Performance of novel sorghum germplasm in Pennsylvania and their response to anthracnose

Sorghum (Sorghum bicolor L.) has the potential to become a widespread commercial feedstock crop in Pennsylvania, either in rotation with maize (Zea mays L.) or grown alongside it. In other locations where sorghum has been grown for a long time, it is attacked by Colletotrichum sublineola Henn. ex Sacc. & Trotter, a fungal pathogen that causes anthracnose (Colletotrichum sublineola) leaf blight (ALB), thereby diminishing yield. Field surveys were carried out in 2011, 2012, and 2016 to monitor the presence of C. sublineola in commercial sorghum fields in six Pennsylvania locations. Senescing, lower leaves developed lesions that yielded Colletotrichum sp., including isolates of C. sublineola. The pathogen was not recovered from field debris, and ALB symptoms were not observed on the younger leaves of plants. In preparation for widespread cultivation of sorghum in Pennsylvania, we evaluated the performance, in field and greenhouse tests, of 158 experimental lines and commercial hybrids, which had been improved in several states in the United States and in other parts of the world. Sources of resistance to ALB and other foliar diseases were discovered that should be useful in breeding programs targeted for Pennsylvania and for northeastern U.S. climatic conditions. Lines received from ICRISAT, especially ICSB94, showed the highest level of resistance in the field. Core Ideas The anthracnose pathogen Colletotrichum sublineola was recovered from senescent sorghum leaves. Colletotrichum graminicola, a pathogen of maize, was also isolated from the senescing sorghum leaves. Resistant germplasm for incorporation into sorghum breeding programs was identified.