I was also thinking calcium. I use limestone in the garden when squash have blossom end rot. Watered in it seems to work right away.
Lime is a yearly additive for us. My husband likes the peletized it is easier to spread and dissolves more quickly. Any brand will probably do. He buys whatever is on sale. I do not know if they all contain calcium- I would think so but, check the label. Who knows where any blight comes from. It is spread by the wind. A few years back every tomato in Massachusetts and surrounding states were hit with blight. Came from big box store plants, supposedly. I always grow manny types and be sure I have a few disease resistant varieties as the heirloom will be the first to perish.Maybe a spray of baking soda or mil will help. I would remove the leaves and tomatoes already effected. Have you grown the same variety in your greenhouse before?In what form do you disperse it? There a brand you prefer?
If it's humidity it's localized, due to the peppers, spinach, basil, other tomato plant and the bromeliad all in close proximity to it. However, I have a constant negative pressure in the tent and run a dehumidifier in the same room.
Not sure where the blight would have come from since I literally cleaned all my pots and my tent from the ground up with hydrogen peroxide and vinegar in January, but weirder things have happened
I think the battle of what smells worse: hydrogen peroxide and vinegar or bleach is a toss up.
