Thursday, March 29, 2012

New Rust disease?

Spring is the time of year when we usually see the first signs of a disease known as Orange Rust. Orange Rust is a systemic disease that is very hard to control, once a plant is infected.  One of the tell tale symptoms are bright orange spots on the undersides and margins of leaves and a spindly overall appearance of the plant. This spring some growers are seeing orange spots on blackberry leaves, but the symptoms are not what we expect...

Below is an email that was just sent out from Dr. Phil Brannen. Growers in the SEUS should be  on the lookout for plants with these symptoms and use your state disease clinic or specialists to help you identify the potential causal organism....

"Commercial blackberry producers should be on the lookout for blackberry rusts (there are several), and they should likewise be maintaining a good rust control program through use of cultural practices and fungicide applications.  Conditions may be particularly conducive for rust development this year due to a warm fall and winter.  There is also the possibility that we are observing a new rust on blackberries in the Southeast.  

Last week, a Natchez thornless blackberry specimen was submitted to the UGA diagnostic clinic in Athens.  Though we sometimes observe orange rust as the leaves emerge in the spring, we did not observe typical symptoms of orange rust, and the spores did not match those of other common blackberry rust diseases.  Also, the producer indicated that all of his Natchez plants were showing this rust symptom, and that would be very unusual for orange rust, as it is usually limited to only a few plants.  Today, I received questions from North Carolina as to rust issues there. 

Charles Hodges (North Carolina State University) writes of a rust on a Navaho thornless blackberry sample:

“I have had a lot of trouble trying to identify the rust species on the specimen of blackberry submitted and am still not sure of just what it is. The symptoms are not consistent with those of orange rust which is characterized by stunted and misshapened leaves, nor are the fruiting bodies and spores similar to orange rust. The rust fruiting bodies and spores on the underside of the leaves more nearly fit the uredinial stage of cane and leaf rust (Kuehneola uredinis). However, there is no evidence of the spermagonial, aecial, and telial stages that should be on the same infected leaf at this time of year. Furthermore, I could not find any fruiting bodies of the rust on the canes, which is common with the cane and leaf rust.”

This description from North Carolina, though highly technical, perfectly matches our Georgia observations as well. It makes me think that we are dealing with a new rust or one that is problematic as a result of the warmer weather we have experienced this year. 

Producers are automatically assuming that this is orange rust due to the timing, and our general recommendation for orange rust infected plants would be complete plant destruction, since it is a systemic rust disease.  However, we have never seen orange rust take over large acreages to date -- always isolated plants in well managed commercial blackberry plantings.  DO NOT assume orange rust and DO NOT automatically dig up symptomatic plants till you truly confirm orange rust is the culprit.  If a specimen is identified as orange rust (county agent can often just send a photo of the symptoms or a hard sample can be sent to the diagnostic clinic in Athens), then we would recommend complete destruction of infected plants.  There may in fact also be more orange rust this year as well, since a warmer fall/winter has possibly allowed a second round of infections -- likely in the fall of last year.  Orange rust management requires fungicide application from early bud break through early to mid-summer, and this normally addresses other blackberry rusts as well.   Follow rust disease management guidelines found in the Blackberry IPM Guide at

Again, don't dig up anything till you truly confirm orange rust.  Based on these initial reports, our current blackberry rust is either a new rusts or one that is generally present but not normally problematic.  Please share this information with your commercial blackberry producers, as they need this information to help them in their management decisions. "

Thursday, March 22, 2012

USDA NASS berry production data

The USDA National Agriculture Statistic Service recently released a report "Noncitrus Fruits and Nuts 2011 Preliminary Summary." This report includes lots of data on production, acreage, value, and prices received of many fruit crops including berries for the period 2009-2011.  However, there are no reports associated with blackberry production in the Southeastern US or California. The reason it is not there is because this agency uses the Census of Agriculture as a basis for commodities that will be included for a period of 5 years. The last Census of Agriculture was taken in 2007. Blackberry production in the SEUS started to kick in in 2008-9. We should be included in the census scheduled for 2012. If you want to look at that report, here is a link: Noncitrus Fruits and Nuts 2011 Preliminary Summary

Wednesday, March 14, 2012

Pruning workshop at Center for Environmental Farming Systems

The Center for Environmental Farming Systems holds a series of workhops each year. Last weekend I was invited down to present a workshop on how to grow and how to prune blackberries. We spent some time inside learning the basics on how to grow blackberries, then we headed out to the field to prune some blackberries, one of my favorite jobs.

First we had a lesson on getting your equipment ready, clean, sharpen and lubricate your pruners now before the season starts. There are a couple of websites associated with some brand name pruners that can help you with this job.

After our cleaning lesson, we started to prune. I always say "Start with the easy cuts, first." Remove canes that are too big, too small or have obvious insect problems like the red necked cane borer (RNCB) galls as seen in above picture. We saw lots of these galls and removed all the canes that had this type of injury. Hannah Burrack has a nice blog post about  RNCB here

Another easy decision is to remove the canes that are too big. You need to use loppers for those.
Then comes the harder part, which ones to leave and which ones to stay?

I handed out a cheat sheet on pruning at the workshop. You can find it here.

Wednesday, March 7, 2012

Dole acquires Mrs. May's to boost natural portfolio

Dole acquires Mrs. May's to boost natural portfolio

So, in addition to the recent addition of SunnyRidge, Dole is adding healthy packaged foods to its portfolio. Will we be seeing more berry packaged treats?

Tuesday, March 6, 2012

Chilling update early March

As scheduled, the blackberry model ended on 28 February. Most stations had lower chilling units than last year. In some cases there was a great difference in the amount of chilling units between the two years and in other instances (400+ units), the difference was not as large (100+).

In the mountains, Mills River and Hendersonville, NC, there was actually more chilling units this year. These are high elevation sites, so there is not much of a concern with low chilling most years.

Here are some season totals of chilling units across the state for this season and the previous season:

LOCATION in NC                                                                                              
                                                                               2011-12    2010-11
Horticultural Crops Research Station, Castle Hayne      453           759
Lake Wheeler Research Station, Raleigh                      854           993
Sandhills Research Station, Jackson Springs                 459           939
Piedmont Research Station, Salisbury                          859          1043 
Lincolnton airport, Lincolnton                                     692          1126 
Hort. Crops Res. Station, Mills River                          1047         1010 
Bearwallow Mountain, Hendersonville                        1108           839

Some keen observers may note that the blueberry chilling unit accumulation for Castle Hayne is different. The blueberry model calculated 882 units at the same location. There are some distinct differences in the models, i.e. start date, assignment of units based on temperatures. (see

Saturday, March 3, 2012

Pruning Demonstration in Gibsonville

Yesterday, Kathryn Holmes, an Extension Agent with North Carolina Cooperative Extension, in Rockingham County, held a caneberry pruning demonstration for approximately 26 people at the High Rock Farm in Gibsonville, NC. Richard Teagues, the owner of the farm, grows blackberries, raspberries and other fruits and nuts and sells them at markets in nearby cities like Chapel Hill.

We started the demonstration with a quick lesson on how to get your pruning equipment ready for a new season. Pruners and loppers should be cleaned and lubricated at least once a year, some tools may need to be sharpened as well. There are several websites that can show you how to do this online. We also talked about when and how to clean pruners while pruning to reduce the spread of diseases. There is a great article on the pros and cons of when to do this, written by Dr. Linda Chalker-Scott Washington State University Puyallup Research and Extension Center. She works with ornmental crops, but the practice would be similar for caneberries.

There are several rows of thornless blackberries and one row of Dormanred raspberry planted in single wire rows. The plants had not been pruned after harvest, so it was a great way to show how to prune the spent floricanes out (canes that had produced fruit last year) and how to thin and prune primocanes that will produce fruit in the upcoming year. The plants had been in the ground since 2009. We discussed how to prune in the summer, how and when tipping is done to minimize cane blight, and increase lateral development. They will be putting in new rows with a t-trellis, which will enable them to produce more fruit per row. Here is a copy of the pruning cheat sheet I provided to them.

Thank-you Kathryn, Mr. Teagues and his son, Howard Johnson, and Christine Bradish for helping me with this rainy day activity.