Amaranthus retroflexus L. (Redroot Pigweed): Effects of Elevated CO2 and Soil Moisture on Growth and Biomass and the Effect of Radiant Heat on Seed Germination

Amaranthus retroflexus L. (Amaranthaceae), Redroot pigweed, is native to North America, but has become a weed of agriculture worldwide. Previous research into competition with food crops found it significantly reduces yields. Additionally, taxonomy, biomass allocation, physiological responses light intensity, water stress, elevated CO2, and herbicide resistance have been investigated. To extend other findings, we investigated growth yield in response (i) soil moisture (ii) drought CO2. seed germination rates following exposure three temperatures for two different time periods. Overall, stress reduced plant height, stem diameter, number leaves. Elevated CO2 (700 ppm) appeared reduce negative impacts on productivity. Heating seeds at 120 °C above either 180 or 300 s rate. These results inform an understanding potential A. future climate change will be used predict occurrence this weed. The finding that exposing high retards suggests fire could prevent from banks, particularly no-till situations, therefore may address infestations further spread