Analysis of yield components in maize (Zea mays L.) hybrids across planting dates is limited. Research was conducted in 2013 and 2014 at Mead, Nebraska, United States with the objective to determine the influence of year, hybrid, drought tolerance type, and maturity classification across planting dates on maize yield and yield components. Early-and late-maturity DroughtGard (with CspB transgene) maize hybrids, and a late-maturity non-DroughtGard maize hybrid were planted at three dates in each

more »

... ear. Average maize yields were 10.8 ± 1.3 t/ha in 2013 and 13.6 ± 1.6 t/ha in 2014 with little difference across planting dates. Yield for 109 to 114 CRM (610 to 650 FAO maturity) hybrids was 13 ± 1.9 t/ha compared to 11 ± 1.6 t/ha for 97 to 100 CRM (450 to 480 FAO maturity) hybrids, and similar yields for late DroughtGard and non-DroughtGard hybrids were found. The yield of the earlymaturity DroughtGard hybrids was associated most with direct effects of the number of ears per square meter (R = 0.53**) and kernels per ear (R = 0.44**) while the latematurity DroughtGard hybrids were affected most by the direct effects of ears per square meter (R = 0.54**) and kernel weight (R = 0.57**). Yield components accounted for most yield differences between hybrids with different maturity classifications. Yield component compensation which occurred between DroughtGard and non-DroughtGard hybrids led to similar grain yields across planting dates. Postoji relativno malo podataka o utjecaju različitih rokova sjetve na komponente prinosa zrna kukuruza (Zea mays L.). Istraživanje s ciljem određivanja utjecaja klimatskih prilika i svojstava hibrida na prinos i komponente prinosa kada se hibridi siju u različitim rokovima, provedeno je u 2013. i 2014. godini u Mead-u, Nebraska, SAD. Rani (FAO 450 i 480) i kasni (FAO 630 i 650) hibridi kukuruza s povećanom tolerantnošću na sušu (DroughtGard) te kasni (FAO 610) hibrid kukuruza slabije tolerantnosti na sušu (non-DroughtGard) posijani su u 3 različita roka u obje godine istraživanja. Prosječni prinos zrna iznosio je u 2013. godini 10,8 ± 1,3 t/ha, a u 2014. godini 13,6 ± 1,6 t/ha i malo se razlikovao između rokova sjetve. Prinos zrna kasnih DroughtGard i non-DroughtGard hibrida (109, 112 i 114 CRM) bio je 13 ± 1,9 t/ha, a ranih DroughtGard hibrida (97 do 100 CRM), 11 ± 1,6 t/ha, pri čemu su kasni DroughtGard hibridi i non-DroughtGard hibrid ostvarili slične prinose. Najveći direktni utjecaj na prinos ranih DroughtGard hibrida pokazali su broj klipova po metru kvadratnom (R = 0,53**) i broj zrna na klipu (R = 0,44**), a kasnih DroughtGard hibrida, broj klipova po metru kvadratnom (R = 0,54**) i masa zrna (R = 0,57**). Na razlike u prinosu zrna između hibrida koji su pripadali različitim vegetacijskim skupinama, najviše su utjecale komponente prinosa. Slični prinosi zrna između DroughtGard i non-DroughtGard hibrida koji su ostvareni u različitim rokovima sjetve, nastali su zbog razlika u kompenzaciji komponenata prinosa.