ABSTRACT
Purple blotch, caused by the fungus Alternaria porri, is one of the more important diseases in garlic crop. It provokes losses between 50 and 60% in the production by the premature destruction of the aerial part of the plants, resulting in the production of small bulbs. With the aim to evaluate the efficiency of available fungicides in Brazil, used both separately and in alternation with chlorothalonil in the control of the disease, 2 experiments were carried out in Piedade, SP, in commercial growings, using cultivar Roxo-Pérola de Caçador. The sprauing were begun at 90 days after the planting. In experiment 1, conducted between August and October 2000, 6 applications of the products were performed, at intervals 7 day. In the experiment 2, conducted between August and October 2001 there were 8 applications, 4 with specific products and 4 with chlorothalonil, at intervals of 7 days, alternately. In both experiments there were 3 evaluations of the purple blotch severity, using a scale from 0 to 100% of foliate area affected by the disease. The values obtained in the evaluations were used for the calculation of the area below the progress curve of the disease. All the treatments differed from the check in both experiments, promoting control levels between 53.4 and 82.5%. The products that stood out more were estrobilurinas azoxystrobin and kresoxim methyl. The products tebuconazole, iprodione and pyrimethanil also promoted good control.
KEY WORDS:
Alternaria porri; Allium sativum, chemical control; strobilurine; triazole.