Seed yield of Valencia peanut (Arachis hypogaea L. ssp. fastigiata Waldron var. fastigiata) cultivars currently grown in Ontario. Canada appears quite sensitive to cooler or shorter than normal growing seasons. High seed yield may be associated with high percentage emergence and early maturity in this unique peanut-growing region. Selection for percentage emergence and maturity was practiced among F₂ derived F₄ families of five populations. Maturity was determined by percentage of pod yield as sound mature seeds Percentage emergence selections and percentage sound mature seed selections were recombined in a Comstock and Robinson design II mating design to develop 16 crosses. F₃ and F₄ bulk progeny of these Crosses were entered in three trials in two locations. Crosses on average had significantly higher percentage emergence and percentage sound mature seeds than the ancestors at only the coolest, shortest season location. Crosses on average were not significantly different from ancestors for pod or seed yield in any trial. General combining ability (GCA) and its interaction with trial were Significant for all characteristics except percentage emergence for the percentage sound mature seed selections. The GCA x trial interactions appeared to be associated with differences in rainfall and temperature in August and September between the two years. Specific combining ability and its interaction with trial were also significant for all characteristics except emergence.