The yellow pigment in plants is actually a compound called "carotenes", that reflect yellow light waves, and that's what your eyes see. It's always present within the leaves thoughout their life cycle, but generally covered up by another pigment that has much more abundance called "chlorophyll". Some yellowing is expected and encouraged by many farmers later in flower, but is debatable if it's actually nessissary. While some photosynthetic activities still occurs with carotenes, chlorophyll is the main reason for most of the growth within the plant. Yellowing too early may slow growth and significantly lower overall yield. Generally speaking, chlorophyll is associated with the chemical, harsh taste within the flower and smoke, and why farmers try to lower the overall am out before drying. Curing will also help with this effect, and it's understood that the more chlorophyll content within the plant, at the time of drying, the longer cure time you'll need for the remaining chlorophyll to break down. In my own experience, most of the growth in the flower is done in the last couple of weeks before harvet, so it's a fine line between feeding, and encouragin chlorosis (yellowing). The best way to tell is to post a picture, and tell us a little more about you garden.
Cant right now they r sleeping but i will in the am just some yellowing id say no more than 10% majority is large fans and some of the shaded undergrowth. Im a few days away from end of week 4 they packing it on check my journal for more detail
In my last grow i lost control of a plant and it ended up going from how your plants look to looking like this in about a week. Had a massive yeild of shit when all was said and done. It got worse than what you see in the picture but i cant find any pictures of it later on.
I was gone for a couple days and didn't water and they got all limpy and started to yellow for nutes i just have to stay on top of them in between full waterings i have to give about half gallon to hold em off till the next day i didnt use grow big on my last nute heavy on bloom tiger blood and cal mag ill ppm them on the next water to see about how much their eating. They seem to be fine with full strength nutes thinking bout 1/4 strenth grow big to kick some nitrogen back a bit from what i read some growers prefer them to eat their leaves to reduce harshness and cure times i got 5 weeks and maybe a few days more then into the darkness before i trim n dry based on the shit ton of big developing colas im pretty sure ill pass 1 lb.
Aslong as my leaves dont curl up and turn brown like some peeps shit ive seen in the end of flower i think ill be fine