Hydroponic growth of Chrysantemum in expanded clay for cut flower

Abstract

To determine the ideal conditions for hydroponically grown cut 'Yellow Polaris' in expanded clay (hardened in nutrient solution) as well al its efficiency as compared to the conventionally grown system, experiments were conducted in the fall/winter and spring/summer seasons, respectively. Four sizes of expanded clay (grain sizes 4-10, 4-13, 10-13, 13-20 mm diameter) were saturated twice or three tirnes a day with complete nutrien solution (14,49; 1,95;12,9;1,51;1,00 e 0,5 mrnol/1 de N; P; K; Ca; Mg e Se 30; 5; 50; 40; 2 e 0,1 µmol// de B; Cu; Fe; Mn; Zn e Mo respectivelly). The plants grown in expanded clay in the fall/ winter seasons had fresh and dry matter production, number of inflorescences, and stem height statistically significantly higher values than those grown in the conventional production system. These characteristics were improves when planting ocurred at the three smallest expande clay grain sizes and saturation with nutrient solution was done twice a day. The plants results from grown in expanded clay at different grain size during the spring/summer were similar to those grown in the conventional production system. Other factors, such as planting season, temperature and moisture may have limited the nutrient absorption by the plants grown in hardened expanded clay.