Journal article
A simple method to estimate harvest index in grain crops
Field crops research, Vol.103(3), pp.208-216
2007
Handle:
https://hdl.handle.net/2376/110495
Abstract
Several methods have been proposed to simulate yield in crop simulation models. In this work, we present a simple method to estimate harvest index (HI) of grain crops based on fractional post-anthesis phase growth (
f
G
=
fraction of biomass accumulation that occurred in the post-anthesis phase). We propose that HI increases in a linear or curvilinear fashion in response to
f
G. The linear model has two parameters, the intercept (HI
o) and the slope (
s). The curvilinear model was assumed to be monotonic: HI
=
HI
x
−
(HI
x
−
HI
o)
·
exp(
−k·
f
G); where HI
x is the asymptote, HI
o is the intercept and
k is a constant modulating the rate of HI increase. The models were tested for barley (Pullman, WA and Uruguay), wheat (Pullman, WA) and sorghum (Australia). A positive relationship between HI and
f
G was in general evident. For barley, the linear model appropriately represented the response of HI to
f
G
, with both HI
o and
s in the vicinity of 0.3. For wheat HI
o and
s were 0.34 and 0.21, respectively, but the curvilinear model yielded a slightly better fitting than the linear model. For sorghum, both linear and linear-plateau models fitted data reasonably well. It is shown that the models work well in crops source-limited or source-sink co-limited during grain filling, but in sink-limited conditions the magnitude of the limitation needs to be characterized to compute HI. A major advantage of this method is that the parameters of the linear or curvilinear model are readily calibrated from yield data and biomass measurements at anthesis and harvest.
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Details
- Title
- A simple method to estimate harvest index in grain crops
- Creators
- Armen R Kemanian - Blackland Research and Extension Center, Texas Agricultural Experiment Station, Temple, TX 76502, USAClaudio O Stöckle - Biological Systems Engineering Department, Washington State University, Pullman, WA 99164-6120, USADavid R Huggins - USDA-ARS, Washington State University, Pullman, WA 99164-6421, USALuis M Viega - Departamento de Biología Vegetal, Facultad de Agronomía, Universidad de la República, Av. Garzón 780, Montevideo 12600, Uruguay
- Publication Details
- Field crops research, Vol.103(3), pp.208-216
- Academic Unit
- Biological Systems Engineering, Department of; Crop and Soil Sciences, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900547761701842
- Language
- English
- Resource Type
- Journal article