Field treatment of three wheat varieties with Trichoderma harzianum bioagent to control Anguina tritici

Abstract

A field experiment was performed to assess the susceptibility of Triticum aestivum L. var. Cham 6, Aras, and Baraka wheat local varieties, treated with Trichoderma harzianum Rifai bioagent, against seed gall infection. Anguina tritici identification was confirmed based on PCR amplification and sequence comparison of 18S small subunit ribosomal DNA. Sequence analysis showed A. tritici isolated from Waset and Kirkuk provinces shared 100% maximum nucleotide sequence identity with the equivalent GenBank sequences from Mexico (AF363107) and India (JF826516), respectively, suggesting their common origin. Field experiment revealed that T. aestivum L. var. Aras was less susceptible to seed call infection when scored 28.9% infectivity percent followed by Baraka and Cham 6 varieties which scored 29.6 and 33.1% infectivity, respectively. T. harzianum root watering treatment could decrease the disease incidence when scored 15.4, 17.5, and 19.7% compared to spraying treatment which scored 19.3, 20.8, and 22.4% infectivity, for Aras, Baraka, and Cham 6 varieties, respectively. Besides, root watering treatment reduced seed gall disease up to 46.71% compared to 33.22% for foliar spraying treatment. Thus, T. harzianum bioagent can be used as an ecofriendly nematicide alternative to control seed gall disease in Iraq.