Category: Amusing Facts

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.

Plant Patents

I love patents.  In fact, I once wrote a novel based on a patent — It was called Patent 22 — If you look this patent up you’ll just find a piece of paper from 1915 which says, essentially, that a search was made for the patent but that it couldn’t be found.  No one wanted to publish it — and reading it now I do realize that it does need some serious work.  Still, I think this little tidbit gives you a little bit of an idea about my interest in patents.  (The paper on file at the patent office is below):

Anyway, here’s the thing that people don’t know.  There are three ways to protect a plant from someone else “stealing” it: Plant Patents, The Plant Variety Protection Act, or a Utility Patent (which is what you or I usually think of when we think of a patent).  The Plant Patent Act passed in 1931 and it is the way that most plants are protected today.  Plants like the Honeycrisp apple which are propagated vegetatively (using cuttings or grafting) are usually protected with this type of patent.  The second type of protection is the Plant Variety Protection Act of 1970.  This Act lets you protect seed propagated plants.  With these two types of protection you wouldn’t think that any other type would be needed — but the Supreme Court has twice ruled that plants can be protected using Utility patents (once in the 1980s and once in the early 2000s).  So, what is the problem with that?  Well, basically, the problem with that is that, while the other ways to protect plants allow for the use of those plants in research or for breeding and farming, using a utility patent prevents anyone from using the patented plant from doing anything with that plant without permission from the patent holder.  And, basically, an entire species of plant can be patented — it has been done before with a bean that someone brought from Mexico into the US — he cornered the market on the bean and noone could sell or breed the bean without his OK.  Sounds insane doesn’t it?  Just my first thought on a cold Thursday morning.

All Right, Linda; I’ll See Your Paraheliotropism and Raise You a Nyctinasty

Amicia zygomeris is a cute little herbaceous thing I picked up on a visit to Plant Delights nursery back in October. For $13, I wanted to be sure it survived the winter, so it’s been in our kitchen garden window, just waiting for spring.

Soon after putting it in the window, I had an “oh no, I’ve killed it” moment one evening.  All the leaves were drooping, yet the soil was moist.  The next morning, it seemed to be back to normal.  The following night, droop city again.

Ah HA! Nyctinasty* at its finest – plant movements to the circadian rhythm.  Tropisms are growth responses, while nastic movements are just that  – reversible movements.  There are other “nasties” out there – photonasty is movement in response to light, hydronasty –  water, etc.   The classic example is Mimosa pudica – sensitive plant – the little leaves fold to the touch (thigmonasty).

Legumes are particularly prone to this – check out the bean plant flapping its leaves in time-lapse video at the “Plants in Motion” website (U. of Indiana Biology Department).  The movement comes from changes in turgor of the cells that attach the leaf petiole to the stem. This spot’s called the pulvinus – think of it as the leaf’s armpit.  What do plants gain from this daily spreading then folding of leaves? Folks have been pondering this for centuries. Darwin wrote about it in “The Power of Movement in Plants” (1880).  Though the biochemical mechanism has been discovered, I don’t believe any conclusions have been reached as to "why".  

 

Amicia zygomeris in the evening. The common name, courtesy of Tony Avent, is  “Gotta Pea". I am not making that up.
 

*BTW, Nyctinasty is also the name of a pop band from Manila. Must be a biologist or two in the bunch.

Friday puzzle answer(s)

Wow!  What a lot of great brainstorming over the weekend!  I would venture to say that The Garden Professors have the smartest students in the world.

On to the answer…or answers.  First, the phenomenon.  It’s called paraheliotropism – literally, a movement to protect (the leaves) from the sun (yes, Trena, it is a tropism!). This is the opposite of another phenomenon called heliotropism, or solar tracking.  Sunflowers famously do this, as do a number of arctic species that collect solar warmth for the benefit of their pollinators.  (An aside:  if you have never watched David Attenborough’s The Private Life of Plants you must add it to your Netflix queue.  Right now.)   

But our saxifrage (thanks, Holly! I’m such a taxonomy imbecile) is reducing solar exposure by positioning its leaves in parallel to the sun’s rays.  This is a reversible movement and helps reduce photooxidative stress, leaf temperature, and water loss.  It’s an important strategy as the newly emerging leaves are actively expanding.  If turgor is reduced by high temperature or water loss, so is the final size of the leaf. 

Finally, these rapidly expanding leaves have relatively thin cuticles (if they were thicker the leaves wouldn’t be able to expand as well).  The cuticle gives further protection to the leaf from water loss due to heat, drought, wind, or even late season freezing events (thanks for that addition, John!).  The cuticle will mature after the leaf has reached its full size.

So, as Foy suggested, this is a way for leaves to "harden off" and reach full size before exposing themselves to the sun.  Aren’t plants cool?

And you are all such great participants!  Group hug!  Now, back to work.

Friday puzzle

Spring is coming…and soon herbaceous perennials will poking their leaves up through the mulch:

Obviously as leaves first emerge they’ll be vertically oriented – but these ones have remained vertical days after emerging.  Eventually they’ll become horizontal.  But today’s question is – what’s the advantage in remaining vertical?  And what’s this phenomenon called?

Answer on Monday – have a nice weekend!

Mistaken Identity, or The Truth?

In the wake of The Garden Professors’ sudden notoriety (see Linda’s Jan. 26 post), my department head sent out a very kind e-mail announcement to our faculty, staff, and grad students. 

However, he referred to us as the "Hort Professors" blog, sans hyperlink. 

A curious staff member (the lovely and talented Pris Sears) searched that title, resulting in the following:

Hort Professors, Hot Professors…kind of the same thing. Thanks, Google! 

Friday Physiology Fun Followup

Astute readers pointed out several morphological adaptations found in drought-tolerant turf weeds:  fleshy taproots, reflective leaf surfaces, etc.  What we can’t see is what many of these plants do physiologically – and that’s photosynthesize using a biochemical pathway that temperate turfgrasses don’t possess. 

This pathway, called C4 photosynthesis, contains some extra preliminary steps not found in plants using traditional (C3) photosynthesis.  The downside:  it takes more solar energy for the plant to photosynthesize.  The upside:  these extra steps allow the plant to "fix" carbon (transforming it from gas to solid) faster, especially when it’s sunny, warm, and droughty.  Practically speaking, this means that C4 plants do not have to keep their stomata open as long and they conserve water more efficiently than C3 plants.

So in the summer – when it’s hot, sunny and dry – the C4 plants in your lawn are operating under optimal conditions, while the C3 grasses go dormant.  The tables turn when the seasons do:  cool, moist conditions favor traditional photosynthesis, and the C4 plants are overtaken by the turfgrasses.

Cool, huh?

Friday physiology fun

It’s still cold and wintery, so let’s imagine ourselves in a happy place…warm, sunny, dry…with dead lawns.

As the photo shows, the turfgrass is dead; this happens every summer during the Pacific Northwest’s droughty summers.  Yet many of the weedy species are obviously thriving.  Why?

Remember, this is a physiology quiz.  You can discount herbicides, fertilizers, etc.  This is a cool (no pun intended) adaptation that many species native to dry, subtropical to temperate environments possess.  And there are serious implications for water use related directly to this adaptation, or lack thereof.

Let’s see lots of brainstorming on this – no points deducted for trying!  (And if you are a true ecophysiology geek, let other people try first before posting the answer.)

Making a difference?

I promise I’ll post a Friday puzzle later.  But I just had to let you know that if you Google “water droplets burn leaves” (without quotes) you’ll get 436,000 hits as of this morning.  Number 3 on the list?  Our blog!

I think I’ll discuss this paper one more time on Wednesday – there are several other serious issues that I think are worth mentioning.

Have a good weekend!

Help! Help! The Sky is Falling!!!

You all remember the story of Chicken Little, right? Chicken Little thought she’d been hit on the head by a piece of the sky and ran around alarming the rest of the barnyard animals, who assumed Chicken Little knew what she was talking about. Had they not all been eaten by Foxy Loxy, I’m sure they would have felt foolish discovering that an acorn, not a piece of the sky, had bopped Chicken Little on the noggin.

On to today’s science rant.

Ann McCormick, one of my GWA (Garden Writers Association) colleagues, alerted me to an online story from Live Science entitled “Water Drops Magnify Sunlight and Burn Leaves.” A quick look at the internet shows that this report has gone viral, with similar headlines from other websites including the venerable Scientific American (“A study in the journal New Phytologist confirms the gardener’s belief that droplets of water resting on some types of leaves can focus sunlight until the plant’s surface actually burns”). It gets more and more ridiculous by the day (“Sun shining?  Then don’t water your plants” courtesy of the Daily Mail in London; “Water droplets can form forest fires” from Calcutta). And so on.

I tracked down the original article in New Phytologist, entitled “Optics of sunlit water drops on leaves: conditions under which sunburn is possible.”  You should take a look at it, if only to become completely intimidated by the physics and computer modeling it contains. I’ll be honest – I didn’t even try to understand this portion but focused on the plant science.

The authors had three actual experiments in addition to the optical modeling.  The first experiment involved placing glass spheres on detached leaves (Acer platanoides – Norway maple) and exposing them to sunlight. Yup, glass spheres caused leaf burn on sunny days – no big surprise there. The second experiment substituted water droplets for the glass spheres and tested Ginkgo biloba as well as maple leaves. Not surprisingly (to me anyway) there was no damage to leaves of either species. The third experiment repeated the second, but tested the leaves of the aquatic fern Salvinia natans and voila! Leaf damage!

I have a lot of issues with this paper and maybe we’ll have to extend blog coverage for a day or two to keep today’s discussion as short as possible. Let me point out just two of the experimental problems

The leaves for experiments 1 and 2 were detached from the plant prior to treatment. How a detached leaf resembles anything in a natural situation is beyond me. Furthermore, these leaves were laid out, covered with glass spheres or water droplets, and left in the full sun for as long as nine hours. (Even so, the leaves covered with water droplets didn’t burn! You go, detached leaves!)

The Salvinia experiments were conducted on leaves scooped out of a pond, placed in two containers, sprinkled with water, and left in the sun for two hours. Then, in the authors’ words, “the experiment was concluded by cutting and scanning several Salvinia leaves – still holding water drops – in the laboratory in order to document their sunburn.” We are not told (a) how many leaves were scanned, (b) how the leaves were chosen, since they didn’t scan them all, and (c) how the reported damage was proven to be from water droplets. >Worse, there are no statistical data. We are simply asked to believe their report in the absence of any evidence except a handful of photographs. (As an aside, I really would like to know how they were able to cut and transport leaves without the water droplets moving!)

The lack of scientific rigor in this article is disappointing, especially in a peer-reviewed journal. Is there any plant scientist would consider detached leaves to be a model for those on an intact plant? Is there any gardener who would consider an aquatic fern comparable to trees and shrubs? Would any species – including aquatic ferns – easily burned by the combination of water and sunlight survive in the real world for long? I don’t think so – hence my myth posting on this very topic several years ago.

Let’s review: leaves of one species of aquatic fern was damaged by something – possibly sunlight – but without enough data presented to really evaluate the claim. None of the tree leaves tested were affected, even though they were detached from the plant and could not benefit from transpirational cooling. Yet the alarm has gone out! Don’t water your garden plants when it’s sunny, or the leaves will burn!!!

Be sure to take everything you read with a grain of salt – or an acorn.

(I will continue discussion of this article further if there is enough interest – that means you need to post a comment!)