The commercial acceptability of three old potato cultivars following latent virus eradication

Abstract

The potato cultivars, Pinkeye, Bismark and Brownell have a long history of culture in Tasmania, and contain, respectively, the latent virus complements potato viruses S and Y, potato virus S, and potato viruses S, X and Y. Forms that had been freed of these viruses were compared with virus infected seed lines in two trials that followed local recommendations for optimum tuber yield. Virus-free forms were taller, leafier, darker green, and slightly later in flowering than infected plants. There was greater production of tubers (1 4- 198%) in smaller size grades at immature crop harvests by the virus-free forms of Pinkeye and Bismark; this was offset to some extent by an increase in fertilizer rate. At crop maturity, virus-free forms generally gave a higher yield; this averaged 9.1 % for Pinkeye, 4.6% for Bismark, and 10.3% for Brownell. The increased vigour after virus eradication has not affected commercial acceptance of Pinkeye and Bismark for the production of new, immature potatoes; it has increased second growth problems of Bismark and Brownell when grown to maturity and in part has led to their decline as commercial main crop varieties.