Glucosinolate Content of Rapeseed ( Brassica napus L. and B. campestris L.) Meal as Influenced by Pod Position on the Plant 1

Three major glucosinolates “gluconapin,” “glucobrassicanapin,” and “progoitrin” were quantitatively determined in rapeseed meal for three pod positions on plants of the varieties ‘Nugget’ ( Brassica napus L.) and ‘Echo’ ( B. campestris L.) grown in three environments. Significant position effects were found for all three glucosinolates in Nugget, but only for gluconapin in Echo when position effects were averaged for three environments. However, within environments the pod position effects did not always follow these patterns. Single pod samples should be restricted to the same position on each plant to reduce the random variation in glucosinolate content. The effect of environment on the glucosinolate content of seed from plants grown under three environments was significant. Comparisons of glucosinolate values for plants grown at different times or locations should be avoided.