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:

Thursday, July 21, 2011

Heat stress in raspberries, part 1

Severe leaf cupping
Moderate leaf cupping
Today in North Carolina, the temperatures are expected to reach 99F (37C). This type of heat is extremely stressful for raspberry plants and very often they will not live for more than a year or two under these conditions. However, we have found that by screening plants in this type of environment, we are able to find some plants that are somewhat tolerant of heat.

Above are pictures of 2 plants in a seedling population taken on the same day last week when it was hot like it is today. The plants are from the same parents, and are in fact, adjacent to one in another in the field at the Sandhills Research Station in Jackson Springs, NC.  The leaves on the first plant are cupped upward, a classic sign of heat stress, while the second plant has leaves that are only moderately cupped. Most of the plants in this population had severely cupped leaves. But a few did not and those are the ones that we will keep, and test in future trials.

Wednesday, July 20, 2011

Southern Region Small Fruit Consortium

"The mission of the Southern Region Small Fruit Consortium (SRSFC) is to enhance collaborative efforts between small fruit growers and grower organizations, industries and service organizations allied with and/or serving small fruit growers, agricultural extension programs and research stations working together to enhance the development of the small fruit industries in the region."

The quote above which is slightly modified from the original form, is taken from the website of the The Southern Region Small Fruit Consortium (SRSFC). The SRSFC is sponsored by seven Universities in the southern US including, North Carolina State University, University of Georgia, University of Arkansas, Clemson University, University of Georgia, University of Tennessee and VA Polytechnic Institute and State University.

Every four months, a newsletter is published online by the SRSFC. The newsletter usually has several articles on recent research or extension information as well as checklists for several small fruit crops. The SRSFC also has a great website that includes IPM and production guides for small fruit crops grown in the region.

Here is a link to their website:
http://www.smallfruits.org/

Here is a link to the latest newsletter:
http://www.smallfruits.org/Newsletter/Vol11-Issue3.pdf

Wednesday, July 13, 2011

Video of Southside Farms on TV

Hi Folks, Here is the video that was mentioned in the previous post about Southside Farms. I tried to post just the segment of interest, but the whole episode comes up. The segment on the Southside Farms starts at about 6:30. I have worked with the Hardings for many years and helped them move from tobacco to fruit and vegetables. They have a retirement community within a few miles of the farm. The retirees (mostly northerners) are very devoted customers. For those of you from not around these parts, you may enjoy watching the entire video to see some of the other wonders of North Carolina. Enjoy!



Watch the full episode. See more NC Weekend.

Friday, July 8, 2011

NC Blackberry Farmer featured on UNC TV this weekend

Southside Farms will be featured on the UNC TV show, North Carolina Weekend tonight at 8:30 and tomorrow morning.  Southside Farms grows all sorts of produce, including blackberries. The show airs tonight at 8:30 and again tomorrow morning.  For those of you outside the viewing area, the show will be online soon (next week?) at http://www.unctv.org/ncweekend/.  Woot!

Wednesday, July 6, 2011

Market prices

Interested in prices of blackberries or raspberries throughout the US? The folks at NC Market Ready have set up a useful link to the USDA site, go to the bottom of the following page  and click where it says "USDA Fruit and Vegetable Market News", where it will allow you to run a report for blackberries or raspberries:
http://ncsu.edu/enterprises/blackberries-raspberries/category/links/

Friday, July 1, 2011

Award Winning Student!

Christine Bradish, a MS candidate just returned from the Berry Health Symposium #berryhealth. She won 1st place in the poster competition.  Christine is working with Drs. Penny Perkins, Wei Jei and myself and is in the final stages of her MS degree at NC State University.


Christine looked for flavonoids in red raspberry that are known to be good for you.  She used metabolite-profiling to qualify, quantify, and compare major flavonoid compounds in primocane-fruiting red raspberry cultivars grown at three locations with varying elevation and average temperatures in North Carolina. 


She found:
 •There was significant qualitative and quantitative differences in the metabolite profiles, due to variation in cultivar, location, and environmental factors. (=not all raspberries are the same in terms of health benefits)

Plants exposed to longer durations of heat stress (over 85°F) had higher total phenolics measurements and antioxidant capacity due to greater production of flavonoid secondary metabolites. (=stress may increase the good compounds in berries)

Implications: 
Utilization of metabolite profiles, such as the ones in this study, could help breeding programs identify key metabolites contributing to antioxidant properties, and define the genotype-by-environment interactions on them. 
This technology may be useful for the development of nutritionally enhanced varieties, and further tailoring for functional foods.
The link to the proceedings is below. Her abstract is on page 61.
http://www.berryhealth.org/Information/2011_preproceedings_sm.pdf