For the past 4 years we've been dealing with smokey days (and weeks) here in southern Alberta. I know the effect of these days on the potato agronomist, but I've been wondering what the effect is on the potato plants.
It turns out there hasn't been much work on the effect of smoke. In articles from National Public Radio (NPR) and the Manitoba Cooperator the researchers speculate on the effect of the smoke but can't say for sure what it will do. In some ways its like a cloudy day, so it could be just reduced photosynthetic rate, but I think there is something else going on.
One of the effects I saw on myself was the light spectrum. As you can see from the picture its not just shady, it's the light that you'd normally expect at sunrise & sunset. I think this spectrum must be doing more to plants than that just slowing photosynthetic rate.
Let me know in the comments what you think and post any other articles or research into this that confirms or refutes this. I'd love to learn.