A previously unknown glyphosate resistance mechanism, amplification of the 5-enolpyruvyl shikimate-3-phosphate synthase gene, was recently reported in Amaranthus palmeri. This evolved mechanism could introgress to other weedy Amaranthus species through interspecific hybridization, representing an avenue for acquisition of a novel adaptive trait. The objective of this study was to evaluate the p...

On a farm in Slovenia two cows died overnight without any previous signs of disease. The cows were fed green forage, containing a big portion of redroot pigweed (Amaranthus retroflexus) at least for four consecutive days. Poisoning with this plant was suspected. Pathomorphological changes established by the necropsy of both cows confirmed the suspi-

We attempted to confirm that seed banks can be viewed as an important genetic reservoir by testing the hypothesis that standing (aboveground) plants represent a nonrandom sample of the seed bank. We sampled multilocus allozyme genotypes from three species with different life history strategies: Amaranthus retroflexus, Carduus acanthoides, Pastinaca sativa. In four populations of each species we...

This study aims to determine the allelopathic potential of Amaranthus retroflexus (Ar) with different climatic zones on seed germination and growth of A. tricolor (At) treated with a gradient N addition. Ar leaf extracts only displayed significantly allelopathic potential on the underground growth of Ar but not the aboveground growth of At. The allelopathic potential of Ar leaf extracts on root...

(14)C-Ethylene was metabolized by etiolated pigweed seedlings (Amaranthus retroflexus L.) in the manner similar to that observed in other plants. The hormone was oxidized to (14)CO(2) and incorporated into (14)C-tissue components. Selected cyclic olefins with differing abilities to block ethylene action were used to determine if ethylene metabolism in pigweed is necessary for ethylene action. 2...

The rate o f photosynthesis in intact leaves o f a triazine-resistant biotype o f Amaranthus retroflexus was about 15% lower than that o f a triazine-susceptible biotype. Differences in photosyn­ thesis between resistant and susceptible biotypes o f Polygonum lapathifolium, Poa annua and Solanum nigrum were not significant, and absent in Chenopodium album and Stellaria media. The results are br...

Resource pulses are a common event in agro-ecosystems. A pot experiment was conducted to assess the effects of nitrogen (N) pulses and competition on the growth of an invasive weed, Amaranthus retroflexus, and a native crop, Glycine max. A. retroflexus and G. max were planted in pure culture with two individuals of one species in each pot and in mixed culture with one A. retroflexus and one G. ...