Tim Tyler writes
In uk.rec.gardening Oz wrote:

:: Tough. Grow your own food.

However in the long term, I'm optimistic - we will figure out
how to avoid poisoning ourselves eventually.

Probably about the same time people stop committing suicide, are
careless at work and stop murdering each other.

Don't hold your breath.

:We are still in the biotech dark ages - there's very much we
:don't know - and ignorance is dangerous.

: Biotech? You approve of GM cultivars?
: I am amazed.
: But yes, they could well help.

I merely mean "biological technology". Perhaps I should have
used the term "biological science" instead.

FWIW, I think GM cultivars will prove to be of great importance
and significance.

However, many of the same sorts of safety issues surrounding
pesticides will apply there - a healthy level of paranoia
may be beneficial there also.

It keeps (so far) GM out of the EU marketplace.
Except for imports of course.

Some of the things I've grown (or am growing) this year:

Basil, Broccoli, Cabbage (black), Cabbage (red), Celery,
Chervil, Chickory, Chickpea, Chop Suey, Collard, Coriander,
Corn salad, Cress (curly), Cress (land), Cress (water),
Fennel, Flax, Kale (red russian), Lettuce, Mibuna, Mizuna,
Mustard (red), Mustard (yellow), Mustard (spinach), Pak
Choi, Spinach (perpetual), Radish, Rape, Rape (salad),
Rocket (salad), Rocket (wild), Sesame, Sunflower, Texel,
Turnip, Alfalfa, Aduki, Clover (red), Fenugreek, Lentils
(puy), Mung, Pea, Soya, Amaranth, Buckwheat, Corn, Kamut,
Quinoa, Rye, Spelt, Wheat, Raspberries, Taeberries,
Loganberries, Wolfberries, Black Currants, Gooseberries,
Hazel nuts, Apricots, broad beans, peas, onions, garlic,
purple sprouting broccoli, swiss chard.

How big is your veg plot?
How big is your greenhouse?

: and what percentage of your total food intake (calories) do home
: grown crops amount to?

Most of my calorie intake comes from fruit, nuts, oils and seeds.
I hardly grow any of them. The fruit I grow are almost all berries.

Given the list above, it should be much more than that unless you are
growing only a few plants of each. In which case I would suggest you are
playing at growing your own food. Two frames each of runner and climbing
french would (even for a veggie) oversupply food for several months.
Heck four of us can't begin to keep up. Courgettes (four plants) we
throw out or give away probably 70+% and swiss chard similarly. I only
have a tiny untended veg plot, too.

I estimate I currently grow about 10% of my calories for the year -
if that.

Then you either have a very small plot, aren't trying or aren't growing
the right things.

::: Noting the strong relationship between plant toxins and pest resistance
::: (it's why the toxins are there in the first place) it would almost
::: certainly be safer to use plants bred for low toxin production and use
::: the much safer pesticides to control the pests.

: Left in case you figure out an answer.

It's possible. I believe what I said on this point before was that
I thought in the long term such a strategy might produce beneficial
results - but that we didn't currently know enough to implement it
safely.

Pah!

As I mentioned, the supposed plant toxins have some beneficial side
effects. "Hormesis" - as it's sometimes called. Engineering or breeding
them out without proper understanding of their roles may prove
counter-productive.

The same may well be true of pesticides of course.
I'm sure that's never been tested for.

::The natural toxins have been around longer,
::our bodies have had a chance to get used to them -
::and there has been more opportunity for study.
:
:: 1) So what if they have been around longer. Think strychnine.
:: 2) Our bodies didn't evolve to consume a small range of food plants.
:: Take out the brassicae and solanum groups and there isn't much left.
:: 3) There has been virtually NIL study on plant toxins.
:
:: So wrong on all three counts.
:
:We know a fair bit indirectly about plant toxins from the study of
:human nutrition.

: Actually we no sod all.

You like leaving out qualifications, don't you? ;-)

True none the less. Things can be nutritious and toxic.
Many animals eat toxic plants for the nutrition, else you get to die of
hunger first and so just have to tolerate the effects of the toxin.

:It may not have been medicine's most explored area - but
:to say we know "virtually NIL" on the subject seems like
:an overstatement to me.

: Give me some examples of LD50, noel and content of a few food plant
: toxins then.

Some other day, perhaps - since doing so would prove nothing.

It proves we have NO DATA on most (if not all) food plant toxins.
So we have no idea how toxic they really are, apart from the odd cases
of illness and death.

::: Eating healthy meat and veg is, and pesticides help enormously here.
::: Not only that, but the abundance of food available today is DIRECTLY
::: the result of the introduction of safe effective pesticides.
::
::...amongst many other modern farming techniques - including the
::use of machinery -
:
:: Irrelevant. It does nothing more than could be and was done by hand
:: (better).
:
:You're mistaken there...

: Hardly, I am a farmer.

Think for a moment about what you're saying, then.

Machines do NOT let me grow more/ac.
They let me grow more per MAN.

::and things like a global market in seeds and produce.
:
:: That's always been there (not that it has any relevance to your
:: submission).
:
:...and there.

: You are still wrong. Like most farmers I know a lot about seed
: development and production.

Perhaps read your own words again, then. You are apparently
claiming that a global market in seeds and produce existed before
the birth of the universe.

Don't be a prat all your life.
Remember seeds were brought back in the first ships that went to the new
world, and in the old world many (most, all?) crop plants had spread
from their original source to the furthest edges in antiquity.

::I suspect that eventually mechanical barriers to pests will eventually
::make many of today's pesticides redundant.
:
:: Dream on, you have no idea what you are talking about.
:
:Rather obviously, I'm talking about growing a greater proportion of
:things "under glass" - or in controlled environments.

: To feed the world?

Yes.

: speechless at the stunning level of ignorance

Don't underestimate technological progress.

I don't, I do understand economics.
Just work out the energy cost of covering the UK arable area under
glass. Go on, have a go.

:You may have noticed that there's been something of a trend in that
:direction over the last hundred years.

: Not in the UK, it's almost zero now other than for cut flowers.

...and watercress, and tomatoes - and an increasing number of other
things.

Watercress is all grown outside hereabouts.
Tomatoes are mostly, if not nowadays entirely, grown outside the UK.

: Far too expensive.

Expense is one of the main problems - but prices are falling.

Eh? Industrial glasshouse costs are rising.

I expect
them to continue to do so.

they will continue to rise, that's for sure.

--
Oz
This post is worth absolutely nothing and is probably fallacious.
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