jeffgillman003

A Dangerous Game

Every once in awhile I become infatuated with some idea and can’t stop for looking for information on it. It usually starts when I want to find a good quote for a particular article or column that I’m writing and then ends up swallowing two or three days. Well, it happened to me again yesterday and spilled over into today. I’m currently finishing up a project with an old friend of mine from college who happens to be a political science professor at the University of North Carolina Charlotte. We’re looking at certain environmental issues and the stances taken on them by both the left and the right. Anyway, I wanted to make a point about biotechnology — that point being that when we graft two plants together we often get different chemicals in the plant which we grafted onto the rootstock than we would get if the plant were growing on its own roots. This is because many chemicals can be translocated from the roots to the leaves or even the fruit. Anyway, I quickly found a number of nice scientific articles to back up my statement, but I also found some other fascinating information about, of all things, tomatoes. There are many plants related to tomatoes that tomatoes can be grafted onto. For example, every spring our plant propagation class grafts potato roots to a tomato top. Tomatoes can also be grafted onto eggplant (which is actually very useful because eggplant roots are very resistant to flooding unlike tomato roots).

While the above examples are interesting, they’re also relatively common knowledge among horticulturists. Here’s the part that’s not common knowledge (or perhaps I should say here’s the part that I didn’t know about — I’ve been known to be ignorant of things that other people consider common knowledge before). Tomatoes can be grafted onto tobacco, and, if they are, they will have nicotine translocated to their fruit — not a lot mind you. Most of the nicotine ends up in the leaves and stems of the tomato plant, but still, why couldn’t a nicotine-laden tomato be developed which could help smokers kick the habit — in a semi-healthy kind of way?

I also found that tomatoes could be grafted onto jimson weed. Big mistake there. Jimson weed develops some pretty nasty alkaloids, and they end up in the tomato fruit. So, if you eat the fruit, your done for. In fact, I found an instance where 5 people were killed because they ate tomatoes grafted onto jimson roots. I am now curious about what happens if you graft tomato onto deadly nightshade — but not curious enough to actually try it.

Dandelions and clover

It was fun to read all of your comments last week about your opinions on lawn care. To follow up on it I’m going to talk a little bit about why I’m not fond of companies which apply herbicides multiple times throughout the year. But first I think I’ll mention why I apply herbicides at all — aesthetics. That’s it — the whole reason. Could I go the no-lawn route? Yes, but I like having a yard to run in. Not a huge yard, but a little yard to play tag with the kids.

What I long for though is the yard from the house that I grew up in. Our house in southeastern PA (About an hour west of Philly and an hour east of Lancaster) was set back about 800 feet from the road and was on old agricultural land. The area around the house was planted in grass in the mid 70s and then it was left alone. Fertilized once the first year I think, but that’s it. Dandelions invaded quickly as did clover. Over the years the clover began to dominate the grass, but not to the point that the grass disappeared, and the lawn actually appeared relatively homogeneous. Dandelions never left, but their numbers declined. The clover grew low and the grass never shot up like it does in a heavily fertilized lawn and so mowings only happened once every two weeks or so (well, OK, sometimes more often depending on the weather and where on the lawn you were — the spot over the septic tank needed mowing every 48 hours or so). The grass did go dormant most summers, but 800 feet from the road there wasn’t anyone to complain, and besides, the clover kept the lawn from appearing completely scorched. The lawn looked good for well over 30 years (until my parents remodeled the house and the yard was torn up).

The typical suburbanite might not have liked this lawn, but to me this lawn looked great, and, besides, it was low maintenance. The reason I’m bothering to tell you about this lawn though is because it illustrates so well what lawn care companies make impossible. They say (and by “they” I mean professors like myself) that pesticides beget pesticides and fertilizers beget fertilizers, and nowhere is that as true as in a well manicured lawn. The herbicide of choice is 2,4 D (though there are many others that are used) which lawn care companies apply multiple times over the the course of a year. This pesticide does a great job of killing dandelions, but it also kills clover. It rarely hurts grass unless it’s grossly over-applied. The problem with killing clover is that this clover is the stuff that fed the grass in the house where I grew up. Clover takes nitrogen out of the air and makes it available to grass every time the lawn is mowed (the clipped off pieces of clover degrade and the nitrogen in them feeds whatever plants are around). Without the clover you need to add fertilizers. So, because the lawn care company is keeping the lawn free of weeds they also need to fertilize because they’re killing all of the natural fertilizer. Here’s the thing, the weed that most people in the suburbs like least, dandelions, is actually very sensitive to low potassium. The lower the potassium in the soil the worse it does. In fact, dandelions can easily be out-competed by grass and clover if potassium is low — just as happened in the yard of the house where I grew up. But do lawn care companies pay attention to this (by using high nitrogen, low potassium fertilizers?) What do you think?

My guess is that many of you thought that I’d cite all kinds of scary side effects of the pesticides used on lawns. Nope. In general I think that, if used properly, they’re pretty safe for humans (with a few notable exceptions). I’ve spent a lot of time reviewing epidemiological and toxicology studies and I can think of many worse things. I am somewhat fearful of what 2,4 D may do to dogs in particular — they can’t excrete this poison like we can. Don’t think for a minute that I’m calling these poisons perfectly safe — I just think there are plenty of other better established reasons to avoid lawn care company pesticide schedules.

Disappointment

Yesterday evening I took my older daughter to dance class while my wife stayed home. While she was entertaining our younger daughter, the TruGreen guy came to the door to tell us that we had weeds in the yard (Damn, I had no idea!). He went on to tell my wife that we really needed to use his company to get rid of them. I was so disappointed that I missed him because I wanted to know all about what he had planned for our yard. Many of our neighbors use TruGreen and I have to say that I’m not particularly impressed. It’s not that they’re not professional — they certainly are. It’s not that they don’t do things by the book — they certainly do. It’s just that the book that we use is getting a bit outdated. When I read TruGreens online FAQ it looked like they actually plan six applications of chemicals per year. I’m assuming (I don’t know this for sure), that at least four of those include herbicides to one extent or another. It looks like people who have no tolerance for weeds should love TruGreen. But really, how many weeds should people allow in their yards? Is it one per square foot? Two? Five dozen? And what are weeds? Is clover a weed? At what point do we say enough is enough and that we’d rather just cope with a few weeds than hose down our whole yard with herbicides.

After reading my own words I feel like some kind of radical. In my job I tend to see two types of people, those who can’t stand pesticides and those who can’t stand weeds. One group is happy to spray five times a year if it means that their lawn will be weed free, and one won’t touch an herbicide. I’m not sure that either group is correct. I tend to handle weeds in my yard the same way I handle haircuts – I hate having my hair cut so I don’t go to the barber that often, but I do go to the barber eventually because my hair looks pretty ridiculous if it grows too long. I feel the same way about weeds (specifically dandelions) which infest the grass in my yard. I prefer not to add herbicides, but there’s a big weed bank in the area and so I end up needing to apply once every two years or so because otherwise it looks pretty bad. Rather than making either the making the weed-free lawn or the no-chemical group happy though I think that it just pisses them both off. They see my unwillingness to commit to one way or the other as a cop-out rather than reasonable moderation. What do you think?

Haber and Bosch

There are people who are fascinated by plants and people who are fascinated by the science of growing plants. While I love plants I must confess that I consider myself to reside more firmly in the latter group that the former. I do love to see the beautiful flowers on an apple tree in the spring, but I’m more fascinated by the nitrogen, phosphorus, potassium and other elements that the tree obtains from the soil. I like to contemplate the complex ecosystem that surrounds the tree, including the tree’s pests and the possible things that we can do to protect the tree from pests. I love to learn about insecticides, herbicides and fungicides, and I especially love to learn about alternatives like beneficial insects that may be used to control pests. Histories that cover fertilizers and pesticides are pleasure reading.

One of the most important things to ever happen to the world as we know it was the discovery of a process to take nitrogen from the air so that we could use it as a fertilizer. During the 1800s we discovered that applying nitrogen to our soils made plants grow really fast. Though this nitrogen could be supplied with manure we quickly learned that Peruvian Guano and Chilean nitrates had more concentrated nitrogen and so less needed to be added to fields to get bigger responses. Incidentally we could also use the nitrogen from these sources for bullets and bombs. Nitrogen is a cornerstone of most conventional explosives. Unfortunately these sources of nitrogen did have a drawback, they are not renewable resources. You may say — Hey, Guano’s renewable! — But you’d be stretching the truth. You see, guano is aged manure where the nitrogen has had a chance to become concentrated.

Anyway, by the time the 20th century rolled around we had used up much of the nitrogen available from South America and so we (and by we I mean the world in general) were hurting for nitrogen — particularly Germany. Germany had a feeling there was going to be a war and she needed a way to get nitrogen other than sailing all the way to Peru or Chile. So she put money into research. Pretty soon two researcher, Haber and Bosch, came up with a method to take nitrogen directly out of the air and make it into ammonia. Once present in ammonia it could then be used to make any number of other nitrogen based compounds, from fertilizers to bombs.

Coincidentally, Haber is also known as the father of chemical weapons. He led the German poison gas program and had a hand in developing such things as mustard gas. He was considered to be a patriot, but, born a Jew, the rise of Hitler wasn’t good for him and he was forced to leave in the early 1930s.

The story of Haber and Bosch is absolutely fascinating, not only because of the colorful characters, but because their discovery is, arguably, the most important factor in the increase of the worlds population over the last century. The best book that I know of on this topic is Enriching the Earth by Vacliv Smil. It’s a great book, but it does get a little technical. But my dad (he’s a chemist) showed me another book yesterday that is much more entertaining and readable than Smil’s book while retaining most of the pertinent science. It’s called The Alchemy of Air by Thomas Hager and, if your interested in fertilizers and the people who first developed them, then this is a must read.

Age

This time of year is very exciting for the students in my plant propagation class because now is when they all get to try grafting. In particular, they get to place buds from an apple tree onto a rootstock. There is nothing like placing a bud from one tree onto another to make a person feel as though they’re a horticulturist (NOT HorticulturALIST — that’s not a real word). Especially if that bud successfully grows on the plant where it was placed and produces a happy new tree — What a warm fuzzy feeling!

There are all kinds of things that a rootstock can offer to the bud placed on it. The rootstock can make the tree a dwarf, it can be resistant to certain diseases which the bud isn’t, it can even add some degree of cold hardiness. In return, the bud produces a cultivar that the grower wants such as ‘Honeycrisp’ apple. Additionally, the bud also offers an older tree. This probably doesn’t make sense at first, so think about it for a second or two. The bud that was grafted onto the rootstock came from a mature tree and so it may be more mature than the rootstock (which may have come from a seed — if the rootstock came from something besides a seed — like cuttings — then the rootstock may also be quite mature). Because the bud from which the top of the tree will grow is more mature than the base the tree will usually come into bearing sooner than if it were grown from seed.

Tree age is a funny thing. Though you wouldn’t expect it, the base of a tree is actually the youngest part of the tree physiologically while the older portion of the tree is at the top from which most new growth comes. The reason for this is that the bottom of the tree was laid down first as the tree first emerged from the soil and so the bud from which that growth came hadn’t had the chance to age much yet. After a few years of growing up the terminal bud developed more and more “age” and so the top of the tree is more mature. Confusing? It confuses me too — and I’m oversimplifying things quite a bit here. Making it even worse, no two tree species seem to age in exactly the same way.

Disney and Japanese Beetles

This past weekend I had the opportunity to speak at Epcot Center in Florida. It was, without a doubt, one of the highlights of my career so far. I spoke 6 times over the course of 3 days. The focus of my talk was garden remedies. I started by talking about Paris Green (a good story for next week), then made fun of some of Jerry Baker’s, Myles Bader’s and Joey Green’s recommendations, and then proceeded to talk about which homemade cures do and don’t work and why. And then I asked the audience for questions. I always ask the audience for questions at the end of my talks, but I’ve never had such a diverse audience before (both gardeners and non-gardeners from all across the country), so it was interesting to see which problems came up the most. The winner was…. Japanese beetle with fire ants and deer coming in a close second and third. With that in mind I thought I’d devote this column to Japanese beetle control.

Above is my newest prize possession — A statue of Mickey thanking me for speaking at Epcot

The first rule of Japanese beetle control is that you can’t control Japanese beetles. Nobody has found a sure-fire cure yet and, if you try too hard, you’re going to poison yourself and everyone in your neighborhood.

The second rule of Japanese beetle control is like unto the first. Don’t trust garden center employees to know a damn thing about Japanese beetle control.

The third rule of Japanese beetle control is not to make the problem worse that it already is. Using a trap to lure Japanese beetles to their demise will kill a few — and may make you feel like you’re doing something — but you will be attracting more beetles to your yard than you kill.

The fourth rule of Japanese beetle control is that killing grubs doesn’t stop the adults. In other words, while killing Japanese beetle grubs is possible (usually using imidacloprid), killing those grubs won’t prevent adults from flying into your yard after they’ve hatched from someone else’s yard.

The fifth rule of Japanese beetle control is that Japanese beetle control is dirty work. Most of the “organic” and biological controls just don’t work that well. If you want to spray a concentrated dish soap spray on the beetles that will kill them, but it won’t last long and it will burn your plants. Same thing with a spray of one of those citrus insecticides. The organic insecticide pyrethrum will kill Japanese beetles, but it won’t last long and spinosad (another organic insecticide) which works for some beetles (it’s better on other insects) just isn’t considered that great. A biological control called Milky Spore Disease is supposed to kill Japanese beetles while they’re grubs, but the truth is that it usually kills less than 50% even in good conditions.

The sixth rule of Japanese beetle control is that, if you’re willing to go to a little bit of trouble, lose a few leaves, and use a little bit of a synthetic insecticide there is a way to protect your plants to some degree. If you’ve ever been around these beetles then you’ll know that they prefer some plants over other — for example, they love roses, and so they’ll attack roses first. If you spray roses with permethrin (a synthetic insecticide) you can get 7-14 days of clean roses, and, if you’re lucky, you’ll kill many of the Japanese beetles before they move on to other plants — this is called trap cropping.

The seventh rule of Japanese beetle control is that these beetles will seek revenge for their dead relatives.

Atrazine, The news, And the reality

A paper was recently published in the Proceedings of the National Academy of Sciences which discussed the dangers of one of the most commonly used weed killers in the United States, atrazine. This paper was written by Tyrone Hayes and colleagues and was immediately embraced by the media because it showed something scary (which the media loves — in case you were wondering). In a nutshell this study showed that frogs were changed from males to females when they were exposed to relatively small amounts of the herbicide atrazine. The next day in class I had a student come up to me and ask me about it and what I thought. I gave him my short answer (class was about to start). Here’s the longer one, but first I want to present you with some notes which will be important as we proceed.

Science does not provide values, instead it is a tool to use with your own personal value system. Some people may put a high value on cheaper production of important food crops such as corn, while others may put a high value the absence of potentially dangerous chemicals. That doesn’t matter to science. Remember that — science doesn’t give a poop what you care about. Furthermore, science doesn’t care what past experiments have found — what one researcher finds another may not find. Who knows why? That’s just the way things happen. On with the story.

Atrazine has been around since 1959. It’s a preemergent herbicide (which means that it kills weed seeds as they germinate) used on a variety of crops, but most frequently on corn. One of the advantages of atrazine is that it works extremely well in no-till growing systems which are used to reduce erosion. Another advantage of atrazine is that it’s cheap. Generally atrazine is considered to have a low toxicity (lower than caffeine for example). Additionally, though there is some data out there showing that it may cause cancer, this is grossly outweighed by data demonstrating that it isn’t carcinogenic. But there is data showing that atrazine is a hormone disruptor potentially affecting such hormones as estrogen and testosterone — and this effect is generally considered real — in other words not many scientists dispute it.

Over the years this hormone effect has been seen as a Bad Thing, but not bad enough to warrant banning this useful herbicide. Then along came Tyrone Hayes — and he started looking at how atrazine affected frogs — despite the recent news surge he has been doing this work for a long time (about 10 years) and has published much of that work. In a nutshell he is showing that atrazine, and to some extent other chemicals, cause hormone problems in frogs, particularly male frogs. Sex change and/or hermaphroditic frogs ensue! Unfortunately (or fortunately depending on how you look at it) other researchers have not been able to show the same things — at least not it the dramatic way that Dr. Hayes has (I’m not implying that they haven’t found problems with atrazine — they have — Dr. Hayes findings just tend to be more dramatic. Speaking of which, if you ever have the opportunity to see Dr. Hayes give a talk GO! He is an amazing public speaker and his slides and words make his findings even more dramatic). There is little to no direct evidence that hormone disruption caused by atrazine is currently affecting humans though many news sources are trying to draw that link. Indirect evidence is pretty weak too — but not nonexistent. The European Union banned atrazine in 2001. Should we follow?

My value judgement follows — yours might be — in fact it probably should be — different.

Here’s what I think. Ban atrazine, or at least regulate it more tightly. Why? Because there are many weeds resistant to it (that’s what happens to old herbicides…). Because there are options which are safer for our ecology (though they are somewhat more expensive). Because this stuff is showing up in groundwater at rates higher than what we’d like to see, and these concentrations will probably continue to rise — a direct result of using the stuff for so many years. Look, we don’t need to cut farmers off from this stuff right now, lets start a phase-out program and get rid of it over the next five years. Why not? If we NEEDED it to produce crops I’d probably be on the other side of the issue, but we don’t, so I reside firmly on the “let’s be cautious about this” side.

My Favorite Drug

I love coffee, but I’m not a big coffee drinker. On average I probably consume a cup of coffee every week or two. Why don’t I drink it more often? For a few reasons: First, I’m too jumpy/jittery/nervous to begin with and I don’t need this stuff making it worse, second, it tends to upset my stomach if I haven’t had a meal beforehand, and third, while I like regular coffee, the stuff that I really love are those insane fru-fru coffee drinks that you can only get at specialty shops for five or six bucks — which seems like a waste of money to me. As you may have guessed, at this very moment, I have an overwhelming urge for a vanilla latte and so, in lieu of that, I have decided to submit this post.

Anyway, as most of you know, coffee is a horticultural crop, and so are most of the other sources from which most of us obtain our (legal) chemical stimulants like chocolate and tea. What most people don’t realize is that the stimulants in chocolate and tea are actually somewhat different than caffeine. Chocolate does contain some caffeine, but its major stimulant is the closely related theobromine (which doesn’t actually have any bromine in it…). Tea (which also has very low amounts of caffeine), on the other hand contains the stimulant theophylline which is, again, closely related to, but not the same as, caffeine.

What blows me away about caffeine is how toxic it is. If caffeine were a pesticide it would need to be labeled as category 2 (there are 4 classes with 1 being the most toxic). Its LD50 (in other words, the amount of this chemical that, if fed to a person, would have a 50% chance of killing him/her) is estimated at about 75 milligrams per pound that a person weighs. According to Starbucks website, one of their tall vanilla lattes contains about that much caffeine, and so you could assume that a 150 pound person could kill themselves by drinking about 150 lattes (or 150 of the smaller cups of espresso from which the coffee is made). Additionally, though findings are inconsistent, caffeine has been linked to certain cancers. The current thinking is that it may affect hormone levels in the body which, in turn, influence hormone related cancers like breast cancer, etc. This research is far from conclusive, but it is concerning.

OK, so here’s the thing that’s interesting to me. There is a small but real contingent of people out there who want to ban the herbicide 2,4 D (I picked 2,4 D randomly – I could have picked Round-up, Sevin, or any other pesticide – but I was thinking of summer, and so 2,4 D, the most commonly used turf herbicide, is what I chose). I’m no fan of 2,4 D and would love to see it used less frequently than it currently is, but it is a useful herbicide, particularly in the production of grassy crops (like corn). In lawns its overuse borders on the insane.

Opponents of 2,4 D would like to see it gone, in large part, because of its toxicity and potential to cause cancer. And, indeed, there are some studies that show that 2,4 D has the potential to cause cancer, though these findings are inconsistent and ultimately inconclusive. Additionally, in terms of 2,4 D’s LD50, it’s about 170 milligrams per pound that a person weighs – over two times LESS toxic than caffeine. I’m not going to bother figuring out how much 2,4 D would be in an average glass of 2,4 D because, well, I’ve never been served a cup of 2,4 D before and hopefully I never will. (If you’re curious as to how much 2,4 D would be in a cup of spray if you scooped it right out of the spray tank — then about 50 mg is a good estimate though it could be higher or lower depending on a lot of factors).

Anyway, this leads me to a ton of further questions, the most important of which is, without doubt, do anti-pesticide activists who fear the health dangers posed by 2,4 D drink coffee?

For those of you interested in these types of questions I encourage you to look over this article: http://www.marshall.org/article.php?id=73 It is posted on the website of a conservative group (which will probably alienate some of you and make others happy) – but it was originally published a number of years ago in a well respected journal and is one of my favorite articles ever in terms of getting the old brain thinking (Please don’t get the idea that I agree with everything in the article – I do not). Bruce Ames, one of the authors, is what we call in academia a “heavy hitter” and so, even if you don’t agree with what he says, his words are well worth reading.

The Fun Never Ends Here At Garden Professors!

I have another post to toss up later today, but first I thought I’d direct your attention to the comments on a post from a few days ago — The post titled International Ag Labs – who are they and what do they do? It’s fascinating to see so many people discussing the benefits of IAL (and more fascinating to read their comments…some of which are thoughtful and some of which are….less thoughtful). The reason that there are so many of them is that IAL apparently sent out a blanket e-mail to their customers to try and get them to respond to Linda’s post. This is absolutely fantastic! I never imagined we would receive so much free publicity!

Interestingly enough I’ve been informed through a semi-reliable source that they (and the truth is that I’m not exactly sure who “they” are) want to try to get Washington State to shut our website down! Again, awesome! This will result in even more publicity! We might even get into the papers!

At this point it’s probably worth telling all of you what I think about IAL based on their tests and recommendations. Their tests look fine — not the format that I’m used to, but no big deal. Their recommendations, on the other hand, seem silly and ill advised to me (I’ve been working with soil tests to one extent or another for about 18 years now). That doesn’t make them wrong, but the accepted science currently out there doesn’t support them. Also, I can’t stand it when a supposedly independent lab seems to be promoting particular products — in my opinion that could, potentially, compromises their objectivity. Look, if you want to believe in a particular method of growing plants then that is your right — far be it from me to dictate your belief system — but, as Linda once wrote to me in an e-mail, that is faith based growing. On this blog we talk about and support science based growing. Faith based growers are always welcome here, but be aware that you probably won’t be happy with everything we write.

Peanuts

I’m not from the South, and so I can’t call myself a Southerner like Holly can, but I did spend 6 years in Georgia. There are lots of things about it which I miss: winters which are more like a Minnesota fall, the almost disgustingly friendly people (OK, there was that one time that I was chased by a guy with an SKS assault rifle — but that was an exception — generally Southerners are the nicest people you could ever want to meet), and, especially, the food. I love okra, I love grits, I love country fried steak, I love mustard greens, collard greens, fried catfish, sweet tea (which is starting to become popular here) etc. And for those of you thinking well shoot, you can get that at your nearest Cracker Barrel (which I frequent) — IT JUST ISN’T THE SAME. One of the foods which I miss the most though — one that hasn’t found its way to Minnesota yet — is the boiled peanut. For those of you who don’t know what a boiled peanut is, it’s a little piece of heaven that has been boiled in a tub of hot salt water for a long time so that, when you break open the peanut’s shell, now the texture of watery cardboard, the seeds inside are soft, warm and, you guessed it, salty. So, why am I telling you this? Because I can’t suppress my excitement any longer. Tom Michaels. a good friend of mine who is a transplant from a Canadian University where he worked on bean breeding, and I recently were talking about boiled peanuts and he told me that he has a peanut variety which will grow here in Minnesota without too much trouble and which is can be used to make hot boiled peanuts. So I’m in the process of finding excuses to plant this critter — I’m going to plant it between rows of trees, in grass plots, in vegetable gardens — and then I’m gonna harvest them all and make hot boiled peanuts through the entire winter next year!