Interaction between paclobutrazol and gibberellic acid, plant growth and seedling quality of tomato

This study was carried out as two replications. The effects of different concentrations of paclobutrazol (0, 25, 50 100, 200 and 400 ppm as spray and seed, 0, 5, 10, 20, 40, and 80 ppm for standard application), application type (spray, seed, and standard application) and application time (first period, second period, and in both periods) in the second year and the effects of different concentrations of paclobutrazol (0, 2.5, 5, 10, 20, 40 ppm with standard application) application time (first period, second period, and in both periods) and the amount (0, 2, 4, 6 ml) on "Alcapone" F1 tomato variety (Lycopersicon esculentum) in terms of seedling length, hypocotyl length, stem diameter, leaf number, seedling fresh and dry weight, root fresh and dry weight, seedling % dry matter, root % dry matter, biomass, root length, internodes length, and the amount of residues on seedling and fruit were investigated in this research. In the seed application, the seeds were soaked with different paclobutrazol solutions for 4 hours and sown. Paclobutrazol applications were carried out in spray and standard application twice when the cotyledon leaves of the seedlings became parallel with the ground (7 days after the sowing the seed) and the true leaves appeared (14 days after sowing the seed). The control plants were provided with distilled water. As a result, paclobutrazol application controlled seedling length at an important level. The increased paclobutrazol concentration caused a decrease in seedling length. Application of paclobutrazol with irrigation water had been more effective than the spray application and seed application in terms of seedling quality. The best seedling quality was obtained by applying the standard method of paclobutrazol twice with 40 ppm, 2ml, in which the cotyledon leaves were parallel to the ground and the first true leaves were seen. No paclobutrazol residue that could be harmful for human and environment health was encountered in neither replications of the study.