Sorghum bicolor Seeds | Red Sorghum

Red Sorghum (Sorghum bicolor) seed — Red Sorghum (*Sorghum bicolor*): Poaceae (grass family), tribe Andropogoneae, genus Sorghum, native to The savanna and highland belt of northeastern Africa, chiefly Ethiopia, Sudan and the Sahel, with an ancient secondary centre of diversity across the Indian subcontinent.

LATIN NAME: Sorghum bicolor

COMMON NAME: Red Sorghum

Plant Profile

Red sorghum is red because of a layer most cereals do not carry at all. Beneath the pericarp of the grain sits the testa, a papery sheet present only in certain genetic lines; where it is pigmented, condensed tannins accumulate with it, and the grain takes on a deep brick colour. Take the testa out of a breeding line, as the white food sorghums have done, and the same grain turns bland. A grower can judge a sample with the tongue: a faint astringency at the back of the mouth means the pigmented layer is there.

Grain sorghum is a stout annual with a solid, pithy stem and a dense terminal head, and it carries no rhizomes; it dies at the first hard frost. That absence is the cleanest way to separate it from the rhizomatous perennial wild sorghums that share the same fields. Sudan grass is finer-stemmed and bred for hay, while the weedy wild forms shatter their grain and tiller far more freely.

Kafirin is the alcohol-soluble storage protein of the grain, a prolamin of the same family as the zein of maize, and its tightly cross-linked body is what makes sorghum flour behave so differently from wheat in a bowl. Red types also make 3-deoxyanthocyanidins, chiefly apigeninidin and luteolinidin, pigments rare among cereals and notable for holding their colour against heat and shifting pH.

Sorghum has a reputation as one of the more awkward cereals to handle in vitro; immature embryos are the usual explant and regeneration proceeds through somatic embryogenesis, often with strongly genotype-specific results. The species also gave plant science an early gift: a compact reference genome published in 2009, which made it a working model for the Andropogoneae, the tribe it shares with maize, sugarcane and the bluestems.

Across southern Africa, sorghum malt is the backbone of opaque home-brewed beer and of the sour porridges that go with it. The tannins of red grain are a mixed blessing here: they slow digestion and make the flour heavier, but they also protect the stored crop from mould and from birds, which is exactly why red types hold their place in risky rain-fed districts.

Science & Biotechnology

Two compounds from this plant have earned it a place in both laboratory and field. Dhurrin is a cyanogenic glucoside concentrated in the young shoot, especially near the leaf tip; when the tissue is crushed it can liberate hydrogen cyanide, which is why early-cut sorghum herbage is a real hazard for grazing stock and why fodder is cured before it is fed. Sorgoleone is a benzoquinone released by the root hairs that suppresses small weeds, and it is one of the best-studied natural herbicide leads in plant science.

Uses & Benefits

The species was brought into cultivation in the savanna belt of northeastern Africa, in what is now Ethiopia and Sudan, and moved west across the Sahel and east to the Indian subcontinent along early trade routes. West African farmers know the crop as guinea corn. It reached the Americas in the cargos of the Atlantic trade and became a staple on small farms in the southern United States, where the sweet-stemmed types were pressed for syrup. It is a C4 grass with twenty chromosomes.

The stiff-headed forms selected for broom-making, long grouped as a variety of the crop, carried the species into the hardware trade of the nineteenth century. Sweet-stemmed types were pressed for a thick syrup that sweetened rural tables long before cane sugar became cheap. In the kitchen the whole grain is boiled like rice, puffed in a dry pan, milled for flatbreads and thin porridge, or malted for brewing.

Growing from Seed

Sown thick, sorghum suppresses weeds partly by shading and partly through sorgoleone in the root zone, and it is often followed by a legume in warm rotations. The stover is useful fodder once properly cured, and standing heads are widely used as a windbreak and as a source of poultry grain on dry farms.

Sorghum will not forgive cold, wet ground. Direct sow into a loam dressed with compost and allowed to warm, at a depth of two to three centimetres, with rows about sixty centimetres apart. Water deeply once to settle the soil and then hold back, because the plant is built for dry spells and resents being fussed over in a wet bed. A little sand in the sowing drill keeps the seed from sitting in a soggy pocket.

When the seedlings have stiffened into sturdy stems, thin them to roughly fifteen to twenty centimetres apart, leaving the strongest plants, and keep the hoe moving while the plants are small. A mid-season side-dressing of compost supports the head; beyond that the crop needs little, and over-feeding tends to produce tall, soft stems that fall before the grain is ripe.

The old enemies are charcoal rot in hot, dry soil, head mould after a wet finish, and the sugarcane aphid, which builds on the underside of the upper leaves. Choose resistant lines, avoid crowding, and do not leave infected stubble in the field. Birds are the other serious competitor, and a red head with a pigmented testa is the practical answer.

Our Take

I sow red sorghum as warm-weather insurance and as a smother crop in the same pass, because sorgoleone does half the weeding for me. For the wider grain palette, compare notes on Sorghum bicolor, keep a row of proso millet beside it, and look at purple maize and foxtail millet if you want a mixed dryland plot.

Vegetable Seeds / Vegetable