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Physiological mechanisms for the rapid growth of Pennisetum clandestinum in Mediterranean climates
Author(s) -
WILEN C. A.,
HOLT* J. S.
Publication year - 1996
Publication title -
weed research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.693
H-Index - 74
eISSN - 1365-3180
pISSN - 0043-1737
DOI - 10.1111/j.1365-3180.1996.tb01651.x
Subject(s) - festuca arundinacea , biology , agronomy , weed , mediterranean climate , festuca , photosynthesis , temperate climate , biomass (ecology) , festuca rubra , poaceae , botany , ecology
Summary Pennisetum clandestinum Hochst ex Chiov. (kikuyugrass) is a C 4 grass that has become an invasive weed in temperate climates. We examined ecophysiological mechanisms that have allowed it to become a successful weed in these locations by comparing P. clandestinum and two other common turigrass species, Festuca arundinacea Schreb. (tall fescue cv. Mojave), a C 3 cool‐season grass, and Stenotaphrum secundatum (Walt.) Kuntze (St. Augustinegrass), a C 4 warm‐season grass, grown in a warm or cool growth regime. We measured rates of photosynthesis over a range of leaf temperatures and also measured growth rate parameters of these species. At leaf temperatures between 25^C and 40^C P. clandestinum maintained the highest rates of photosynthesis in both temperature regimes. Under warm temperatures, this species rapidly increased biomass and leaf area to a greater extent than either of the other two grasses. Theoretical whole plant photosynthesis (mean leaf area × mean photosynthetic rate) was higher for P. clandestinum than for the other two species in both growth regimes and over most leaf temperatures. Our results suggest that P. clandestinum is a successful weed in Mediterranean climates as a result of its capacity to photosynthesize over the full range of temperatures found in those climates, its rapid growth during warm weather and its apparent tolerance to moderately cool temperatures.