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Red–far-red ratio of reflected light: a hypothesis of why early-season weed control is important in corn

Published online by Cambridge University Press:  20 January 2017

Irena Rajcan ,
Kevin J. Chandler  and
Clarence J. Swanton
Irena Rajcan
Affiliation:
Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada
Kevin J. Chandler
Affiliation:
Department of Plant Agriculture, University of Guelph, Guelph, ON N1G 2W1, Canada
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Abstract

A plant's ability to detect and adjust morphologically to changes in light quality (red–far-red [R:FR] ratio) is one mechanism by which a crop plant responds to weeds. To test this hypothesis, two experiments were conducted where corn was grown in growth cabinets under different light environments. First, to determine the effect of R:FR ratio on corn growth and development, treatments of high R:FR (1.37) and low R:FR (0.67) ratio were compared. These were established by planting corn in pots and then placing trays of either turface (a baked clay medium with high R:FR) or commercial grass sod (low R:FR) on each side of a row of corn pots. Grass sod was used to simulate low-growing weeds. The low R:FR sod treatment resulted in corn plants which were taller, had larger leaves, and greater shoot–root ratio than plants growing in the high R:FR turface treatment. In the second experiment, the effect of R:FR ratio on corn leaf azimuth position was examined. This was accomplished by adding a third treatment where each corn row had sod placed on one side and turface on the other. The proportion of leaves in four azimuthal classes was recorded. In the presence of sod, the proportion of leaves perpendicular to the corn row decreased, and this altered the proportion of leaves in other classes. Therefore, corn seedlings detected changes in light quality caused by the presence of sod (which simulated low-growing weeds) and responded by adjusting carbon allocation and leaf orientation to optimize the interception of light quantity and quality. These results support our hypothesis that low-lying vegetation can alter the growth of corn seedlings before competition for resources occurs. This change in growth may help explain the importance of early-season weed control in corn.

Keywords

Corn, Zea mays L.Light qualityweed–crop interactions
Type
Weed Biology and Ecology
Information
Weed Science , Volume 52 , Issue 5 , October 2004 , pp. 774 - 778
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

Ballaré, C. L., Scopel, A. L., and Sanchez, R. A. 1990. Far-red radiation reflected from adjacent leaves: an early signal of competition in plant canopies. Science 247:329–331.CrossRefGoogle ScholarPubMed
Bosnic, A. C. and Swanton, C. J. 1997. Influence of barnyardgrass (Echinochloa crus-galli) time of emergence and density on corn (Zea mays). Weed Sci 45:276–282.CrossRefGoogle Scholar
Casal, J. J., Sanchez, R. A., and Deregibus, V. A. 1986. Effects of plant density on tillering: the involvement of the R/FR and the proportion of radiation intercepted per plant. Environ. Exp. Bot 26:365–371.Google Scholar
Daynard, T. B. 1971. Characterization of corn (Zea mays L.) canopies from measurements of individual plants. Agron. J 63:133–135.Google Scholar
Dew, D. A. 1972. Index of competition for estimating crop losses due to weeds. Can. J. Plant Sci 52:921–927.CrossRefGoogle Scholar
Girardin, P. H. and Tollenaar, M. 1992. Leaf azimuth in maize: origin and effects on canopy patterns. Eur. J. Agron 1:227–233.Google Scholar
Girardin, P. H. and Tollenaar, M. 1994. Effects of intraspecific interference on maize leaf azimuth. Crop Sci 34:151–155.CrossRefGoogle Scholar
Hall, M. R., Swanton, C. J., and Anderson, G. W. 1992. The critical period of weed control in grain corn. Weed Sci 40:441–447.Google Scholar
Hunt, P. G., Kasperbauer, M. J., and Matheny, T. A. 1989. Soybean seedling growth responses to light reflected from different coloured soil surfaces. Crop Sci 29:130–133.Google Scholar
Kasperbauer, M. J. and Hunt, P. G. 1992. Cotton seedling morphogenic responses to FR/R ratio reflected from different colored soils and soil covers. Photochem. Photobiol 56:579–584.CrossRefGoogle Scholar
Kasperbauer, M. J. and Hunt, P. G. 1998. Far-red light affects photosynthate allocation and yield of tomato over red mulch. Crop Sci 38:970–974.CrossRefGoogle Scholar
Kasperbauer, M. J. and Karlen, D. L. 1994. Plant spacing and reflected far-red light effects on phytochrome-regulated photosynthate allocation in corn seedlings. Crop Sci 34:1564–1569.CrossRefGoogle Scholar
Knezevic, S. Z., Weise, S. F., and Swanton, C. J. 1994. Interference of redroot pigweed (Amaranthus retroflexus) in corn (Zea mays). Weed Sci 42:468–573.Google Scholar
Novoplansky, A. 1991. Developmental responses of portulaca seedlings to conflicting spectral signals. Oecologia 88:138–140.CrossRefGoogle ScholarPubMed
O'Donovan, J. T., de St. Remy, E. A., O'Sullivan, P. A., Dew, D. A., and Sharma, A. K. 1985. Influence of the relative time of emergence of wild oat (Avena fatua) on yield loss of barley (Hordeum vulgare) and wheat (Triticum aestivum). Weed Sci 33:498–503.Google Scholar
Rajcan, I. and Swanton, C. J. 2001. Understanding maize-weed competition: resource competition, light-quality and the whole plant. Field Crops Res 71:139–150.Google Scholar
Swanton, C. J., Weaver, S., Cowan, P., van Acker, R., Deen, W., and Shrestha, A. 1999. Weed thresholds: theory and applicability. J. Crop Prod 2:9–29.Google Scholar
Tollenaar, M. 1989. Response of dry matter accumulation in maize to temperature: I. Dry matter partitioning. Crop Sci 29:1239–1246.CrossRefGoogle Scholar
Tollenaar, M., Daynard, T. B., and Hunter, R. B. 1979. Effect of temperature on rate of leaf appearance and flowering date in maize. Crop Sci 19:363–366.CrossRefGoogle Scholar