Contrasting strategies to cope with drought conditions by two tropical forage C4 grasses

Drought severely limits forage productivity of C₄ grasses across the tropics. Napier grass (Pennisetum purpureum) and Brachiaria hybrid cv. Mulato II are tropical C₄ grasses used for livestock production due to their reputed resistance to drought conditions. However, there is scant information on the mechanisms used by these grasses to confront to water-limited conditions. A new study published by Cardoso et al. in AoB PLANTS provides an overview of the dynamics of growth, water uptake and water use in these two grasses. This information in combination with observations of leaf rolling scores suggested that Napier grass and Mulato fall respectively into contrasting “water spending/water saving” models of water use. As such, Napier grass might be targeted for areas with intermittent and short periods of drought, whereas Mulato II might be a better option for areas with longer drought spells.