Kernel Number Determination in Argentinean Maize Hybrids Released between 1965 and 1993

By L. Echarte, Fernando H. Andrade, C. Vega, M. Tollenaar. 2004

161 citations recorded by the source corpus.

Grain yield and the stability of harvest index are greater in newer than in older Argentinean maize (Zea mays L.) hybrids. The objective of this study was to elucidate mechanisms underlying the superior yield and harvest index stability of newer Argentinean maize hybrids using the relationship between kernel number per plant (KN(P)) and plant growth rate during the period bracketing silking (PGR(s)). Three experiments were performed at Balcarce, Argentina, during two growing seasons (1998-2000). Maize was grown under a wide range of plant densities (from 2 up to 30 plants m(-2)) to generate contrasting availability of resources per plant. Growth of individual plants during the period bracketing silking was estimated through a nondestructive method on the basis of relationships between actual shoot dry matter and morphometric variables, including stem and ear diameters and ear length. Detasseling and silk pollination synchronization treatments were imposed in one experiment to also modify available resources per kernel and kernel sink strength. Newer hybrids set more kernels per unit PGR(s) than older hybrids as is indicated by (i) the lower threshold PGR(s) for kernel set and (ii) greater potential kernel number at high availability of resources per plant, for newer than for older hybrids. At low and intermediate PGR(s), the greater kernel set per unit PGR(s) in newer vs. older hybrids was attributable to greater partitioning of dry matter to the topmost ear during the period bracketing silking, whereas number of kernels set per unit of ear growth rate did not differ. In contrast, kernel set per unit of ear growth rate was greater in newer than in older hybrids when PGR(s) was high. Results of this study indicate that genetic yield improvement in maize is attributable, in part, to increased partitioning of dry matter to the ear during the critical period bracketing silking.

Subfields: Agronomy and Crop Science, Plant Science

View Paper: https://www.semanticscholar.org/paper/e7eafd49b585bd03c799059cb72195eb9abafd2e

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Citations in the corpus

The Response of Leaf Photosynthesis and Dry Matter Accumulation to Nitrogen Supply in an Older and a Newer Maize Hybrid (2008, unknown): “Previous reports also indicated that newer maize hybrids had a greater tolerance to low N conditions than older hybrids (Tollenaar and Wu, 1999; Banziger et al., 2002; Echarte et al., 2004 ).”
Physiological Basis of Successful Breeding Strategies for Maize Grain Yield (2007, result): “For the purpose of this paper, we will primarily restrict our examination of genetic improvement to the ERA hybrids, unless noted otherwise; however, the observations made in the ERA hybrids are consistent with fi ndings from other maize genetic improvement studies (e.g., Castleberry et al., 1984; T”
Effect of Crowding Stress on Dry Matter Accumulation and Harvest Index in Maize (2006, methodology): “Plant dry matter was estimated for each labeled plant at approximately 10 d before and 15 d after silking using the allometric relationships described in Echarte et al. (2004) to estimate PGRS for each labeled plant.”
Coupling time to silking with plant growth rate in maize (2007, background): “Applying these coefficients uniformly to all plants is supported by several studies showing a consistent relationship between ear growth rate and plant growth rate around flowering across environments (Andrade et al., 1999; Vega et al., 2001; Echarte et al., 2004 ).”
Maize Nutrient Accumulation and Partitioning in Response to Plant Density and Nitrogen Rate: I. Macronutrients (2013, methodology): “Hybrid variation for the dry mass relationship has been previously reported (Echarte et al., 2004; Luque et al., 2006; D’Andrea et al., 2008), but the hybrids evaluated in this research were not substantially different in either ear or plant components (<10% variation).”
Drought tolerance improvement in tropical maize source populations: evidence of progress (2006, background): “ Echarte et al. (2004) also found that yield progress in Argentinean hybrids was mainly attributable to increased partitioning of dry matter to the ear.”