2018 ASHS Annual Conference

The only variety of Zinnia peruviana L. that is available commercially is 'Red Spider'. To determine whether other germplasm of potential commercial interest exists within this species, we evaluated 12 accessions of Z. peruviana obtained from the USDA Ornamental Plant Germplasm Center and compared them to 'Red Spider'. Six plants of each accession were grown in the greenhouse and evaluated for plant height, internode length, and leaf shape. The flowers were evaluated for floret ray shape, size and color, and number of ray florets per flower. A subset of the accessions were also evaluated in the field for disease resistance compared to 'Red Spider' and other commercial zinnia varieties. Although the Z. peruviana accessions evaluated in this study had similar plant and flower characteristics typical of the species, significant differences were found among accessions for plant height, flower size, and floret color. No significant differences were found among Z. peruviana accessions for powdery mildew and bacterial leaf and flower spot disease ratings in the field, although their overall scores for disease development were lower than that of other commercial Zinnia violacea varieties. Some accessions of Z. peruviana showed potential as new zinnia varieties and it is recommended that further studies be done on their commercial value as cut flower and home garden types.