Three trials were conducted in Linhares county to study the chemical control of papaya (Carica papaya) powdery mildew (Ovulariopsis sp.). In all trials disease severity was visually estimated using a scale from 0 to 4. In the greenhouse, a trial was arranged in a completely randomised design with five replications using 'Improved Sunrise Solo Line 72/12'. Three sprays of triflumizole (150, 225, and 300 mg.l-1 a.i.), sulphur (1560 mg.l-1 a.i.) and methyl thiophanate (700 mg.l-1 a.i.) were evaluated at seven-day intervals during four weeks. The other two trials were carried out in an orchard of cv. Baixinho de Santa Amália, using a completely randomised block design with four replications. In each trial, five biweekly sprays and five evaluations were done: one before the first spray and the others 21, 35, 49, and 63 days after the first spray. In the greenhouse, all treatments differed from the control in relation to the area under the disease progress curve (AUDPC). Triflumizole was the most efficient fungicide. In the first field trial the most efficient fungicides in reducing the AUDPC were sodium bicarbonate (2000 mg.l-1 a.i.) and sulphur (1560 mg.l-1 a.i.) followed by triflumizole (150 to 300 mg.l-1 a.i.). Methyl tiophanate (700 mg.l-1 i.a.) did not differ from the control treatment. In the second field trial, azoxystrobin (20 to 100 mg.l-1 a.i.) applied at 14 or 28-day intervals, with or without adjuvant, and sulphur (1560 mg.l-1 a.i.) did not decrease the AUDPC. The results revealed the possibility of using sulphur and sodium bicarbonate to control papaya powdery mildew in the field.
