Independent Grape Growers - Paso Robles Area
Gold Members


September Blog – Biological Soil Fertility & Late Season Botrytis

Special Blog Post on Fall Concerns





Cristy Christie
Black Diamond VermiCompost
Post Harvest Biological Soil Fertility


Grape growers around the globe are recognizing the need to add nutrients to their vineyards after harvest.  In-season tissue analysis determines post-harvest soil and foliar applications of nutrients to help the vines build and store the carbohydrates and sugars. These nutritional needs have been well documented by universities and growers alike from South Africa to Australia New York to here on the West Coast.  As grapes enter dormancy, the maximum crop potential for the next growing season has most likely already been determined.

What else can growers do to add value to their pocketbook next year? Not only is early season growth potential determined by the nutritional reserves that have been built up prior to leaf drop (photosynthesis), root activity is also largest immediately post-harvest. But what is it that makes the root systems active and vigorous? A large part of the answer is found in the soil life.  Call it productive soil, healthy soil, microbial soil life or the soil food web, it’s all the same. Plants have amazing communication skills. The vast majority of soil microbes have yet to be identified, but what we do know is when a large variety are added to soil, the entire plant, including fruit, above and below ground, benefit.

[Excerpt] Extensive communication occurs between plants and microorganisms during different stages of plant development in which signaling molecules from the two partners play an important role. Fungal and bacterial species are able to detect the plant host and initiate their colonization strategies in the rhizosphere by producing plant growth-regulating substances such as auxins or cytokinins. On the other hand, plants are able to recognize microbe-derived compounds and adjust their defense and growth responses according to the type of microorganism encountered. You may want to re-read that a time or two to begin to realize how complex and fascinating the conversation is that takes place between soil microbiology and a plant’s root system. Minerals and microbes must both be present for the cycle to be effective.  If you want to learn more, the entire article can be found here.

There are dozens of studies and abstracts on the value of healthy soil microbiology, but suffice it to say that it’s just good farming practice to add a good dose of it with post harvest nutrients.  By adding teas and/or extracts, nutrients stored in the bodies of the microbial life are not lost through irrigation to contaminate ground water. Hair-thin fungal hyphae, or tentacles, wrap around soil particles in their search for food, forming aggregates that create great soil texture. Both the fungi and soluble organic matter are held in the soil. Bacteria release a sticky mucous that enable them to cling to solid particles of mineral and organic matter, ensuring they too remain in the soil and, like the fungi, aid in the formation of aggregates.

Properly made compost teas and extracts, when using vermicompost as the base, adds a plethora of soluble plant nutrients and growth compounds, a diverse microbial population, and organic matter that provide an ongoing supply of nutrients. The plant receives a consistent and reliable food source when bacteria and fungi feed on the organic matter. This below ground surface microbial activity releases some of the nutrients to the soil and retains others for their own energy and reproduction. When nematodes and protozoa in turn feed upon them, the nutrients stored in the bacterial and fungal cell walls are released to the soil in a highly soluble plant available form. When we feed the soil, the soil feeds nutrients to the plant.

You can learn the differences between aerated compost teas and extracts here. Supply the minerals and nutrients your vines need, add tea or extract to that solution and let nature go to work while you take a short break from the vineyards task list.

Since you have read this far…(thank you!)…I hope you will take advantage of the offer that follows. It’s a substantial discount, and we are confident that your vines will wake up next year with healthy vigor and a stronger immune system.



Dr. Lowell Zelinski
IGGPRA President

As we move into fall, most diseases of grapes, especially Powdery Mildew are no longer an issue. This assumes it has been prevented and/or controlled in the past and is not a concern right now.

But we are not out of the woods yet. There is another fungal disease of grapes which commonly occurs in the fall, but may be a pest all season long, namely Botrytis. This article will discuss the ecology and control of Botrytis in wine grapes in the Paso Robles area.

The botany of Botrytis is complex and is not really worth going into in this article. It has two different names, one for the sexual stage, which is rare and one for the asexual stage which is very common. Botrytis can infect almost all dicots (broad leaf plants) and many monocots (grasses). If you have any weeds in your vineyard they are probably a host for Botrytis. This includes the Oak trees that occur throughout Paso.

Botrytis can also survive in the soil for many years. Basically, there is no way to avoid the inoculum, it is everywhere, all the time. If this is the case, how does it not cause major problems all of the time? The answer is that it is the environmental conditions plus plant conditions that allows Botrytis to thrive. Other than on grape flowers and ripe “damaged” fruit Botrytis will not reproduce unless environmental conditions are sufficient for its growth. Botrytis needs a source of nutrients on which to feed. Flowers and damaged berries provide that source of nutrients. The environmental conditions where Botrytis can grow and thrive are fairly broad, temperature can go almost down to freezing and as high as 85 and it will do just fine. Botrytis also likes high humidity’s and even free water (like rain and heavy dew). The high humidity will most likely occur inside clusters, where after a fall rain event water will accumulate and is very difficult to get rid of.

Condition that do not favor Botrytis are dry weather, open clusters, open canopies, windy weather, low humidity, intact fruit (no damage to berry walls by birds and/or wasps).

Botrytis infected fruit is a problem on the wine making side also. Which is why so many wineries will not accept fruit with high levels of Botrytis. One the issues on the winery side is that Botrytis will convert many of the simple sugars (glucose and fructose) to more complex forms which can not be fermented. This cause fermentation to stop before the desired level of alcohol is reached. Additionally, Botrytis can release a chemical that actually kills the fermentation yeasts, which can cause stuck fermentations, further exacerbating the low alcohol problem. It also causes problems in color stability and in white varieties it can lead to browning of the juice/wine. Finally, off flavors and aromas can results in wines made from grapes high in Botrytis.

How is Botrytis controlled in the Paso area? I know this all sounds like doom and glum but actually Botrytis is only a minor problem in Paso. A major reason is our variety selection. Pinot noir can easily get Botrytis because of its thin skin characteristic (actually, the movie Sideways was right here). We also have fairly dry harvest seasons. Recall, that Botrytis need either free water or high humidity to really become a problem. The only times I’ve had an issue is when the zinfandel grapes would not sugar up and harvest was delayed until mid-November. Of course, it rained enough a few weeks before harvest that the inside of the cluster got wet and didn’t dry out. This caused two problems, the free water needed for Botrytis was available, and the berries swelled and, especially on the insides of the cluster the berry skin ruptured and therefore the fruit was no longer intact.

Finally, I have found that a fungicide spray just prior to berry closure (the time when the berries begin to touch each other) with a material that has efficacy against Botrytis has been beneficial. This has to planned month ahead of potential problems but in my experience it has been worthwhile.

January News

Rain – What Rain
Associate News


Winter Irrigations

If it rains between November and March we don’t need to irrigate in the winter. This year (2017-18) rainfall as been abysmal – with the only month getting some – but still way less then normal was January where we had about 2 inches in one storm. We’ve had a tiny bit (.25 inches or less) in another storm but it essentially doesn’t count.

Grapes don’t need a lot of water in the winter, but the roots are susceptible to cold injury. Cold injury will occur if low temperatures get into the teens, with some rootstocks being much more susceptible then other. In my experience 101-14 is especially susceptible.

One thing that can really help with cold tolerance is adequate amounts of water in the top 2 feet of the soil. This isn’t required to satisfy evapotranspiration requirements but more to mediate the fluctuations in soil temperatures. That is, wet soils temperatures do not change as much as do dry soils. What this really means is that on really cold nights, the temperature at the root depth in the soil will not be as cold as the air temperature.

The cold temperature effect is complex and has to do with hormones produced in the roots just before bud break and these effect the “pushing” of buds along cordons. In general, the hormones that encourage bud break are reduced and the number of buds that push – and produce clusters (yield) is reduced

My recommendation is that any month were the rainfall does not exceed 1 in, that WINTER irrigation be applied at about 12-24 gallons per vine. The exact amount depends on rootstock, soil, and current water content on the root zone (one of the reasons to invest in soil moisture monitoring sensors).


IGGPRA elections for 5 new board members will be conducted via email very soon as well as at the member annual meeting on February 16, 2018. The meeting will coincide with our annual spaghetti western mixer and is the only event that is for members only. Visit the website on 2/1/18 to see candidates and their bio’s. You will also receive a ballot by regular mail in the first few days of February

Associate News

Central Coast Party Helpers is a GOLD associate member and they help out at all of our mixer events. They are fantastic and if you ever have a party or event you need help with I highly recommend them. They are having an Open House this Wednesday January 31, 2018 between 5 and 7 pm at their new location at 503 13th Street in Paso Robles.

Check out their website

The 2017 Season in Review

The 2017 Season in Review

The fall is the time of change for grape growers in the Paso Robles Area. Grapes are harvested. Grape vines with vigorous canopies only a month ago are now losing leaves and going to sleep. It is time to invoice your wineries and hope they pay quickly, so you can pay your bills. Hopefully, in a few weeks you can relax and maybe even take a vacation.

You know that in a few short months you will be right back at it, worrying about frost, Powdery Mildew sprays, do I need a new purchase agreement, should I buy crop insurance, when do I start irrigation’s and many more things that make grape growing challenging and exciting.

But, before we rush ahead, let’s review the 2017 season. One of the biggest events of the 2016 (fall) and 2017 (winter and spring) was that we FINALLY got an average amount of rain in the Paso area and some areas, especially on the Westside, more than usual. This amount of rain was beneficial in many ways. It leached accumulated salts out of the root zone, and this lead to decent canopy growth for the first time in years. This caused other problems later in the season, but more about that later.

The rainfall did cause a few issues, namely later spring growth of cover crops and/or weeds in between the rows. This growth interfered with frost protection practices, i.e mowing, but I heard of very few instances of frost damage in 2017. Another issue associated with the “normal” amount of rain, was the ability to spray pre-emergent herbicides under the vines last winter. This lead to some weed control issues, but nothing really bad.

May, June and July all seemed pretty average, which is a good thing. The one thing grapes love is consistence. The can deal with warm weather and they can deal with cool weather, but not rapid changes between them both. There were a few times in May and June where we went from warm to cool to warm in just a few days, but in general these weren’t bad. July was consistently hot, but that is July.

Then came August and early September. The middle part of August was nice, maybe even cool by August standards, with many days having high temperatures in the 80’s. Then came the last week of August and the first few days of September. WOW! Some of my vineyards had temperatures which exceeded 110 for close to 10 days. Grapes are in general a hardy plant, but few plants (other than Cacti) are that hardy. It appears that yields were affected primarily on the eastside of Paso, with many blocks yielding less than 2 tons per acre.

My first harvest of the year is always a block of Sauvignon Blanc, that usually gets harvested in late August or early September. This year harvest was September 6th and I got almost 7 tons per acre. It is usually a high yielding block, but this was a record.

I was excited, that maybe it would be a good year for all blocks, but turns out that blocks right next to this one were some of the poorest I have had. Close, but not as bad as 2015.


Associate News


• An All-Wood Sustainable Pest Control Solution
• Designed in conjunction with Dr. Martin Cody
• Handmade out of wood by Amador County craftsmen – Four Models





Associate News – VIP Lunch 7-12-17


Invites you to join us for a BBQ Tri-Tip Sandwich lunch Wednesday, July 12th 2017 11AM TO 1PM

10 Volpi Ysabel Road Paso Robles, Ca

Come by and meet the newest member of our Team, Brian, and check out our



LUMINITE LIGHT TOWER for night harvest and events

and the latest in pruning:

FELCOTRONIC labor saver pruners

For more information please call Lee at: 805-226-9960

2017 Harvest Hoedown

Celebrate the coming of harvest in the Paso Robles Wine Country

at the Third Annual 


August 5, 2017 (Paso Robles, California) – Wine grape harvest is just around the corner in the Paso Robles wine country. Traditionally, farmers held celebrations at the onset of harvest to help usher in a bountiful season. The Independent Grape Growers of the Paso Robles Area (IGGPRA) is bringing this time-honored tradition back with its 3rd Annual Harvest at The Loading Chute barn in Creston, California on August 5, 2017, from 6 pm – 10 pm.

The Harvest Hoedown is a good ol’ fashioned harvest celebration where many old customs are brought back to life. The event was developed to let local growers kick of a little steam and to help promote the burgeoning wine region.

2016 Harvest Hoedown

“The Harvest Hoedown is an opportunity for wine lovers and other guests to mix and mingle with local growers,” said IGGPRA president, Lowell Zelinski. “One of the missions of our organization is to promote local wine grape production and help educate the wine loving community about what we do. Events like this are rare opportunities for consumers to meet growers and see another side of the industry.”

There will be a wood-pit barbecue, barn dance and a pie baking contest that all guests are welcome to enter. Guests can also take part in a Wine Walk, which is a spin-off of cake walks that were held in yesteryears. Everyone can participate in the Wine Walk and have a chance to win wine or other prizes.

Winners of 2016 Fruit Pie Contest

To help set the scene, the event is held in the historic barn at The Loading Chute in Creston, California. The small country town with a population of 94 people is set in the Paso Robles wine region. It was founded in 1884 on the Rancho Huehuero Mexican land grant, and now has its own defined AVA (American Viticulture Area) called the Creston District AVA. It has been home to celebrities such as Alex Trebek, Carrie Fisher and L. Ron Hubbard. The Loading Chute restaurant, where the event is being held, is a local, iconic favorite.

This year, guests can kick up their heels to the sounds of local favorites The Shawn Clark Family Band. They’ll be playing old and new country favorites. The barbecue includes tri-tip and chicken with all the fixin’s.

After dinner, guests can sample an array of pies entered in the pie baking contest. There are two categories: fruit and cream pies, and anyone can enter. The winners will be determined by popular vote. Complete details on entering the contest are on the website and you may enter when you purchase your tickets. Seating is limited and guests must be over the age of 21. Discounted early admission is $25/pp and $15/pp for IGGPRA members through July 26, 2017. After that regular admission is $40/pp and $25/pp for IGGPRA members.

Tickets are available online at

For more information or to register by phone, please call (805) 591-4204.

Thank you to our sponsors for making this event possible:

Special Deals from Our Associate Members

As a associate member benefit IGGPRA will occasional promote special events and other deals that may be of interest to you.
Please support our associate members

Hidden Power Cycle Clinics

Jim’s Supply Company



What’s happening at IGGPRA this month

Short notes on upcoming IGGPRA and local industry events that you may want to know about!

Visit the IGGPRA website for information about your organization. Take advantage of the IGGPRA marketplace where you can post grapes, bulk wine and other items for sale.

Membership renewal is underway right now! Please visit the website to renew today. You should receive an email reminder this week.

Election for Board of Directors, Approval of By-Laws amendments and Adoption of IGGPRA Policies will be occurring very shortly. Please remember to vote! A mailed ballot will arrive shortly as well as an email ballot. You can also vote at our Membership Annual Meeting on February 23. Click here for more details.

You also get an agenda for the Annual Meeting by email shortly.

Associate Member Events (This will become a regular feature)

On Wednesday, February 8, 2017 Wilson Orchard and Vineyard Supply will be hosting Infaco USA, a leading manufacturer of battery operated pruners and tying machines, for a customer demonstration day in Paso Robles, CA. We will have Simon Rodrigues, Infaco International Technical Sales Manager, at our store so that he can answer any questions on machines you have, are interested in purchasing, or assist you with training your operators. We invite you to stop by and see what Infaco products can do for you like increasing efficiency, labor savings and decreasing worker injuries. We look forward to seeing you on Wednesday. (77 Marquita Ave. Paso Robles, CA 93446)
If you are a grower your Pesticide Use Permit and / or your Private Applicator License may have expired on January 1. Check your records and renew them prior to needing to buy chemicals this year.
The Regional Water Quality Control Board has new regulations for you to follow this year. These include well testing, eNOI updating, and increased fees for surface water quality monitoring. More info soon in an upcoming blog post.

Smoke Taint Remediation in Finished Wines

MAV logo PMS Colors HiRes 4x2.jpg

By: Bob Kreisher, President – Mavrik N.A (

For Remediation Services* please contact:

Matt Zinkl, Product Marketing Specialist

Phone: 707-228-0442 (cell), Email:

Smoke Taint From Wildfires Update: What Do We Know Now?

Smoke taint is an annoying obstacle to making the best wine possible from the grapes you have.  But it can be overcome with patience and determination.

What is smoke taint?

Measurement of guaiacol and 4-methylguaiacol is a convenient and reliable way to determine the likelihood of smoke taint. It correlates well

Read more »

Smoke Taint and You

What to do when smoke gets in your vines
By: Becky Zelinski

When wineries ask you how you knew whether or not smoke taint has affected your vineyard, it’s best to be know the answers. Growers can find out how to be prepared at the September IGGPRA (Independent Grape Growers of the Paso Robles Area) seminar to be held at La Quinta Inn & Suites on Wednesday, September 21, 2016 from 1 p.m. to 3 p.m. In addition to smoke taint, the latest updates on Red Blotch and Bunch Rot will be discussed.

Like it or not, the California Central Coast has been affected by its share of smoke in 2016. It’s difficult to know at this point which vineyards have been affected with smoke taint and to what degree. Therefore, the million-dollar question on the minds of every grower is: has my fruit been affected; and if so, to what degree and what does it mean?

The short answer is: it’s complicated. Believe it or not, smoke taint is variable from vineyard to vineyard and even within a vineyard. The taint is caused by a

Read more »

European Grapevine Moth eradicated!

This is great news!

European Grapevine Moth Eradicated From California