Plant damage assessment in Urochloa spp. to categorize resistance to spider mites (Acari: Tetranychidae) attack

Abstract

Despite improved brachiaria (Urochloa spp.) grasses increase the productivity in African livestock systems, its adoption and establishment in the region is challenged for the attack of spider mites (Acari: Tetranychidae) during dry seasons. Breeding for resistance to key pests is one of the principal objectives in the Urochloa scheme for East Africa. Thus, developing high-throughput phenotyping methodologies for screening the high diversity of the tropical forages’ gene banks is crucial to identify potential sources of resistance, categorize the current available germplasm and optimize the selection process. 26 accessions of Urochloa spp. were assessed for resistance to red spider mites under greenhouse conditions in Mbita, Kenya with no-choice tests. For this report, we compared two techniques of analyzing digital images for plant damage to decide which is more accurate for categorizing tolerance.