Life-cycle of Globodera rostochiensis on potato in Italy

Abstract

The life-cycle of Globodera rostochiensis was studied outdoors in 1980-1981, at Catania and Bari in a subtropical climate and at Avezzano in a temperate climate. Second stage juveniles (J 2) were able to invade potato roots when temperatures were above lODe. G. rostochiensis developed during the winter months at Catania and Bari, where the first generation was completed by the time the potato tubers were harvested. A second generation was started in Bari, but was not completed; only a few J 2S from the newly formed cysts penetrated potato roots, and high late spring temperatures and lack of suitable potato roots prevented their development. At Avezzano, the long growing potato season and lower temperatures provided more favorable conditions for the development of G. rostochiensis, which completed two generations: the first by the end of June and the second by the end of August. At Bari the nematode required 126 and 168 cumulative day-degrees, and at Avezzano 275 and 450, to attain the stages of adult female and cyst, respectively.