David Hare-Scott wrote:
Pavel314 wrote:
snip

Cundall is pretty good. In this case you are treating the plant
harshly in the short term to turn a metabolic switch. Once that is
done you need to treat it well so it has lots of energy to put into
fruit. Continued harsh treatment will just give you a stunted plant.

The converse might be a pumpkin plant. A healthy plant in full sun
will produce fertilised flower numbers in excess of what the vine
can support to ripeness. Treating it harshly will get you nowhere.
In this case you to maximise yield you should be nice to it, give it
lots of water and fertilser. Don't generalise too much.

David- Hide quoted text -

- Show quoted text -

I've noticed that digging around the roots of fruit trees seems to
increase the yield the next year, much like pruning, although I've
never done a scientific measurement with controls and such. My theory
is that when plants are injured, they try to reproduce their species
as much as possible in case they don't survive. But that's probably
attributing too much conscious intent to the plants.

Paul

You are right that it isn't wise to attribute too much to plants but
this behaviour isn't so complex that it implies thought or conscious
intent. As I understand it the damage (and other actions that the plant
is able to detect) cause the production of hormones (gibberellins) which
control various aspects of growth and development.

So for some plants cutting the top off causes production of new shoots
lower down, disturbance of roots produces suckering, a certain period of
cold breaks dormancy and stressing tomatoes can switch them from
vegetative growth to flower and fruit production. Some of these
substances can be extracted or synthesised to produce the same effect
when applied by the grower without taking the action that generates it
naturally.

I'm repeatedly struck by how poorly taken care of tomato plants set
fruit, it has to be survival of the species reaction. Billy has
mentioned how you don't want tomatoes to believe it is the eternal
summer of bliss. But you don't want to produce plants that yield a poor
or damaged harvest.

It seems to me that some species, like cucurbits, don't need the cues
to reproduce. Tomatoes sure do.

The trick is if you are going to influence the behaviour of a plant in
such a way that you need to understand what the consequences are likely
to be in that particular case. For example, to encourage fruiting by
pruning fruit trees you need to know which wood on each type of fruit
tree bears the flowers, it isn't all the same, so your pruning shouldn't
be the same for all.

Every plant seems to fill a little different niche, and is adapted
differently. Perennials think beyond the current year in ways that
aren't always obvious.

Enough rambling from me! I've exhausted my knowledge base!

Jeff

David