One thing to be aware of with the evapotranspiration PDF – for nectarines, peaches and apricots in December and January you’ll find that the trees have the same ET as ET0… which calculates to 100% if you do the math. Critically thinking, that’s not right. Beats me why though in most cases we’ve got enough rain those months to make irrigation not necessary at all. So I use the 40% or less value calculated from February or November until Spring. 
Far far better than keeping it at 80-90% year-round!
