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.

Lunar control? Or lunacy?

Yesterday one of my dear skeptical colleagues sent me a link to a new article on lunar influences on plants (you can find it here).  Briefly, the authors argue that scientific evidence supports the concept of a lunar cycle influence on plants.  Interspersed within the discussion are references to seasonal and daily plant cycles, along with legitimate references to these verifiable phenomena.  (Had these references to circadian and diurnal rhythms been left out, the literature citations would have been rather paltry.)  Plants depend on these daily and seasonal cues for a variety of physiological and behavioral activities; lunar cycles have little obvious relevance to plants.  Nevertheless, “planting by the moon” is a belief system that has existed since ancient times.

This article is a great example of how pseudoscience insinuates itself with legitimate science.  Many of the references used as evidence for lunar effects on plants are of nebulous quality as they haven’t been reviewed by the scientific community; these include self-published books or lectures.  Furthermore, for every article that claims a lunar effect, I can find another discounting it entirely.  That being said, there are some legitimate papers indirectly linking lunar cycles with plant biochemistry.  Coincidentally, the lead author of one of these articles is a close friend and colleague whose research credentials are impeccable.

Here’s where the fascinating and complex nature of species interactions helps explain conflicting data.  Lunar cycles do affect certain species, including some herbivorous insects which are dependent on moonlight for feeding.  During the full moon, such insects feed more heavily and affected plant populations retaliate by altering the digestibility of their tissues. It’s likely that these biochemical changes have been erroneously attributed to direct lunar influence rather than herbivore defense.

To demonstrate direct lunar influence, one would need to study plants in an herbivore-free, controlled environment so that the only variable under consideration was lunar cycle.  Under such controlled conditions, would the same changes be noted over time if plants weren’t eaten by moon-managed insects?  Would you see changes if you modified the lunar cycle to make it longer or shorter (again without insects)?  Positive and repeated results would be necessary to establishing a role for lunar control.

As with so many other mystical explanations of natural phenomena, the real story is infinitely richer and more satisfying.

Do These Come In Control Top?

For those color-conscious gardeners who can’t bear to have visible tomato ties (or panty lines):

Only $2.99 for eight pieces?  Whatta deal!

Do you know how many tomato ties you can get from a pair of hose? Especially if you are a “long”? About fifty. Of course they’ll be nude or black, unless you bought into that purple trend last season.


ps:   I do like Lusterleaf’s (company responsible for the above) can o’ twine with the handy cutter-top, though. $4 and it has lasted through several seasons.

Selling dawn redwood

As with last week, this past week and weekend were largely occupied by my role as a faculty advisor for the MSU Horticulture club.  This weekend was our annual Spring Show and Plant Sale.  Each year our undergraduates commandeer the Horticulture department’s conservatory, bring in a boatload of plants, pavers, turf and mulch and design and install a landscape.  It’s actually quite a process to watch.  http://www.youtube.com/watch?v=4NTPzB6YVSk
In addition to the Spring Show the Hort Club puts on a plant sale, which is the group’s principle fund-raiser for the year.  My duty station for this year’s plant sale was working outside in the tree sales yard.  For the record, retail is not my thing but, hey, it’s for a good cause. The star of our tree sale this year was a container-grown 14’ dawn redwood (Metasequoia glyptostraboides).

For those not familiar with this tree, dawn redwood is an incredible tree.  It’s a deciduous conifer, similar in many respects to bald cypress (Taxodium distichum) but with a finer, more refined character.  Metasequoia is considered by some to be a ‘Living fossil’, similar to Gingko biloba.  The genus Metasequoia was originally described in 1941 from Chinese fossils from the Mesozoic era.  Although local people in China knew the tree and used it as an ornamental, living trees were not formally described by botanists until 1948.

Dawn redwood is well adapted to wetter sites

Seed collected by Arnold Arboretum in the late 1940’s were distributed to universities and arboreta and this attractive, fast-growing tree found its way into the nursery trade.  Ironically, millions of Metasequioa have been planted as ornamental trees but the species is considered critically endangered due to loss of its native habitat in China.  Dawn redwood is extremely fast growing and some trees planted in the U.S. from the original collections in the 1940’s are reportedly 3’ in diameter.

Dawn redwoods on MSU campus

So, how did I fare in nursery sales for a day?  Put it this way, I better hang on to my day job; retail is still not quite my thing – though I did move the dawn redwood and got to spend a good bit of my weekend talking about this awesome tree.

Friday geography answer

As several of our astute readers knew, the photo from Friday was taken on the west coast of the Salton Sea in California.  Specifically, it’s at Salton Sea Beach, a nearly deserted region that I managed to make more picturesque through careful photography.  Here’s another picture of the same beach:

There were few plants at Salton Sea Beach – a palm tree here and there – and only a few waterfowl like these pelicans:

The Salton Sea is really the Salton Sink – it’s a low area that has occasionally and naturally filled with water.  Given the high rate of evaporation in the region, the lakebed became highly saline over the centuries.

So what does this all have to do with a gardening website?  Well, the reason the Sea exists today is because of natural flooding combined with agricultural development.  Initially the Sea was seen as a boon to tourism, so spots like Salton Sea Beach and Salton City (near curiously named Squeaky Springs) became tourist destinations.  But as agricultural runoff began to change the nature of the Sea, fish populations failed and so did the tourism industry.

You can see the algal bloom where runoff meets the sea (check out this Google map here).  These desert valleys have been used for conventional agricultural production for many decades, and the results are seen in a sea full of fertilizers and pesticides.

In any case, a visit to the Salton Sea is both fascinating and depressing.  It’s well worth the effort.

Friday geography quiz!

Like last week’s, today’s quiz is a little different.  (I haven’t forgotten about last week’s question – just haven’t gotten a good answer yet!  Never fear!)  In any case, you know I spent some time in Palm Desert CA last week.  On one of our day trips, I took the following picture (we are looking east):

So here’s the question:  where are we?  (It was a day trip, so not terribly far from Palm Desert.)  You can ask questions that I may or may not answer.  Monday’s answer will tell you lots more about this “accidental” landscape!