DBannedanswered grow question 4 years ago This can be caused by a lot of things from fungi, nutrients lock and watering ph.
Try to trouble shoot you plant and observed whats doing.
Start with reducing nut. Just give the plant ph’d water. Check your soil ph and makE sure ur temp and humidity its balance.
Check out the link below it might help👊
https://www.420magazine.com/community/threads/orange-rust-spots-on-older-leaves-pics.85351/
Happy grow!!