Response of 44 sugarcane cultivars to Puccinia kuehnii in the period 2013-2014

It is necessary to develop studies that provide more knowledge about resistance and allow improving strategies for the prevention and control of orange rust. For this reason, the objective of this work was to evaluate the response of 44 sugarcane cultivars to orange rust in the period 2013-2014. The experiment was established in July 2013, with 44 cultivars. The evaluations were performed in 2 cm2 and directed towards the areas where the highest number of symptoms were found on leaves +3 and +5. A simple rank analysis of variance was performed using the Kruskal-Wallis test (p≤0.01). Only 16 cultivars showed orange rust pustules, both on plant cane and first shoot. With more than 25 % of the leaf area affected were cultivars ‘C95-416’, ‘C89-559’, ‘C88-523’, ‘CP52-43’, ‘C86-456’, and ‘C89-147’. The number of pustules/cm2 on sugarcane leaves increased with increasing plant age, with the highest percentages in the period from January to April. No significant differences were observed in the number of pustules present on leaves +3 and +5 and greater disease severity was determined on sugarcane plants.