Thermotherapy of Russet Burbank Potato Tubers and Plants Infected with Alfalfa Mosaic Virus. Walter J. Kaiser, Research Plant Pathologist, USDA, ARS, Regional Plant Introduction Station, Washington State University, Pullman 99164. . Plant Dis. 68:887-890. Accepted for publication 19 April 1984. 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, 1984. DOI: 10.1094/PD-68-887.

Alfalfa mosaic virus (AMV) was eradicated from tubers of greenhouse- and field-grown Russet Burbank potato by hot-air treatment at 37 C for 4–5 wk. Virus could not be detected by repeated inoculation of susceptible test plants or by gel immunodiffusion tests in plants arising from these heat-treated tubers. Heat treatment effectively eliminated AMV from all sizes of tubers tested (<50–>100g). Survival of heat-treated tubers after 4 and 5 wk was ≥60% regardless of tuber size. The virus also was eliminated from shoot tips (1–1.5 cm) of AMV-infected plants after 6–8 wk of exposure to alternating temperature regimes (35–37 and 27 C). Exposure of whole virus-infected plants to such treatment for 6–14 wk caused temporary remission of virus symptoms; however, plants were still infected with AMV after removal from the elevated temperatures. Continuous exposure of AMV-infected plants at 35 C resulted in death of all heat-treated plants within 6 wk, before AMV-free shoot tips could be propagated.

Keyword(s): potato virus.