Winter is a Great Time for Education

Most of us are quite content to ignore our fruit plantings during the winter. At least I know I am guilty of that. Winter brings about other challenges for me — end of year reporting, conferences to attend, data to analyze, papers to write, etc. I know that everyone has their own stuff to deal with too making it difficult to keep your mind on something that isn’t growing (or at least appears that way). Of course there are a myriad of things that could be done to improve the planting, of which pruning and sanitation are some of the most important. However, I believe the most important thing to do during the time when it is too cold to get outside and you would rather bundle up in a blanket next to a warm fire is to learn. Education is a never-ending process. New things are discovered every year about fruiting crops. New pests, new varieties, new methods of management, etc. The great thing is that you no longer need to drive somewhere during sleet, snow, or icy drizzle to get to a meeting. Extension is starting to embrace online education techniques like webinars and blogs to keep clientele apprised of new discoveries. I would also encourage social media interaction. There are lots of Extension specialists and agents on Facebook, Twitter, Instagram, Snapchat, Pinterest, etc.  These are all platforms to interact with us. If you don’t know how, just ask and any of us would be happy to help you learn these new things.  The world is digital and not going back. If we can find common ground with our learning environments we can all be so much better informed. So, what to do during this winter? Try something new and learn, learn, learn.

On the IARC, Red Meat, and the Media

Recently, the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO) came out with a statement that said, based on a literature review, red meats are probable carcinogens (Group 2A) and processed meats are carcinogenic (Group 1). The short memo can be read here. Other clarifications of what the Groups mean and about the red and processed meats can be found here and here. All of these documents are more revealing than most of the news stories have portrayed the issue. Headlines like, “Bacon is carcinogenic!” lead one to believe that eating bacon will give you cancer. This type of hyperbole leads to a great deal of angst among the readership, most of whom will not read the links I provided above. We have probably all heard the phrase “If it bleeds, it leads” in regard to the media. I am not here to berate the media over the way they cover the stories — they have a job to do and writers have someone to answer to for their performance. In some cases, I think the writers don’t recognize, or don’t care, how their stories can impact other people. Can a negative, and incomplete, story on bacon depress sales, leading to a loss of income for farmers, resulting in layoffs, tarnished careers, bankruptcies, etc. Hmm, it could, but it’s a story so run with it, torpedoes be damned. There are other topics when this has also been true recently, that go beyond the news into another arena altogether. So, the onus is on the reader to separate real news from the hogwash passing off as news these days.

In regards to the red meat story, the IARC says that processed meat is carcinogenic to humans. Do you know what else falls into this group? Alcoholic beverages, diesel engine exhaust, outdoor air pollution, solar radiation, tobacco use, and wood dust among a whole list of other things. One’s exposure to any one of these things will vary by individual, but the IARC is not explicit on how much exposure will lead to cancer expression. They have a guess based on 10 studies (50 grams daily of processed meat leads to an 18% increase in possibility of colorectal cancer). Yet, in fact, they do not know the answer to that. It is a complicated interaction of genes and environment. But, based on the way it is presented in some media articles, processed meat such as bacon must be as dangerous as using tobacco or breathing diesel engine fumes. Right? Well, no. The IARC is not addressing risk and so items within the same group should not be compared.

The IARC states that “high consumption” of red meats may lead to “small increases of risk of several cancers”. In fact, they state that “these risks are small” and do not define “high consumption”. They also state that the evidence is “limited”. Their best guess is that for every daily portion of 100 grams (3.5 ounces) of red meat, cancer risk is elevated by 17%. Overall the classification is rather meaningless unless it can be bound contextually by parameters that make sense and can be employed in everyday life. Essentially the IARC is saying, “We think folks should not eat as much red meat and especially processed meats based on some studies we analyzed. They could, possibly, play a role in cancer development, in some people, in some places…we think…based on the limited evidence available.” Okay, so no big deal, right? Dial back the consumption of red meat. It won’t guarantee you won’t get cancer, but it can’t hurt. But when the media got hold of the story, it took on a life of its own.

Me bashing the media wouldn’t solve anything and there is no reason to do it — in many cases the media is a good outlet for information, but information consumer needs to beware. Every media story starts with a source. If possible, go back to the source to get the straight story, because every media story has a bias (either intentional or unintentional) and an interpretation. That interpretation may be right or wrong or some of both. In any case, this is my interpretation of the IARC red meat story — I hope you will read the provided links to decide for yourself.

Mississippi Vaccinium Journal Oct-Dec 2015

The latest issue of the Mississippi Vaccinium Journal is out. In it several topics are covered including some SWD research, red leaf color, government programs, revised publications, and more.  Check it out by downloading the PDF at the link below:

Mississippi Vaccinium Journal. 2015. Vol. 4 Issue 4

A Proposal for Citing Blog Posts

A few days ago I became aware that a post from my blog was cited in a peer-reviewed journal article, which was very exciting. It was the first time this happened for me and I believe it shows the continuing breakdown of the division between traditional and digital scholarship.  The blog post in question was written by three guest authors and the citation used in the journal article was published as below:

Werle, C., B. Sampson, and J. Adamczyk. 2012. African fig fly: A new pest in Mississippi? Mississippi Fruit and Nut Blog. ( (accessed 21 May 2015).

Now, there is nothing wrong with this citation — it hits all the points it is supposed to: author names, date, title of blog post, name of the blog, and last accession date.  However, there is one element missing.  Blogs may have only one author, but many times guest authors appear on blogs. Or in some cases multiple authors share a blog. In these cases, the above citation is incomplete. In a case where there are guest blog authors, the blog owner should be recognized in some way. My suggestion is to call them a curator.  To point out an analogous situation, in a multi-author book, the editor is also in the citation.  Below is how I would see that working for such a blog:

Werle, C., B. Sampson, and J. Adamczyk. 2012. African fig fly: A new pest in Mississippi? In: E.T. Stafne (cur.) Mississippi Fruit and Nut Blog. ( (accessed 21 May 2015).

The same could be done for multiple curators of the blog site, for example:

Werle, C., B. Sampson, and J. Adamczyk. 2012. Fig flies in Mississippi In: B. Abbott and L. Costello (curs.) Agriculture blog. ( (accessed 21 May 2015).

If the curator is not specifically mentioned by name, but is rather institutional, substitute that as in the example below:

Werle, C., B. Sampson, and J. Adamczyk. 2012. Fig flies in Mississippi In: Mississippi State Univ. Ext. Serv. (cur.) Agriculture blog. ( (accessed 21 May 2015).

Of course there are variations not covered here (no author on post, no date given, etc.), but I believe adding the curator is a more complete and representative form of citation that what is currently given in the links below: [APA style] [MLA style]

Growing Bunch Grapes in Mississippi

Last Friday I gave a presentation at the Fall Flower & Garden Fest entitled “Growing Bunch Grapes in Mississippi”. This festival is held every year in Crystal Springs, Mississippi at the Mississippi State University Truck Crops Experiment Station. I usually attend and give a talk on some aspect of fruit crops. This year it was bunch grapes. Of course one cannot cover all aspects of growing grapes in a 30 minute block, but the link below will take you to the presentation (as a PDF file). It gives some of the very basics when considering bunch grapes in our climate. So, take a look and if you have any questions feel free to ask!

Growing Bunch Grapes in Mississippi

Pecans Drop Leaves in Drought Conditions

We are in a drought in south Mississippi. Sure, some areas have had more rain, some less, but things are very dry overall. By my calculations (with data from which may or may not be the most accurate) since June 1 we are 20.75 inches in deficit from the average in Poplarville.

Month     AVG     2015     Deficit

June       5.3 in    0.88 in   -4.42 in

July         6.4 in   1.35 in    -5.05 in

August    5.4 in   0.93 in    -4.47 in

Sept.       3.9 in   1.13 in    -2.77 in

Oct.         4.1 in   0.06 in    ????

So, as you can tell things are not good in terms of rainfall.  Pecans, in particular, need a good bit of rain especially during the crucial time of nut filling.  Which, as it turns out, is when the rain stopped falling this year.  Un-irrigated orchards suffered tremendously, with many trees having no nuts at all and then eventually losing a massive amount of leaves, like the tree below.

A defoliated pecan tree. Leaves dropped due to drought conditions.

A defoliated pecan tree. Leaves dropped due to drought conditions.

Unfortunately this is a common sight around south Mississippi. I hear that things are a little better in central Mississippi and not bad in north Mississippi in terms of pecan production this year.  Many trees have also tried to send out new growth to compensate for the lost leaves.

New leaves appearing in October on drought stressed pecan trees.

New leaves appearing in October on drought stressed pecan trees.

These new leaves and shoots have a high probability of being damaged by cold weather when it finally comes for good. This new growth will not have time to properly harden off for the winter. Defoliation can lead to poor return bloom next year as well as overall tree stress which can affect yields and fruit quality.

If your tree is in this shape what can you do?  If you have the capacity to water the tree do so.  If not, then there is nothing to do but hope for more rain.

Ratios of Reproductive to Vegetative Growth in Six Blackberry Cultivars


Blackberry fruit is gaining popularity in the U.S. and overseas.  New cultivars have been developed in recent years that provide more options for growers and homeowners alike.  Although proven in major blackberry growing regions around the world, these cultivars have not been tested extensively in potential emerging areas.  In Oklahoma, some growers noticed that canes were dying with ripening fruit still attached.  The fruit would not reach maturity and thus be unharvestable.  One potential cause is an unbalanced leaf-to-fruit ratio.  In this study, six blackberry cultivars were used to assess the reproductive and vegetative growth ratios.  Three plots with three canes per plot were individually harvested, had leaf counts, and leaf area measurements.  Leaves were counted on canes in mid-June, during harvest, and mid-July, immediately after the final harvest.  ‘Apache’ had the greatest number of leaves per berry in June (2.6) and July (2.0).  In June, all other cultivars (Chickasaw, Natchez, Ouachita, Triple Crown, and Tupi) were not significantly different from each other, but ranged from 1.4 to 1.1 leaves per berry.  In July, ‘Chickasaw’ was significantly different, having only 0.6 leaves per berry. ‘Natchez’ produced the most berries and the most leaves.  These data may help give insight into the phenomenon of premature cane death.


Blackberries are gaining popularity in the U.S. and around the world as a healthy fruit crop. New cultivars provide more growing options for commercial growers and homeowners alike.  These new cultivars have been proven in major blackberry growing regions around the world, but in emerging blackberry growing areas they may not have been extensively tested.

In Oklahoma and Mississippi, both states where blackberry production is small, some growers noticed ripening fruit that shriveled while still attached to the cane.  This has occurred in other states as well. There was no evidence of usual pests that could cause that condition such as raspberry crown borer, red-necked cane borer, wind damage, etc.  One potential theory is that an unbalanced leaf-to-fruit ratio could be to blame.

Fernandez (2012) reported that ‘Natchez’ had lots of red fruit, but few leaves on floricanes, and few primocanes during the 2012 growing season in North Carolina; whereas ‘Ouachita’ had abundant fruit, leaves, and primocanes.  Borda (2012) in California also noticed this issue.

Materials and Methods

Six blackberry cultivars were used to assess the reproductive and vegetative growth ratios: ‘Apache’, ‘Chickasaw’, ‘Natchez’, ‘Ouachita’, ‘Triple Crown’, and ‘Tupi’.  These were planted in 2009 at the Oklahoma State University Perkins Experiment Station in Perkins, Oklahoma. They were not pruned in the first growing season and the first harvest of any fruit took place in 2010.  During the first harvest, noticeable premature fruit shrivel was apparent and it was not attributable to insect, disease, or abiotic causes.

Primocanes were pruned to 42 inches (107 cm) tall in June 2010.  Spent floricanes were removed in fall and winter 2010-2011.  The laterals on the remaining floricanes were pruned to 15 inches (38 cm).  The plants were trellised with floricanes tied up to wires.

Data was taken during the 2011 season.  Three plots of each cultivar were sampled, with three canes per plot used for yield, brix, leaf counts, and leaf area.  Harvest periods were June 1 to July 15 for ‘Natchez’ and ‘Tupi’, June 8 to July 22 for ‘Chickasaw’, June 13 to July 28 for ‘Ouachita’, and June 20 to July 28 for ‘Apache’ and ‘Triple Crown’.  Leaves were counted on canes in mid-June and mid-July. Means were separated by t-test (P<0.05).


‘Natchez’ had the most average leaves per floricane in both June (323) and July (416). ‘Tupi’ had the fewest in June and was equal to ‘Apache’, ‘Chickasaw’, and ‘Triple Crown’ in July (Table 1 and 2).

Table 1. Mid-June leaf number per floricane on 6 different blackberry cultivars.

Cultivar Mean # Leaves/Floricane Mean Separation
Natchez 323 A
Ouachita 239 B
Apache 230 B
Triple Crown 198 BC
Chickasaw 198 BC
Tupi 163 C

Table 2. Mid-July leaf number per floricane for six blackberry cultivars.

Cultivar Mean # Leaves/Floricane Mean Separation
Natchez 416 A
Ouachita 265 B
Triple Crown 240 BC
Apache 183 BCD
Tupi 171 CD
Chickasaw 111 D

‘Natchez’ produced the most berries and ‘Apache’ the fewest (Table 3).

Table 3. Total number of berries produced per floricane on six blackberry cultivars.

Cultivar # of berries/floricane Mean separation
Natchez 279 A
Triple Crown 210 AB
Ouachita 190 B
Chickasaw 186 B
Tupi 148 BC
Apache 98 C

‘Chickasaw’ had the fewest leaves per berry (0.6) with all others similar (Table 4).

Table 4. Number of leaves per berry for six blackberry cultivars.

Cultivar Leaves/berry Mean separation
Apache 2.0 A
Ouachita 1.7 A
Natchez 1.5 A
Triple Crown 1.5 A
Tupi 1.3 A
Chickasaw 0.6 B

The leaf area (cm2) to fruit (g) ration was highest for ‘Ouachita’ and lowest for ‘Chickasaw’, which was not statistically different from ‘Triple Crown’ and ‘Apache’ (Table 5).

Table 5. Leaf area to fruit ratio of six blackberry cultivars.

Cultivar cm2 of leaf area/g of fruit (July) Mean Separation
Ouachita 14.16 A
Tupi 9.07 B
Natchez 7.20 BC
Triple Crown 4.91 CD
Apache 4.64 CD
Chickasaw 1.44 D

Canes with more leaves also produced fruit with higher brix (R2=0.21) (Fig. 1).

Figure 1. Effect of leaf number on fruit sugar content (brix) of six blackberry cultivars.

Effect of leaf number on fruit sugar content (brix)

Effect of leaf number on fruit sugar content (brix)

The issues with the fruit were not seen as prominently in 2011 as compared to 2010.  Weather conditions were mild in 2010 when compared to 2011 when severe heat, drought, and cold were all experienced (Table 6).

Table 6. Extreme weather conditions in Oklahoma during 2011 compared to 2010.

March April May June July August Sept. Oct.
Avg Hi 60 72 79 90 92 96 86 78
Avg Hi 63 77 79 97 104 101 84 75
Winter 2011
Jan 28 Jan 29 Feb 3 Feb 10 Feb 16 Feb 17
76 77 -1 -13 77 81

‘Chickasaw’ had fewer overall leaves but this could have been caused by droughty conditions, suggesting that ‘Chickasaw’ may have a lower drought tolerance than the other cultivars. ‘Natchez’, the cultivar most prominently tied to the condition of on-cane shriveling fruit, did not display these characteristics during 2011.

Other crops have different leaf area to fruit ratios than what was found in this study.  Apples are around 3 cm2/g, cherries are 22, grapes 8 to 12, and strawberries 15.  From this one year of data, blackberries averaged around 7 cm2/g.

The results from this study lead to other questions that may be asked to fully reach the answer.

  • Were the younger root systems not able to support fruit production in 2010?
  • Did the fall and winter pruning help to balance the crop load for 2011?
  • Did the heavy first year crop seen in 2010 reduce return bloom in 2011?
  • Did the extreme weather in early 2011 play a role in reducing the overall crop later in 2011?


Bolda, M. 2012. Pruning of ‘Natchez’ blackberry. Strawberries and Caneberries. University of California Agriculture and Natural Resources blog

Fernandez, G. 2012. Natchez overcropping? Team Rubus blog. North Carolina State University Extension.

The original abstract for this study was published as noted below:

Stafne, E.T and B. Carroll. 2012. Ratios of Reproductive to Vegetative Growth in Six Blackberry Cultivars. HortScience 47(9):S105 (abstr.).

Fall Color in Blueberries

Ah, fall.  That time of year when a respite from oppressive heat and humidity comes to south Mississippi. Fall, to me, is the best time of year.  Growing up in Michigan I appreciated the great leaf color show every year. If pressed, I will admit to missing that (but not the awful dreary weather that comes with it).  Most of the plant species in south Mississippi are not known for their fall color. Sure, there are some Swamp Red Maples (Acer rubrum) and Sweetgums (Liquidambar styraciflua), but most don’t have really good fall color. One primary reason for that is the lack of cold temperatures. Blueberries do have some fall color, some cultivars and species more so than others.  But, let’s talk more about why fall color happens in the first place.

Many blueberry leaves turn red in the fall — or so it seems.  Actually the red pigments are there the whole time, it is just that the chlorophyll (green) overshadows the other colors. In the fall, these chlorophyll pigments degrade, leaving behind the red and orange colors. Chlorophyll breaks down in sunlight so the plant needs to continue synthesizing new chlorophyll to keep the green color in its leaves. The conditions that promote this are warmth and sunshine, both at their peak during summer. Part of the chlorophyll degradation is the plant preparing for winter — it is reallocating nutrients back to the root system. Since leaves are mainly disposable on deciduous species, it makes sense for the plant to take nutrients like Nitrogen and return it to a permanent plant structure. Once stored in the roots it can be reused in the next year.

Blueberries have anthocyanins in the leaves. Once the chlorophyll is lost, the leaves appear red due to the color spectrum of light it is absorbing. This is a natural process that helps the plant maintain leaves while it reallocates nutrient reserves to the root system.  Of course there are times of the year when we don’t want to see red leaves on blueberries, especially in the spring after a frost/freeze event, but seeing red during the fall is a natural, normal thing that portends the coming winter.

Great red fall color can be seen on commercial blueberry cultivars, but also native Vaccinium species like V. elliottii and V. darrowii. Below is a photo of ‘Springhigh’, a southern highbush blueberry released from the University of Florida blueberry breeding program.

Fall color of 'Springhigh' blueberry

Fall color of ‘Springhigh’ blueberry

Many blueberry plants are still green here in south Mississippi. Many won’t turn red, or at least not completely, before falling off the bush. Some cultivars retain their leaves throughout the winter. So much variation among blueberry cultivars and species! Enjoy the fall — while it lasts.

Measuring Grapevine Growth

For three seasons I have had a study going on how grapevines respond to producing a crop in the season after they were planted.  In 2013 I planted three cultivars — Blanc du bois, Villard blanc, and Miss blanc.  In that first season I was able to get them trained onto the cordon wire (single wire high curtain system). In season two I had three different treatments: removal of blooms, removal of fruit at veraison, and harvested fruit.  In season three, all vines were harvested (some even going to produce a commercial product, but that is a discussion for a later post) and today I measured trunk calipers.  I have not analyzed the data yet, but I will look at cultivar and treatment effects on vine trunk size.  Below is a photo of the process:

Caliper measurements on a grapevine trunk

Caliper measurements on a grapevine trunk

I have a little more data to collect and then I will be able to start analyzing the data and writing up the results. This study was also done in Oklahoma before I moved to Mississippi, only with different cultivars. It will be interesting to see how the results compare. Growing grapes is expensive and growers need to start recovering expenses quickly. If grapes can be harvested starting one year earlier then the time to recover initial capital outlay will be shortened.  However, we need to make sure that has no lasting impact on vine health, thus this study. Since I couldn’t find any other studies like it in the literature I decided to answer the question myself.  And soon, I will find out the results.  It is exciting!

MS Pecan Fall Field Day 2015

Pecan Fall Field Day 2015

When to Harvest Pecans
Harvesting of Pecans
Post-harvest Cleaning and Storage (Food Safety)
Winter Care of Trees
Grading Pecans for Sale
Nursery Tour

Thursday, October 8
Registration 1:00 – 1:30 p.m
Program 1:30 – 5:00 p.m.

Pecan Hill Farms
19470 Highway 18
Raymond, MS 39154

For more information, please call Max Draughn 601-594-4393