Development of Peanut Germplasm Highly Resistant to Leaf Spot and the Peanut Root-Knot Nematode.

Chemical control for pathogens such as the peanut root-knot nematode (Meloidogyne arenaria) and late leaf spot (Cercosporidium personatum) can be expensive. Peanut (Arachis hypogaea) producers can increase profitability if they can reduce input costs while maintaining high yield. Development of cultivars with multiple disease resistances would allow growers to reduce input costs. The object of this work was to combine resistance to leaf spot with resistance to the peanut root-knot nematode. Coan, a cultivar with excellent resistance to the peanut root-knot nematode was crossed with Georganic, a cultivar with excellent resistance to leaf spot. Single seed descent was used to advance the material to the F₄ generation. Progeny were evaluated for resistance to leaf spot in unsprayed field plots. Leaf spot resistance selections were then evaluated for resistance to the peanut root-knot nematode in a greenhouse screening trial. Progeny with resistance to both pathogens were identified and will be releases as germplasm.