Kernel growth and quality traits of maize hybrids with different end-use at contrasting post-flowering thermal environments

MAYER, L.I.; ORDÓÑEZ, R.A.; SAVIN, R.; CIRILO, A.G.; MADDONNI, G.A.

Bento Gonçalves -RS

Congreso; 6th International Crop Science Congress; 2012

International Crop Science Society

Even though the night time warming is the major trend of world climate change, many productive areas are also subjected to an increment of the mean daily maximum temperature. Knowledge acquisition on the impact of thermal environment on maize kernel weight (KW) and its relative structural and chemical composition would be valuable to maintain or improve grain yield and/or grain quality. We conducted two field experiments (Exp.1 and Exp.2) during 2009-10. Exp.1 was carried out at FA-UBA, (34°35´S, 58°29´W; 26masl) including 3 contrasting grain hybrids (Flint: Mill522, Semi-dent: 2A120HX, Pop-corn: P802) grown under two temperature regimes (control and heated) around mid-day during the effective grain-filling period. Heating (33?42°C at ear level) was applied along two 15-days periods (ES: early stage, LS: late stage). Exp.2 combined a grain hybrid (Pioneer 31N28) and a forage one (Lapopi) grown under 2 nitrogen supplies (non-fertilized and 200 kg N ha−1) at Algerri (41°49´N, 0°38´E; 345masl) and Montferrer (42°20´N, 1°25´E; 820masl). Post-flowering mean temperature at Algerri was 4-6°C lower than at Montferrer. Warmer thermal environments during the active kernel growth, due to either a manipulative treatment (Exp.1) or a geographic difference (Exp.2), determined lighter KWs (between -10 and -15%), which were always promoted by a shorter (p