"Jasbird" wrote in message
...
What is the conversion rate from growmore to plant matter?

Yes, I already know that there is no such thing as that but ..., in an
ideal situation for each gram on growmore how much plant matter will be
produced?

Over 90% of the weight of most fruit and vegetables consists
of water. 94% in the case of tomatos,and much other fruit.

http://www.beyondveg.com/tu-j-l/raw-...ooked-2f.shtml

The purpose of the major NPK elements, nitrogen, phosporus and
potassium is simply to allow the plants to develop to their full
potential, which in reality means developing more and larger
cells to hold more water.

The major determinant of plant size is photosynthesis, the metabolising
of sugars by the action of sunlight on the chlorophyll in the leaves
in combination with water.

Plant elements are often most noticed by their absence, both major
elemnts such as NPK and minor elements such as boron. And most soil
is sufficeiently permeated with most of these elements so as to
support an appropriate range of plants. For those climatic
conditions at least.

Basically if a plant doesn't get enough of an essential element
then its growth will be stunted as compared with an average plant.
However providing more than it needs, won't produce a larger plant.
Instead it can be positively harmful by inhibiting the take-up of
other essential elements. Thus tomatoes are given extra potassium
to promote flowering (in a loose sense, anyway), but because this
inhibits the take up of calcium from the soil or compost, most
tomato feeds are dosed with extra calcium in addition.

In other words - just enough - but no more than enough.

To fully answer your question it would be necessary to grow
selected strains of genetically identical plants under totally
controlled conditions - under artificial light and using a sterile
growing medium such as rockwool. Which, because such conditions
are untypical of the way in which most plants are grown would
be of little benefit to anyone.

....



- assuming that no other nutrients are limiting. I want to
know the theoretical maximum.

I use growmore on my garden vegetables and I usually put it around each
plant, half a teaspoonful at a time.

So, for instance, what is the most growmore I should give each
individual parsnip or strawberry plant?


....

Again impossible to answer without knowing the existing fertility
of your soil. However given that strawberries are 95% water you
can see what the plants should definitely not run short of.


michael adams