Abstract
Developmental rates of soybean [Glycine max (L.) Merr. 'Braxton'], johnsongrass [Sorghum halepense (L.) Pers.], quackgrass [Elytrigia repens (L.) Nevski], redroot pigweed (Amaranthus retroflexus L.), sicklepod (Cassia obtusifolia L.), and velvetleaf (Abutilon theophrasti Medic.) were compared among plants grown in all combinations of two temperature levels (avg. day/night of 26/19 °C and 30/23 °C) and two CO2 levels (350 and 700 ppm). Neither temperature nor CO2 affected johnsongrass tillering rate, but plants began tillering earlier at higher temperatures. Adverse effects of higher temperatures on quackgrass development were alleviated by elevated CO2 conditions. Plastochron rate was higher at higher temperatures in all dicot species (soybean, redroot pigweed, sicklepod, and velvetleaf), and was higher at elevated CO2 in all dicots except velvetleaf. Calculating plastochron rates on a degree day basis removed differences between temperature treatments, but did not affect responses to CO2. Responses of dicot branch and branch leaf production to treatments varied among species. Branch production per day increased with higher temperatures in redroot pigweed, decreased with higher temperatures in sicklepod, and was unaffected by temperature in soybean. The relationship between main axis and branch developmental rates was altered by temperature in soybean, and by both temperature and CO2 in sicklepod, but was unaffected by either treatment in redroot pigweed. These results indicate that developmental responses to temperature and CO2 depend on both the species and the aspect of development being considered. Key words: Plastochron index, CO2 by temperature interaction, johnsongrass, quackgrass, redroot pigweed, sicklepod, velvetleaf
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.