EFFICACY OF SELECTIVE GAMETOCIDES ON LOLIUM-PERENNE L

The efficacy of six chemicals as selective male gametocides on perennial ryegrass plants was studied by making use of a genetic marker technique. In a preliminary screening experiment each of the chemicals was used in five concentrations and in five treatments at several stages of development at or near ear emergence. Promising treatments from within this experiment were assessed in more detail subsequently. In most treatments female fertility was impaired more than male fertility. In the treatments in which the desired effect was found, i.e. male fertility was depressed appreciably more than female fertility, the differential gametocidal selectivity of the chemicals could not be considered distinct enough to merit application on a field scale. © 1969 OXFORD UNIVERSITY PRESS.