Importance of Canopy Attributes in Determining Dry Matter Accumulation of Pigeonpea under Contrasting Moisture Regimes

Nam, N H and Subbarao, G V and Johansen, C and Chauhan, Y S (1998) Importance of Canopy Attributes in Determining Dry Matter Accumulation of Pigeonpea under Contrasting Moisture Regimes. Crop Science, 38 (4). pp. 955-961.

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Abstract

Using two automated rain-out shelters, 6 genotypes of pigeon peas (Cajanus cajan) were grown under well-watered conditions or with water deficit imposed from flowering until maturity at the ICRISAT Asia Center, India. Water deficit significantly decreased the cumulative intercepted photosynthetically active radiation (CIR). The relationship between biomass accumulation and CIR was linear and water deficit affected the slope of the relationship (i.e., radiation use efficiency, RUE) (b = 1.92 g MJ sup(-1) for well watered vs. 1.43 g MJ sup(-1) for water deficit). Genotypes differed in RUE under well watered (1.70-2.19 g MJ sup(-1)) and moisture deficit (1.30-1.66 g MJ sup(-1)) conditions. Genotypic variation in canopy attributes was significant. Leaf area duration significantly correlated with crop growth rate (CGR) only under well watered conditions. Cumulative intercepted radiation and RUE accounted for nearly 99% of the genotypic variation in CGR under both moisture regimes, of which RUE alone contributed nearly 90%. Variation among genotypes in CIR alone did not explain the differences in dry matter accumulation under either moisture regime. Only RUE explained more than 90% of the genotypic variation in CGR and 70% in total dry matter under both moisture regimes. The results indicated that RUE is critical in determining pigeonpea productivity under well-watered and moisture-deficit regimes.

Item Type: Article
Divisions: UNSPECIFIED
CRP: UNSPECIFIED
Subjects: Mandate crops > Pigeonpea
Depositing User: Library ICRISAT
Date Deposited: 17 Sep 2011 05:52
Last Modified: 17 Sep 2011 05:52
URI: http://oar.icrisat.org/id/eprint/1698
Official URL: http://dx.doi.org/10.2135/cropsci1998.0011183X0038...
Projects: UNSPECIFIED
Funders: UNSPECIFIED
Acknowledgement: We are grateful to Dr. R.C. Nageswara Rao for many stimulating discussions during the preparation of this manuscript. Also, we thank Dr. N.C. Turner (CSIRO, Perth, Australia), and Dr. Bill Payne (Oregon State University) for their suggestions in improving this manuscript
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