Extension of areas cultivated with sunflower within our country during the last decade to over 800 ths. Ha and up to over 1 million Ha in 1999, as consequence of the high demand on the internal and external market, is representing a real danger. This is due to the fact that the 6-7 years return period for the same lot can no more be observed. Such a return period is required due to the continuance in the soil of the several pathogen agents as Plasmopara helianthi Novot, Sclerotinia sclerotiorum (Lib) de Bary, Sclerotinia bataticola Taub. Research has been performed on a brown luvic soil. The precursory culture has been wheat. The experiments have been tri-factorial, factor A has been the cultivated hybrid (a 1 – RP64F50 –; a 2 PR64A89, factor B – the agricultural fond (b 1 – N 50 P 100 K 100 ; b 2 – N 100 P 100 K 100 ), and factor C cultivation density (c 1 – 45.000 plants/ha; c 2 -50.000 plants/ha). Experiences have been performed during the experimental cycle 2010-2012. The studied hybrids have genetic strength to blight attacks (Plasmopara helianthi), species 304, already existing in our country. These hybrids are tolerant to Phomopsis and Sclerotinia, resistant to fall and breakage, resistant to dryness and heat, highly productive and having high content of oil. The crop results are revealing the superiority of PR64A89 hybrid that has overcome by 9% the crop of PR64F50.nIncreasing of nitrogen dose from N 50 to N 100 on the constant usage of P 100 K 100 has increased the crop by 14%. Increasing the density from 45,000 to 50,000 plants/ha has lead to crop decreasing by 12%. Thousand seeds mass has been negatively influenced by increasing the density, on both fertilization levels, on both hybrids, oscillating between 58 and 61 g. at PR64F50 hybrid and between 60 and 65 g to PR64SA89 hybrid. A similar tendency has been manifested and the hectoliter mass has been situated between 43 – 45 kg/hl at PR64F50 and between 38-43 kg/hl at PR64A89. The content of oil in PR64F50 hybrid has decreased following the doubling of nitrogen dose from 45 to 42% and to PR64A89 46-44 %.

sunflower, technological links

Presentation: oral