The seeds of tropical fodder grass development

The usual way wild species are used in breeding is to improve their domesticated relatives. But in Bajra–Napier Hybrids (BNH), it’s the crop that is used to improve the wild, or at least wilder, relative.

BNH are pretty important forages in tropical and subtropical livestock systems, but you don’t hear too much about them other than from specialists. I certainly hadn’t, until a recent social media blitz from ICRISAT.

They are made by crossing pearl millet (bajra, Pennisetum glaucum) with Napier grass (Cenchrus purpureus, formerly Pennisetum purpureum). This has the effect of combining nicely complementary traits into a highly productive fodder plant.

The best thing about BNH is their high yield of biomass. Under ideal conditions, annual green fodder production can exceed 200–300 tonnes per hectare, which comfortably outperforms other forage grass options. This productivity is due to fast growth, profuse tillering, and efficient nutrient uptake. For smallholder dairy systems, where land is usually at a premium, such a yield advantage translates pretty quickly into higher milk output per area. Also, BNH are perennial, which reduces costs over time, as fields can remain productive for several years with proper care.

And their nutritional profile is pretty good. Crude protein is typically 8–14%, depending on management and cutting stage, while digestibility remains ok if the plants are harvested relatively early, before they start getting woody, say at 45–60 day intervals.

BNH are resilient, being tolerant to drought and intermittent water stress, a trait inherited largely from pearl millet, though they also respond well to irrigation and fertilization. That makes them widely suitable, everywhere from low-input rainfed systems to intensive peri-urban dairying.

All that said, there are drawbacks. Perhaps the main one is that BNH are typically sterile, not producing seeds, and must be propagated vegetatively, through stem cuttings or root splits. This means farmers depend on planting material supply chains that are often weak or informal. Diseases can also be transmitted more easily with vegetative material. Plus high biomass production demands big nutrient inputs, particularly nitrogen, with inadequate fertilization quickly eroding both yield and quality. That can be expensive.

In response, a significant recent line of research has focused on developing seed-propagated BNH. This is technically tricky, because sterility in the classic hybrids is linked to genomic incompatibilities between the parental species, due to their different ploidies, or numbers of chromosomes. So breeding strategies have explored chromosome doubling, intermediate ploidy levels, and backcrossing to restore partial fertility while retaining the desirable forage traits.

Seeds simplify dissemination, reduce transport costs, and mitigate the spread of vegetatively transmitted diseases. They also enable more formal seed sector engagement, including developing new varieties. Sure, trade-offs remain: some seed-propagated lines show lower biomass yields or less persistence compared to established clonal hybrids, and ensuring consistent performance across environments is still a work in progress. So it’s good to see ICRISAT and others on the case.

ICRISAT is advancing forage research with trials on seed-propagated Bajra–Napier Hybrids (BNHs) a shift from traditional stem cuttings to a scalable, seed-based approach.

Bajra–Napier, a key fodder crop for dairy systems, combines the high yield and perennial nature of Napier… pic.twitter.com/kKBQ58IuIn

— ICRISAT (@ICRISAT) April 20, 2026