Olive mill waste water spreading in southern Tunisia: effects on a barley crop: (Hordeum Vulgare. L)

Abstract

This study is designed to assess the impact of different concentrations of Olive Mill Waste Water (OMWW) on the phenological behavior of a local barley variety (Arthaoui: Hordem vulgare L.) during three consecutive crop years. For developing this work, a complete randomized block design was installed with four amounts of OMWW equivalent to 0 m³/ha (T0), 15 m³/ha (T1), 30 m³/ha (T2) and 45 m³/ha (T3), a local barley variety (Arthaoui) and 3 replications. The results showed a highly significant reduction as well as of the tiller and ears number compared to the control according to the increase of OMWW concentration especially for the highest amounts either T2 and T3 respectively 30 m³/ha and 45 m³/ha. This reduction was although observed but it was less accentuated for the treatment with an amount of 15 m³/ha compared to the other rates. In addition, barley yield components were negatively affected by “OMWW” in particular yields plots that received higher doses as 30 m³/ha and 45 m³/ ha. Obviously, the straw and seed yield are catastrophically affected with relatively different degrees depending on the dose applied but also on the cumulative effect of successive applications during the three years of study. Indeed, richness of these effluents on salts especially in sodium and chlorides, on polyphenols and other compounds with variable toxicity is causing physiological disturbances that are negatively reflected at different phenological stages of barley as tillering, stem elongation and heading giving the catastrophic results in terms of seed yield. Keywords: OMWW, Barley, tiller number, ear number.