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Effect of Weed Competition on Sunflowers

Published online by Cambridge University Press:  12 June 2017

B. J. Johnson*
Affiliation:
Georgia Sta., Experiment, Georgia 30212

Abstract

Sunflowers (Helianthus annuus L.) produced maximum seed yields when kept weed free for a period of 4 to 6 weeks after planting. This was accomplished with one cultivation anytime between 2 and 6 weeks after the early planting in 1969, with two cultivations 2 and 4 weeks or 4 and 6 weeks after the late planting in 1969, and with one cultivation at 4 weeks after either the early or late planting in 1970. The average height of sunflower plants was not influenced by weed competition if weeded at either 2 or 4 weeks after planting, whereas, head and seed size were not affected if weeded at 4 weeks after planting. The oil content of seed was higher in plots with the least amount of weed competition.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

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References

Literature Cited

1. Buchanan, Gale A. and Burns, Earl R. 1970. Influence of weed competition on cotton. Weed Sci. 18:149154.CrossRefGoogle Scholar
2. Burnside, O. C. and Wicks, G. A. 1967. The effect of weed removal treatments on sorghum growth. Weeds 15:204207.CrossRefGoogle Scholar
3. Burnside, O. C. and Wicks, G. A. 1969. Influence of weed competition on sorghum growth. Weed Sci. 17:332334.CrossRefGoogle Scholar
4. Dawson, J. H. 1964. Competition between irrigated field beans and annual weeds. Weeds 12:206208.CrossRefGoogle Scholar
5. Dawson, J. H. 1965. Competition between irrigated sugar beets and annual weeds. Weeds 13:245249.CrossRefGoogle Scholar
6. Duncan, David B. 1955. Multiple range and multiple F test. Biometrics 11:142.CrossRefGoogle Scholar
7. Hill, L. V. and Santelmann, P. W. 1969. Competitive effects of annual weeds on Spanish peanuts. Weed Sci. 17:12.CrossRefGoogle Scholar
8. Knake, E. L. and Slife, F. W. 1965. Giant foxtail seeded at various times in corn and soybeans. Weeds 13:331334.CrossRefGoogle Scholar
9. Robinson, R. G., Johnson, F. K., and Soine, O. C. 1967. The sunflower crop in Minnesota. Minnesota Agr. Ext. Bull. 299, 131.Google Scholar
10. Weatherspoon, D. M. and Schweizer, E. E. 1969. Competition between Kochia and sugar beets. Weed Sci. 17:464467.CrossRefGoogle Scholar
11. Wilson, H. P. and Cole, R. H. 1966. Morningglory competition in soybeans. Weeds 14:4951.CrossRefGoogle Scholar