I was looking for some information regarding the lighting requirement for various vegetables. Mainly the websites speak of full sun, part sun, part shade etc - fairly subjective ,.. and then in hours of direct sunlight - which is actually relative to the place where you live.

Actually I was searching for a more scientific answer to my query that allows me to measures in foot candles / lux, the requirement of each plant. Not much luck. Then I found this, supposedly by an expert (link provided below) which said that you need 1234.4 as a minimum to grow tomatoes with some success. That made me curious. I have a shady area around my house which is very accessible to me. Through my light meter I measured the light and depending on the time of day (from 10 am to 4 pm), I had readings of 1000 to 1800 foot candle readings and this is not the peak summer time right now. I suppose it would be around 25% higher then this during summer months of June, July and August. The temps would be a problem then though (but they can be controlled in that space)

This made me wonder as to why do I need direct sunlight in the desert over here, when I have enough light in the shade over here?

Can some expert comment on this? Based on earlier discussion on this forum, I do have the feeling that shady areas may work in the desert better (or atleast equally well) than areas under direct sun light

Secondly is there any such website / book / other resource which gives a more scientific answer to the light requirement of vegetables?

Here is a link that might be useful: Tomatoes and Foot candles