On 18-Sep-2003, "Fred" wrote:

You'll have to forgive my lack of technical expertise or knowledge, I'm a
layman but have particular questions to ask about this subject.

From news items and reading New Scientist it appears to me that all the
efforts to produce new cultivars and added properties have so far involved
the transfer of genes from one plant or animal to another in order to
imbue
the particular plant with a particular quality.

Have any efforts been made not to do this, but to increase the efficiency
of
the photosynthesis operating in the plant? I have read that photosynthesis
is in nature a very inefficient process, possibly less than 2% efficient.

The first step in photosynthesis, where light is turned into chemical
energy, is nearly 50% efficient. There is not much scope to increase its
efficiency.

The figure of 2% efficiency is probably arrived at by dividing all the
energy in the sunshine falling on the plant by the amount of energy locked
up in the above-ground parts of the plant. The difference between 50%
efficiency in the primary step and the 2% efficeincy over all is related to
the energy used in growing the plant, including its roots, maintaining it,
and propagating it. A comparable calculation for an electric power station
would have to take into account all the energy used in mining and
transporting the coal, building the power station and maintaining it. The
efficiencies of power stations are usually calculated by dividing the energy
released by the coal by the energy in the electricity produced. These
figures are misleading.

Surely
there's huge potential for improvement in this?
Instead of no-freeze tomatoes or disease-resistant crops we'd have crops
which grow in a quarter the time or yield many times the usual amounts in
the same cultivated acreage and with no additional nitrogen required and
no
danger of cross-species gene or resistance transfer.

Thanks
Fred.