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Harvest Index in Spaced Populations and Grain Weight in Microplots as Indicators of Yielding Ability in Spring Wheat 1
Author(s) -
Fischer R. A.,
Kertesz Z.
Publication year - 1976
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1976.0011183x001600010014x
Subject(s) - biology , sowing , crop , agronomy , yield (engineering) , gene–environment interaction , competition (biology) , grain yield , poaceae , irrigation , shoot , test weight , genotype , ecology , biochemistry , materials science , gene , metallurgy
A set of 40 adapted homozygous spring wheat ( Triticum aestivum L.) genotypes were grown under similar conditions of irrigation and high fertility utilizing large plots and microplots seeded at normal densities, and spaced plants (60 × 60 cm grid). The objective was to see how well spaced plant traits, especially grain weight and harvest index, and microplot yields predicted true yielding ability as measured with the large plots. Phenotypic correlation coefficients were calculated using genotype means. Microplot yield was highly correlated (r = 0.67 at the 1% level) with large plot yield but explained less than half of the variation between the genotypes. Much of the residual was probably related to the highly significant genotype Χ plot type interaction. With spaced planting, yield/plant was correlated (r = 033 at the 5% level) with crop yield. Better correlations with crop yield were obtained with plant and shoot harvest indices (r = 0.56 and 0.66, respectively, at the 1% level). No numerical components of yield measured on spaced plants gave better correlations with crop yield than yield per plant itself. These results emphasize the major effect that the degree of interplant competition, probably primarily for light in this case, has on the performance of a genotype. As the degree of competition declined going from crop plots to spaced plants, genotypes which can more fully occupy the increased space available were favored; thus, the performance of non‐erect genotypes improved noticeably relative to erect ones. We conclude that harvest index measurement offers promise as a predictor of yielding ability where the seed available is limited.