jeffgillman003

Harvesting an Experiment

This has been an exciting week for me. On Monday we started cleaning off 72 rootballs of various tree species that had been planted 5 years ago for a study. These trees had been planted in containers and become potbound at the nursery from which we received them. We treated them in one of three ways. Either we did nothing (in other words we just dropped the pot bound tree in a hole), we used the standard methods that Universities recommend for slicing potbound roots (Four deep slits down the sides and a deeply cut X across the bottom), or we cut off all of the circling roots by cutting the pot bound root system into a box shape.

A root ball cut into a box shape

The plan was to harvest after 4 years to see what happened – we decided to wait 5 – and boy did we see some interesting stuff. At this point our results are preliminary – we need to run statistics before we can say anything conclusively – but this is what my eyes tell me.

Trees that had their roots cut into boxes suffered reduced growth the first few years, BUT, their root systems look as good as any root systems that I’ve seen – almost no circling.
We planted our trees with the surface of the soil at the same level as the surface of the media in the containers – which is too deep in most cases. For trees with circling roots this created a severe problem as the circling roots often surrounded the stem – potentially causing suffocation of the tree later in life.
Root systems that were cut using the 4 slit method didn’t look much different from those that weren’t cut at all.
The number of large roots emanating from all of the treatments appeared to be about the same (we’ll need to run the stats before I commit to this one). This is particularly interesting because many people expect large roots that are circling to continue circling — but that isn’t what usually happens (unless the hole where the tree is planted has hard sides which can force the roots to circle just like the container did).

This root system was from a control — no root pruning at all, but still plenty of large roots.

No matter what the results/statistics end up saying there will be more questions. For example, all else being equal, how damaging are circling roots to the health of a tree if the tree is planted properly (no stem tissue under the surface of the soil) and the circling roots are under the surface of the soil? If the answer is that circling roots under the surface of the soil aren’t very damaging (after all, there’s no stem tissue for them to crush) then why are we bothering to try to root-prune pot bound plants at all – what we should really be concentrating on is planting at the proper depth.

All the above is hypothetical though – I just enjoy thinking about this stuff as the data starts to roll in. As we get more definitive answers and start to run the statistics I’ll let you know more.

Genetic Engineering, Veal, and Rennin

Today I thought I’d go just a little off topic. Lots of people out there are really upset about the idea of putting genes into plants, like putting genes for Round-Up resistance into soybeans, or genes for caterpillar resistance into corn. And, I do agree, this is a pretty powerful technology that needs to be used carefully – probably more carefully than it’s being used right now with plants.

But the funny thing is, one of the places where transgenic creatures really dominate the market is in a place that is almost never considered. Today 80-90% of cheese made in the United States is produced using bacteria genetically engineered to produce rennin. What is rennin you ask? Renin is the stuff normally found in a cow’s stomach which causes milk to curdle – and cheese to be created. For those of you interested in looking into this further look up rennet which is the substance in a cow’s stomach which naturally contains rennin.

After looking around a bit I really can’t find that many people upset about the use of genetically engineered microbes to produce rennin. Actually, some people who are quite sensitive to environmental concerns may prefer it. Historically rennin comes from dead young cows – it’s a byproduct of veal production (kind of a nasty industry if you ask me). Rennin that comes from genetically altered bacteria has nothing to do with dead cows and so vegetarians often find cheese produced with genetically engineered rennin to be more appropriate.

Are Pretty Flowers Useful?

Yesterday I had the opportunity to listen to Marla Spivak, a very highly regarded bee scientist, talk about how bees defend themselves from disease. Very interesting stuff. I took a lot of information away from the talk, two bits of which I want to share with you.

The first is a vocabulary word — propolis – go ahead, google it (I don’t think too much inappropriate stuff will pop up) – it’s an antimicrobial “ointment” which bees create from stuff like the resins on tree buds.

The second is that the number of bee colonies is the US has been going down in the US since 1945 for a number of reasons. One of the most important of which is the fact that we like to kill flowers, such as dandelions and clover, which bees like, and then we plant crappy flowers – at least as far as the bees are concerned. The whole crappy flower thing isn’t something that I’d spent much time thinking about, so it was kind of an ah-ha moment for me.

Here’s how it works. People tend to like double flowers. Double flowers usually occur because the male parts of the flowers – the parts which normally contain pollen – instead develop into petals. It’s a mutation – very pretty – but it inhibits the flower from reproducing itself through seed and it certainly isn’t great for bees who rely on pollen for food. So when we plant our gardens we are removing plants that bees may love because we consider them weeds. Then we replace these flowers with what amounts to plastic fruit. My opinion – this is probably more significant to the lives of both honey bees and native bees than whether we plant natives or exotics.

So let your yard go wild! The bees will thank you.

How to get the information out?

Over the last two weeks I’ve been dwelling on the information that people get about gardening from various sources. I’m not talking about really serious gardeners – I’m talking about the guy down the block who might grow six tomatoes, two cucumbers, and a head of lettuce. He’s got 6 trees on his property and he keeps his lawn nice, but not immaculate, by mowing weekly and fertilizing and applying herbicides once a year. Where is this guy getting his gardening information? Can we (and by we I mean scientists like the garden professors) do something more than we currently are to reach him so that he’s using up to date information?

A couple of days ago I walking into the place where I get my taxes done – I’ve had the same person doing my taxes for the last 14 years or so and I’ve become friendly with her – and, after we got the paperwork done she introduced me to the receptionist by saying that I speak and write books about gardening. The receptionist (who doubled as the cashier) wanted to know more so I said “You know Jerry Baker?” She said “yes, I have a bunch of his books and I just bought a set for my father.” I said “Oh…Well I’m the guy who tells you that most of Jerry’s remedies don’t work.

She didn’t seem particularly impressed with me (and the cost of filing my return was higher than usual – coincidence?)

Anyway, my question to you is, how do we reach people like that?

Bordeaux Mix

One of my favorite stories about pesticides is the story of Bordeaux mix. It’s a story of France in the 1800s (so it must be pretty romantic, right?) and how they were suffering from a shortage of grapes. Don’t feel sorry for them — it was really their own doing. Over the course of the 19^th century grape vines were brought from the United States to test their merits against European grapes. It was quickly discovered that, for the most part, American grapes were not the equal of European grapes for winemaking. Unfortunately for the French, however, along with the grapes came a disease: downy mildew. This mildew absolutely ravaged grape vines across Europe, and particularly France from the time that it was introduced, around 1878.

Meanwhile there was another problem for grapes growing in France. People. People like to eat grapes beside the side of the road and so, throughout France’s grape growing regions, grapes on the sides of the road were typically bare. Unlike downy mildew, however, grape growers had a pretty good idea what to do about people. They sprayed nasty stuff on the grapes. This nasty stuff took many forms, but the one which was most effective was a mixture of copper sulfate (basically you dissolve copper in sulfuric acid) mixed with lime. Brushed on a plant’s foliage, it was darn ugly.

Then came 1882; a terrible year for downy mildew. Grape vines were losing their leaves all over Europe, except for those vines beside the sides of the road. There the grape vines were doing just fine. The reason was the copper in the lime/copper sulfate mixture which was eventually dubbed Bordeaux mixture because of where it was first used. Bordeaux mixture is still available today, and is one of the most important tools in the organic grower’s pesticide arsenal. Unfortunately it’s nasty stuff – it builds up in the soil and it’s toxic to earthworms and a wide variety of different plants and aquatic organisms. Using this stuff once in a while – such as once a year – isn’t terrible, but regular use is a good way to ruin your plot of land.

One final thought – Those American vines which originally brought in mildew? They eventually became very important to French wines because of another introduced pest, phylloxera. They were used as rootstocks because they were resistant to this pest — unlike European grapes.

Building a House of Straw — With Brix!

Before I get into the meat of this issue I wanted to mention that, a couple of weeks ago, Purdue came out with a statement which basically supported a post that I had previously written – one where I stated that there’s not a lot of good evidence that using Roundup leads to sudden death syndrome in soybeans. Yeah me! Well, not really – that’s not the way science works. While it is nice that other scientists agree with my conclusion, that doesn’t mean that Round-up isn’t affecting soybeans – it just means that there’s no evidence of it right now. Science doesn’t stop because a few scientists agree.

Same with compost tea – Linda and I have both posted about compost tea and we agree that, at this point, there’s no reason to use it. But science doesn’t stop, and it wouldn’t be completely surprising if, someday, someone comes up with a compost tea type product which is actually reliably useful.

Now on to the flavor of the day! Brix. So, what is brix you ask? Brix is a measurement of solids in a water (usually these solids are sugars). It’s easy to test brix by using something called a refractometer which measure how light bends when it passes through a thin film of water. We use brix in foods to tell how sweet they are. We just take a little sample of sap or juice, put it on a refractometer and bang, we know about how much sugar we have (actually, as I mentioned earlier, any dissolved solid, not just sugar, can alter measurements, as can non-solids, like alcohol. But the dominant thing affecting the brix measurement is usually sugar content).

Though it isn’t exactly mainstream, there is something out there called brix based gardening. Basically, the goal of brix based gardening is to increase the brix of the food we eat. Increasing the brix means increasing the sugar. The theory is that the higher the brix of a food the better it is – in terms of taste, resistance to insects, resistance to disease, healthiness. The list goes on and on.

The biggest problem with arguing that gardening based on brix is a bad idea is that there is a nugget of truth in brix based gardening. Moreso than compost tea (in my opinion), brix has proven itself useful in certain situations. Particularly in wine making, brix is used to quantify the sugar content of your grapes so that you can predict the sweetness of the wine you will produce (it will also help tell what level of alcohol you’ll get). As time goes on at the end of the season grapes increase their sugar content, so grapes are picked according to when the brix is right for the wine you want to produce. Another grain of truth is that with higher brix you’ll get less insect pressure. This stands to reason, at least to some extent, because insects are usually looking for nitrogen rather than sugar.

But along with the little grain of truth comes some BS. For example, the idea that eating a food with a higher brix reading means that you’re eating a healthier food is just silly. It just means that you’re eating a sweeter food. The idea that higher sugar levels mean a healthier plant is also silly. In fact, one of the most significant things which can make brix go up is putting the plant under drought stress. Under drought stress, with less water, the concentration of sugars in sap naturally increases (because there’s less water to dilute it). Raisins are sweeter than grapes! Furthermore, the variety of the plant which you grow has an extreme effect on brix. Chardonnay grapes may have a low brix (around 21), a late harvest Riesling may have a brix of 42!

I have seen an inordinate amount of gobbledygook about mixing different fertilizers to get the perfect ratio of nutrients to increase brix. First, it’s important to realize that fertilizers can alter sugar content. For example, fertilizing heavily with nitrogen will increase growth of the plant but will usually decrease sugar concentration (hence brix). Indeed, from what I’ve seen, nitrogen seems to be the biggest player in sugar content.

That said, calcium and phosphorus based fertilizers seem to be the favorites among brix based gardeners – but from what I can find research hasn’t actually shown that these fertilizers increase brix on anything approaching a reliable basis. Another common recommendation is a molasses based fertilizer – once again, research on molasses doesn’t seem to show that it can do much to increase brix. Honestly, it looks to me like those recommending high brix as necessarily a good thing for us and our plants and then offering methods to do it are putting a scientific veneer on witchcraft – at least until further research comes along. I am sure that those favoring brix-based gardening will disagree with me – if you do and you read this I would welcome seeing some published papers which support your claims.

Breaking up Tree Week with an Important Announcement! (Or Not — depending on how you feel about shameless plugs)

OK, here it is, my one and only shameless plug — because my publisher says: Hey! You need to at least let people know that the book exists!

So — I’m excited to say that my next book, How The Government Got In Your Backyard, which I co-wrote with my good friend (and old college roommate) Eric Heberlig, who is an Associate Professor of Political Science at UNC Charlotte, is finally out.

In case it isn’t immediately obvious, I love to write. This is my fourth book — and in many ways I think it’s my best. In it Eric and I look at the science and politics behind a number of environmental issues — everything from Plant Patents and Illegal Plants (think marijuana) to Organic Food, Global Warming and Biotechnology. We look at the political right and left, investigate the science behind what they believe, and try to give unbiased opinions. Some people have already let us know that we’re wrong! (Which we find amusing — but that’s another story).

What we don’t try to do in this book is make up your mind for you — that’s your job based on your priorities.

Guano

One of the best organic fertilizers out there – at least in terms of how plants respond to it — is bat guano. As most of you probably already know, bat guano is made of bat droppings. What you probably don’t realize is that bat droppings need to be aged for a while in an arid environment before they become guano. Caves provide the perfect environment for this to occur, and so that is where most bat guano comes from.

Because guano needs to be aged in special surroundings before it is used it is not a rapidly renewable resource. Instead it’s kind of like peat in that it takes anywhere between decades and thousands of years for the raw material from which it is made to develop into the stuff that we use. Furthermore, by harvesting bat guano we can actually damage the ecosystems present in the caves from which the bat guano is harvested. Think about it – bats generally feed outside the cave, so when they defecate inside the cave they are actually bringing new nutrients into the cave – nutrients that other creatures can use. Whole ecosystems are based on this poo! So when we harvest bat guano from a cave what we are doing is disturbing a specialized ecosystem – a very unique system.

So am I encouraging you away from bat guano? No more than I would encourage you to consider reducing your usage of peat – or of oil — or any other non-renewable resource. I can’t deny that it’s a great fertilizer, but if you want to use an organic fertilizer why not at least consider one that is renewable instead of one that is from a limited resource and which may cause harm to a unique ecological system?

Sudden Death Syndrome in Soy — Biggest Threat to the Entire Food Chain?

This past week we received an interesting e-mail about something called “sudden death syndrome” which we were asked to blog about. Here’s the article we were sent. We don’t always take requests, but we thought that this was an interesting one, so we decided to write a little post about it. Sudden death syndrome is basically a fungal disease which affects the roots of soybeans. Recently there has been some press out there about how Round-up ready soybeans are particularly susceptible to this disease and that the spraying of roundup itself can lead to favorable environments for it.

This is a particularly attractive disease for a number of groups because it provides fuel to their fire. The anti-biotech group likes it because it makes Round-up ready crops look bad, the anti-pesticide group likes it because it makes pesticides look bad, the anti-Big Ag group likes it because it makes Monsanto look even more evil than usual. So, in short, lots of happily indignant people.

So is it true? Is using Round-up and Round-up Ready Soybeans a sure way to condemn ourselves to a soyless future? On a side note this is something I really care about – I am a chronic soy sauce user. If something is good without soy sauce it then it is going to be even better with it. Well, I spend most of Monday and Tuesday looking through scientific articles and here, in a nutshell, is what I came up with:

Sudden death Syndrome is certainly real, and it can devastate a field. It was around before Round-up and it will be here after Round-up is gone. The biggest factor in whether it will be a bad year for SDS is the weather. So what about the Round-up connection? This is something that has been looked at by researchers, and here’s what they find. In terms of the fungus responding well to Round-up – some studies show that it does – most that it doesn’t. Round-up Ready varieties of soybean may be resistant or non-resistant to SDS and, of course, the non-resistant varieties won’t fare as well as the resistant varieties if SDS is present (it seems possible that this is where the whole hullabaloo started — a field full of Round-up Ready soy but which wasn’t resistant to SDS contracted the disease while nearby non-Round-up Ready soy which did happen to be resistant to SDS did fine.)

Now there are some studies, mostly in test-tubes and greenhouses, which show that Round-up could make SDS worse, but in the field, where it actually matters, there just aren’t that many studies which show a correlation between using Round-up Ready soybeans and SDS — and more studies that show that there isn’t a correlation. What it all comes down to is that there is a possible relationship between Roundup and SDS, but, despite a lot of research (both government and industry dollars flow easily to agronomic crops), this link isn’t crystal clear and may not exist at all.

An Early Valentine’s Story

In honor of Valentine’s day I have a story about love and betrayal to share….OK, maybe not….perhaps something more along the lines of branches and ants. Same difference right?

There was once a tree that was much loved. It was planted in a cute little corner of a street next to a historic building and was well cared for by its owners. Its many limbs rose to the sky in a seething mass which made the tree look vigorous and robust…and those who planted the tree were very happy.

Over time, however, the people who planted the tree neglected it. The street where it was originally planted changed from a bustling center for traffic to a lonely, out-of-the-way road. As it was ignored its branches grew together and made a mess — and nobody noticed this mess — except for a little horticulturist who had to walk by the tree every day on his way into work.

The little horticulturist was fascinated by the tree. Not because the tree was a particularly fine specimen, no, that wasn’t it at all. Instead the little horticulturist was fascinated by the tree because its limbs grew together so closely that they actually appeared to be grafting with one another, something that the little horticulturist would often spend hours contemplating (what can the little horticulturist say — sometimes he liked to avoid real work).

Two limbs apparently grafted together!

Then one day something terrible happened. An evil green insect invaded the street where the tree lived, and all of the ash trees on that street had to be cut down. Even though the tree couldn’t be infested by the insect (it was a hackberry), it was still on the list. The little horticulturist pleaded with the groundskeepers to keep the tree, but orders were orders and the tree had to go.

But unbeknownst to the groundskeepers the little horticulturist knew one of the people cutting down the tree and asked the tree cutter to save him some of the trees limbs where they appeared to be grafted together. And the tree cutter did, and delivered them to the little horticulturist.

But alas! The grafts that the little horticulturist had seen were not truly grafts at all! They were rotted out sections of trunk which had grown around each other! The little horticulturist was crestfallen! How could this be? He left the decaying limbs in his office as he considered what to do next.

Hmmm…There’s no graft after all –what a mess!

Days stretched into weeks and the limbs continued to sit in the little horticulturists office. And then, one day, from the depths of the limbs sprouted new life! Winged carpenter ants flew around the room and into neighboring rooms! Colleagues shouted curses and obscenities! Graduate students were afraid to use the drinking fountain because of the masses of ants which alighted there! The custodians took to wearing dust masks! And, despite incessant pleading by almost everyone, the little horticulturist would not part with the limbs because he wanted to have props whenever he told the story of the day the ants took over the 4th floor.

The moral of this story is that you shouldn’t hold onto things once you figure out that they’re worthless.