Hybrid-maize—a maize simulation model that combines two crop modeling approaches

Abstract

A new maize (Zea mays L.) simulation model, Hybrid-Maize, was developed by combining the strengths of two modeling approaches: the growth and development functions in maize-specific models represented by CE-RES-Maize, and the mechanistic formulation of photosynthesis and respiration in generic crop models such as INTERCOM and WOFOST. It features temperature-driven maize phenological development, vertical canopy integration of photosynthesis, organ-specific growth respiration, and temperature-sensitive maintenance respiration. The inclusion of gross assimilation, growth respiration and maintenance respiration makes the Hybrid-Maize model potentially more responsive to changes in environmental conditions than models such as CERES-Maize. Hybrid-Maize also requires fewer genotype-specific parameters without sacrificing prediction accuracy. A linear relationship between growing degree-days (GDD) from emergence to silking and GDD from emergence to physiological maturity was used for prediction of day of silking when the former is not available. The total GDD is readily available for most commercial maize hybrids. Preliminary field evaluations at two locations under high-yielding growth conditions indicated close agreement between simulated and measured values for leaf area, dry matter accumulation, final grain and stover yields, and harvest index (HI). Key areas for further model improvement include LAI prediction at high plant density, and biomass partitioning, carbohydrate translocation, and maintenance respiration in response to above-average temperature, especially during reproductive growth. The model has not been evaluated under conditions of water and/or nutrient stress, and efforts are currently in progress to develop and validate water and nitrogen balance components for the Hybrid-Maize model.

Calibration of a crop model to irrigated water use using a genetic algorithm

“…These estimates are similar to those reported by others from field or growth chamber research or currently being used in other crop simulation models. Reported corn TG values range from 7.2 to 8 • C (Hesketh and Warrington, 1989;Yang et al, 2004). For grain sorghum, a TG of 8.5 • C is reported by both Craufurd et al (1998) and Hammer et al (1989) while SORKAM (Rosenthal et al, 1989) uses 7 • C as a base temperature, all of which are marginally higher than the 6.2 • C estimated here.…”

“…Reported corn WA values ranged from 14.5 to 43.3 t ha −1 MJ −1 m −2 (Cantarero et al, 1999;Muchow, 1990;Hammer et al, 1998;Kiniry et al, 2004;Idinoba et al, 2002;Sinclair and Muchow, 1999) with the range being attributed to differences in environmental conditions and calculation method. Reported WA specifically for use in crop models for corn have ranged from 43.3 in CERESMaize (Yang et al, 2004), 39.8 for ALMANAC (Kiniry et al, 2004) and 35.0 to 40.0 t ha −1 MJ −1 m −2 for CropSyst (Stockle et al, 2003).…”

“…Several researchers have reported optimum temperatures for growth in corn to be 22.5 • C (Wilhelm et al, 1999) and 25 • C (Grzesiak et al, 1981). CERES-Maize uses 26 • C as the optimum temperature for growth (Jones et al, 1986) while Yang et al (2004) currently use 30 • C in the Hybrid Maize model for maximum growth and assimilation. Our optimized corn temperature for optimum growth is within the range of the values used by other simulation models and slightly higher than those reported from research trials.…”

Analysis of Adaptive Response of Maize (<i>Zea mays</i>) Varieties from DR-Congo to Water Stress

“…Several studies have described to the effects of drought on plants [5] [6]. The effects drought on an annual scale depends on its starting period in relation to the crop stage and its duration.…”

“…The effects drought on an annual scale depends on its starting period in relation to the crop stage and its duration. Water stress affects several physiological and morphological traits such as leaf temperature regulation [6] [7], stomatal conductance, leaf area [8], as well as photosynthesis [5] [9].…”