Pollination in Pecans

Pecans are wind-pollinated.  Trees are monoecious, meaning both male and female flowers are on the same tree. Thus, self-pollination is possible, but ultimately undesirable.  There are two main pecan flowering types: protandrous and protogynous.  When male flowers release their pollen before female flowers are receptive, those flowers are protandrous (also called Type I).  When female flowers are receptive to pollen before pollen is shed from the male flowers on the same tree it is called a protogynous flower or Type II.

Some protandrous (Type I) pecan trees include Caddo, Cape Fear, Cherokee, Cheyenne, Creek, Desirable, Gafford, Giles, Jackson, Oconee, Oklahoma, Pawnee, Peruque, and Western.  Some protogynous (Type II) pecan trees are Burkett, Candy, Choctaw, Elliot, Forkert, Kanza, Kiowa, Mahan, Maramec, Mohawk, Mount, Oakla, Podsednik, Schley, Shoshoni, Stuart, Sumner, and Wichita.

Pecan has what is called dichogamous flowering, when male and female flowers mature at different times.  Dichogamy promotes cross-pollination within and between species.  It is also known as heterodichogamy.  Dichogamy may be an intermediary step between synchronous dichogamy and dioecy (male and female flowers on separate plants).  The degree of dichogamy is variable within pecan trees and can be affected by weather.  Moist, warm springs favor male flowers, whereas cool, dry springs favor female flowers.  Some members of the hickory family may switch flowering type depending on the environment in the year.  This has been documented in Shagbark (Carya ovata) and Mockernut (Carya tomentosa) hickories. Complete dichogamy means that no self-pollination is possible.  Incomplete dichogamy results in some level of selfing.  Dichogamy encourages cross pollination and discourages self-pollination.  Self-pollinatino can lead to inbreeding depression in some plants.

Inbreeding depression occurs when two closely related individuals mate.  Some species have a strong negative response to this situation, whereas some have an intermediate response, and some little to none.  There can be ramifications of selfing, including fruit abortion, suppressed kernel development, and low plant vigor.  The unfit do not survive, thus resulting in a reduction in the number of successful mating individuals within a population.  Selfing also limits the gene flow from other populations.  Genes from other populations help to perpetuate individuals that adapt to environmental stresses.  Species with a strong tendency against self-pollination have greater genetic diversity within populations.  Within pecans, the level of inbreeding is low or inbred seedlings die early and never enter the mating process.

Thompson and Romberg (1985) reported that a single gene determines dichogamy in pecan trees.  This means that the trait is qualitative, or is controlled by a single gene or very few genes.  They reported that protogyny is the dominant trait and protandry is recessive.  This is common throughout the hickory family.  Beedanagari et al. (2005) found that protogyny and green stigmas were linked traits as were protandy and red stigmas.  These traits were tightly linked with little recombination.  This means that the more tightly linked the traits are, the rarer the recombination possibility will be.

There are benefits to dichogamy, with the largest being genetic variation.  More genetic variation leads to better pecan tree survival, continued evolution, and better climate adaptation.  Inbreeding, mating of close relatives or selfing, tends to bring out bad traits and thus ultimately makes the tree non-competitive with its non-inbred neighbors.

References

Beedanagari, S.R., S.K. Dove, B.W. Wood, and P.J. Conner. 2005.  A first linkage map of pecan cultivars based on RAPD and AFLP markers. Theoretical and Applied Genetics 110:1127-1137.

Thompson, T.E. and L.D. Romberg. 1985. Inheritance of heterodichogamy in pecan. Journal of Heredity 76:456-458.

Commentary: Should We Be Worried About Funding for Science?

Recently, I saw a post on Twitter that linked back to this article: “Should the Government Fund Only Science in the “National Interest”?  After reading the article I was appalled.  Now, for full disclosure, I have never received (or even applied for) an NSF grant.  I have, however, applied for and received federal grants from sources other than NSF.  That being said, I wonder if the folks who are scrutinizing the NSF funding practices actually understand science at all.  Science in not just in the domain of the United States.  Science transcends geopolitical borders, language, race, creed, religion, and everything else.  The aim of Science is discovery by asking questions and solving problems.  The thing about Science though, is that researchers rarely make discoveries that result in a singular impact.  The research results are part of a larger puzzle — pieces fit together until we can see the larger picture.  But, many times we have no idea how many pieces are needed to complete the puzzle.  That is why we need the participation of all scientific fields.  The dictating of which fields and studies are “of highest priority”  is not something we should let politicians decide, but rather by scientists via peer-review.  The NSF is a model organization worldwide for funding of important, relevant research.  Diminishing that would  harm scientific discovery across the globe.  Mentioned specifically are “climate change education project, archaeology studies in Ethiopia, anthropology work in Argentina”.  I don’t know about you but I think education on climate change is important.  I also think archaeological and anthropological studies are important because guess what — understanding human history and nature affects the current understanding of ourselves.

Funding for scientific research is difficult enough to garner without it being further restricted.  If I want to do an experiment I have to figure out a way to get money to do it.  Usually that is in the form of grant funding.  The days of allocated funding are over and that is a shame.  I know I spend an inordinate amount of time writing grant proposals and filling out associated forms and other paperwork knowing that the chances are slim that the proposal will get funded.  I think if politicians really want to stop “wasted resources” they should look at the current grant funding model.  In my experience, hundreds of hours are spent developing these proposal and only a small portion are funded.  The real waste is the man-hours spent to develop these proposals that do not get funded.  I sure would like to see a study done on how much time is spent (and ultimately, unrewarded) doing proposals vs. the amount awarded (cost:benefit).

Science is under fire in this country and around the globe.  When I was younger, “University Professor” was highly regarded and trusted.  Now, I am not so sure.  The dictating of which science matters will only further erode the profession.  And who does that benefit?

MSU Fall Flower and Garden Fest 2014 — Presentation on Fruit Crops

Last week, I gave a presentation on Fruit Crops for your Yard at the MSU Fall Flower and Garden Fest that was held in Crystal Springs.  This is a big event, with over 5,000 attendees each year.  You can find more info on this event at this link: Fall Flower and Garden Fest

As for my participation, I presented on some of the common fruit crops that are grown in Mississippi.  Unfortunately, the time is short (45 minutes) and I can’t go into all the details I wish I could.  But I tried to give the basics on several different popular fruit crops.  To access the PDF version of the presentation, click below:

Fruit Crops for your Yard

Translating the Value of Extension Scholarship

Earlier this summer I was asked to give a webinar for Next Generation Extension – University of Nebraska Southeast Research and Extension Center (http://nextgenerationextension.org/) on the topic of online scholarship.  This grew out of a webinar that I gave in July (Peaks and Pitfalls of Extension Scholarship in an Online World) and a couple papers I published in the Journal of Extension (http://www.joe.org/joe/2013october/comm1.php and http://www.joe.org/joe/2014april/tt1.php).  In this webinar I tried to address online scholarship, how it is viewed in academia (as I see it) and how we can better use and value it.  The links below will take you to the recorded webinar (thanks to Next Generation Extension) and also a PDF version of the slide show.

Translating the Value of Extension Scholarship

Translating the Value of Extension Scholarship

Webinar is available here: https://connect.unl.edu/p7pjtc99xp8/

The PDF version is here: Translating the Value of Extension Scholarship

If anyone has questions or comments I would be happy to hear them!

MPBs Mississippi Roads to Feature Poplarville and Hattiesburg

I was fortunate enough to be involved in the blueberry portion of the filming. Look for me (and some other blueberry folks) on October 16 at 7pm.  For more info, read below.

A Road Trip To A Blueberry Jubilee And An Extra Table

The newest episode of Mississippi Roads features the Blueberry Jubilee held in the south Mississippi town of Poplarville and Extra Table, a philanthropy founded by renowned Hattiesburg chef, Robert St. John. The episode will air Oct. 16 at 7 p.m. on MPB TV.Mississippi Roads gets a taste of Poplarville at its 31st annual Blueberry Jubilee. More than 10,000 people flood downtown Poplarville every year for the festival. Visitors make the trip for the arts and crafts, storytelling, live entertainment and, of course, the amazing food they can only find at the jubilee. The proceeds of the Blueberry Jubilee provide grants to fund programs and projects that serve the community.Next, Mississippi Roads pulls up a chair at chef Robert St. John’s Extra Table. Extra Table is an organization that focuses on reducing the prevelance of food deserts and hunger in the state by stocking food banks and soup kitchens with healthy food.

In 2009, St. John received a call from a local food bank asking him for help—the food bank’s shelves were empty and 800 families needed food. So, St. John contacted Sysco, his restaurants’ food distributer, and delivered enough healthy food to stock the food bank and feed the 800 families. This got St. John thinking.

“What if every restaurant and home had an extra table to serve people in need? What would that look like?” said St. John.

In order to address the severe food insecurity problem facing his community, St. John partnered with Sysco and by 2011, Extra Table was delivering new healthy and nutritious food to agencies at below wholesale prices on a regular basis.

“Extra Table receives donations from private companies and individuals—100 percent of all donations go towards buying healthy food which we deliver directly to agencies keeping their shelves filled,” said St. John.

Extra Table cuts the food costs of the agencies it serves significantly. This enables the agencies to allocate those funds to programs that serve the community in other ways.

“The money that was going towards buying food is pumped directly into the community. The agencies use that money to provide things like after school programs and career prep workshops,” said St. John.

For more about the Blueberry Jubilee and Extra Table, tune in to MPB TV on Oct. 16 at 7 p.m. for Mississippi Roads.

Mississippi Public Broadcasting (MPB) provides instructional and public affairs programming to Mississippians through its statewide television and radio network. MPB enhances the work of educators, students, parents and learners of all ages by providing informative programming and educational resources. MPB’s locally-produced programming focuses on the people, resources and attractions that reflect Mississippi’s unique culture and diverse heritage. Children’s television programs constitute a major portion of the daytime and weekend morning schedules. MPB provides a valuable resource to Mississippians in disseminating information as part of the state’s emergency preparedness and response system. Since 1970, MPB has won over 400 national, regional and statewide awards, including Emmy®, Edward R. Murrow and Parents’ Choice Awards. For more information on MPB, its programs, mission or educational resources, please visit www.mpbonline.org.

October 9, 2014
Jeannie Huey
601.432.6777
jeannie.huey@mpbonline.org

Mississippi Chill Hour Accumulation

I have previously wrote on the topic of chill hours, but I also get a lot of requests for what the accumulated hours are for the season.  This year I will be posting them on this site on the page entitled Chill Hours (on the right hand side of your screen).  By visiting this page, you will be able to keep up to date on the accumulated chill hours as reported by locations in five counties in Mississippi — Copiah, George, Jones, Lee, and Wayne.  The recordings are reported by volunteers, so they may or may not be available for each week.  In the future I hope to put together data from previous years (at least those I have) and also make them available on the site.

As of today, the first posting is up.  Each recording season runs from October 1 to April 1 of the following year.

A Unique Piece of Mississippi Viticulture History

A couple weeks ago I was on the coast and drove by this sign (see photo).  I knew it was there, as I had looked for it previously, but had forgotten to take a photo.  This time my wife was able to get a shot for me, it is below. Very interesting to know that a commercial vineyard was so close to the coast — and that a Mississippi winery shipped wine across the U.S.  Can history repeat itself?  I did a cursory look for an remnant grapes, but didn’t see any.

Brown's Vineyard, Waveland, Mississippi

Brown’s Vineyard, Waveland, Mississippi

If you want to find this for yourself it is on Hwy 90 just West of Bay St. Louis, on the South side of the road.

Mississippi Vaccinium Journal Oct-Dec 2014

The October-December 2014 issue of the Mississippi Vaccinium Journal is at the link below. In this issue we cover a couple of non-typical pests, recap some research presentations and a workshop, and present a publication on the economic impact of the Mississippi blueberry industry.

Also, as this is the last issue of the year, please send me any comments you may have on it. These help me plan the future direction of the newsletter and cover more of what you want to read.

Thanks for reading and have an enjoyable Fall!

Mississippi Vaccinium Journal Volume 3 Issue 4

Strange Gall on Grape Vine

Earlier this year I found a strange growth occurring on a grape vine in my yard.  It looked like a nut coming from the bud.  It was hard and woody.  Having seen similar things on other plants, I had an idea that an insect caused this phenomenon.  After asking colleagues about it and doing some research, we whittled it down to Schizomyia vitiscoryloides.  It is in the same Family as gall midges.  It is in the Order Diptera, along with gnats, mosquitoes,and true flies.  In this case, it appears the egg was laid in or near the bud.  The plant responds with unusual growth around the larva that develop from the egg.  Inside, the larva is protected and can feed.  The larva eventually falls to the ground where it will pupate.  Removal of the galls is not usually necessary, but it may help reduce future populations.  See the photos below for the gall and the inside of the gall with the yellow-colored larva.

Gall on grape vine

Gall on grape vine

Inside of the gall, with the larvae

Inside of the gall, with the larva