Anyone expert on PAR LIGHT REQUIREMENTS

[Guest Dave L]

I know there are no stupid questions, but I may get close with this one.  I have a relatively new all season greenhouse with a variety of palms and tropical plants.  I have an automated shade system that can respond to temperature and PAR light levels.   When it gets too hot (Now it is set at 80F) the shades close to reduce the heat a few degrees.  I attempt (with not great success) to keep the house at 75-80 F degrees day and 60-70 at night.  During the day the outside PAR can reach almost 2000.  I have researched this subject and I cannot find any source that can tell me if too much PAR is harmful.  I know that ideal PAR for growing is between 400-700, but is too much harmful?  I'd like to program the shades to close when the PAR is too high, but I'm not sure I need to.  Some of what I've read indicates that more is better....HELP PLEASE? 

[Rickybobby]

I haven’t investigated par with palms but it is very big in salt water coral keeping and all I can say is if the palm is acclimated to the sun the par shouldn’t be an issue 

[Guest Dave L]

Thanks for the reply.  Since I am growing in a greenhouse I am concerned that I may be getting too much light.... My research is not finding anything that suggests too much PAR light. So I am still curious

[Rickybobby]

My family has a commercial greenhouse and there is no issues growing anything tropical inside now of course our latitude does make a difference closer to the sun the more par