Hostname: page-component-cd9895bd7-mkpzs Total loading time: 0 Render date: 2024-12-18T20:02:17.780Z Has data issue: false hasContentIssue false

Soil water thresholds for photoinduction of redroot pigweed germination

Published online by Cambridge University Press:  12 June 2017

John Cardina
Affiliation:
Department of Horticultural and Crop Sciences, Ohio State University, Wooster, OH 44691

Abstract

Perception of light by phytochrome is a mechanism that triggers weed seed germination in response to soil disturbance. Photoconversion of phytochrome from the red light absorbing form to the active far-red absorbing form depends on hydration of phytochrome. This research was conducted to determine the soil water threshold for the photoinduction of germination by the brief exposure of light that occurs during soil disturbance, and to determine how this threshold is affected by the fluence of the light stimulus and fluence sensitivity of the seed population. Redroot pigweed seedling emergence and germination response to red light (R) was studied for a range of water potentials. Water potential gradients were established by incubating seeds in soils wetted to various water contents, or in polyethylene glycol 8000 (PEG) solutions. After imposing the light treatments, seeds were returned to a fully hydrated state. Seedling emergence in response to R increased as the volumetric water content (θv) of soils increased. At volumetric water contents of 4.0%, R-induced seedling emergence was inhibited 50% compared to photoinduced seedling emergence at the highest soil water contents tested. Attenuation of photoinduction was more pronounced at low vs. high R fluences in freshly imbibed seeds, but was unaffected in seeds that exhibited enhanced fluence sensitivity. In ecosystems where seasonal soil moisture extremes are prevalent, the photoinduction of seed germination may be limited in dry microsites such as surface crusts or under extreme drought conditions.

Type
Weed Biology and Ecology
Copyright
Copyright © 1997 by the Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Cone, J. W. and Kendrick, R. E. 1986. Photocontrol of seed germination. in Kendrick, R. and Kronberg, G., eds. Photomorphogenesis in Plants. Dordrecht, The Netherlands: Martinus Nijhoff/W.D. Junk Publishers, pp. 443462.CrossRefGoogle Scholar
Duke, S. O. 1978. Interaction of seed water content with phytochromeinitiated germination of Rumex crispus L. seeds. Plant Physiol. 19: 10431049.Google Scholar
Gallagher, R. S. 1996. Ecophysiological aspects of phytochrome-mediated germination in soil seed banks. Ph.D. dissertation. The Ohio State University, Columbus, OH. 121 p.Google Scholar
Hartmann, K. M. and Nezedal, W. 1990. Photocontrol of weeds without herbicides. Naturwissenschaften 77: 158163.CrossRefGoogle Scholar
Jury, W. A., Gardner, W. R., and Gardner, W. H. 1991. Water retention in soil. in Soil Physics. 5th ed. New York: J. Wiley, pp. 3470.Google Scholar
Klute, A. 1986. Water retention: laboratory methods. in Klute, A., ed. Methods of Soil Analysis Part 1—Physical and Mineralogical Methods. 2nd ed. Agronomy Monograph 9. Madison, WI: American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, pp. 635662.CrossRefGoogle Scholar
Michel, B. E., Wiggins, O. S., and Outlaw, W. H. 1983. A guide to establishing water potential of aqueous two-phase solutions (polyethylene glycol plus dextran) by amendment with mannitol. Plant Physiol. 72: 6065.Google Scholar
Rawlins, S. L. 1986. Water potential: thermocouple physchrometry. in Klute, A., ed. Methods of Soil Analysis Part 1—Physical and Mineralogical Methods. 2nd ed. Agronomy Monograph 9. Madison, WI: American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, pp. 597633.Google Scholar
[SAS] Statistical Analysis Systems. 1988. SAS/STAT User&s Guide. Cary, NC: Statistical Analysis Systems Institute. 1028 p.Google Scholar
Sauer, J. and Struik, G. 1964. A possible ecological relation between soil disturbance, light flash, and seed germination. Ecology 45: 884886.CrossRefGoogle Scholar
Scopel, A. L., Ballaré, C. L., and Sánchez, R. A. 1991. Induction of extreme light sensitivity in buried weed seeds and its role in the perception of soil cultivations. Plant Cell Environ. 14: 501508.Google Scholar
Steele, R. G. and Torrie, H. 1960. Linear regression. in Principles and Procedures of Statistics. New York: McGraw-Hill, pp. 173174.Google Scholar
Taylorson, R. B. 1972. Phytochrome controlled changes in dormancy and germination of buried weed seeds. Weed Sci. 20: 417422.Google Scholar
Vertucci, C. W., Vertucci, F. A., and Leopold, C. A. 1987. Water content and the conversion of phytochrome regulation of lettuce dormancy. Plant Physiol. 84: 887890.CrossRefGoogle ScholarPubMed