Factors influencing incidence of internal brown spot in Russet Burbank potatoes

Studies were conducted to determine factors influencing incidence of internal brown spot (IBS) in Russet Burbank potatoes. A significant decrease in the incidence of IBS occurred as planting date was delayed from March 31 to May 12. IBS increased during storage particularly at the higher storage temperature and in larger tubers. Foliar application of maleic hydrazide (MH) significantly reduced IBS from a high of 33% of tubers to less than 10%. The incidence of IBS in tubers was lower in the field as well as in storage from plants sprayed with MH. Tubers with high specific gravity had greater incidence of IBS than low gravity tubers. Results indicate that IBS is a physiological disorder influenced by factors affecting growth of tubers.