Is the most "Effected" part of your plant(s) getting the most or direct amount of sun? What strain are they?, Are you using treated water or just tap? Have you been doing clumsy trimming or watering and hitting the plants? 2 of mine have that and they are next to each other and the portions of the plant that are weak are closest to the sun and I noticed after giving them 1/2 times more water (15 gallons every 2 days instead of 10 gallons, or spread evenly each day) they were more resilient and the leaf rust shit was getting noticeably less... also hitting them foliar spray style with dechlorinated tap water once a week seemed to help. All best to you man. Mine are still iffy but budding decently enough.