Abstract: Mycelial growth on PDA of Fusarium graminearum, F. oxysporum f. sp. tuberosi, F. sambucinum and F. solani, causal agents of potato tuber dry rot, depends upon temperatures ranging from 5 to 40°C. An interaction between pathogens tested and temperatures used for culture incubation was observed (at p≤0.05). These Fusarium species showed in vivo both thermal pics of aggressivity: a first one at low temperatures (10-15°C) and a second at higher temperatures (30-35°C). Nevertheless, at temperatures less than 25°C, F. sambucinum and F. graminearum were the most aggressive, while F. solani was the most aggressive at temperatures superior to 30°C.