr. Burrack focused on her Spotted Wing Drosophila work, Dr. Veazie discussed pre and post harvest handling of fruit and I talked about the replicated trials of blackberries and raspberries in and out of tunnels.

I gave the participants a tour of the replicated breeding trials. The caneberry breeding program has several locations where we test our materials. One of the locations is here at the Upper Mountain Reserach Station in Laurel Springs. This is our highest sight, at about 2500-3000' elevation and is in USDA hardiness zone 6. The average high temperatures in summers are in the low 80's and nights are cool as well....compared to the rest of the state. Raspberries love it here!

At this location we have one of our mirror 'variety' trials. We have a mix of varieties and selections from our breeding program, USDA and other Univ. breeding programs as well as recently named varieties. Each of the varieties was growing both under high tunnels and outside of tunnels. This allows us to compare overall growth, ripening season and fruit quality among lots of other attributes. Primocane fruiting raspberries were in the early part of their season, while floricane fruiting types had finished a couple of weeks ago. Floricane fruiting blackberries were still producing fruit and primocane fruiting types were flowering and had lots of green fruit. We will post the data on the NC Market Ready Portal at the end of the season here:
(There is data from other locations at this site that you may want to check out as well).

Dr. Penny Perkins-Veazie discussed pre and post harvest handling of raspberry and blackberry fruit. Participants comments included, "I never knew raspberries came in so many different colors of red". They also learned that most customers don't like dark red berries. She also discussed how picking pink berries will last longer on the shelf.  She recently wrote an article about this. I will post a link on a later blog post.

Dr. Hannah Burrack discussed her work with spotted wing drosophila (SWD). This location is what she calls "Ground Zero" for SWD. Participants got to see SWD in all of its stages and learn more about how it impacts fruit production. She has a blog of her own where she regularly updates her findings.

A BIG thanks to all of the folks at the Upper Mountain Research Station that helped get the fields looking tip top and setting up the field and inside venue. I sincerely appreciate all you do for the caneberry programs. Sponsors included the College of Agriculture and Life Sciences, the North Carolina Agricultural Research Service and the North Carolina Cooperative Extension Service at N.C. State University; the N.C. Department of Agriculture and Consumer Services; and the N.C. Tobacco Trust Fund Commission.

Thursday, August 25, 2011

Hurricane Preparation

Just a quick note to caneberry growers in Eastern NC. #HurricaneIrene looks be be heading for NC. The Nursery folks at NCSU have prepared a nice list of things to do before and after a hurricane. Not all of the items will be appropriate for your situation, but many will. Here is a link.

Thursday, August 18, 2011

Caneberry workshop Aug 31

There will be a blackberry and raspberry workshop in Laurel Springs at Upper Mountain Research Station on Aug. 31 from 9-12. Lunch will be served.

We will have tours of the raspberry and blackberry plots (some are in tunnels). Dr Hannah Burrack will be there talking about insects of importance to caneberry production including spotted wing drosophila. Dr.Penny Perkins-Veazie will be discussing post harvest handling of caneberries. 

For addition information, contact Ray Horton at 704-904-4117 or Margaret Blevins at 336-982-2501.

Tuesday, August 16, 2011

Coming soon to your community

Have you seen the "Got to be NC Grown" panels on trucks around the state? Well now we have a truck that has a blackberry and raspberry theme! Thanks to the NC Tobacco Trust Fund Commission, NC Department of Agriculture and Consumer Services and NC State University for promoting these fantastic crops.

Friday, August 12, 2011

NC Blueberry Blog

Bill Cline, the NCSU Blueberry Specialist has a blog. It has lots of great information on cultivars and diseases. Check it out at

Wednesday, August 3, 2011

Heat stress in raspberries, part 3

The final chapter in the raspberry heat stress story is about picking the right parents.  We have determined that some species of raspberry do better than others in the heat so we are using them in some of our crosses.

Above is a picture of 'Mandarin'.  This variety was released from NCSU in 1955. It is more resistant to heat than other varieties (note the other plots in the field behind it that are not doing as well). 'Mandarin' is 1/4 R. parvifolius, a species that is native to Asia

'Mandarin' is not available from nurseries, the fruit is small and soft and the yields are low, so it can not compete with newer varieties. However, we are using 'Mandarin' and some of its relatives in our program and are making progress in finding a heat tolerant variety with good fruit traits. 

Friday, July 29, 2011

Tuesday, July 26, 2011

Heat stress in raspberries, part 2

So, many of you are probably thinking "Why would anyone try to grow raspberries in a hot, humid environment like North Carolina?" Well, you are not the only one that has had that thought. There are several points that I want to make in regard to this idea.

First, North Carolina has multiple environments. The three primary regions are the Coastal Plain, Piedmont and the Mountains.  So, within the state we have a range of elevations from sea level to over 3000 ft (ca 1000 m). This allows us to grow our plants in a wide range of environments.  In the summer, all regions are hot, some are just not as hot, with high temperatures only in the 80's. However, this range of climates allows some growers to produce fruit earlier in the season and some can go later in the season. We are not trying to produce raspberries in the coastal plain in mid July. That is just too hot for this delicate fruit.

Second, in warm conditions, fruit set is often a problem. However, in our screening process, we find that some of our test plants that are able to survive the heat and have flowers that can produce fruit.  And it is this last group that we choose to select and propagate for further observations. 

Third, even if a raspberry variety can survive in the hotter areas, we find that fruit size improves when we move it to our more moderate locations (see example of fruit size above). The two pictures are fruit from the same selection planted in two different places. The hotter location is SH (the Sandhills) and Sal (Salisbury) is only 90 miles away. 

Lastly, we are finding, thanks to Dr. Penny Perkins-Veazie, that even though some of the newer varieties look good at harvest, once we pick them they go downhill rapidly. Amazingly, the test plants from our program always seem to do better. 

The role of the environment on the performance of a variety is huge. In fact plant breeders spend alot of time evaluating GXE (Genotype X Environment) interactions. We know that the environmental influence on raspberry performance is significant and that our hot and humid climate enables us to screen in an environment that is not ideal for most raspberry varieties. But we are trying and think we are making good progress.

Friday, July 22, 2011

Blackberry and Raspberry Post Harvest Evaluation

Evaluation of blackberry post harvest traits
We have an amazing team of scientists at NC State University working on blackberries and raspberries (Team Rubus). One of the newer members of our team is Dr. Penny Perkins-Veazie. Dr. Perkins-Veazie, worked for many years at USDA-ARS as a post harvest physiologist. She is  now located at the Plants for Human Health Institute at the NC Research Campus in Kannapolis. One of the projects we have is the evaluation of raspberry and blackberry fruit post harvest traits. She is also working to determine which varieties contain antioxidant compounds in Rubus fruit.

In the picture above, Dr. Perkins-Veazie shows a graduate student how to evaluate the post harvest traits of blackberries.

There is You Tube a video link to this protocol at: