Plant looks like my lilies a couple weeks longer into fall here where I'm at. It's the end of the growing season, seed pods on them are or would be nearly done growing, so leaves are no longer needed (all energy stored in the bulb that is needed). Thus leaves yellow and die off, then the rest of the plant as the seeds scatter.

Your plant is ready for harvest. Nutes wouldn't help anything and may go into the buds and make them taste funny I'm thinking. You CAN keep it as is and allow it to continue to ripen a bit before harvest, but it will start drying itself in a couple weeks either way it looks like. yay for harvest season!

BTW, feel free to cut any fully yellow leaves - the plant doesn't need them anymore. Any green is still being used for energy and growth into the buds.