Effect of pre- and post-anthesis water limitation on some agronomic characteristics, yield and yield components of hexaploid triticale (X Triticosecale wittmack)

To study the effect of pre-and post-anthesis water limitation on agronomic characteristics, grain yield and it’s components of hexaploid triticale (X Triticosecale wittmack), a field experiment was conducted in split plot design using RCBD, with three replications in Mashhad Agricultural Research Station in two successive cropping seasons (2001-2003). Main plots (L) were water limitation in different growth stages with 6 levels (L1: optimum conditions, L2: Water Limitation from seedling to double ridge stage(vegetative pre-anthesis), L3: Water Limitation from double ridge to anthesis stage (reproductive pre-anthesis), L4: Water limitation in post-anthesis stage, L5 and L6 received rainfall during cropping seasons with only one supplementary irrigation at anthesis or milky stage, respectively). Five hexaploid triticale genotypes (Juanillo 92 and four promising lines) were assigned to sub plots. Results showed that water deficit in vegetative pre-anthesis stage (L2) reduced grain yield, No. of grains per spike, kernels weight per spike, No. of grains per square meter, total dry weight at anthesis and seed set percentage in comparison to optimum condition (L1). However, grain yield in pre-anthesis water stress reduced less than L3 and L4 treatments. Out of four treatments (L1, L2, L3 and L4), water stress in double ridges to anthesis (L3) had the highest negative effect on grain yield (in comparison to L1 and L2 47% and 30% less grain yield, respectively) and it’s components. Water stress from double ridge to anthesis also produced minimum No. of grains per square meter (in comparison to L1 and L2 52% and 39% less grain per square mater, respectively). However, 1000 kernel weight was increased in comparison to L1 and L2. Water stress in post-anthesis (L4) had negative effect on grain yield, 1000 kernel weight, days to physiological maturity, grain filling duration and No. of grains per square meter. Irrigation at anthesis (L5) was more effective than milky stage (L6) under natural conditions (without using rain shelter). Genotypes No.3 (Ardi-1/Topo1419//Erizo-9 CTY87-852) and No. 4 (Cargo/Ibex//Civet#2) had the lowest water stress susceptibility index (SI) and high grain yield under optimum conditions.