The paper presents the results of a triennial study of the sowing system influence on the yied, grain weight per head, plant set per ha and of the grain moisture of a medium-early sunflower hybrid. Standard sowing was performed with the PSK OLT sowing machine at a row spacing amounting to 70 cm, while a twin row sowing was performed with the MaterMacc Twin Row-2 sowing machine at a row spacing of 22×48 cm. Both sowing machines were adjusted according to the ISO standard 7256/1 and 7256/2, with a high QFI index (PSK OLT: 96.32 %; MaterMacc Twin Row-2: 93.93 %). The research was conducted at the Gorjani Experimental Field on psudogley bearing the textured markings of a silty loam, with a weak acid reaction and a small amount of humus. An analysis of variance determined a statistical significance of the sowing system on the grain yield and the grain mass per sunflower head. Sowing in twin rows achieved the higher yields for all three research years : 19.59% in 2017, 19.11% in 2018, and 18.45% in 2019. Plant density was not statistically significantly affected by the sowing systems and vegetation year, but the grain moisture was statistically significantly different between the analyzed research years.
Keywords: sunflower, standard sowing, twin row sowing, yield, sowing machine
Vjekoslav Tadić, University of Josip Juraj Strossmayer of Osijek, Faculty of Agrobiotechnical Sciences Osijek, Vladimira Preloga 1, 31000 Osijek, Croatia, email@example.com