Eficiência e viabilidade econômica do controle químico da ferrugem do eucalipto em condições de campo

Abstract

Originally from South America, eucalyptus rust is caused by the fungus Puccinia psidii, and has become a limiting disease for eucalyptus cultivation in Brazil, requiring the adoption of control measures, for example the chemical control. To evaluate the efficiency and economic viability of fungicides to control eucalyptus rust, a test has set up in the field. The experimental design adopted for the test has randomized blocks, 3 × 3 (3 products and 3 doses) in factorial arrangement, with 0.5, 1.0 and 1.5 mL or g of commercial product per liter of solution. The treatments were: 1-) control; 2-) Fungicide azoxystrobin (strobilurins); 3-) Fungicide tebuconazole (triazole); 4-) Fungicide tebuconazole + trifloxystrobin (triazole + strobilurins). Four replicates were used to assess plant disease severity based on the percentage of damaged leaf area. Higher fungicide doses led to a greater reduction of the disease in the plants at 7 and 15 days after the application. The fungicide tebuconazole + trifloxystrobin at 1.5 mL / L was the most efficient against eucalyptus rust under field conditions. The fungicide tebuconazole was the most economically viable at the three tested doses.