Sowing Depth on Emergence of Different Safflower Genotypes (Carthamus tinctorius L.)

The objective is to evaluate the germination of four different safflower genotypes at six sowing depths. The study was carried out in the experimental field of the Western Paraná State University, in Cascavel, in two stages- in protected environment and in the field. In a protected environment, the experimental units were vessels with a 0.10 m diameter and a 0.20 m height, maintaining a 0.05 m water level. Using 10 seeds per vase, filled with substrate composed of vermiculite and macronutrients. For the field, the experimental units were divided in 3 blocks with 1.50 m rows, with 30 seeds spaced in 0.05 m, spacing between 0.30 m rows, totalizing blocks of 6 m by 1.8 m. For the analysis, we performed a 5 × 4 factorial, with four replicates being 5 depths (0.02; 0.04; 0.06; 0.08 and 0.10 m) and 4 genotypes, with analysis of percentage, speed index, mean time and average speed of emergence and morphometric characteristics of the plant. High emergence rates occurred for the lowest sowing depths, ranging from 60 to 80%. At the greatest depths, the averages were below 50%. At 0 m depth, there was no emergence for both sites. For the emergence speed index, the averages ranged from 0.47 to 1.34 seeds per day for the protected environment and 2.26 to 16.42 seeds per day for the field experiment. For both sites, the IMA-2103 genotype had the best performance for the evaluated indices. The depths indicated for planting are 2 and 4 cm.