Sudan Grass

Sorghum sudanense

Description

Annual and sometimes biennial grass. Fibrous roots, erect and thin stems, 150-250 cm high. Long (20-60 cm), narrow (8-15 mm), green, often reddish leaves. Inflorescence in the shape of a panicle, with an average length (20-35 cm). The spikelets on a panicle are less fragile than those of Johnson grass [lien vers la fiche] and do not fall at complete maturity. Frequent cross-fertilisations. n=10.
The grains are coated in yellow-reddish or brownish lemma. Smaller and without stalk (compared to Johnson grass [lien vers la fiche]). PMG = 10-15 g.

Native to eastern Sudan, it was introduced to United States (1909) where it is grown as a forage crop. Nowadays it is found in South America, Europe, North Africa, South Africa and Australia.

As toxic as Sorghum halepense [lien vers la fiche], Sudan grass is very nutritious and appreciated by livestock. It is used very often in annual grasslands. It provides one cut (generally for hay or silage) leaving several regrowths for grazing or the production of grains. Dry culture provides a lower yield than irrigated culture (which makes it possible in certain cases to use it for biannual grasslands).
Climate: Sudan grass loves and requires heat. Its growth stops in cool temperatures, and the plant is completely destroyed in the event of frosts.
Soil: In dry crops it requires relatively rich, deep and fertile soil. Irrigated, it grows well in all soils. It does not well tolerate wet and marshy, or very dry soils. Sudan grass generally manages to plunder the reserves of the soils, the water and nutrients, leaving it poor and exhausted.

A first cut is carried out at the beginning of flowering after 7-10 weeks (following seedlings). It is followed by two/three regrowths, in particular if Sudan grass is irrigated. Thus, it is possible to mow, harvest grain and to graze the same area. In the southernmost Mediterranean regions, only one regrowth is generally observed.