VIEW ARTICLE

Techniques

Comparison of Techniques for Inoculating Sunflower Heads with Three Species of Rhizopus. S. M. Yang, Conservation and Production Research Laboratory, Science and Education Administration, Agricultural Research, U.S. Department of Agriculture, Bushland, TX 79012; C. A. Thomas, Plant Protection Institute, Science and Education Administration, Agricultural Research, U.S. Department of Agriculture, Beltsville, MD 20705. Phytopathology 71:458-460. Accepted for publication 13 October 1980. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1981. DOI: 10.1094/Phyto-71-458.

Seven methods of inoculating sunflower (Helianthus annuus) heads with Rhizopus arrhizus, R. oryzae, and R. stolonifer were compared. The insertion of a wheat-grain culture of Rhizopus into the sunflower receptacle with forceps consistently produced severe head rot in susceptible hybrids grown either in the field or in the greenhouse. Six alternate methods of inoculation either did not produce rot on all susceptible hybrids, or when rot developed following inoculation by these methods it was not always severe. The results of this study indicate that the insertion inoculation technique is suitable for mass screening of sunflowers for resistance to Rhizopus head rot.