Bare stalks are becoming a more familiar sight on several farms. Many growers have started their last pass, but several will still need most of this month to complete harvest provided the weather cooperates.
Cured quality continues to be good with most crops now having matured quite well.
Not many problems are being reported. We are however seeing some White Mold (caused by Sclerotinia sclerotiorum) in fields on a few farms. Damage from this disease can occur on leaves, as well as on the stalk. A thick, white-coloured mold will be present and will often contain black, pea-sized overwintering bodies called sclerotia. Leaf drop can occur when the infection is at the leaf axil (click here for picture). At this time in the season, there is no control for the disease. White Mold is not known to spread during curing.
One disease that we have seen in kilns is Pole Rot (caused by Rhizopus arrhizus), which appears as a grey, fuzzy mold on the leaf often at the butt end of the stem. Strategies for limiting damage from this disease are to minimize the time spent yellowing, such as yellowing at as high a temperature as possible (i.e. 40.6°C or 105°F) and then moving quickly to colour fixing which is less favourable for the development of the disease (i.e. above 43.3°C or 110°F). In past years, some growers have been successful with closing the ventilators and flashing the dry-bulb temperature for a short period of time while yellowing. This procedure is discussed in more detail in OMAFRA’s tobacco publication 298.
Blue Mold has not been reported in Ontario this year. The most recent report of Blue Mold in the U.S. was near Hillsboro, Ohio in early September. Other reports in the U.S. have come from Windsor, Connecticut; Greeneville, Tennessee; Abingdon, Virginia and Lancaster, Pennsylvania.