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Genotype and environment effects on dynamics of harvest index during grain filling in sorghum

Hammer, G.L. and Broad, I.J. (2003) Genotype and environment effects on dynamics of harvest index during grain filling in sorghum. Agronomy Journal, 95 (1). pp. 199-206.

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Publisher URL: http://www.agronomy.org/

Abstract

An approach based on a linear rate of increase in harvest index (HI) with time after anthesis has been used as a simple means to predict grain growth and yield in many crop simulation models. When applied to diverse situations, however, this approach has been found to introduce significant error in grain yield predictions. Accordingly, this study was undertaken to examine the stability of the HI approach for yield prediction in sorghum [Sorghum bicolor (L.) Moench]. Four field experiments were conducted under nonlimiting water and N conditions. The experiments were sown at times that ensured a broad range in temperature and radiation conditions. Treatments consisted of two population densities and three genotypes varying in maturity. Frequent sequential harvests were used to monitor crop growth, yield, and the dynamics of HI. Experiments varied greatly in yield and final HI. There was also a tendency for lower HI with later maturity. Harvest index dynamics also varied among experiments and, to a lesser extent, among treatments within experiments. The variation was associated mostly with the linear rate of increase in HI and timing of cessation of that increase. The average rate of HIM increase was 0.0198 d-', but this was reduced considerably (0.0147) in one experiment that matured in cool conditions. The variations found in HI dynamics could be largely explained by differences in assimilation during grain filling and remobilization of preanthesis assimilate. We concluded that this level of variation in HI dynamics limited the general applicability of the HI approach in yield prediction and suggested a potential alternative for testing.

Item Type:Article
Corporate Creators:Department of Employment, Economic Development and Innovation (DEEDI), Agri-Science, Crop and Food Science
Business groups:Agri-Science, Crop and Food Science
Additional Information:Reproduced with permission from © American Society of Agronomy. Access to published version may be available via Publisher’s website.
Keywords:Anthesis to physiological maturity; emergence to anthesis; harvest index; leaf area index; grain filling; sorghum.
Subjects:Agriculture > Agriculture (General) > Agricultural meteorology. Crops and climate
Plant culture > Field crops > Sorghum
Science > Biology > Genetics
Science > Statistics > Simulation modelling
Deposited On:26 Mar 2004
Last Modified:25 Oct 2011 02:12

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