Field performance of lentil (Lens culinaris Medik) affected by aging of different seed sizes and water stress

A sub-sample of lentil seeds was kept as bulk (S1) and the other seeds were separated by a sieve with four millimeters diameter. Consequently, three seed lots including bulk (S1), large (S2) and small (S3) seeds were obtained. Seeds of each size were divided into three sub-samples. A sub-sample was kept as control or high vigor seed lot (A1). The other two sub-samples with about 20% moisture content were artificially aged at 40°C for 2 and 4 days (A2 and A3, respectively). The field experiment was conducted as split plot factorial, based on RCB design in three replicates. Factors were irrigation treatments (irrigation after 70, 120 and 170 mm evaporation) in main plots, seed size (three levels) and seed aging (three levels) in sub-plots. Means of plant height, plant biomass and grain yield per unit area significantly decreased with decreasing water availability and seed vigor. The reduction of plant height due to seed aging was larger under severe water limitation, compared with other irrigation treatments. The highest branches per plant, plant biomass and grain yield per unit area were obtained by plants from large seeds (S2). The advantage of plants from large seeds in grain yield per unit area was more evident under limited irrigation conditions. Therefore, cultivation of large and vigorous seeds may somewhat alleviate the negative effects of drought stress on field performance of lentil.