HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via ISI Web of Science (8) Citing Articles via Google Scholar Google Scholar Articles by Swanton, C. J. Articles by Rahimian, H. Search for Related Content PubMed Articles by Swanton, C. J. Articles by Rahimian, H. Agricola Articles by Swanton, C. J. Articles by Rahimian, H. Related Collections Weed Management Pest Management Systems Production Agriculture

INTEGRATED WEED MANAGEMENT

Effects of Temperature and Photoperiod on the Phenological Development of Barnyardgrass

^a Dep. of Plant Agric., Univ. of Guelph, Guelph, ON, Canada N1G 2W1
^b Dep. of Agronomy, College of Agric., Mashhad, Iran

cswanton{at}plant.uoguelph.ca

An understanding of the environmental variables influencing the phenological development of weeds is essential for simulation model development. Temperature and photoperiod are important variables governing the phenological development of weeds. Growth cabinet studies were conducted to characterize the phenological development of barnyardgrass [Echinochloa crus-galli (L.) Beauv.] in response to variations in temperature and photoperiod and to determine the duration of the juvenile phase and the effect of temperature and photoperiod on reproductive development. Barnyardgrass was adapted to a temperature range of 6.5 to 52°C. Phenological development of barnyardgrass was described in terms of thermal days (cumulative day degrees above a base temperature for leaf appearance, tiller appearance, and shoot elongation). For modeling purposes, three development phases of barnyardgrass at a constant temperature of 20°C were described: (i) a juvenile phase of 1.5 thermal days; (ii) a photoperiod-sensitive inductive phase of 4.1 thermal days; and (iii) a photoperiod-sensitive postinductive phase of 19.5 thermal days. Photoperiod sensitivity of barnyardgrass did not differ with stage of development when expressed as a rate. Interpretation of constant sensitivity to photoperiod will simplify simulation of weed phenology in mechanistic models.

Abbreviations: ANOVA, analysis of variance • DAE, days after emergence • IWM, integrated weed management • LD, long day • PPFD, photosynthetic photon flux densities • SD, short day