Effect of using selected growth regulators to reduce sunflower stand height

• DOI: 10.17221/213/2018-pse
• Publication Date: 2018-06-12T11:36:50Z
• Authors: Tomáš SPITZER; Jan BÍLOVSKÝ; Jan KAZDA
• Keywords: 0106 biological sciences; shortening; helianthus annuus; Plant culture; wind damage; shoot growth; phytohormone; 01 natural sciences; SB1-1110

Influence of plant growth regulators chlormequat chloride, chlormequat chloride + ethephon, ethephon, and mepiquat chloride + prohexadione-Ca + pyraclostrobin + ammonium sulphate (BAS67800F + BAS00800D) on decreasing sunflower height was evaluated. It was determined that sunflower height can be reduced by as much as 30 cm. In the case of BAS67800F + ammonium sulphate, there was a slight difference between application at BBCH 31-33 and BBCH 50-51, whereas for ethephon better application time was at BBCH 50-51. For chlormequat chloride, application at BBCH 31-33 was better, but height reduction did not endure until harvest. Flower head diameter shortly before harvest was not affected at any tested regulator. Flowering was delayed primarily at applications at BBCH 50-51.