RESPONSE OF TRITICALE GRAIN-YIELD AND YIELD COMPONENTS TO NUMBER OF CUTTINGS IN A MEDITERRANEAN ENVIRONMENT

In six field experiments conducted over 2 years, the effect of one or two cuttings on grain yield of triticale (x Triticosecale Wittmack) we re investigated. In addition, the relationships between triticale grai n yield its components were analysed. Grain yield of the uncut plots i nvariably exceeded the plots with one or two cuttings, regardless of t he environment or year. The reductions in grain yield caused by one cu tting ranged from 27% to 60% under rainfed conditions and 18% to 20% u nder irrigation. With two cuttings the reduction was 45% to 70% for ra infed, and 35% to 48% for irrigated conditions. The yield components w hich most influenced grain yield of triticale under cutting treatment were the number of ears m-2 in all six experiments and the number of g rains per ear under rainfed conditions. At the rainfed sites in 1989 c uttings diminished the number of ears m-2 mainly by increasing plant m ortality. Nevertheless, at the rainfed sites of 1990 and at the irriga ted site of both years, the reduction in the number of ears m-2 with c uttings was due principally to a lower survival of tillers per plant.