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The Nobel Prize for Weed Science

MONDAY, NOVEMBER 23, 2020.  BY LARRY WHITTED, INDEPENDENT PCA.

Several years ago, for my birthday, my oldest daughter gave me a copy of a book by A.J. Jacobs entitled The Know-It-All. While I couldn’t understand the reasoning behind that particular gift, my friends and family found my receipt of it to be highly amusing.

However, upon reflection, perhaps it partially explains my low expectations for the upcoming meeting season. Now that the harvest is complete and there is a chill in the air, my attention turns to continuing education. However, after 40 years as a pest control adviser, I haven’t been anticipating learning that much new information.

Nevertheless, for the first time, I signed up for the 2020 Sustainable Ag Expo which is normally held in San Luis Obispo but has gone virtual this year due to COVID. I settled into my office chair and chose as my first session Vineyard Weed Management presented by Dr. Anil Shrestha, the chairman of the Viticulture and Enology Department at Fresno State.

I was stunned at how good Dr. Shrestha’s program was. If there was a Nobel Prize for Weed Science I would award it to Dr. Shrestha. Unlike almost every other weed management presentation that I have attended for the last 40+ years, he included data about yield and grape quality, not just how many weeds he could kill.

In 2014 I wrote an article for the Coffee Shop blog on this very topic. It was titled Herbicides and Winegrape Yield: A Research Gap. In that blog post, I argued that weed scientists should collect yield data when they perform an experiment, not just count dead weeds. My point was that the purpose of the enterprise is to produce grapes, not kill weeds, so the ultimate goal needed to be measured.

I have made this point in person to various weed scientists after their presentations only to be told that it was simply too difficult, cumbersome, and expensive to measure yields. Therefore, I had pretty much given up on that goal.

So you can imagine my surprise when I was listening to Dr. Shrestha’s presentation and he started presenting yield data to accompany his weed control data. Then he also started including various parameters of winegrape quality, too. This was more than I had ever dared ask for! I can remember the last time that I had heard anything like this; it was in the 1970s when weed scientist Boysie Day at U.C. Berkeley told me about the yield increases he measured when he started using pre-emergent herbicides in California citrus groves.

This was a good reminder, as if I needed one, that indeed I don’t know it all. I’m now looking forward to our new virtual meeting season with renewed enthusiasm to learn something new.

Larry Whitted, PCA, currently serves a key role as the Lodi Winegrape Commission’s Research, Education & Communication Committee Chair. You can learn more about Larry by reading a blog post about him HERE. As a guest blogger on lodigrowers.com, he brings a fresh, logical perspective to many viticulture topics such as negotiationsbiocontrol, and spray programs.


In addition to the great presentation on weeds, this year’s Sustainable Ag Expo includes talks about climate adaption, leafroll and red blotch, winegrape supply and demand, invasive insects, biocontrol, irrigation, rootstocks, regenerative agriculture, biochar, floor management technology, vineyard, growing healthy soils, and marketing sustainability. To register before the Expo ends on December 4, visit sustainableagexpo.org.

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