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.
Helianthus annuus; shoot growth; phytohormone; shortening; wind damage
Balodis O., Gaile Z. (2009): Influence of agroecological factors on winter oilseed rape (Brassica napus L.) autumn growth. In: Proceedings of the 15th Annual International Scientific Conference Research for Rural Development. Jelgava, University of Agriculture.
Baylis A. D., Dickst J. W. (1983): Investigations into the use of plant growth regulators in oil-seed sunflower ( Helianthus annuus L.) husbandry. The Journal of Agricultural Science, 100, 723- https://doi.org/10.1017/S0021859600035516
Bianco J., Daymond J., LePage-Degivry M.T. (1996): Regulation of germination and seedling root growth by manipulations of embryo GA levels in sunflower. Acta Physiologiae Plantarum, 18: 59–66.
KOUTROUBAS S.D., DAMALAS C.A. (2015): Sunflower response to repeated foliar applications of Paclobutrazol. Planta Daninha, 33, 129-135 https://doi.org/10.1590/S0100-83582015000100015
Koutroubas Spyridon D., Damalas Christos A. (2016): Morpho-physiological responses of sunflower to foliar applications of chlormequat chloride (CCC). Bioscience Journal, , 1493-1501 https://doi.org/10.14393/BJ-v32n6a2016-33007
Koutroubas S.D., Vassiliou G., Damalas C.A. (2014): Sunflower morphology and yield as affected by foliar applications of plant growth regulators. International Journal of Plant Production, 8: 215–230.
Koutroubas S.D., Vassiliou G., Fotiadis S., Alexoudis C. (2004): Response of sunflower to plant growth regulators. New directions for a diverse planet. In: Proceedings of the 4th International Crop Science Congress, 26 Sep–1 Oct 2004, Brisbane, Australia.
Kuryata V. G., Poprotska І. V., Rogach Т. І. (2017): The impact of growth stimulators and retardants on the utilization of reserve lipids by sunflower seedlings. Regulatory Mechanisms in Biosystems, 8, 317-322 https://doi.org/10.15421/021750
Lovett J. V., Campbell Desnee A. (1973): Effects of CCC and Moisture Stress on Sunflower. Experimental Agriculture, 9, 329- https://doi.org/10.1017/S0014479700010127
Polat T., Ozer H., Öztürk E., Sefaoğlu F. (2017): Effects of mepi-
quat chloride applications on non-oilseed sunflower. Turkish Journal of Agriculture and Forestry, 41: 472–479.
Rademacher Wilhelm (2000): G ROWTH
: Effects on Gibberellin Biosynthesis and Other Metabolic Pathways. Annual Review of Plant Physiology and Plant Molecular Biology, 51, 501-531 https://doi.org/10.1146/annurev.arplant.51.1.501
Rajala A., Peltonen-Sainio P. (2001): Plant Growth Regulator Effects on Spring Cereal Root and Shoot Growth. Agronomy Journal, 93, 936- https://doi.org/10.2134/agronj2001.934936x
Spitzer T., Matušinský P., Klemová Z., Kazda J. (2011): Management of sunflower stand height using growth regulators. Plant, Soil and Environment, 57, 357-363 https://doi.org/10.17221/75/2011-PSE
Wanderley Christina da Silva, Rezende Roberto, Andrade Carlos Alberto Bastos (2007): Efeito de paclobutrazol como regulador de crescimento e produção de flores de girassol em cultivo hidropônico. Ciência e Agrotecnologia, 31, 1672-1678 https://doi.org/10.1590/S1413-70542007000600011
Weiss E.A. (2000): Oilseed Crops. 2nd Edition. London, Blackwell Science.