So what happens when a big commercial farm gets blue mold? Does the entire crop have to be eradicated or just the infected plants?
What I have seen in that case is, if it is shade tobacco, (which is never topped--it would be impossible to top the plants without damaging an unacceptable number of leaves, the plants now being 9-10 feet tall and their tops straining against the top of the net--somebody would have to go with a tall stepladder and top each plant--not gonna happen) the area infected is destroyed and the crop is sprayed with fungicide. These days, because the crop is sprayed on a schedule during its whole lifetime regardless of whether or not blue mold is present, outbreaks are usually limited and small, as this one appears to be.
I know whose tobacco this is, since there is a limited number of shade growers in Southwick, MA, although there are more broadleaf growers.
Broadleaf is treated the same way. The infected plants are removed and buried, the crop is sprayed, and then hope for the best.
They don't top the broadleaf plants prematurely just because of a limited outbreak of blue mold. The rest of the crop still needs to come out as well as possible. Most of the broadleaf would be topped by now, or getting topped these next 2 weeks.
The degree of economic damage is the main factor. Commercial crops are insured, but at barely break even payouts--no profit in insurance settlements. Ten percent loss of the crop is bad but not a calamity. Insurance will pay something, and no emergency actions are taken except what is possibly an extra spraying. Probably, the spraying would be already scheduled. We sprayed for blue mold 6 times a season, roughly every 10 days to 2 weeks.
BTW, the fact that the shade is not topped brings the problem of "blossom rot" when flowers fall onto leaves not yet primed. This is a problem during the last 2-3 primings--the flower burns a hole right through the leaf almost overnight. Workers passing through the field are told to knock blossoms off leaves whenever they see them there. Of course, only a small fraction of good leaves suffer blossom rot, it mostly affects leaves at the very top that are not picked--it depends on the wind and weather, how much of a problem it will be.
So, usually, if the affected area is big enough for an insurance claim, the area is allowed to stand until the adjuster sees it (he will come right away,) photos are taken, and the plants destroyed. Possibly this particular area where the infected plants are is in a part of the lot that didn't receive a full covering of fungicide. It happens.
This outbreak doesn't sound too bad. There are no other reports of blue mold elsewhere in the Conn Valley so far, and the crop will be fully harvested in a couple weeks. There is more danger for broadleaf, which isn't fully harvested until mid-September. The shade leaves of the best quality and the greater quantity are already curing in the sheds.
Maybe I'll get the chance to drive over there and find out some details. I'm due for my monthly trip to Conn.
The remedy that deluxestogie gives above seems to be designed for cigarette tobacco. The fact that only wrapper tobacco (potentially) is raised in the Connecticut Valley precludes that kind of action. We would basically get rid of the infected plants entirely and carry on. Wrapper harvested early isn't worth the big money that Conn farmers need to realize on tobacco crops, given the high cost of raising tobacco here. Better a total loss with insurance than bringing in a poor crop of wrapper.
CT
