Extract Variegated thistle, mintweed, sorghum, mangolds, and oaten hay have been shown to cause nitrate poisoning in animals under certain conditions. To our knowledge, this is the first observation in New Zealand on nitrate poisoning of cattle by turnip tops and redroot (Amaranthus retroflexus). Connor ( 1951 Connor, H. E. 1951. Dept. Sci, & Indust. Research, Bull., 99 [Google Scholar] ) states that redroot contains appreciable quantities of nitrate in the stems and branches and could possibly lead to poisoning.