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Sweet sorghum: a potential resource for bioenergy production 217

classify the species of sorghum (Harlan and De Wet, 1972). A total of 15 sorghum
varieties cultivated are virtually and clearly identified from 5 main and 10 interme-
diate races, respectively, between their derivatives of hybrid combinations. The fac-
tors considered for identification were that the characters of spikelet are mostly
firm and steady, the less subjective by environment, and easily attachable in rela-
tionships (Perumal et al., 2007). Bicolor is considered the most ancient one and
durra as the most superior with the existing races (Venkateswaran et al., 2019).
The improvement in sorghum exists with the use of tertiary wild relatives, even
though breeding methods which are nonconventional are required to cross the bar-
riers. At the same time, these techniques are not commonly available to breeders in
all sectors as these species may be an important gene donor in the future. More
genes for desirable characters and higher biological yield are needed for progressive
enhancement of cultivated sorghum (Venkateswaran et al., 2019).
Sweet sorghum is contributed by Africa to the world, which is in the top five
cereal crops. Cultivation started in Africa and thereafter spread in India, China, and
European countries. Sorghum was found in the Nabta Playa archeological site in
the southern Egypt around 8000 BCE (Doggett, 1988; Stahlman et al., 2000). It is a
genus of numerous species of grasses, among which grains and fodder plants were
produced (Stahlman et al., 2000).

10.2.2 Production
Sweet sorghum is produced in more than 100 countries, which includes Asia,
Africa, Oceania, and the Americas and is usually grown in slightly warm climatic
conditions. The estimated production capacity of sweet sorghum in the world is
around 68.9 MMT and contributes 85% of the energy requirement. It is the food to
thousands of people living mainly in the semiarid tropical regions of Africa and
Asia (Bruinsma, 2017). Sweet sorghum is considered highly flexible and tolerant
species because it can be cultivated in all parts of the world at different temperature
conditions. It, being a photosynthetically efficient plant, has the capability of beat-
ing the stress from heat and drought conditions. The largest sweet sorghum pro-
ducer is the United States which contributes over 16% of the world’s output and
developed countries produce one-third of sorghum in the world, which is quite sig-
nificant comparing the remaining production from over the world which has 70%
of the area for sorghum cultivation. Mexico is the dominant player in the produc-
tion of sorghum with 94% contribution in the region of Central America and
Caribbean, while Argentina and Brazil dry regions are dominant in Southern
America. In Oceania the only main contributor is Australia, whereas Italy, Ukraine,
and some parts in France are contributing in sorghum production from Europe.
More than 85% contribution of Asian share in sorghum production comes from
China and India. The annual production of sorghum is 5.5 MMT from planted area
of 5.8 million ha (Bruinsma, 2017; Stahlman et al., 2000). Fig. 10.1 depicts the pro-
duction of sweet sorghum in the world, wherein the United States, Nigeria, India,
Mexico, etc. exhibit higher production.