Photothermal impact on maize performance: a simulation approach

Crop simulation models can be robust tools to help develop an understanding of a plant's response to a given set of weather and soil conditions and the interaction with various crop management scenarios. This study was conducted to simulate controlled-environment conditions using the CERES-Maize model to obtain a quantitative understanding of different maize cultivar responses to a range of temperature and photoperiod combinations. Nine-day length treatments ranging from 8 It to 16 h, together with minimum temperature (T-min) treatments ranging from 5 degreesC to 35 degreesC and maximum temperature (T-max) treatments ranging from 15 degreesC to 45 degreesC, were applied to nine maize (Zea mays L.) cultivars. Increasing T-max up to 35 degreesC at any given T-min enhanced biomass production for all cultivars; a further increase of T-max above 35 degreesC had a negative impact on biomass. Increasing temperature also accelerated developmental rates for both anthesis and maturity. An identical mean temperature obtained from various T-min or T-max combinations resulted in a different crop performance, indicating specific responses to either high or low values of T-min or T-max. The highest potential yield levels were found at rather low temperature combinations of a T-max of 20 degreesC and a T-min of 10 degreesC; yield varied from 10.2 t ha(-1) to 23.2 t ha(-1) for these conditions, mainly caused by extremely long growing seasons. Photoperiod showed no effect across all treatments, due to a low sensitivity to changes in day length for the cultivars used in this study. It can be concluded that crop simulation models can help provide an understanding of weather and crop interactions for a complex environment that are rather difficult to conduct under control led-environment conditions and are resource intensive. (C) 2004 Elsevier B.V. All rights reserved.