Statut des principales maladies cryptogamiques foliaires du blé au Maroc en 2013

Abstract

Objective: This study describes the status of the principal cryptogamic foliar diseases of wheat in three cereal regions in the northwest of Morocco during the 2012-2013 season cereal. An inventory of these diseases has been established. Methods and results: Fifty (50) fields of wheat and forty two (42) durum wheat fields were surveyed between April and May 2013. The diseases were identified based on their typical symptoms and the microscopic examination of the spores of their different fructification after the samples incubation. The prevalence, impact and severity of attacks was determined for each foliar fungal disease. Septoria leaf blotch, brown rust and net blotch were by far the most important foliar diseases in wheat fields, with prevalence of 85.4, 76.6 and 63.0 % respectively. At fields of durum wheat, the situation was characterized by the predominance of brown rust (79.0 %), leaf blight (70,1 %), and Septoria (45.8 %). Powdery mildew was less prevalent (14,2 %) on bread wheat and 11,4 % for durum wheat and less severe (8,0 %) saw its late appearance in the cycle of wheat. No symptoms of yellow or black rust was found in this study. Conclusion and application: Despite of the record cereal production of the 2012-2013 season (over 97 million cwt) due to exceptional rainfall, these climatic conditions have boosted the development and spread of fungal diseases. Following this alarming situation, and to mitigate their impact on the performance, a fungicides program was widespread. Septoria diseases caused by Septoria tritici was the dominant among the identified diseases.Keywords: Morocco; wheat; status; inventory; fungal diseases; prevalence; impact; severity.