GC22D-08:
Temperature, Sowing and Harvest Dates, and Yield of Maize in the Southwestern US

Tuesday, 16 December 2014: 12:05 PM
David Stack1, Boksoon Myoung1, Menas Kafatos1, Seung Hee Kim1 and Jinwon Kim2, (1)Chapman University, Orange, CA, United States, (2)University of California Los Angeles, Los Angeles, CA, United States
Abstract:
Since sowing date of maize is sensitive to climate variability and changes, it is of a practical importance to examine how sowing dates affect maize yields in various temperature regimes in the southwestern US. A 21-year (1991-2011) simulation of maize yield using Agricultural Production Systems sIMulator (APSIM) with observed meteorological forcing, shows that earlier sowing dates are favorable for higher yields primarily by increasing the length of growing season in cold mountaineous regions. In these regions, warmer conditions in the sowing period tend to advance the sowing date and then enhance yield. Over low-elevation warm regions, yields are less correlated with sowing dates and the length of growing season, perhaps because growing season temperatures are high enough for fast growth. Instead, in the warm regions, maize yields are sensitive to temperature variations during the late growing season due to adverse effects of extreme high temperature events on maize development.