Agronomy and Horticulture Department


Date of this Version



Published in CROP SCIENCE, VOL. 19, MAY-JUNE 1979.


N-2 red clover (Trifolium pratense L.), carrying high levels of resistance to the yellow clover aphid (Therioaphis trifolii (Monell)) and the pea aphid (Acyrthosiphon pisum (Harris)), was released to researchers and commercial breeders in July 1978. It was developed by five cycles of phenotypic recurrent selection for yellow clover aphid (yeA) resistance and three such cycles for pea aphid (PA) resistance. Thirty-five diverse sources of germplasm, used in the initial evaluations for aphid resistance, were listed previously.