Isolation and Identification of Fungi Associated With The Wheat Roots Rot Disease and Determination of Its Pathogens and Control Methods 2- Disease Control Integration in Field

Abstract

The results of isolation of fungi associated with infected wheat plants in rot disease from four regions in Salah Aldin governorate (Til-Qsiaba , Mukiashefa , Bajy and Sammara) showed six genuses of fungi, Fusarium spp. was the most frequent fungus resulting in55.17 % followed by Rhizoctonia spp. (42.82%). The field experiment using sham -6 studied the vegetative parameters including plant length, dry weight and chlorophyll content, minimum values of these parametrs recorded with ( F.graminearum and Rhizoctonia spp) were 26.1cm , 1.003 g and 4.7 SPAD,respectively, this parameters were increased to higher values in present of both biocontrol agent T. harzianum and A.brasilense, resulting in 36.93,2,59g and 19.57 SPAD, respectively. The highest infection percentage and infection severity in present of both pathogens ( F.graminearum and Rhizoctonia spp) were 73.8 and 70.7%, respectively, while minimum reduction in infection percentage and infection severity were (44 and 43.9%) and (34.2 and 35.3%) in treatments of ( T. harzianum + A.brasilense with the both pathogens) and vitavax (1.2 g/lit. carboxcin 37.5% and thiram 37.5%) with the both pathogens.The results of resistance induction showed that PAL and peroxidase activities in present of both biocontrol agents superior on vitavax and control treatment. The treatment of ( F.graminearum and Rhizoctonia spp) proved it sever pathogenicity through the completely reduction in wheat yield (sham-6) in all yield parameters including grains number and grain weight . plant-1 ,in addition to the biological control in treatment of ( T. harzianum + A.brasilense with the both pathogens) proved it efficiency in yield production resulting in 25.77g , 2.05 g and 25.09g of these parameters, respectively compared to 25.55g,2.14g and 26.49g, respectively, in preset of vitavax, without significant differences between them.