A greenhouse experiment was conducted to study the effects of Alternaria triticina with and without foliar dusting of fly ash (0.0, 2.5, 5.0, 7.5 g plant(-1)/day(-1)) on the growth, yield, photosynthetic pigments, protein and lysine contents of three cultivars of wheat, Triticum aestivum. Dusting of 2.5 and 5.0 g fly ash caused a significant increase in growth, yield, photosynthetic pigments, protein and lysine contents of all the three cultivars. Dusting of 5.0 g fly ash caused a higher increase in the parameters than the 2.5 g dusting. However, dusting of 7.5 g fly ash had an adverse effect on growth, yield, photosynthetic pigments, protein and lysine contents. Cultivar HD-2009 suffered highest reductions in growth and yield and showed greater infected leaf area and disease symptoms from A.triticina followed by HD-2329 and Lok-1. Inoculation of A.triticina to plants dusted with 2.5/5.0 g fly ash gave higher reduction in growth and yield than did plants inoculated with A.triticina without fly ash. Cultivar Lok-1 showed highest growth, yield, photosynthetic pigments, protein and lysine contents followed by HD-2329 and HD-2009.