Hello. We are in week 4 and have and issue with ye...

I see chlorosis, necrotic spots, and pale leaves. They are starving to death, deficiency. It's a problem with uptake, or problems in the root zone which will express as all kind of deficiency. Without the necessary details to go on, it's can be cold temperatures, root aphids, incorrect ph in the soil, or several other possibilities. Foliar feeding can immediately help, but it's a temporary help until you find out what the real problem is.