Submitted to: Potato Country USA
Publication Type: Popular Publication
Publication Acceptance Date: 8/21/2006
Publication Date: 9/15/2006
Citation: Munyaneza, J.E. 2006. Impact of the Columbia Basin potato purple top phytoplasma on potato tuber processing quality. Potato Country USA. 22:12-13.
Technical Abstract: Recently, the Columbia Basin potato purple top phytoplasma has been identified as the causal agent of the recent potato purple top disease outbreaks that occurred in the Columbia Basin of Washington and Oregon. It has also been determined that the beet leafhopper is the major vector of this plant pathogen in this important potato growing region of the United States. Tubers were collected from chipping potato varieties Atlantic, FL-1833, FL-1867, and FL-1879 and French fry varieties Russet Burbank and Umatilla Russet. The impact of this phytoplasma on the potato tuber quality was assessed by measuring specific gravity, fry color, and checking for internal defects of the collected tubers. Processing results indicated that there were significant differences in tuber solids and sugar content between infected and non-infected potato plants. Some of the tubers from infected potato plants showed 100% No. 4 USDA fry color, which is not commercially acceptable. The amount of reducing sugars increased considerably in stored tubers. In addition, tubers from infected potato plants produced commercially unacceptable chips in all the chipping cultivars tested. Very few internal defects were observed.