Sweet sorghum [Sorghum bicolor (L.) Moench ssp. saccharatum]
Sweet sorghum is an annual C4 grass species of tropical origin, with high biomass productivity potential. The plants (Fig. 1) are self-pollinating and the inflorescence is a panicle (Fig. 2). It is cultivated mostly in areas where the rainfall is not enough and temperatures are too high for profitable maize production. In Mediterranean zones, its main growing period coincides with the dry season so the crop will need to be irrigated. Cultivation in Spanish conditions takes place from April-May to October (Fernandez, 1998). Harvest should take place when the grain is at the milk or wax-milk stage. Values of more than 30 t ha-1 of dry matter yield (Matei, 2000) and up to 12 t ha-1 of sugar have been reported (Fernandez, 1998). The best genotypes can produce 6000 l ha-1 of ethanol (Bassam, 1996)
Figure 1. Plants of sweet sorghum Figure 2. Panicle of sweet sorghum
The greatest limitations of the crop according to Alexopoulou and Chatziathanassiou (1999) are concerned with a small processing period, one or two months, and a need for a specific harvesting machine that separates leaves and panicles from stems.
Cultural practices are similar to what is used for maize. The surface soil layer, though, needs to be better prepared for sorghum due to the lower sized seed. Plant density of 100,000 to 120,000 plants/ha may be reached with 8 kg/ha of seeds (Alagarsamy, 2004).
References:
http://www.acclaimimages.com/search_terms/sweet_sorghum.html
Alagarsamy, S. A. (2004). What is sweet sorghum. India.http://www.indutourismnews.com/sweet.html
Alexopoulou, E. and Chatziathanassiou, A. (1999). Description of growing experiencie on sweet sorghum in Greece. European Energy Crops InterNetwork, Biobase,Greece.
http://eeci.net/archive/biobase/B10214.html
Bassan, N. (1996). Sweet sorghum (Sorghum bicolor L Moench). In Renewable Energy. Potencial energy crops for Europe and the Mediterranean region, p.126-129. Federal Agricultural Research Centre (FAL) Braunschweig, Germany.
Fernandez, J. (1998), Outlooks of sweet sorghum crop for ethanol protuction in Spain based on varietal results in multilocal trials. European Energy Crops InterNetwork, Biobase, Spain. http://eeci.net/archive/biobase/B10191.html
Matei, M. (2000). Energy crops in Romania, European Energy Crops InterNetwork, Biobase, Romania.