The reaction of sugarcane to Puccinia melanocephala Syd. & P. Syd. populations is intensely influenced by environmental conditions, make it difficult to conduct field evaluations of genotypes. This work aimed to develop a method for rust inoculation in leaf segments. The segments were obtained from 30-day-old plants of the susceptible variety SP70-1143. These were inoculated (2 x 10(4) viable spores/mL) and kept in test tubes. The treatments consisted of different incubation conditions, considering the variables (i) use or not of wet chamber after the inoculation; (ii) immersion of ¼ or ¾ of the section in the liquid contained in the test tube and; (iii) addition or not of benzimidazole in the water of the tube. The best treatment consisted of immersion of ¾ of the section in test tubes containing water, with no moist chamber after the inoculation. After incubation (21 °C ± 1ºC, 12 h of photoperiod) the sections remained viable for 20 days and showed good rust development. The method showed similar results when compared to the inoculation of whole plants of 3 varieties, making it possible to discriminate efficiently their reactions to rust.
Saccharum sp.; screening tests
