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.
No, this is not an in-depth coverage of the native grapes that exist in Mississippi and Louisiana. It is more a plea for help in identifying grapes and marveling at the diversity. The photo below shows three grape clusters from three different vines at two different locations. The longer, loose cluster was found in Covington, LA whereas the shorter two are both from Poplarville, MS.
The larger cluster is loose, which is a good trait to have in order to reduce disease. It also has red flesh and would help with deeper color for wine (teinturier). The small cluster in the middle had the best flavor of the three. In fact the other two had little flavor to speak of, but the middle cluster had a nice burst of fruitiness that made it stand out. It is small and tight clustered though. The bottom cluster has a decent size and is fairly loose. The vine it came from was extremely productive with hundreds of these clusters all over it (well the vine is huge and goes across many trees). I should have taken photos of the leaves, but did not. I plan to save some of the seeds and might grow some out just to take a look. If anyone out there has experience in IDing native grapes, please give me a suggestion to go on. Below are the search results for Vitis species within MS and LA from plants.usda.gov
|State Search for Genus = vitis
State and Province Distribution = U.S. States (Louisiana, Mississippi)
61 records returned
Click on an accepted name below to view its PLANTS Profile with all synonyms, distribution map, more information, and web links if available. Synonyms are indented beneath accepted counterparts.
The 2014 Muscadine Field Day was a great success. The cooperative event by Mississippi State University and the USDA-ARS is held every year in McNeill, MS. The weather was cool (relatively), so the crowd came out — about 110 in all. The educational portion of the program covered muscadine history, health properties, and pollination. Attendees were then free to ask questions and taste the ripe grapes. See the photos below for a quick peek at how it all went.
Yesterday I gave a presentation on “Best Fruit Crops for Mississippi Farmers’ Markets”. It was part of the “Microfarming – Growing for Farmers’ Markets” workshop put on by Dr. Rick Snyder and others. You can see more info on the workshop as well as links to other information related to Farmers’ Markets here: http://farmersmarkets.msstate.edu/conference/.
The full presentation can be accessed here as a PDF file: Fruit Crops for MS Farmers Markets
The 2014 Muscadine Field Day in McNeill, MS will not be held on August 23. It has been rescheduled for Saturday, September 13.
Nutrient deficiencies can adversely affect grapevines, not only the growth of the vine itself, but also the fruit. Here in Poplarville, the soil pH is low. To give you an idea, in general this area is good for growing blueberries. Blueberries thrive in soil pH of 4.2-5.2, which is too low for most grapevines. Often in other regions I have seen Iron (Fe) deficiency but here, because of the low soil pH, I am seeing Magnesium (Mg) deficiency show up. The photo below shows what late season leaf symptoms look like. I don’t remember which vine this came from — some cultivars appear to tolerate the soil pH better than others.
So, what to do about it? Raise the soil pH with lime is the first thing. If that doesn’t alleviate the problem, then foliar or soil applied sprays may be necessary. My colleague at Cornell University, Hans Walter-Peterson, gives an excellent primer on Mg deficiency and offers suggestions for correcting it. You can find that here: http://www.growingproduce.com/uncategorized/managing-magnesium-in-grapes/. The eXtension grape community of practice has a good article on other potential disorders too — that article can be accessed here: https://www.extension.org/pages/31599/grapevine-problems:-leaf-spots-not-caused-by-insects-or-disease#.U-jgJfldV8E
You may be inclined to think, “It is after harvest, so I shouldn’t worry about it”. Nutrient deficiencies can lead to poor winter hardiness, overall vine stress, and other issues. It is best to correct the problem rather than to let it negatively affect the vine.
Recently I purchased a VT02 Visual IR Thermometer for use on grapes and grapevines. This instrument has been used in various studies, mainly those addressing irrigation scheduling, stomatal conductance, and other water-related issues. I have used a similar instrument previously in Oklahoma and blogged about it here: okgrapes.wordpress.com/?s=infrared.
Yesterday, I went to the vineyard and looked at some of the few bunches left on vines that bird had not carried off or destroyed. I took IR readings on two different cultivars, ‘Lake Emerald’ and ‘Rubaiyat’. ‘Lake Emerald’ is a white-skinned grape. It was released by the University of Florida in 1954 and resulted from a cross of ‘Pixiola’ and ‘Golden Muscat’. This is the first year it has produced fruit (2nd leaf) and the clusters have not fully ripened yet, but is getting close. You can read more about ‘Lake Emerald’ here: http://mrec.ifas.ufl.edu/grapes/cultivarbulletins/Lake%20Emerald%20circularS-68%201954.pdf. ‘Rubaiyat’ is a cross of ‘Bailey’ and Seibel 5437. It has red skin and red flesh. It was released by Oklahoma State University in the 1970s. You can read more about ‘Rubaiyat’ here: http://www.grapes.okstate.edu/PDFs/2006/Rubaiyat.pdf
Below are the images I took of the clusters during mid-day. Ambient air temperature was around 35 C. As you can see, cluster temperature was greater than air temperature.
The temperature difference is nominal, just 0.7 C higher for Rubaiyat (the red grape). Rubaiyat was also ripe, or past ripe. The “cooler” tones around the bunch are leaves and air (or other objects). I still need to work with the instrument to optimize its use. While outside I also looked at leaves that had problems (disease, nutrient deficiency, etc.) vs. normal, healthy leaves. The problem leaves invariably had slightly higher temperatures. I attribute this to reduced transpiration from damage to the leaves. I also tested some blueberry plants. I saw some differences in canopy temperature among cultivars, but not sure what to attribute it to — could be water stress, leaf age, or some other factor.
I have a vineyard in Poplarville, MS with several different varieties of bunch grapes. Some will make it, some won’t, but it is interesting to look nonetheless. Below are some notes I made today on their growth and development. These are all in their second leaf and first fruiting year.
Victoria Red — some Pierce’s Disease symptoms (PD), not extremely productive, clusters variable in size and shape, some vines no crop while others better, bird depredation and bees a problem, fruit is crisp and sweet with good flavor (close to neutral), some seeds, vines have good vigor, non-slipskin
Cimarron — very few clusters, small cluster size, slipskin with “Welchy” flavor, some PD symptoms, moderate vine vigor
Sunset — no crop, possible PD symptoms, low vigor
Cynthiana — moderate vigor, no fruit
Rubaiyat — possible PD symptoms, vine vigor varies among vines, some vines no fruit and some lots, slipskin, red flesh, flavor mild to neutral, good sized clusters when present, some vines appear stressed, some uneven ripening, some nutritional deficiency symptoms, bird and bee depredation
Lake Emerald — good fruit set, not ripening yet, evidence of nutritional deficiency, clusters loose, vine vigor good to moderate
Daytona — no fruit, vine vigor low to moderate
Champanel — few clusters, slipskin, mild fruit flavor, cluster size medium to large, “slimy” pulp, some nutritional deficiency symptoms, possible PD symptoms, vine vigor moderate, clusters loose
V12-375(?) — little fruit, vigorous growth, not ripening yet, clean foliage except a couple older leaves with possible PD or nutrient deficiency symptoms
Conquistador — no fruit, vine vigorous, shows nutrient deficiency, some leaves drying out and dying
Himrod — poor growth, no fruit
FAMU 99 — moderate vine vigor, no fruit
MidSouth — low to moderate vine vigor, little fruit, small clusters, intriguing “raspberry” flavor, slipskin
The varieties below have been harvested as of July 24. Although they were not at optimal soluble solid levels, bird depredation dictated an early harvest so that my study would not be ruined.
Villard blanc — long, loose clusters, brix around 16, some leave damage from Pristine, nonslipskin, obvious “wine”-like grape flavor, vines moderate vigor
Blanc du bois — vines vigorous, large to medium cluster size, brix around 17-18, anthracnose a problem, slipskin
Miss blanc — less vigorous than VB and BdB, less fruit too, brix around 15
If you have questions or comments on these I would love to hear them.
Last year I planted some ‘Victoria Red’ in Poplarville, MS. They are not part of a study, but rather for observation — what kind of diseases will show up, how much to they produce, and will they survive? So far, things have worked out okay. Right now they are rolling on toward harvest. This is the first year they are being fruited, so I don’t want to jump to too many conclusions yet. At this point, I see some variability in cluster size. I also see symptoms of Pierce’s Disease. Whether or not these symptoms will lead to the demise of the vine is to be determined. Below are a few photos that I took a couple weeks ago, as the clusters were starting veraison.
Next year will really be interesting on these vines. I only have fewer than a dozen, but they should yield some nice fruit (I hope). If you are interested you can find more information on Victoria Red at this link:
Getting vines is difficult. I see that Double A Vineyards advertises them but is out of stock. Your best bet may be to get some from a nursery in Texas (where the cultivar was tested and released from). I will continue to update the progress of this promising cultivar.
Download the flyer here: Muscadine Field Day 2014
UPDATE: August 18 — The Field Day is rescheduled for SEPTEMBER 13.