Tomato Herbicide Injury, August Growing for Market

Roma tomatoes with damage from Triclopyr herbicide July 2016.
Photo Puck Tupelo

This time last year, we were suffering from a herbicide problem which stunted our Roma paste tomatoes. No, we didn’t spray herbicide on them. Someone else sprayed Triclopyr growth regulator herbicide (Ortho Poison Ivy Killer)  on poison ivy down the road, behind some trees. He sprayed on  5/23, and made repeat sprays twice, about two weeks apart (approx. June 4th and 18th). As the crow flies, it might be 600 ft or so from the tomatoes.

Some other brand names of Triclopyr include Grandstand, Alligare, Garlon and Horsepower. Other growth regulator herbicides include 2,4-D, Aminopyralid, Dicamba, Diflufenzopyr, Picloram, Quinclorac, as well as Triclopyr.

On June 18 2016, we noticed some of the younger leaves on our plants were curling inwards and buckling an odd way. There were no obvious spots or mottling, but the sick plants were stunted. Most of the damaged plants were in groups in low areas.

I thought it was a virus. We decided not to handle the plants until we had a diagnosis, for fear of spreading disease. We got help from the wonderful Virginia Tech Plant Diseases Clinic, who said the plants did not have any of the viruses they could test for, or that they knew, and the damage closely resembled growth regulator herbicide damage. But we don’t use herbicides, we protested.

On 6/30 we found out about the initial Triclopyr spraying, but the Plant Disease Clinic at that point agreed that drift was unlikely, given the distance and trees in between our tomatoes and the poison ivy, and the pattern of damage. Triclopyr damage usually appears within one week, not 25 days later (we didn’t find out about the second and third spraying until later). On the other hand, we did not know of any other use of growth regulator herbicide nearby. Their final report, at the end of July, named herbicide drift as the probable cause.

Roma paste tomatoes with oddly curled leaves due to growth regulator herbicide vapor drift.
Photo Puck Tupelo

I researched some more and found information about volatilization on a herbicide website.

High temperatures and low humidity favor herbicide volatilization, which can lead to vapor drift.

We now think that the herbicide sprayed on the poison ivy evaporated or volatilized on that very hot day, formed a little cloud that dropped down in the middle of our tomato patch and did its damage. Tomatoes are very sensitive to herbicides. 68 of our 246 plants showed some damage – about 25%. The Plant Diseases Clinic said:

Symptoms were consistent with chemical injury from a growth regulator type herbicide . . .  Herbicide residue in straw mulch from herbicide-treated pasture or manure from animals fed on herbicide-treated pasture can cause similar symptoms. Since your tomatoes are growing out of the problem it is very unlikely that the problem was caused by herbicide residue in compost/manure/straw used to amend the soil.

To definitively rule out herbicide residue in compost or the soil, I did a bioassay using snap bean seeds planted in numbered pots with tomato plot soil, compost like we’d used, and other garden soil. Beans emerge and grow quickly and can show up herbicide damage.  Most of my bean seed in the bio-assay got dug up and eaten by something. . . such is agriculture! Only one bean came up (out of 48). The bean plant looked fine. It was in a pot of soil from one of the worst tomato plants. This indicated that it was not a problem in the soil (eg from compost or other soil amendments).

The fact that the plants grew out of the problem, making normal leaves later, also suggested it was not a problem in the soil, but an incident after planting. Unfortunately though, after not string weaving for over a month, the plants were a (stunted) jungle and enthusiasm for string-weaving them had plummeted. We got very poor yields that year. Even after all the investigations, my thoughts were:

Drift still seems rather unlikely to me – the pattern of damage, the tiny ready-to-spray bottle so far away. . . It’s sobering how damaging those herbicides can be!

Since then I have acknowledged it most likely was  vapor drift.

I’ve now found a Herbicide Injury Image Database from the University of Arkansas Extension Service. It covers 18 herbicide groups and you can search not just by herbicide group, but by brand name of herbicide, by crop and even a paired search of crop and herbicide. Sadly it doesn’t include the very pairing (tomatoes and Triclopyr) that we were most interested in, but it does have many, many good photos of other combinations.


Recently a friend was showing me her damaged greenhouse tomatoes, which were growing out (recovering) after suffering some damage which caused the stems to make stubby shortened branches. She thought she’d caused the problem by using horse manure after stacking it for “only” 6 months. She thought she was looking at a type of “burning” from manure that was too fresh. I thought it might be damage from one of the “killer compost” herbicides which survive in hay or straw from sprayed fields, survive through composting, survive through livestock digestive systems, and wreak havoc on vegetables.

I looked through the Tomato section of the Herbicide Injury Image Database but I didn’t see exactly what my friend’s plants had. It most resembled the Quinclorac (Facet, Quinstar) damage but I really don’t know.

Tomato damaged by Quinclorac herbicide.
Source (www.uaex.edu) (Dr. Cal Shumway, Dr. Bob Scott, and Dr. John Boyd)

Unmarketable tomatoes ripen on vines affected by contaminated mulch at Waterpenny Farm. (By Margaret Thomas For The Washington Post)

Waterpenny Farm, Sperryville, Virginia suffered herbicide in hay mulch in 2007. The hay they bought had been sprayed with Grazon. They lost 12,000 plants with a harvest worth $80,000. Grazon is another of the growth regulator herbicides like the Triclopyr we were blighted by.

You can read more about “Killer Compost” in these articles by Cindy Conner, Mother Earth News (several samples of off-the-shelf Purina horse feed were contaminated with clopyralid) and Joe Lampl Growing a Greener World TV

Chert Hollow Farm suffered fungicide spray and wrote about pesticide drift part 1 in three episodes, part 2 and part 3. 

Don’t let this happen to you (if you have any control over it) and if it does, seek help.


On a happier note, the August Growing for Market magazine is out. There is a long article about Triage Farming: How to choose what to do when there’s too much to do by Matt S. An important topic and just the time of year when this massive problem hits us. Matt has a sense of humor, which really helps in hard times. There’s also an article European cultivation tools by Sam Hitchcock Tilton. This is followed by Farmers market metrics: Collecting data has many benefits for vendors by Darlene Wolnik. Then a very appetizing article about berries by Michael Brown and a dramatic article on big floral installations for weddings and other events, by Gretel Adams, which includes some very eye-catching and original ideas.

Upcoming events, Growing for Market article, Organic Broadcaster

Harvesting Zephyr yellow squash.
Photo Brittany Lewis

Starting with what’s being harvested now – squash and zucchini are coming in nicely. The hoophouse Gentry yellow squash (chosen for being fast-maturing) is coming in by the bucketload, and the outdoor yellow squash and zucchini have started producing.


I’m off to Burlington, Vermont this weekend, for the Mother Earth News Fair. I’m giving two workshops:

Cold-hardy Winter Vegetables,on Saturday 6/10 at 11 am on the Yanmar Sustainability Stage, immediately followed by book-signing at the Mother Earth News Bookstore noon- 12.30.

Producing Asian Greens on Sunday  6/11 at 3.30 pm on the Heirloom Gardener Stage.

I’m also doing demonstrations of tomato string-weaving at the New Society Publishers booth 2611, near the Mother Earth News Stage (not the Bookstore this time), at 10 – 10.30 am and 3-3.30 pm on Saturday and 10 -10.30 am, 11- 11.30 am and 2- 2.30 pm on Sunday. Check out my Events page to see the pink sparkly tinsel tomato plant models I use!


At the Heritage Harvest Festival near Charlottesville, Virginia, on Friday September 8 (the Premium Workshops before the main Festival), I’m presenting on Growing Sweet Potatoes at 3.30-4.30 in classroom 7, followed by book-signing at the Monticello Bookshop.


The June/July summer issue of Growing for Market magazine is out, and includes my article on Hoophouse soil salt buildup. This is an issue we have been dealing with – we see white deposits on the soil. I did a lot of research and found ways to water the salts back down deep in the soil profile. I also gathered information on how to measure and monitor salinity, and how to understand the test results and their different testing methods and different units of measure. I learned about salt tolerance of different crops, the plant symptoms of excess salinity, and how to prevent the problem in future. This topic is rising in importance as more people use hoophouses with drip irrigation systems. We were blithely ignorant for our first several years of hoophopuse use, as salinity takes a few years to really develop, and there wasn’t much information available.

I’m also looking forward to reading the other articles, especially Summer lettuce lessons from Southern growers by Jesse Frost. There are some great photos of beds covered with hoops and shade-cloth, which show a good system. I always appreciate articles written for southern growers, which can be in short supply.

Daisy Fair in Utah’s zone 5 has written about moveable tunnels with in-ground hydronic heat. So there’s information for cold climates too. Sam Hitchcock Tilton has an article with tips learned from Dutch and Swiss farmers. Robert Hadad advises on careful monitoring of costs of production in order to actually make a living from farming. The flower growing article in this issue is from Debra Prinzing and is about American Flowers Week, a chance to highlight American-grown flowers with some light-hearted fun photos.


The May/June Organic Broadcaster just arrived in its paper format – I’ve had the digital one for a while. Good thing I’ve got that long car ride to Vermont this weekend to catch up on my farming reading!

The front page story this time is about Kansas farmers, Tim and Michael Raile, transitioning thousands of dryland (non-irrigated) acres to Organic steadily over the next 5 or 6 years. Dryland farming focuses on moisture retention. The Railes grow a wheat/corn/
sunflower/milo (grain sorghum)/fallow rotation. They are also trialing some ancient grains.

Organic production in the US is not meeting demand, and organic imports are increasing, including organic soy and feed corn, not just bananas and coffee. More farmers want to produce Organic poultry, eggs, milk and meat. And so they are looking for Organic feed at an affordable price. This is often imported, which raises issues about how Organic Standards vary from one country to another, and the bigger issue of sustainability – not always the same as Organic! Does it really make sense to ship in grains to feed livestock?

Harriet Behar writes about the true meaning of Organic and overall methods of production. It’s not just about following rules on allowed inputs and materials – it’s a whole approach to how we treat the soil, our plants and livestock.

Hannah Philips and Brad Heins share research on how cover crop choices can influence the fatty acids and meat of dairy steers. Jody Padgham writes about CSAs responding to competition and decreasing membership by offering more options on shares and delivery. Gone are the days of “One box, one day, one price” CSAs. Numerous modifications of the basic CSA model have sprung up to better fit the diverse needs of customers (members). Kristen McPhee writes about the Vermont Herb Growers  Cooperative, which buys from various small-scale growers and aggregates orders to larger buyers. Other topics covered include lessons learned from Hawaii’s GMO controversy, paying for end-of-life care without losing your farm, and many short items and classified ads. As always, a newspaper packed with information.


And by the way, we’re also picking blueberries – ah! heaven!

Blueberries.
Photo Marilyn Rayne Squier

Growing for Market, Sweet potato propagation and yields

The April issue of Growing for Market is out! For those of you growing sweet potatoes, Andrew Schwerin from NW Arkansas has written an interesting article. I’ve written about starting sweet potato slips before and I have a slideshow that includes three methods of  starting your own slips.  He and his wife Madeleine grow 1500 feet of sweet potatoes each year, a third of their growing area.

I was interested to note their reasons for growing so many sweet potatoes (apart from the obvious fact that they can sell that many). Sweet potatoes are not a big moneymaker in terms of the space occupied. Here at Twin Oaks we pondered similar issues this winter when deciding which crops to grow.  We worked down a list of 25 factors, deciding which were important to use. We chose our top handful of factors and then worked down a list of crops we might grow, awarding points (or not!) for each factor for each crop. This helped us narrow down what to focus on this year. And yes, we are growing sweet potatoes! I wrote about this in Growing for Market in February 2017.

These growers listed the following factors as their reasons to grow sweet potatoes:

  • Sweet potatoes produce well in our soil

  • They aren’t troubled by intense summer heat

  • Extensive vines will smother most weeds

  • Few pest or disease issues

  • Most of the labor is in early October, between intensive harvests of summer and fall crops

  • They store long-term for steady sales through the winter

Sweet Potato harvest at Twin Oaks. Photo McCune Porter

They like Beauregard, and wanted to try using the single node cutting method, as advocated by Anthony and Caroline Boutard – see my Sweet Potato slideshow for details. Initially they were excited about the single node cutting process, as their roots produced exponentially more growing shoots each week. OK, maybe exponential is a bit of an exaggeration, but it gives the sense of it. Because they had so much propagation material, they started making 5-node slips, rooting clusters of cuttings in pots of compost, 3 nodes in the soil for roots, 2 nodes above ground.

Some of their single node cuttings failed to thrive, both in the trays and in the field, so they developed a 2-node cutting system instead, and also used their five-node slips. And so they had a trial of three sweet potato cutting methods, with plants in different 100 ft beds. In the past (using the regular slips method) they have averaged yields of 500-600 lbs of sweet potatoes per 100 ft bed, with a range from a poor 250 lbs to a few successes with 1000 lbs/bed. Of course, yield is not the only important feature of a market crop, although understandably it has a high profile for those growing 1500 row feet for sale.

At harvest, they found that their single-node sweet potato plants were producing a couple of hundred pounds per 100 ft bed. The 2-node beds produced about 500 pounds per bed, of relatively few, very large (6 – 20 lb) sweet potatoes. The plants with 3+ nodes in the soil gave more reasonable sized potatoes. They tend to get jumbos, so they have started planting closer (10″) to tackle this – not many customers want jumbos.

In his article in Growing for Market,  Anthony Boutard pointed out that single-node cuttings do produce fewer tubers which are larger and better formed. This is a big advantage for growers in the north, but less so in the south. The Arkansas growers have found that the 2-node cuttings are even better at this tendency in their location, which is much further south than Anthony Boutard’s farm.

Beauregard sweet potatoes saved for seed stock.
Photo Nina Gentle

Other articles in this month’s Growing for Market include Managing a cash crisis
How to climb out of the hole by Julia Shanks, the author of The Farmer’s
Office. Farmers deal with a very seasonal cash flow, and may well have gone into farming with good farming skills but not good business skills. Julia writes about four rules for getting out of a financial hole.

  1. Quit digging (don’t incur any more inessential expenses).
  2. Keep the dogs at bay (communicate with your creditors about how you plan to pay, and how you plan to keep producing the goods).
  3. Climb out (increase revenue in as many ways as possible).
  4. Get your head out of the sand (don’t panic, face realities, be proactive).

She goes on to list 10 ways to protect yourself from getting in such a hole again.

Sam Hitchcock Tilton has an article about cultivating with walk-behind tractors, ie, weeding and hoeing with special attachments. There are some amazing walk-behind
weeding machines (manufactured and homemade) throughout the world. There
is an entire style of vegetable farming and scale of tools that have been forgotten, in between tractor work and hand growing – the scale of the walk-behind tractor. The author explains how commercially available tools can be adapted to work with a BCS or a carefully used antique walk-behind tractor.

Mike Appel and Emily Oakley contributed Every farm is unique, define success your own way. Money is not the only measure. Quality of life, family time, and personal well-being are up there too, as are wider community achievements. Farming is equal parts job and lifestyle, and the authors recommend having a strategic plan for yourself and the farm, which you update every couple of years to pinpoint goals and the steps you need to take to reach them.

Cossack Pineapple Ground Cherry
Photo Southern Exposure Seed Exchange

Liz Martin writes about husk cherries (ground cherries) and how to improve production of them, to make a commercial crop viable. Who would have guessed that hillling the beds before planting can make harvest so much easier, because the fruits roll down the sides?

Judson Reid and Cordelia Machanoff wrotea short piece: Fertility tips and foliar testing to maximize high tunnel crops, and Gretel Adams wrote about  Scaling up the flower farm. Many of the ideas also apply to vegetable farms.