Temperature Responses and Potential Distribution of Itchgrass (Rottboellia exaltata) in the United States

Abstract

To estimate the potential growth and distribution of itchgrass (Rottboellia exaltata L. f.) in the United States, we grew the plant in 36 combinations of day and night temperatures in controlled-environment greenhouses. Day temperatures ranged from 17 to 32 C and night temperatures from 11 to 26 C. Total dry weights, leaf areas, heights, and numbers of tillers were determined at 3, 31, and 58 days after emergence. Mathematical growth analysis techniques were used to calculate net assimilation rates (NAR) and leaf area durations (LAD). Maximum dry matter production (the product of NAR and LAD) and maximum leaf area production occurred at 32/26 C. Dry matter production and leaf area production were greatly reduced by day temperatures below 29 C and night temperatures below 23 C. The retardation of dry matter production by low night temperature was due mainly to reductions in LAD rather than to reductions in NAR. Low day temperatures reduced dry matter production through combined effects on LAD and NAR. At the warmer day temperatures, tiller production increased with decreasing night temperature. Flowering occurred at all day temperatures and at all night temperatures of 14 C or greater. Based on its growth responses to temperature, itchgrass would reach 75 to 100% of its maximum potential growth in the Gulf Coast states, the lower Midwest, the South Atlantic states, and the Southwest. Therefore, it represents a serious potential weed problem in these regions.

Climate Impacts on Agriculture: Implications for Crop Production

“…For example, itchgrass (Rottboelliia cochinchinensis), an invasive weed associated with signifi cant yield reductions in sugarcane for Louisiana (Lencse and Griffi n, 1991), is also highly competitive in corn, cotton, soybean, grain sorghum, and rice systems (e.g., Lejeune et al, 1994). Th e response of this species to a 3ºC increase in average temperature stimulated biomass by 88% and leaf area by 68% (Patterson et al, 1979), projecting increases in growth for the middle Atlantic states (Patterson et al, 1999). Northward migration of other invasive weeds, such as cogongrass (Imperata cylindrica) and witchweed (Striga asiatica), is also anticipated (Patterson, 1995a).…”

Invasive species and climate change: an agronomic perspective

“…Lejeune et al 1994). The response of this species to a 3 • C increase in average temperature stimulated biomass and leaf area by 88% and 68% respectively (Patterson et al 1979), suggesting projected increases in maximum growth for the Middle Atlantic States (Patterson et al 1999). Northward migration of other invasive weeds, such as cogongrass (Imperata cylindrica) and witchweed (Striga asiatica), is also anticipated (Patterson 1995a).…”

Growth and yield responses of rice to carbon dioxide concentration

“…Table 2 shows the results of the mathematical growth analyses for three sampling periods. Since biomass increment (A HO is roughly equivalent to the product of NAR and LAD (Patterson et al 1979), differences in A W among CO 2 treatments can be explained in terms of these two components.…”