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!

Agenda for 2015 Muscadine Field Day

Below is the agenda for the 2015 Muscadine Field Day.  It will be held tomorrow morning.  More detailed information, including location, times, etc. was published on this blog here:

2015 Muscadine Field Day Agenda

2015 Muscadine Field Day Agenda

A Year with No Fruit

This year I have received several calls wondering why certain trees and vines produced little or no fruit this year.  It is a fair question — what would cause this problem?  Assuming there really was no fruit or the fruit failed to develop properly (rather than a disease issue) the answer points to pollination.  Will all the rain and cool temperatures we had this spring, conditions were poor for pollination in some crops in some locations.  Some crops that I have seen with poor or no crop this year are pears, peaches, pecans, and muscadines.  I’m sure there are plenty of others as well.  Rain and cool weather deters pollinators from visiting open flowers.  Rain also dampens the pollen itself and makes it so that it cannot readily be dispersed. Timing is the critical thing, as one cultivar may have a full crop and another nothing.  It could even vary from plant to plant of the same cultivar, and also from field to field (i.e. a neighbor might have a good crop whereas you have little or nothing). So the interaction of rain and flower opening is where things can go wrong.  Of course other things can reduce pollination (lack of pollinator insects, lack of pollinizer trees, disease, frost, drought, excess heat and humidity, etc.) but this year I put my money behind the wet and cool conditions.

This pecan tree, located in Poplarville, MS, has no nuts at all

This pecan tree, located in Poplarville, MS, has no nuts at all.

It is not just trees that had a hard time this year.

'Fry' muscadine with no fruit

‘Fry’ muscadine with no fruit.

Some cultivars were impacted but were able to set some fruit, although it will not be a full harvest by any means.

'Janet' muscadine with some fruit, but limited by poor pollination conditions.

‘Janet’ muscadine with some fruit, but limited by poor pollination conditions.

Is there an upside to not having much fruit this year?  Well, bud fruitfulness should be increased for next year, especially in the pecan trees.  So, just like the mantra of the Chicago Cubs — There’s always next year!

Firmness and Splitting in Grapes

This year I harvested several different cultivars of grapes for the purpose of seeing what kind of firmness and splitting data I could get.  It was not a true study, just a quick “look-see” to get an idea of how it would work.  Below is some of the observations I was able to get (will help from Dr. Donna Shaw and Lavonne Stringer). Brix (sugar levels) were recorded first to see how high they were at harvest.  Nine cultivars were chosen — Blanc du bois, Champanel, Cimarron, Conquistador, FAMU99, MidSouth, Miss blanc, Victoria Red, and Villard blanc.  As you can see below, sugar levels were low for most, although these were only samples and the entire vine was not necessarily harvested.

Brix measurements of 9 grape cultivars

Brix measurements of 9 grape cultivars.

Individual berries were then tested for firmness, as seen below.  In most cases, the lower the brix, the better the firmness. This is not surprising as unripe berries would be expected to be firmer.  One big exception was Conquistador which was the firmest berry by far, even at nearly 18 brix.

Firmness of nine grape cultivars.

Firmness of nine grape cultivars.

Finally we looked at how the berries split if exposed to water. We did this in two ways, individual berries and also as whole clusters. The results were almost the same both ways but I will show both. MidSouth, FAMU99, and Conquistador showed a tendency to split when submerged in water overnight. So in this case firmness did not seem to be strongly tied to splitting tendency.

Individual berry splitting of nine grape cultivars.

Percentage of individual berry splitting of nine grape cultivars.

Things were mostly the same when whole clusters were submerged, although there was a little more on Blanc du bois. The difference was small though and with replication and a larger sample size may not be significantly different.

Percentage of berries from whole clusters that split from nine grape cultivars.

Percentage of berries from whole clusters that split from nine grape cultivars.

I was surprised by the lack of splitting from Victoria red. It has what I would characterize as a thinner skin than most of these cultivars, yet it did not split at all. A good thing to know.  Obviously Conquistador has a tendency to split, as ~50% of exposed berries did just that.  Next year we will give it another go-round and see what happens then.

Education and Experimentation via Mississippi Bunch Grapes

And when I say “grape harvest” I mean bunch grapes, not muscadines (which will come later in the season).  This year the vines in my vineyard were in the 3rd leaf.  I harvested a little fruit last year, but this year was the first “big” harvest. Since most of the harvested vines were part of a study, I did various measurements on them (total weight, cluster and berry weights, brix, TA, pH), but had a conundrum — what do I do with the fruit?  The majority of the harvested grapes was from three cultivars: Blanc du bois, Miss blanc, and Villard blanc.  I also harvested a little from MidSouth.  In the end I gave it all away, some of it to folks who helped harvest, but also some to help a business do some experimentation of their own.

Mark and Travis from Lazy Magnolia Brewing Company helping harvest a few vines of Miss blanc

Mark and Travis from Lazy Magnolia Brewing Company helping harvest a few vines of Miss blanc.

Lazy Magnolia Brewing Company is located in Kiln, Mississippi.  Just after I moved here in 2011, my wife and I went for a visit to the brewery where we met Mark Henderson, co-owner. We asked questions about the brewery biz and he asked what we did for a living.  After telling him I worked with grapes, he became very interested and said he wanted to source some local grape juice for a project.  I told him, “good luck” because there was none to be had.  Later, I connected with a local grower, Dr. Wayne Adams, who had some fruit but not enough to supply Mark.  I planted the grape vines as a response to his request. After moving here, I thought my days with grapes was probably over, but what I have found out is there there is a strong interest in Mississippi just like everywhere else. In 2014 I wrote a Specialty Crops Block Grant funded through the Mississippi Department of Agriculture and USDA-NIFA that focused on grape education.  This vineyard helps to bolster that education component.

Fast forward to 2015 and I have vines producing fruit.  I again contacted Mark and asked if he wanted the juice to do some experimenting on.  He said yes.  Unfortunately the Blanc du bois was not in good shape.  It had a good bit of rot caused by early season anthracnose then bunch rots.  The very rainy month of May did it no favors.  However, Miss blanc and Villard blanc were in relatively good shape.

Harvested Miss blanc fruit ready for data measurements

Harvested Miss blanc fruit ready for data measurements.

After getting the fruit in from the field, we took some data measurements then pressed it for juice.  Mark and Travis from Lazy Magnolia came up to help with that process along with my collaborator Dr. Donna Shaw from USDA-ARS in Poplarville.

Dr. Shaw (left) and Mark Henderson (right) pressing Miss blanc grapes for juice

Dr. Shaw (left) and Mark Henderson (right) pressing Miss blanc grapes for juice.

It is a very messy job, but being able to taste the fresh juice is rewarding. Of course it happened to be on one of the hottest days of the year, but then again it is July in South Mississippi!  We were able to get about 20 gallons of juice from 18 Miss blanc vines.  A couple of days later we were able to get 10 gallons of juice from 17 Villard blanc vines.  I also gave Mark about 2 gallons of MidSouth juice (which is acidic but has an intriguing “raspberry” flavor).  So he has between 25-30 gallons to try something (wine, mead, beer, or something else entirely). This project is a beginning to see how Mississippi-grown grapes can be used for marketable products.

If you, or someone you know, is interested in growing bunch grapes in Mississippi please contact me.  Although it is not easy to do, it can be done with the right cultivars and management practices.  Developing markets is another important step in the process, and Lazy Magnolia is exploring whether or not grapes can make a marketable product for their business model with the help of Mississippi State University Extension Service.

A Few Early Grape Clusters

This morning I was out in the vineyard to harvest a few grape clusters for a study on Spotted Wing Drosophila (SWD) egg laying habits conducted by Dr. Blair Sampson.  These cultivars are unusual in that they are rarely grown outside of the southern U.S.  I harvested one or two clusters (depending on the number of berries available per cluster) from ‘Victoria Red’ (Ark 1123 x Exotic), ‘Cimarron’ (V. cinerea var. canescens x Seneca), ‘MidSouth’ (De Grasset x Galibert 255-5), ‘FAMU 99’ (unknown to me), and ‘Champanel’ (V. champinii x Worden).  These are not fully ripe in the eating or processing sense, but they are close enough for this study to work.  Below is a photo of ‘Champanel’, ‘Cimarron’, and ‘MidSouth’.

Champanel, MidSouth, and Cimarron (Top to Bottom)

Champanel, MidSouth, and Cimarron (Top to Bottom)

So, even though I have these in my vineyard it doesn’t mean they do well.  This is the first year I’ve had Champanel grapes, but overall it looks decent.  The vine looks healthy, not a lot of rot (which is really saying something this year), no PD symptoms, and a good bit of fruit.  I had trouble establishing the vine for whatever reason, but it looks good now.

MidSouth is an intriguing vine that I have written about before.  It has a moderate vigor and moderate yield.  The vine is suffering from a nutrient deficiency (that I believe is Mg) that some vines in the vineyard show symptoms of as well.  However, overall the vine looks okay.  The flavor is what I like — it reminds me of raspberry.  It isn’t quite ripe yet though and acid levels are high.  It was never recommended as a wine grape although it could be useful in blending (maybe).

Cimarron is a cultivar released from Oklahoma State University in the 1970s.  A strong Concord-like flavor and aroma.  It does not do well in south Mississippi.  Vines have PD symptoms and have only produced a small amount of fruit.  Terminal portions of the cordons are dying back now and some clusters along with it (from PD).  I suspect they may die back to the ground over the winter and come back, but it is no way to get a viable amount of grapes.  Too bad too, as the clusters don’t have any rot and they look nice.  Other OSU cultivars, Rubaiyat and Sunset are also in the vineyard but have little to no fruit and exhibit PD symptoms.  They are non-starters too.

In the coming weeks I will be harvesting more fruit — even hope to crush some of the Blanc du bois, Miss blanc, and Villard blanc (and perhaps a couple others).

Netting Grapevines Against Birds

Last year I had problems with birds destroying some grapes before I had the chance to harvest them (full disclosure: I had several conferences last year that I attended while it was close to harvest time.  I rolled the dice that the fruit would still be there when I got back — no such luck). This year I am taking no chances!  Last week the bird netting went up on two of the four rows in the vineyard and this week the other two will be covered as well.  Since the vineyard is so small, it was relatively easy to put the netting over the rows and secure it.  Below are a few photos (taken by Richelle Stafne) of the process.

Throwing the netting over the row.  It helps to be tall.

Throwing the netting over the row. It helps to be tall.

Pulling the netting over the vines to make sure it covers the canopy.

Pulling the netting over the vines to make sure it covers the canopy.

Securing the netting by using zip ties. Other materials can be used such as string, twine, or bread ties. The netting was tied to the irrigation wire with the zip ties.

Securing the netting by using zip ties. Other materials can be used such as string, twine, or bread ties. The netting was tied to the irrigation wire with the zip ties.

The job is finished and we admire our efforts while sweating in 90+F heat and humidity.

The job is finished and we admire our efforts while sweating in 90+F heat and humidity.

The netting will remain on until harvest.  Once all fruit is harvested it will be removed and stored for next year.  Netting is an added expense to the vineyard and it makes management more difficult, but it is a necessity to protect the fruit from birds. There are different kinds of netting, some will last longer than others (and hence are more expensive), so it depends on an individual managers needs which kind to purchase.  Tractor implements are available to help with this process in large-scale operations.

Anthracnose on Bunch Grapes

More rain is falling today and is expected for the next few days.  All this wet and cooler weather creates good conditions for anthracnose infections.  Anthracnose (Elsinoe ampelina) can be severe in years with heavy and consistent rainfall (like this year).  Optimal conditions for disease development are in the upper 70s F.  The spores are splashed from plant to plant by rain.  It is seen most commonly on young, succulent green shoots and leaves.  The lesions are sunken on shoots and on leaves the leaves can be distorted and have a shot-hole appearance.  A photo of the disease on a ‘Victoria Red’ cluster is below.

Severe anthracnose infection on Victoria Red grape cluster

Severe anthracnose infection on Victoria Red grape cluster

How can anthracnose be controlled?  If you are in the Deep South, not too easily, I’m afraid.  Sanitation can help (get rid of infected plant parts).  Canopy management that promotes sunlight penetration and good airflow can also help.  But likely the best way is a dormant fungicide spray or two of lime sulfur followed by subsequent fungicide applications until veraison. More in-depth information can be found here:

MidSouth Grape

I have been intrigued by the ‘MidSouth’ grapevine growing in my vineyard; enough so, that I tracked its entire pedigree down to the species level.  Here is what I found:

50% Vitis champinii

37.89% Vitis vinifera

5.08% Vitis rupestris

4.69% Unknown (probably V. vinifera and V. rupestris, but could not confirm)

1.56% Vitis berlandieri

0.78% Vitis lincecumii

It is an intriguing vine — moderately vigorous with moderate crop load.  Fruit set was very good this year and it is early compared to the other grapes I have in the vineyard.  Last year it had a distinct “raspberry” flavor, but I want to replicate that again in my mouth before declaring it as a consistent trait.  It is somewhat susceptible to anthracnose (caused by Elsinoe ampelina), as you can see in the photo below. ‘MidSouth’ has its faults — relatively low sugar levels, higher than desired acid, seeded, disease susceptibility, etc., but overall it is a cultivar with an interesting background.

Developing 'MidSouth' cluster in early May2015

Developing ‘MidSouth’ cluster in early May2015