New major food crops developed in recent times are:
few
many
some
none

I would say major new food crops are probably few although ongoing research such as at Agriculture and Agri-Food Canada has developed 14 new varieties of cereal recently as a small example so this is promising for the future especially since by 2050 the world's population is projected to reach over 9 billion people so food production needs to keep pace with such a high figure.

Well, both latitude and intensity of light affect temperature because, the higher the light intensity, the higher the temperature and since latitude is the measure of how close you are to the equator, then the closer to the equator you are, the higher the temperature is.