MANAGEMENT OF ROOT ROT DISEASES OF EIGHT WHEAT VARIETIES USING RESISTANCE AND BIOLOGICAL CONTROL AGENTS TECHNIQUES

This study is focused on the screening of eight wheat varieties against Fusarium graminearum and Rhizoctonia solani root rot fungal diseases and their management through biological control agets (BCA) treatments under greenhouse conditions in Department of Plant Pathology, University of Nebraska, Lincoln (USA). These two soil-borne pathogens contributing to significant yield reduction and enhanced growth and yield of Wheat varieties (WVs) after BCA treatments. Experimental trails were set up by applying agar plug inoculation and BCA culture suspension techniques. Highest rating against R. solani was observed in WV Seher-2006 (5.0(A)) while lowest shown by Galaxy-2013 (1.5(FG)). On the other hand, maximum rating was observed in Seher-2006 (6.25(A)) while minimum in Punjab-2011 (3.0(B)(-E)) against F. graminearum. It was observed that T3 and T4 reduced maximum DS of V-1 as indicated 1.5(B) and 1.75(B). Treatment T4 also showed maximum fresh weight (FW) (0.11g) and dry weight (DW) (0.28g) of root after BCA treatments against R. solani. Maximum FW and DW (0.49g, 0.35g) of V-1 roots were also measured against T3 treatment while minimum mass (0.05g and 0.04g) was calculated against T-7 (check). However, maximum fresh and dry weight of V-7 and V-8 roots were observed against T4 treatment. It was noted that all varieties treated with BCA showed more FW and DW of roots as comparison to control (-ve control). However, BCA treatments against all analyzed WVs did not show significant difference. So, all treatments were reduced DS of WVs and increased biomass and yield of wheat plants. Galaxy-2013 variety (Vs) was declared as resistance against R. solani for year 2016-17 and three varieties (Faisalabad- 2008, Millat-2011 and Punjab-2011) were announced as moderately resistant to R. solani root rot. Comparatively, it was estimated that F. graminearum was more vulnerable as comparison to R. solani. The biological control activity of Trichoderma viride and Bacillus subtilis secreted enzymes and secondary metabolites in wheat plants and induced systemic disease resistance against Fusarium graminearum and Rhizoctonia solani. Therefore, it is concluded that BCA treatments are very effective techniques for the management of fungal pathogens without climatic pollution as in chemical spray form.