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Density and row spacing effects on irrigated short wheats at low latitude

Published online by Cambridge University Press:  27 March 2009

R. A. Fischer ,
I. Aguilar M. ,
R. Maurer O.  and
S. Rivas A.
R. A. Fischer
Affiliation:
International Maize and Wheat Improvement Centre (CIMMYT), Londres 40, Mexico 6, D.F.
I. Aguilar M.
Affiliation:
International Maize and Wheat Improvement Centre (CIMMYT), Londres 40, Mexico 6, D.F.
R. Maurer O.
Affiliation:
International Maize and Wheat Improvement Centre (CIMMYT), Londres 40, Mexico 6, D.F.
S. Rivas A.
Affiliation:
International Maize and Wheat Improvement Centre (CIMMYT), Londres 40, Mexico 6, D.F.
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Summary

During four winter seasons eight spacing and density experiments were made under irrigated high fertility conditions in north-west Mexico (latitude 27° N). Experiments included various Triticum aestivum and T. durum genotypes of spring habit, short stature derived from Norin 10 genes, and contrasting plant type. Measurements included dry-matter production, photosynthetic area index, and light interception during one experiment, total dry matter at maturity in most others and grain yield and its numerical components in all experiments.

Grain yield and most other crop characters were unaffected by row spacings within the range 10–45 cm interrow width. The optimal seeding density for maximum grain yield was 40–100 kg/ha (80–200 plants/m2). Yield reductions at lower densities (20, 25 kg/ha) were slight and accompanied by reduced total dry-matter production. Yield reductions at higher densities (160–300 kg/ha) were also slight and were associated with more spikes/m2 but fewer grains/m2 and reduced harvest index. It is suggested that lower than normal preanthesis solar radiation or weather conditions leading to lodging can magnify these yield depressions at higher densities.

Measurements showed rapid approach of crops to 95% light interception, reached even at a density of 50 kg/ha within 50 days of seeding. It is suggested that provided this occurs before the beginning of substantial dry-matter accumulation in the growing spikes (60 days after seeding) there will be no loss of grain yield with reduced seeding density. Results point to a ceiling photosynthetic area index for maximum crop growth rate although there was a tendency for rates to fall at very high indices (> 9). This tendency was associated with very high density, high maximum numbers of shoots, poor survival of shoots to give spikes (< 30%) and reduced number of grains/m3;. The relatively low optimal densities seen here may be characteristic of genotypes derived from Norin 10.

Genotype × spacing, genotype × density and spacing × density interactions were generally non-significant and always small. There was a tendency for the presence of non-erect leaves or branched spikes to reduce the optimal density, but large differences in tillering capacity had no influence. Differences in lodging susceptibility can however lead to substantial genotype x density interactions.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 87 , Issue 1 , August 1976 , pp. 137 - 147
Copyright
Copyright © Cambridge University Press 1976

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References

Agarwal, S. K., Moolani, M. K. & Tripathi, H. P. (1972). Effect of sowing dates, levels of nitrogen and rate of seeding on dwarf wheat (Triticum aestivum L.). Indian Journal of Agricultural Science 42, 47–52.Google Scholar
Ciano, (1968–1969). Informe Anual, Centro de Investigaciones Agricolas del Noroeste, Secretaria de Agricultura, Mexico.Google Scholar
Donald, C. M. (1963). Competition among crop and pasture plants. Advances in Agronomy 15, 1–118.Google Scholar
Fischer, R. A. (1975). Yield potential in a dwarf spring wheat and the effect of shading. Crop Science 15, 607–13.Google Scholar
Friend, D. J. C. (1961). A simple method of measuring integrated light values in the field. Ecology 42, 577–80.CrossRefGoogle Scholar
Holliday, R. (1960). Plant population and crop yield: Part 1. Field Crop Abstracts 13, 159–67.Google Scholar
Holliday, R. (1963). The effect of row width on the yield of cereals. Field Crop Abstracts 16, 71–81.Google Scholar
Kanemasu, E. T., Feltner, K. C. & Vasecky, J. F. (1971). Light interception and reflectance measurements with Ozalid paper. Crop Science 11, 931–3.CrossRefGoogle Scholar
Martinez, G. J. M. (1973). Evaluacion de 12 genotypes de trigo en funcion de fecha y densidad de siembra. Informe interno, CIANO, Mexico.Google Scholar
Puckridge, D. W. & Donald, C. M. (1967). Competition among wheat plants sown at a wide range of densities. Australian Journal of Agricultural Research 18, 193–211.Google Scholar
Reitz, L. P. & Salmon, S. C. (1968). Origin, history and use of Norin 10 wheat. Crop Science 8, 686–8.CrossRefGoogle Scholar
Thorne, G. N. & Blacklock, J. C. (1971). Effects of plant density and nitrogen fertilizer on growth and yield of short varieties of wheat derived from Norin 10. Annals of Applied Biology 78, 93–111.CrossRefGoogle Scholar
Vela, C. M. (1971). Evaluacion de 4 genotipes de trigoen varios espaciamientos y desidades de siembra. Informe interno, CIANO, Mexico.Google Scholar
Willey, R. W. & Holliday, R. (1971). Plant population, shading and thinning studies in wheat, Journal of Agricultural Science, Cambridge 77, 453–61.Google Scholar