Note to readers, attached is the complete final report for FNE97-188
Mr. Williamson began working with sweet sorghum in the hope of finding a use for his maple sugaring equipment during times of the year when it is not needed for rendering maple syrup. In his two earlier projects (FNE95-114 and FNE96-157) he determined that sorghum can be grown successfully in the climate of southern Vermont, but that not just any cultivar will do. He also found that his evaporating pan, while generally serviceable for sorghum, required some modification, as sorghum sap has a much higher sugar content than that of maple, and is thus more prone to burn. In this his third and final SARE project dealing with sweet sorghum, Mr. Williamson conducted variety trials and made certain adjustments to his equipment.
Mr. Williamson grew thirty cultivars of sorghum at three locations around Bennington, Vermont. Soil texture and fertility, competition from weeds, and management practices differed among the sites. He evaluated each variety for its rate of maturation at each site, and the sap of each for sugar content and taste. When harvesting sorghum for syrup it is not necessary to wait for the grain to mature; in fact, peak sugar content occurs at the soft dough stage. Mr. Williamson prefers early maturing sorghum however, in Vermont’s short growing season, so that he can collect the seed of these somewhat hard-to-come-by varieties himself. Uniformity of maturation is also preferable, as this facilitates harvesting.
For most varieties maturation was not uniform from one site to another, and drought during the summer of 1997 delayed all of them. Mr. Williamson did however observe uniformity in these six cultivars – Blackstrap, Early Orange, Early Orange 2, Waconia Orange, Simon, and Umbrella. He determined that a sap sugar content of 13% or greater, as determined by a Brix reading, is necessary to make harvesting worthwhile, and he observed this level, in early October, in the Moes Miller, Smith, Della, Orange, Simon, Ames Amber, and Waconia Orange cultivars. Among these high-sugar varieties, those with the best taste were Della, Ames Amber, and Waconia Orange.
Mr. Williamson modified a corn harvester for use with sorghum, so that it would cut the stalks and chop them into three-inch billets that can be easily fed to a press. He also designed a new evaporating pan, with the help of a collaborator, for use with either sorghum or maple sap.
Mr. Williamson’s project has attracted a lot of attention. He has demonstrated his sorghum syrup, and the process by which he makes it, at the Vermont Maplerama Tour, has been written up repeatedly in New England Country Folks, The New England Farmer, Sugarmaker, and other periodicals, and he was a speaker at the 1997 conference of the National Sweet Sorghum Producers and Processors Association, where he spoke about his variety trials.