Hello, I’m John Clark and I work at the University of Arkansas System Division of
Agriculture, and I’m at the Division’s Fruit Research Station near Clarksville.
This is where our fruit breeding program has been based since its beginning in 1964.
Dr. James Moore had a broad dream when he began the fruit breeding program, working
on a range of crops.
But one of our most important crops and where we’ve had our greatest success is blackberries.
The first blackberries were released in 1974: the varieties Comanche and Cherokee.
And a whole series of those have been released since then.
The first thornless was Navaho, which took twenty-five years to get the canes to stand
upright and get thornlessness in the canes.
And the floricane-fruiting varieties that followed such as Arapaho, Apache, Ouachita
and Osage have all made major contributions to commercial blackberry production for shipping,
local markets, and they’re really good at home also.
Then we began to work in the late 90’s in primocane fruiting: a true breakthrough in
blackberry production to allow fruiting for a longer period.
These are some of the key achievements of the program and it’s really exciting to
get to share them with you today.
I’m often asked: "What is a primocane-fruiting blackberry?"
Well the first thing we need to talk about is what is a blackberry botanically?
Blackberries and their cousin raspberries are very unique plants.
They have a perennial root system which means they live year after year after year, but
they have biennial canes, meaning the canes live two years.
This is quite unusual in the plant kingdom.
Most of the blackberries you’ve seen are floricane-fruiting varieties, where the primocane
grows the first year, the first year of growth, it goes through a dormant period, and the
second year it flowers and fruits, and after flowering and fruiting, it senesces and dies
and the new primocane is growing for next year’s crop.
And one of the key things about floricane-fruiting varieties, the type that goes through the
dormant period, most of the ones in the world today, is this time of year the primocanes
are vegetative and you can see the growing point has no flowers.
This is the floricane-fruiting cane and this cane will fruit next summer providing fruit
from May to July, depending on where you’re located in the Northern Hemisphere.
Now primocane-fruiting blackberries are something entirely new.
And the primocane-fruiting variety produces fruit on the current season cane or the primocane.
This cane emerged from the crown or root system this year and the cane terminated in flowers
and the small berries developing.
In the blackberry world this is a breakthrough because it offers a number of advantages.
First, in theory you can get two crops on the same plant.
You can also, in appropriate environmental conditions, get fruit until frost.
Another advantage potentially of primocane-fruiting blackberries is in cold regions of the country
or world, where the canes will not overwinter due to damaging temperatures.
With the primocane-fruiting cultivars they can grow from the crown or the root system,
emerge, flower and fruit on the current season canes.
Now it may take some special management to do that but it opens up a lot of new windows.
So what does that mean in production?
This allows production for an extended period —
not just the four to six weeks that we often think about blackberry production being active in a region.
But in theory can move to six months, possibly more, with various cultivars
of floricane-fruiting, primocane-fruiting and management of the canes.
So primacane fruiting gives us an opportunity to expand production areas, regions, environments
blackberries be grown and really important is keep blackberries on the market shelf so
consumers always have them on hand for buying opportunities.
Primocane fruiting is one of the biggest things I’ve seen come along in blackberries and
it’s exciting to be a part of this new technology for blackberry producers.
Let’s talk a little bit about the history of primocane fruiting and blackberries.
The trait was found in a wild plant found in Virginia many years ago.
In Arkansas we’ve been working for the last twenty-one years on primocane fruiting to
improve it and incorporate it in our blackberry breeding program.
I remember the day, September 27, 1997 when we selected the first
fourteen primocane-fruiting blackberry selections.
I remember leaving the field that day thinking, “Wow, this is exciting.”
The first thought, “this is almost a new crop and it will be fun for the next twenty-five
years of my career to improve this.”
The other thought was “Wow, those berries aren’t very good.”
They were small little berries.
Many of them had poor flavor.
Often many of them were doubles, many of them had poor color, so I looked at that and said,
“How are we going to make that better?”
Well it’s been quite the story to be where we are today: primocane-fruiting cultivars
that have diverse times of flowering, thornlessness, high fruit quality, high productivity.
We’ve got a long way to go to make the perfect primocane-fruiting blackberry but we are well
on our way at the University of Arkansas.
This is Prime-Ark® 45, released in 2009 from the University fruit breeding program.
Prime-Ark® 45 is the world’s first shipping-quality primocane-fruiting blackberry.
It has large fruit, very good flavor, good shipping capability and high productivity.
I’m holding floricane-fruiting plants right now that have borne fruit in June and the
blooms are now present on the primocanes to produce the primocane crop.
Prime-Ark® 45 is thorny so that’s something to consider.
It works well in commercial production; however you might want to think about that for pick-your-own
because oftentimes pick-your-own customers are concerned about thorns.
Prime-Ark® 45 is a great choice and one that a lot of people are really happy with.
This is Prime-Ark® Freedom.
It was the world’s first thornless primocane-fruiting blackberry, released in 2013.
Prime-Ark® Freedom is unique, and we finally got the thorns off the plants; however, it’s
more of a homeowner or pick-your-own or local market berry because it does not ship as well
as Prime-Ark® 45 or Prime-Ark® Traveler.
But look at these berries.
Wow, these are impressive.
These are floricane berries that have ripened in late June here in Arkansas and right now
there are small green berries on the primocanes which will produce the second crop.
These are bragging berries.
This is Prime-Ark® Traveler, a 2014 release from the University fruit breeding program.
This is the world’s first commercial shipping-quality, thornless primocane-fruiting blackberry.
It has large fruit, very nice flavor, it has a sub-acid flavor that consumers really like.
These are floricane fruit ripening in late June in west central Arkansas.
But right now, the canes are setting the primocane crop and that’s a crop that in certain conditions,
particularly mild climates, you can extend the production season for quite a long time.
Prime-Ark® Traveler has been a lot of fun to develop and I hope it will cause lots of
satisfaction with growers and consumers.
One of the key aspects of managing erect-cane blackberries is the tipping of the primocanes
during the growing season.
This needs to be carried out on all blackberries, and for example here you see the branching
that occurs after tipping the primocane.
If this is not done, the cane will continue to expand and can get outside of the areas
you want the plants to grow.
You can see the point that the primocane was tipped here several weeks ago has resulted
into multiple lateral branches which are producing numerous berries.
This is a key component of managing erect-cane blackberries, and it increases the fruiting
area of primocane-fruiting varieties.
Research in Oregon and in California has shown that multiple tippings are really valuable
for increasing yields.
For instance, tipping at about a foot-and-a-half to three-feet tall, and then tipping the laterals
that result from that at the same length multiplies the growing points, multiplies flowering, increases yields.
So that has to be looked at carefully as you manage primocane-fruiting varieties so that
you get all you can from the plants for high levels of productivity and increased grower profits.
This is a primocane and the tipping is done approximately shoulder height.
It’s very simple, just a cut like that and that will maintain the hedge row that you
want to have to keep your plants under control and keep the canes where you want them.
Wow, that’s simple.
And as long as you do it, particularly when the canes are small and the tips are soft,
you get the maximum response and its greatest health opportunity for the plant to heal the
cut and result in nice lateral branching.
The lateral branches are critical for increased yields, creating a beautiful hedge row, lateral
branches, high productivity and blackberries that are easy to maintain.
One of the first challenges I saw with primocane-fruiting blackberries back in 1997 was the impact of
heat on the primocane fruiting potential.
My observations over the last twenty years is pretty much when it gets on above ninety-degrees Fahrenheit
for multiple days or extended periods, that hinders primocane fruiting.
Hinders it how?
First off, when it gets really hot, on up around a hundred, it will stop the flowering process.
It will inhibit bud formation.
It can lead to double fruits, it can make the berries smaller.
It can make poor quality and poor color, so it can be quite dramatic.
The cane I’m holding here is developing very nice with full-set berries.
And so this is developed in the upper eighties showing adaptation in that climate.
Primocane fruiting has got a long way to go before it’s adapted to all growers and all
regions of the country.
So everybody’s going to have to pitch in and do a little bit to figure out what is
best for every region and down to each farm.
Primocane fruiting is one of the true breakthroughs in new blackberry production technology.
But there’s a lot to be done to develop the exact growing methods for homeowners,
local markets, and commercial producers.
There’s a lot to do to adapt the technology to farms across the country and world.
It’s an exciting time and that’s something to look forward to in the years to come for
increased blackberry production.