Hostname: page-component-8448b6f56d-m8qmq Total loading time: 0 Render date: 2024-04-19T11:42:30.514Z Has data issue: false hasContentIssue false

Phosphorus effects on competitive interactions of smooth pigweed (Amaranthus hybridus) and common purslane (Portulaca oleracea) with lettuce (Lactuca sativa)

Published online by Cambridge University Press:  12 June 2017

Joan A. Dusky
Affiliation:
Everglades Research and Education Center, University of Florida, Belle Glade, FL 33430
William M. Stall
Affiliation:
Horticultural Science Department, University of Florida, Gainesville, FL 32611
Donn G. Shilling
Affiliation:
Agronomy Department, University of Florida, Gainesville, FL 32611
Thomas A. Bewick
Affiliation:
University of Florida. Current address: Cranberry Experimental Station, P.O. Box 569, East Wareham, MA 02538

Abstract

Replacement series studies were conducted under controlled conditions to determine the effect of phosphorus (P) rates and population densities on the competitiveness of smooth pigweed and common purslane with lettuce. Densities were 2, 4, and 8 plants per 113 cm2, whereas P rates were 0, 0.4, and 0.8 g PL−1 soil. A P-deficient Histosol (0.3 mg water-extractable P L−1 soil) was used. High P fertility enhanced the competitive ability of lettuce in smooth pigweed-lettuce mixtures. Smooth pigweed was not responsive to P rates. However, luxurious P consumption by smooth pigweed occurred, reducing the amount of the nutrient available for lettuce absorption. In common purslane-lettuce mixtures, the weed was responsive to P rates, increasing its competitive ability, whereas no increase in lettuce competitive ability was observed. Both weed species were more competitive than lettuce. Competition for P appears to be the main mechanism of common purslane interference on lettuce grown in low-P organic soils. Alternative fertilization strategies (i.e., banded applications) may reduce the effect of smooth pigweed on lettuce.

Type
Weed Biology and Ecology
Copyright
Copyright © 1998 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

Cousens, R. 1991. Aspects of the design and interpretation of competition (interference) experiments. Weed Technol, 5: 664673.CrossRefGoogle Scholar
de Wit, C. T. 1960. On competition. Versl. Landbouwk. Onderz. 66: 182.Google Scholar
Hochmuth, G., Hanlon, E., Nagata, R., Snyder, G., and Schueneman, T. 1994. Crisphead Lettuce: Fertilization Recommendations for Crisphead Lettuce Grown on Organic Soils in Florida. Gainesville, FL: University of Florida, pp. 23.Google Scholar
Jolliffe, P. A., Minjas, A. N., and Runeckles, V. C. 1984. A reinterpretation of yield relationship in replacement series experiments. J. Appl. Ecol. 21: 227243.Google Scholar
Radosevich, S. R. 1987. Methods to study interactions among crops and weeds. Weed Technol. 1: 190198.CrossRefGoogle Scholar
Rejmanek, M., Robinson, G. R., and Rejmankova, E. 1989. Weed-crop competition: experimental designs and models for data analysis. Weed Sci. 37: 276284.Google Scholar
Roush, M. L., Radosevich, S. R., Wagner, R. G., Maxwell, B. D., and Petersen, T. D. 1989. A comparison of methods for measuring effects of density and proportion in plant competition experiments. Weed Sci. 37: 268275.Google Scholar
Sample, E. C., Soper, R. J., and Racz, G. J. 1980. Reactions of phosphate fertilizers in soils. Pages 263304 in Khasawneh, F. E. et al., eds. The Role of Phosphorus in Agriculture. Madison, WI: Amer. Soc. Agron.Google Scholar
Shrefler, J. W., Shilling, D. G., Dusky, J. A., and Brecke, B. J. 1994. Influence of phosphorus fertility on intra- and interspecific interference between lettuce (Lactuca sativa) and spiny amaranth (Amaranthus spinosus). Weed Sci. 42: 574578.Google Scholar