Re: Pumpkin Lighting
Hi,
I would say the limiting factor is the CO2 content in the air rather than sunlight.
The normal CO2 content in the air is about 0.03 percent. But the highest photosynthesis rate of a plant occurs at a CO2 concentration of about 0.05 to 0.06 percent.
However, concentrations of more than 0.08 to 0.1 percent are harmful to the plant.
I know back in spring someone on this list talked about using additional CO2 in the root zone of the plant. What happened to that experiment? Any results?
Growing the plants in a greenhouse with an additional CO2 supply would be something to try. Just my two cents...
Best wishes,
Martin
What's left? Sunlight...the one variable
> that most just take for granted as something beyond our control. Why not
> maximize that, too?
"Frank Edwards" <edwardsfam@earthlink.net> schrieb:
> Wayne:
> Thanks for the info. I've been thinking the same thing about using the extra
> light to stave off the natural dieback of the plant and encourage longer
> fruit growth into September. I think it's an idea that will see its day
> sometime in the next ten years. I mean, everyone's maximizing his/her soil,
> getting the best seeds/crosses. What's left? Sunlight...the one variable
> that most just take for granted as something beyond our control. Why not
> maximize that, too? But as you've pointed out, I'd be looking at an initial
> investment of several hundred dollars...(ouch! Not sure I can justify
> spending that much just for an experiment. Especially when others are
> growing well over 1000# along my line of latitude without lights.) Sounds
> like you had a nice set-up. Sorry to hear they got lifted...especially
> before you had any results.
> Frank
> Hudsonville, MI
>
> ----------
> >From: Pumkinguy@aol.com
> >To: pumpkins@hort.net
> >Subject: Re: Pumpkin Lighting
> >Date: Tue, Nov 18, 2003, 3:43 PM
> >
>
> > Frank,
> > Never had any results one way or the other. The lights are extremely hot
> > as you might imagine. As I recall, I had them about 6 feet away from the top
> of
> > the leaf canopy. The bulbs were 1,000 watt coated supermetallarc . Lighting
> > experiments are not for the faint of heart (moneywise). As I recall the bulbs
> > were 75 dollars each and special fixtures are required (2or 3 hundred each).
> > One of my wild unproven thoughts was that by altering day length, I might be
> > able to ward off maturity in the fruit. The lights were fitted with a
> photocell
> > to come on during very dark, cloudy weather and also at night for a few extra
> > hours.
> > Wayne
> >
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