Biological and genetical characteristics of hybrid maize Kneza 683A

The basic biological and economic properties of the hybrid maize Kneza 683A, created in Maize Research Institute - Kneza, R. Bulgaria by the method of interline hybridization are briefly described. The hybrid is acknowledged during year 1994 after two years variety-testing in SVTC (State Variety-Testing Commission) with standards American hybrids of maize H 708 and Ivana. During the period of testing, in year 1992 and 1993, in condition without irrigation, the average enlargement of yield on hybrid maize Kneza 683A (8 140 kg/ha), in comparison with hybrid maize H 708 (7 210 kg/ha) was 11, 42% and with hybrid maize Ivana (7610 kg/ha) was 6,51%. In conditions with irrigation, the average enlargement of yield on hybrid maize Kneza 683A (10 610 kg/ha), compared to first standard H 708 (9 890 kg/ha) was 6,78%, and compared to second standard Ivana (10 570 kg/ha) was 0,37%.The hybrid maize Kneza 683A, was examined in year 1994 and 1995 in R. Macedonia in conditions with irrigation and in R.Bulgaria, without irrigation. In comparison with standard american hybrid of maize H 708 (11 233 kg/ha), in our country the average enlargement of yield on the hybrid maize Kneza 683A (11 556 kg/ha) was 2,79%, and in R. Bulgaria was 8,04%. In the examination in year 2006 in R. Macedonia in conditions with irrigation, the average enlargement of yield on the hybrid maize Kneza 683A (11 600 kg/ha) in comparison with standard Kneza 630 (8 830 kg/ha) was 8,04% and hybrid Kneza 621 (11 200 kg/ha) was 3,44%. After examination from SVTC, in year 2007, the University "Goce Delcev" Stip, Institute for Southern Crops in Strumica in our country have registered the hybrid on the sort list. In 2008 was organised seed production on area of 1 ha and there was yield of 2000 kg/ha, which means that although the late sowing there was good yield of seed. In field conditions the hybrid is practically resistant to the economically important disease by the maize. The seed production of the hybrid maize Kneza 683A carry out with simultaneously sowing of the parental components using cytoplasmic male sterility (CMS) and fully restoration of fertility in hybrid generation. The hybrid maize Kneza 683A successfully shift the late Bulgarian and foreign hybrids (group 600 by FAO), since is more drought-resistant and considerably exceeds them by grain yield and silage mass from a unit of area.