Impacts of Smooth Pigweed (Amaranthus hybridus) on Cover Crops in Southern Ontario

Abstract

Amaranthus hybridus is a noxious weed in Ontario, with demonstrated allelopathic properties that can lead to decreased agricultural production. We tested the germination and growth of five cover crop species exposed to A. hybridus extracts, and to dried or fresh materials in soil. A germination index was calculated, and the dry weight of plant organs were measured to quantify responses to treatments. All species had reduced germination (≤29%) in 100% extract. Trifolium pratense had significant root weight reductions in extract (52%) and dried (72%) treatments, whereas shoot weight only decreased (48%) in dried treatment. Medicago sativa shoot weight decreased (52%) in 20g fresh treatment, while root weight decreased (62%) in dried treatment. Shoot weight of Raphanus sativus increased (32%) at mid-extract concentrations, while root weight increased (33%) only with dried treatment; however, both its shoot and root weight decreased (>40%) in fresh treatment. Only the shoot weight of Lolium multiflorum increased (41% in 75% extract and 55% in dried treatment). Both Cichorium intybus shoot and root weights decreased (~50%) in fresh treatment. Crop responses to A. hybridus are complex, and material and species-dependant. Further testing in the field may provide a more comprehensive understanding of how to improve the management of A. hybridus.

Growth performance and ferulic acid composition of Amaranthus species and Mitracarpus villosus in competition with weeds species

“…Little to no previous works have been done to elucidate the effects of weed competition on Amaranthus species because they are considered as noxious weeds that should be controlled to limit their impacts on other economic crops (Bukun 2011;Ma et al 2015;VanVolkenburg et al 2020).…”

The Probable Use of Genus amaranthus as Feed Material for Monogastric Animals

“…Several authors have reported that the main species used as grains are: A. cruentus , A. caudatus , and A. hypochondriacus which are also known to be dual purpose varieties [ 2 , 3 ]. However, popular leafy species are A. hypochondriacus , A. tricolor , A. hybridus , and A. blitum as described in Table 1 [ 2 , 3 , 4 , 5 , 6 ]. Amaranth belongs to a group of plants in the same genus that are considered to be an annual to short-lived perennial and can be subdivided into grain and vegetables.…”