Performance of salt-tolerant forage genotypes of millet Pennisetum glaucum (L.) R. Br.] in Eastern Mediterranean conditions

Abstract

In this study the aim was to evaluate alternative crops able to tolerate thefuture rise in salinity, likely to occur in the East Mediterranean coastal areas. For this, two genotypes of pearl millet (Tall and IP13) were submitted to saline conditions (4, 8, 12 dS.m-1 and 2 dS.m-1 as control) in a field trial. Water consumption using neutron probe technique, physiological response and the production were studied. The neutron probe technique showed that 96% of consumed water originated in the upper 0.45 m. As salinity increased, water consumption became shallower, suggesting a different root distribution. Physiological aspects related to plant height, foliar potassium and uptake of nitrogen were investigated. Tallest plants were found in 4 dS.m-1 in Tall, and in 2 dS.m-1 in IP13. Foliar potassium was similar in Tall variety, while IP13 excluded the potassium, in order to reduce cellular ions. In Tall the 15N technique showed that 40-50% of plant N originated from the fertilizers, irrespective of saline conditions. Fresh weight was not different between 4 and 8 dS.m-1, in three cuts out of five in 2016 and 2017. Tall produced higher dry matter, especially under saline conditions. Best water use efficiency was in 4 dS.m-1 (10.4 kg.m-3 in Tall; 8.8 kg.m-3 in IP13). The plotting of dry matter production against salinity gave quadratic equations, with a peak at 5.6 dS.m-1 for IP13 and 7.1 dS.m-1 for Tall. Tall can be used for phytoremediation of soils in coastal areas, and as a forage crop.