Hello...I have been growing Goldings and Mt Hoods in my garden for 10 years with no problems; vigorous growth, good yields. This year, after the usual explosive spring growth, growth slowed dramatically, and leaves began to develop brown discoloration and become brittle. New growth at the base of the plant is now pale green and spindly, and sidearms are slow to form on the main bines. No sign of major insect problems. I have scoured the internet for information, but the only things that looks similar are downy mildew (which would seem unusual here in hot, dry Colorado...) or verticillium wilt. Any input would be appreciated; see attached photos. Thanks!