Geographical Distribution of Tan Spot Severity on Durum Wheat
Salma Tissaoui
*
LR14AGR02, Laboratory of Bio-aggressors and Integrated Pest Management in Agriculture, National Agronomic Institute of Tunisia, University of Carthage, Tunis, Tunisia.
Marwa Hassine
LR14AGR01, Laboratory of Genetics and Cereal Breeding, National Agronomic Institute of Tunisia, University of Carthage,Tunis, Tunisia.
Amira Mougou-Hamdane
LR14AGR02, Laboratory of Bio-aggressors and Integrated Pest Management in Agriculture, National Agronomic Institute of Tunisia, University of Carthage, Tunis, Tunisia.
Bouzid Nasraoui
LR14AGR02, Laboratory of Bio-aggressors and Integrated Pest Management in Agriculture, National Agronomic Institute of Tunisia, University of Carthage, Tunis, Tunisia.
*Author to whom correspondence should be addressed.
Abstract
Tan spot is a severe foliar disease of wheat worldwide caused by the necrotrophic pathogen P. tritici-repentis. Recently, in Tunisia tan spot has been observed in many wheat fields in various cereals regions. In fact, disease detection and assessment of symptoms importance was carried out in several locations of Tunisia. The surveys showed the presence of two symptoms type where the most frequent lesion type is necrosis with chlorosis, which is the most distributed. The prevalence of disease varied between regions and bio-climatic stages where 63.87% was recorded in sub-humid and 30% in middle semi-arid. Disease severity and incidence were high in sub-humid region (Beja and Jendouba), but low in semi-arid medium (Zaghouan and Ben Arous).The recorded severity varied between inspected wheat varieties, but rating score did not exceed 3. Therefore, Khiar and Monastir were the most resistant, but Carioca was the susceptible variety. This different reaction of tested varieties is due to their genetic difference. Thirty stains of P. tritici-repentis species were isolated and morphological characterized.
Keywords: Tan spot, wheat, prevalence, severity, varieties