Effect of two different plant growth regulators on production traits of sunflower

Abstract

The plant growth regulators (PGR) are an organic compounds that modify plant physiological processes. PGR applied to the field crops promotes photosynthesis, stimulates plant growth, improves flowering and protects plants against unfavourable year weather conditions. Listed is an assumption to the yield of high quality. The effects of year weather conditions, biological material (hybrids) and foliar application of two different PGR (Terra-Sorb® Foliar – containing free amino acids and Unicum® – containing Abiestins®) on the yield-forming parameters, seed yield and the oil content in seeds of three selected hybrids of sunflower (NK Brio, NK Neoma, NK Ferti) were studied in this paper. The field poly-factorial experiments were realized during two growing seasons of 2012 and 2013. The experimental area is situated in the maize-growing region (climatic region: warm; climatic sub-region: mild dry or dry; climatic zone: warm and dry, with mild winter and long sunshine) and soil is silt loam Haplic Luvisol. The climatic conditions in chosen experimental years were different in quantities and distribution of precipitation at main growth period of sunflower plants (June to August) and allows evaluating the yield stability between used hybrids and foliar treatments. The results showed that the application of selected PGR has contributed to an increase of sunflower seed yield, mainly through increase the weight of thousand seeds (rp = 0.761; P < 0.001). Similarly, oil content in seeds was significantly higher in treatments with PGR, especially with preparation Terra-Sorb® Foliar containing free amino acids. The study describes the relationship between quality (oil content in seeds) and quantity (seed yield) of sunflower production (rp = ‒0.41; P < 0.01). Results showed that PGR can be an important rationalization tool of the sunflower cultivation technology.