Canadian Journal of Plant Science (2000) 80, 929-938

Jian Zhong Huang, Anil Shrestha, Matthijs Tollenaar, William Deen, Hamid Rahimian and Clarence J. Swanton (2000)
Effects of photoperiod on the phenological development of redroot pigweed (Amaranthus retroflexus L.)
Canadian Journal of Plant Science 80 (4), 929-938
Abstract: Mechanistic weed models focus on determining the outcome of weed and crop interference. An understanding of weed phenology is essential for simulation model development. Phenological development is a major factor determining the outcome of weed–crop competition. Growth cabinet studies were conducted to characterize the influence of photoperiod on the phenological development of redroot pigweed (Amaranthus retroflexus L.). Results indicated that redroot pigweed is a quantitative short-day species. Four development phases of redroot pigweed were described according to its response to photoperiod: (1) a juvenile phase of 1.1 d; (2) a photoperiod-sensitive inductive phase of 7.9 d; (3) a photoperiod-sensitive post-inductive phase of 39.9 d; and (4) a photoperiod-insensitive phase of 2.2 d. This information is useful for the development of mechanistic models and for comprehending the distribution and competitive ability of redroot pigweed with crops. The utilization of these results could help in predicting the phenological development of redroot pigweed.
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Database assignments for author(s): Clarence J. Swanton, Anil Shrestha, William Deen

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Amaranthus retroflexus (weed)