I shall now type something that just goes to show, you may stop lots of stuff with great ventilation, but dryness encourages OTHER beasties. I planted a peach to train as a fan on my southern end of the GH last year. Good old thompson & morgan firstly sent me one with very few laterals on the bottom 2 foot of the plant, after I moaned, they refunded me, but I still planted and am attempting to slowly bend the branches down.
Now last year, I grew loads of toms, took a while to ripen but the GH was packed. The peach developed quite a nasty outbreak of red spider, no other plants affected thankfully. This leads me to believe T&M provided me a plant already infested, as if it had come through the ventilation it would have been hitting toms first. I kept spraying the peach with misted water several times a day, then used some form of bug killer after the toms had finished, I then used a pest candle end of the year, then after cleaning the gh this year used another candle. This morning I found webbing on the growing tips, it's back. Just ordered Phytosieulus persimilis, and a follow up for 2 weeks later, hoping this will clear it up.
I ordered from ladybirdplantcare. Quite reasonable for 2 seperate deliveries 2 weeks apart, £23.90. I shall post updates on here if I remember. I really want rid of RSM, makes me paranoid about everything in my greenhouse at the minute. I've cleared all leaves dropped, and all my other plants are up the other end, misting a few times a day with a hand sprayer til my phytos arrive. Anyone think of anything else I can do to slow them down or help contain the outbreak?
Thanks in advance