Vine Lines: Petiole Sampling To Monitor Grapevine Nutrient Status

Vine Lines: Petiole Sampling To Monitor Grapevine Nutrient Status

Farming is all about timing. Some of the things we need to do are time-flexible like pruning, while others are time-sensitive like applying a spray for powdery or downy mildew. Missing a spray to control mildew can leave you with a problem for the rest of the season. Monitoring the nutrient status in vines is also a “time-sensitive” activity.

Bloom And Veraison Petiole Sampling

The best way to find out what fertilizers you might need to apply is to analyze “petiole” (leaf stem) samples at bloom time and again at veraison (berry softening). Bloom time is important because insufficient levels of micronutrients at bloom can have a season-long effect on fruit quality. Veraison is important since at this time there is a major change occurring within the vine (the beginning of fruit ripening). This involves the uptake and remobilization of macronutrients (potassium in particular).

For vinifera (European/California) varieties, research work has been completed on both bloom time and veraison vine growth stages to establish desirable levels for individual nutrients. For the labrusca and hybrid varieties, critical nutrient levels are established for veraison with research underway for desirable levels at bloom time.

Sampling Procedures

When sampling at bloom time and veraison, it is important to use a consistent approach each year.

• Vineyard Location(s): If a vineyard is uniform in growth, you can select one location. If one area has consistently better growth than another, you may select two areas to sample. For each area being sampled, select specific rows that are representative and use the same rows each season.

• Timing and Petiole Position: For the bloom time sample, the vines would ideally be at 70% to 80% bloom (50% to 100% bloom is OK, too). If you are ahead of or behind this timing, it should be noted for each sample. At bloom, the petioles sampled should be the ones opposite the first grape cluster. For a veraison sample, the sample should be obtained at the beginning of berry softening with the petiole obtained from a mid-cane position. A total of 70 to 80 petioles are sufficient for each sampled area. When taking a sample, snap off the petiole and blade from the cane, then discard the leaf blade and save the petiole.


• Varieties and Rootstocks:
Don’t mix varieties. While critical levels of some nutrients are the same across varieties, there can be significant differences. Research during the last 10 years has also identified significant differences in nutrient uptake among rootstocks. Therefore, don’t mix rootstock samples.

• Sample Handling: Petiole samples should be placed in a paper bag and labeled with the location, row number, growth stage, and date. The samples should be delivered or shipped to an agricultural laboratory. If there is going to be a delay in delivery, the paper bags should be left open to air-dry. Do not use plastic bags since this can result in molds growing on the green tissue.

Interpretation Of Results

There are a number of laboratories across the U.S. that can perform an analysis of your samples. The Extension service (farm adviser) offices in each state typically maintain a listing of agricultural laboratories. You should not use an environmental laboratory since their fees are higher than ag labs.

You will want to run a “complete” analysis which will include the macronutrients (nitrate-nitrogen, total nitrogen, total phosphorus, potassium, calcium, and magnesium) plus the micronutrients (sodium, boron, zinc, manganese, iron, and copper). Other micronutrients might be included depending on the area.

When you submit your sample, tell the lab that the analysis is for grapes, the type of grape (vinifera, labrusca, or hybrid), the variety, and the growth stage (bloom or veraison). Based on these sampling parameters, the lab should print the critical levels for each nutrient across the bottom of the report. It is important to ask the lab if the critical levels that they include in your report are based on university research or their personal experience. Unfortunately, sometimes labs develop their own set of critical or desirable levels for individual nutrients and do not indicate the basis of these numbers. It is not that the values that a lab uses are not appropriate, but you should be aware of their source. It is also a good idea to use an “independent” lab, not one associated with an ag chemical dealer.

Survey Sampling Versus Problem Diagnosis

A good vine nutrition monitoring program would include “survey” sampling at bloom time and veraison every year. In addition, there may be noticeable differences in vine growth or leaf symptoms within a vineyard that appear to be due to a nutrient deficiency or excess. Obtaining “symptom vs. non-symptom” or “good vs. poor” growth samples can frequently let you know if the problem is nutritional or not.

Topics:

Leave a Reply

Grapes Stories
(Photo credit: Wikimedia Commons)
Grapes
May 13, 2016
Just How Many Acres Of Grapes Have Been Planted In California?
Nat DiBuduo of Allied Grape Growers says reports may be misleading and there are more than 48,000 nonbearing acres coming into production. Read More
Convex landforms in Virginia are advantageous for grape growers as shown at this summer vineyard meeting. (Photo credit: Tremain Hatch)
Grapes
May 13, 2016
Virginia Looks To Boost Wine Business Through Grants
More than $800,000 is up for grabs for those interested in expanding or adding new vineyards in Virginia. The Virginia Read More
Partial rootzone drying: Two emitters deliver water alternately to either side of a vine’s rootzone. (Photo credit: Yun Zhang)
Grapes
May 13, 2016
Irrigation Method Can ‘Trick’ White Grapes
Washington State University scientists believe they have discovered a sweet spot for irrigating white wine grapes. Dr. Markus Keller, a Read More
Brown marmorated stink bug. (Photo credit: USDA)
Crop Protection
May 6, 2016
Scouting Tips For Growing Grape Pest Threat
Grape growers should be on the lookout this fall for two pests that are popping up in vineyards along the Read More
red blotch featured image
Crop Protection
April 27, 2016
Vector Transmitting Red Blotch Virus Found
Researchers at the University of California, Davis (UC-Davis) have found the vector that seems to be spreading grapevine red blotch, a Read More
Vineyard Labor Downsized GP
Grapes
April 25, 2016
Vineyards Honored For Sustainability
California Green Medal recognizes wineries and vineyards with a focus on sustainability. Read More
Botrytis in 'Riesling'

Photo: Wikimedia commons photo
Grapes
April 22, 2016
Spring Rains Could Increase Phomopsis And Botrytis Infections On Grapes
Areas that don't typically see many infections could be in for a surprise this year, thanks to a wetter spring. Here are some tips to keep these diseases at bay. Read More
The Latest
Grapes
May 24, 2016
Sea Change Coming To California Winegrap…
Vines continue to be pulled from the state’s interior, while planting is expected to increase along coast and in Delta area. Read More
Disease Control
May 19, 2016
Native Plants Reduce Need For Vineyard W…
Scientists in eastern Washington are finding drought-tolerant alternatives to roses at the end of vineyard rows that not only save Read More
Grapes
May 18, 2016
Minnesota Has New Cold-Hardy, Lower-Acid…
The University of Minnesota has released a new cold-hardy grape that holds promise for winemakers wanting to make dryer wines Read More
Grapes
May 13, 2016
Just How Many Acres Of Grapes Have Been …
Nat DiBuduo of Allied Grape Growers says reports may be misleading and there are more than 48,000 nonbearing acres coming into production. Read More
Grapes
May 13, 2016
Virginia Looks To Boost Wine Business Th…
More than $800,000 is up for grabs for those interested in expanding or adding new vineyards in Virginia. The Virginia Read More
Grapes
May 13, 2016
Irrigation Method Can ‘Trick’ White Grap…
Washington State University scientists believe they have discovered a sweet spot for irrigating white wine grapes. Dr. Markus Keller, a Read More
Crop Protection
May 6, 2016
Scouting Tips For Growing Grape Pest Thr…
Grape growers should be on the lookout this fall for two pests that are popping up in vineyards along the Read More
Crop Protection
April 27, 2016
Vector Transmitting Red Blotch Virus Fou…
Researchers at the University of California, Davis (UC-Davis) have found the vector that seems to be spreading grapevine red blotch, a Read More
Grapes
April 25, 2016
Vineyards Honored For Sustainability
California Green Medal recognizes wineries and vineyards with a focus on sustainability. Read More
Grapes
April 22, 2016
Spring Rains Could Increase Phomopsis An…
Areas that don't typically see many infections could be in for a surprise this year, thanks to a wetter spring. Here are some tips to keep these diseases at bay. Read More
Grapes
April 21, 2016
McManis Family Vineyards: Treating Emplo…
It’s no coincidence that more than half the full-time vineyard workers at McManis Family Vineyards have been with the company for 20-plus years. Read More
Grapes
April 21, 2016
Are Muscadine Grapes The Next ‘Super Fru…
UF/IFAS researchers are seeking to expand market, educate consumers. Read More
Grapes
April 20, 2016
Samuel Filler Named New York Wine & …
Filler will take over beginning in January, replacing long-time President Jim Trezise. Read More
Grapes
April 15, 2016
Using Wastewater For Vineyard Irrigation
New research shows wastewater could be a sustainable solution for irrigating vineyards. Read More
Grapes
April 15, 2016
Cornell Researcher Wins Award For Helpin…
Marc Fuchs receives the New York Wine & Grape Foundation 2016 Research Award for addressing and combating grapevine diseases. Read More
Grapes
April 7, 2016
New Technology Guides Vineyard Managemen…
VinSense LLC has received a grant from the National Science Foundation to fund expansion of a software program that helps growers make irrigation and other vineyard management decisions based on climate, weather, soil variation, and other factors. Read More
Grapes
April 7, 2016
New Program Helps Pennsylvania Vineyards…
Grape growers in Pennsylvania’s Lake Erie basin are being invited to participate in a new program called VinES (Vested In Environmental Sustainability). The goal of the program is to reduce pollution into Lake Erie while increasing growers’ profitability. Read More
Grapes
March 31, 2016
Three Tips For Preventing Trunk Disease
Trunk disease can be avoided with proper preventative measures. It may require an investment of time and money upfront, but you’ll save on replanting costs in the long run.  Read More
[gravityform id="62" title="false" description="false"]