Production of Nicotiana glauca R.C. Graham aerial biomass in relation to irrigation regime

Nicotiana glauca R. C. Graham is a member of the Solanaceae, naturalized in the areas of warm-arid climates of the Iberian Peninsula. This species could have a great importance as a possible energy crop, because of its drought hardiness, sprouting capacity, large biomass productivity and high content of non-structural carbohydrates. In this work the production of the above-ground biomass of Nicotiana glauca was studied in relation to the irrigation regime in a cycle of cultivation. Primary values — leaf area, leaf dry weight and stem dry weight — were determined by non-destructive methods, in order to follow individually the development of each plant. From these primary values, growth indexes were calculated, and the behaviour of the species is discussed in relation to the environment. From the results obtained, it is deduced that Nicotiana glauca is a species adapted to conditions of water deficit and high temperatures. It is concluded that Nicotiana glauca could be cultivated in marginal lands of warm-arid climates; and a production of above-ground biomass of 3·9 t d.m. ha⁻¹ year⁻¹ was estimated, from which it would be possible to extract about 900 kg of easily fermentable carbohydrates.