Effect of sowing time on yield of ZP maize hybrids

Abstract

These experiments were conducted in the period 2003-2008 in Zemun Polje. Five hybrids were investigated in six sowing dates - on April 5th (Sd1), 15th (Sd2) and 25th (Sd3), and on May 5th (Sd4), 15th (Sd5) and 25th (Sd6). Three unfavorable years for the maize production were distinguished in this period: 2003 with 210.0 mm, 2007 with 290.1 mm and 2008 with 224.6 mm of precipitation; 2005 was moderately favorable, with 387.4 mm of precipitation. Two years were favorable for the maize production, both in terms of precipitation amounts and distribution: 2004 with 427.6 mm and 2006 with 417.1 mm. The highest average yield was achieved in Sd2 (11.21 t/ha - 100%). On the other April sowing dates, average yield was lower: on Sd1 - 11.04 t/ha (98.48%), on Sd3 - 10.97 (97.86%). The effects of the May sowing dates were significantly lower comparing with the Sd2: Sd4 - 10.53 t/ha (93.93%), Sd5 - 10.46 t/ha (93.31%) and Sd6 - 9.71 t/ha (86.62%). The highest yielding hybrid was ZP 684 (11.16 t/ha). These results doubtlessly point to the mid April sowing date as an optimum for maize in Serbia.

Vreme setve spada u faktore koji imaju značajan uticaj na nivo prinosa kukuruza. Optimalan rok setve bi se mogao definisati kao vreme setve kojim se obezbeđuje nicanje kukuruza u najpovoljnijem trenutku kako bi se maksimalno iskoristili uslovi vegetacionog perioda i formirao što veći prinos. Ova ispitivanja obavljena su u periodu od 2003. do 2008. godine u Zemun Polju. Ispitivano je pet hibrida u šest rokova setve: tri u aprilu (5., 15. i 25.) i tri u maju (5., 15. i 25.). U toku ispitivanja, tri godine su bile nepovoljne za proizvodnju kukuruza: 2003. sa 210,0 mm padavina, 2007. sa 290,1 mm i 2008. sa 224,6 mm. Jedna godina (2005) je imala umereno povoljne uslove - 387,4 mm padavina. Dve godine su bile povoljne u smislu količine i rasporeda padavina: 2004 sa 427,6 mm i 2006. sa 417,1 mm. Najviši prinos ostvaren je pri setvi kukuruza 15. aprila (11,21 t/ha), koji je uzet kao referentna vrednost (100,00%). U ostalim rokovima setve u aprilu prinos je bio niži: Sd1 11,04 t/ha (98,48%), Sd3 10,97 t/ha (97,86%). Setvom u maju, ostvareni su statistički veoma značajno niži prinosi u odnosu na referentnu vrednost: Sd4 - 10,53 t/ha (93,93%), Sd5 - 10,46 t/ha (93,31%) i Sd6 - 9,71 t/ha (86,62%). Hibrid ZP 684 imao je najviši prosečan prinos (11,16 t/ha), dok su svi ostali prinosi bili niži: ZP 680 za 8,23%, ZP 434 za 7,71%, ZP 580 za 4,75% i ZP 578 za 3,05%. Ove činjenice nedvosmisleno ukazuju da je setva kukuruza u aprilu, a posebno polovinom ovog meseca, najpovoljniji rok setve u Srbiji.