Effects of Two Triazole Seed Treatments,Triticonazole and Triadimenol,on Growth and Development of Wheat

The triazole fungicides, triadimenol and triticonazole, applied as seed treatments at various rates on spring wheat, affected plant growth, shoot development, and root axis production. The main growth regulatory effects were reductions in lengths of the coleoptile, the first leaf and the subcrown internode. A marked effect on tiller appearance occurred with high rates of triadimenol. Modification of root-system development included a reduction in the number of seminal roots, increased outgrowth of roots associated with the coleoptilar node, and a reduction of roots at the first foliar node (correlated with reduced production of Tiller 1). Seed treatment effects on both shoot and root development illustrated the close relationship between these plant structures. Both fungicides induced both beneficial and deleterious effects on wheat growth and development, but the magnitude of deleterious effects was less with triticonazole than with triadimenol.