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ABSTRACT
Crop simulation models have potential for evaluating the effects of plant traits leading to the design of a crop ideotype for a target environment. The objective of this study was to design a large-seeded and a small-seeded peanut (Arachis hypogaea L.) ideotype for Thailand using the cropping system model (CSM)-CROPGRO-Peanut model. The sensitivity analysis was performed, utilizing the cultivar coefficients of a large-seeded line (L-line) and a small-seeded peanut line (S-line) as initial values, by changing the value of each coefficient for consecutive runs of model simulation over 10 locations for three growing seasons and 30 yr. The durations of the developmental phases were adjusted first to maximize seed yield within a fixed life cycle duration. Then the growth and the partitioning parameters were adjusted to maximize biomass and seed yield, respectively. The final outcomes were the designed peanut ideotypes with the following characteristics: early flowering, long duration from beginning seed to maturity and from first flower to end of leaf expansion, large leaf size, high specific leaf area, high leaf photosynthetic rate, high partitioning of assimilates to pods and seeds, more determinate growth habit, and moderately long seed filling duration. Seed yield improvements of 4.03 and 52.91% were achieved over the L- and S-lines, respectively. This study demonstrates the capability of the CSM-CROPGRO-Peanut model for evaluating the effects of different genetic traits and for designing a crop ideotype for a target environment.
Abbreviations: CSM, cropping system model; DSSAT, Decision Support System for Agrotechnology Transfer; EMFL, the number of photothermal days from emergence to flowering; FLLF, the number of photothermal days from first flowering to end of leaf expansion; FLSD, the number of photothermal days from first flowering to first seed; FLSH, the number of photothermal days from first flowering to first pod; HI, harvest index; LFMAX, the maximum leaf photosynthetic rate; L-ideotype, large-seeded ideotype; L-line, large-seeded line; L-mod, modified largeseeded line; LAI, leaf area index; NAR, net assimilation rate; Nc.Ac., North Carolina Accession; PD, photothermal day; PODUR, the photothermal time required for a cultivar to reach final pod load; S-ideotype, small-seeded ideotype; S-line, small-seeded line; S-mod, modified smallseeded line; SDPDV, average seed number per pod; SDPM, the number of photothermal days from first seed to physiological maturity; SFDUR, seed filling duration...