I only work with organics so here’s what I can tell you:
I have come to trust a product called Milstop. It’s essentially baking soda with a different formulation, organic, safe to use til harvest; I do recommend a bud wash post-harvest just to rinse off whatever might be left.
Milstop is also recommended to be combined with another organic fungicide called Cease and this combo is very effective esp. if you catch any mold getting started very early on. I try not to use this blend once buds are really getting going but again a water/H2O2 wash at harvest will handle any residue.
I have also tried OxiDate 5.0 - similar to hydrogen peroxide - and seen incredible results, especially in the final weeks before harvest and right up til the day you cut it down. This stuff is serious business however, a bit pricey and many places won’t ship it due to hazard if it leaks, and you MUST wear PPE like gloves and face shield while using it. The concentrate will burn bare skin white the same way peroxide does, but stronger, and you really don’t want it getting in your eyes either, diluted or not.
Once dry it poses no danger.
Hope this helps.
@bobbydylan Honestly it depends on how the season is going. If I’m having a lot of disease pressure and wet weather I might go right up til just before harvest, but if the weather gods have smiled upon me and my IPM’s timed right, the last Milstop spray would be a week or two before harvest (or first cut, if you’re like me and harvest in stages). It can leave a whitish residue on leaves for a little while after spraying; it’s harmless but will rinse away in a water/peroxide bud wash.
If you’re doing a organic grow, i would look into Growers Ally Crop Defender 3. It’s a fungicide, miticide and insecticide all in one bottle. Two different mix ratios. 40ml/gallon for infestations or 10ml/gallon for preventative. I’ve use about all of their products and love it. Safe up to the day of harvest and won’t affect your finished product.