More on Bella

I was wrong in my previous update.  I saw that Bella had rotated and jumped to the conclusion that it would carry on rotating.  Oops.  This morning I found Bella pointing back into the house again:-

It seems that Bella still rotates a third of a turn clockwise each day then resets at night, as per any Northern plant (plants from below the Equator rotate anti-clockwise).  This pattern of rotation hasn't changed, only because the curve of the plant has been deliberately turned toward the pole, Bella now rotates to point away from Sol instead of towards Sol.  Funny old world.  So I haven't yet established if phototropism will beat heliotropism in getting a bramble to point at the Sun, all I've done thus far is to mess about with Bella's heliotropic behaviour.

Still, it's interesting to know.

Some early results

  The week's numbers are up on their respective pages.  Jake is pretty much dead.  Growth was seen in Bella and Rosie, whilst Tiny 1 has shrank.  Tiny group aren't doing well, which I suspect is due to the lack of direct sunlight.  Milo and Doodle have shoots of 2cm apiece, and those shoots are showing tiny leaves.  That Rosie has grown in the week since going outside is pretty awesome.  Fizz is turning very green at the tip.  It seems that maybe a purple shoot transplanted without roots to a sunny spot turns green to make the most of the Sun.  Any further growth by Fizz will require sugars made in the green parts of the plant.

  Bella has rotated.  Alas, stupid me didn't get a top-down photo of Bella and Jake at the start of the experiment, which means I can't now measure how many degrees Bella has rotated by.  I can show you the face-on pic from the start though, which shows Bella to be pointing a scant few degrees anticlockwise of the centre of the label.  Today Bella is pointing approx. 45º clockwise of the centre of the label.  That's a big difference.  Also, Bella has not gotten any straighter.

  What Bella's rotation means in the grand scheme of things is unclear.  If Jake hadn't died then I could say that, with cuttings of this species, under these conditions, heliotropism beats phototropism.  As it happens, this result is only borne out in 50% of my sample.  I cannot say what Jake might've done because Jake didn't do anything.  I can say that there is an isolated instance where, with cuttings of this species under these conditions, heliotropism has beaten phototropism; but I cannot claim evidence of a general tendency within R. fruticosus without further evidence.  The behaviour of Bella is exciting though, as it suggests that I'm fishing where the fish are.  I guess we know the shape of Rubus 4...

I'm going to throw some pictures at you now.

Bella

Milo

Doodle

Tiny Group

28/11/2012 Data

Numbers are in.

The numbers are in centimetres, but plants don't grow by whole centimetres at a time.  Thus the numbers refer to "rounding bounds", wherein a plant listed as 12cm could be anything from 115mm to 124mm, and once it reaches 125mm it is listed as being 13cms.  Statisticians might be better able to explain this than me.

With the exception of Tiny2, all the plants appear to be growing.  However, the only plants which have moved up to a new rounding bound this week are Milo and Tom1.  Data is in the group pages.  I'll update the measurements page when Rosie and Jim go outside.

J

On the primary DV

So why length?  Why not dry mass?  

The answer is simple: I'm starting with cuttings, not seeds.

  Seeds are fairly uniform things anyway, and the size of a seed as variable is as nothing to overall growth when compared with the variable of quality of the growth medium.  A small acorn in rich soil will grow a bigger tree in a given amount of time than a big acorn in clay.

  Cuttings are different.  They aren't very uniform in starting size and also they are from established plants.  They have stem structures in place like cambium and xylem.  Some may even have lignified or lignifying cores.  That difference can have a far more tangible effect on the outcome than the size of a seed.

  If Fizz and Doodle grow at the same rate then Fizz will still be bigger than Doodle.  If they grow proportionate to their starting size then Fizz will end up significantly bigger than Doodle.  What is needed therefore is a starting measurement which is capable of being compared with the final measurement.  To record the dry mass is to kill the specimen entirely.  I cannot do that at the start for then there would be no experiment.  The ashes of dead plants don't conveniently grow into new plants so that you can cremate them again in three months' time.

Dry mass is more accurate, more scientific, but it cannot be used in this instance.  Length therefore is a useful proxy for how much mass the plant is accruing.

On watering

A bit last-minute, but it occurs to me that these experiments need a watering scheme for the indoor plants.  I've already decided on pro re nata - or when the plants need it - but even then there's a decision to be made: PRN per plant, PRN per group, or PRN globally?

I've decided on globally.  That means that when I decide (completely arbitrarily) that enough of the indoor plants need watering then all will be watered.  If too few are in need of water then none shall be watered.  I reckon this approach should strike a balance between taking care of the needs of indoor plants and a perceived need to mimic the behaviour of rain in nature, which doesn't much care about the watering needs of an individual plant.

This will take effect after the fortnight's run-in.  There's no point in abusing the shoots before they've put out roots or else they'll all fail.