Tan spot, caused by the necrotrophic fungus Pyrenophora tritici-repentis, is an economically serious disease worldwide. However, little has been learned about the importance of this disease in Tunisia. This study was carried out to determine the distribution of tan spot in nine districts of Northern Tunisia and to assess its prevalence, incidence and severity according to the prospected districts and the most cultivated varieties. Surveys of 414 wheat fields were conducted in 2016, 2017 and 2018. Tan spot was detected in all prospected districts with a frequency of 37%, 64% and 89% in 2016, 2017 and 2018, respectively. Based on prevalence, incidence and severity data, the disease was especially important in Manouba and Zaghouan in 2016, in Bizerte, Ariana, Jendouba, Siliana and El Kef in 2017, and in all visited districts except for Siliana in 2018. It was more serious on durum than on bread wheat. The commercial durum wheat varieties ‘Maali’, ‘Karim’ and ‘Razzak’ were the most grown in Northern districts. ‘Maali’ was the most susceptible during the three years, while ‘Karim’ and ‘Razzak’ showed susceptible reaction only during two years; 2016 and 2017 for the first and 2017 and 2018 for the second. The recently introduced cultivars ‘Carioca’ and ‘Monastir’ and the bread wheat varieties ‘Utique’ and ‘Haidra’ were less susceptible than old improved durum wheat varieties. These findings are useful to farmers to choose most tolerant varieties in their growing area.

褐色斑点，由坏死性真菌Pyrenophora tritici-repentis引起，是世界范围内一种经济上很严重的疾病。然而，关于这种疾病在突尼斯的重要性了解甚少。这项研究旨在确定突尼斯北部九个地区的棕褐色斑点分布，并根据预期的地区和种植最多的品种评估其流行程度，发病率和严重程度。在2016年，2017年和2018年对414个麦田进行了调查。在所有探矿区均发现棕褐色斑点，2016、2017和2018年的频率分别为37％，64％和89％。根据患病率，发病率和严重程度数据，该病在2016年的马努巴和Zaghouan，2017年的比塞大，阿里亚纳，詹杜巴，西莉安娜和埃尔克夫以及除西莉安娜之外的所有访问地区尤其重要。2018年更为严重在硬质小麦上比在面包小麦上。商品硬粒小麦品种“ Maali”，“ Karim”和“ Razzak”是北部地区种植最多的品种。“ Maali”是三年来最易感的人群，而“ Karim”和“ Razzak”仅在两年内显示出易感人群的反应。第一个是2016年和2017年，第二个是2017年和2018年。最近引进的品种'Carioca'和'Monastir'以及面包小麦品种'Utique'和'Haidra'比旧改良硬粒小麦品种更不易受感染。这些发现对于农民在其种植地区选择最耐病的品种很有用。最近引进的品种'Carioca'和'Monastir'以及面包小麦品种'Utique'和'Haidra'比旧改良硬粒小麦品种更不易受感染。这些发现对于农民在其种植地区选择最耐病的品种很有用。新近引进的品种'Carioca'和'Monastir'以及面包小麦品种'Utique'和'Haidra'比旧改良硬粒小麦品种不易受感染。这些发现对于农民在其种植地区选择最耐病的品种很有用。。