Armillaria root rot is the major pine disease in Brazil. Symptoms of this disease are yellowing of the needles, decline, root rot, resin exsudation and plant death. Temperature is an environmental factor that affects pathogens, the disease or both. This work evaluated the behaviour of three isolates of Armillaria sp. obtained from P. elliottii var. elliottii. The fungus isolates were submitted to temperature ranging from 16 to 26 ºC, by using dry biomass production in liquid medium as a measureable variable. All isolates produced higher amount of biomass at 22 ºC. A cubic regression showed a maximum point of temperatures between 21,8 e 23,2 ºC. The best temperature for fungus isolates growth was around 22 ºC.
fungal physiology; pathogen; root rot