Fungicide management of maize head smut (Sphacelotheca reiliana) by seed treatment
Keywords:Maize, Head smut, Sphacelotheca reiliana, Propiconazole, Tebuconazole, Triadimenol
AbstractTwo pot experiments were conducted at Lumle Centre in the 1991 and 1992 seasons to evaluate the effectiveness of maize (Zea mays L.) seed treatment with triadimenol (Baytan), Sumi-8 (diniconazole), and tebuconazole (Raxil-50) in the prevention of head smut (Sphacelotheca reiliana). In both years these fungicides effectively controlled the disease since the plants from treated seeds suffered less than 3% smut. These fungicides were tested next under conditions of artificial exposure at three mid-hill sites in farmers' fields in the 1994 season except that propiconazole (Tilt-250) replaced Sumi-8. Propiconazole, tebuconazole, and triadimenol were applied at the rate of 4 mL or 4 g kg·1 of maize seeds. The lowest number of smutted plants was produced by propiconazole (0.7%), and followed by teuconazole (6.1%) and triadimenol (13.2%) treatments while the untreated control suffered 35.9%. The per cent head smut control by the three fungicides was highly significant (P < 0. 001) compared with the untreated control. Propiconazole treatment of seed produced a stunting effect at the seedling stage from which the plants recovered later in the growth phase. However, 2-3 ml propiconazole kg·1 seed treatment produced relatively less detrimental effect on germination or seedling growth.