Regresar

Distribution and importance of wheat and barley diseases in Tunisia, 1989 to 1991.

Abstract:

Surveys of wheat and barley diseases were conducted in 1989, 1990 and 1991 in most of the cereal-growing areas of Tunisia. Disease incidence was in general highest in 1990 and lowest in 1989. Barley fields had higher levels of infection than wheat fields. Net blotch (Pyrenophora teres), powdery mildew (Erysiphe graminis f. sp. hordei), barley stripe (Pyrenophora graminea) and covered smut (Ustilago hordei [U. segetum]) were the most frequent barley diseases. Whereas net blotch and powdery mildew were found in almost all the governorates, covered smut was more frequent in the centre and south and barley stripe was found only in some districts. Scald (Rhynchosporium secalis) incidence was very irregular, but was found in many governorates of the country. The most frequent diseases of wheat were: leaf rust (Puccinia recondita), powdery mildew (E. graminis f. sp. tritici), free-state streak, barley yellow dwarf luteovirus, Septoria leaf blotch (Mycosphaerella graminicola) and root rot (Fusarium graminearum [Gibberella zeae], F. culmorum and Bipolaris sorokiniana [Cochliobolus sativus]). These diseases were mainly found in the north and centre of the country. Diseases such as free-state streak, Hessian fly (Mayetiola destructor) and tan spot (Pyrenophora tritici-repentis) which were not important in the past have become more frequent.