Breeding and selection of inbred lines ZPPL 146 and ZPPL 159 and hybrids developed from them (ZP 633, ZP 735 and ZP 737, primarily intended for feed) have been carried out for almost three decades. These inbred lines and hybrids have high nutritive values, they are rich in pigment properties, have efficient photosynthesis and other relevant parameters characteristic for standard hybrids. Observed maize hybrids are very important as carbohydrate rich nutrients. Feed produced from these hybrids is of high productivity and high quality. Due to their high productivity of total dry matter per area unit, these hybrids represent one of the most important forage products. Moreover, the study presents the importance of the chemical composition of maize hybrid grain in essential biogenic substances particularly pigments that have antioxidant properties.

IzvodU radu su prikazani rezultati ispitivanja uticaja rastućih količina azota na produktivnost genotipova soje u različitim agroekološkim uslovima. Istraživanja su obavljena na dva lokaliteta, u Institutu za kukuruz "Zemun Polje" (zemljište tipa černozem) i u selu Kloka (privatan posed, zemljište tipa gajnjača) -donja Jasenica 2009. godine. Poljski mikroogledi izvedeni su metodom razdeljenih parcela (split plot), u četiri ponavljanja.Dobijeni rezultati pokazuju da su se, u proseku za oba tipa zemljišta, masa zrna po biljci i prinos povećavali upotrebom do 60 kg ha -1 za 7,1 odnosno 7,5%. Varijanta đubrenja sa 90 kg ha -1 dala je niže vrednosti ispitivanih parametara u odnosu na osnovu-fon (P60K60) za 5,4% odnosno 5,7%.

The aim of this study was to observe direct and joint effects of three factors (genotypes, ecological environmental conditions and the applied crop density) on the level of defoliation intensity and yield. Three inbred lines (G) of maize (G1–L217RfC, G2–L335/99 and G3–L76B004) were used in the study. The trials were performed in two years (Y) (Y1 = 2016 and Y2 = 2017) and in two locations (L) (L1 and L2) under four ecological conditions of the year–location interaction (E1–E4) and in two densities (D1 and D2) (50,000 and 65,000 plants ha−1). Prior to tasselling, the following five treatments of detasseling and defoliation (T) were applied: T1—control, no leaf removal only detasseling, T2–T5—removal of tassels and top leaves (from one to four top leaves). The defoliation treatments had the most pronounced effect on the yield reduction in G1 (T1–Tn+1… T5), p < 0.05. The ecological conditions on yield variability were expressed under poor weather conditions (E3 and E4), while lower densities were less favorable for the application of defoliation treatments. The result of joint effects of factors was the lowest grain yield (896 kg/ha) in G3 in the variant E3D1 for T2 and the highest grain yield (11,389 kg/ha) in G3 in the variant E2D2 for T1. The smallest effect of the defoliation treatment was on the kernel row number (KRN).