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The results of 12 sugarcane cultivars evaluated against sugarcane orange rust disease on the plant strain in two planting cycles (spring and cold) are shown. The number of pustules and the length of the most frequent pustule on leaves +1, +3, +5 and +7 at three, four, five, six and seven months of age were evaluated in a 2 cm² sampling station. The percentage of area occupied by pustules was calculated using a mathematical expression. Data were processed through the SPSS statistical package and analysis of variance and Tukey's test were performed for the sources of variation: leaves, evaluation dates, cultivars and cycles. The results showed differences for all sources of variation, leading to the conclusion that, although the affectations are not of great intensity, there are differences in the manifestation of symptoms in the different cultivars, and that studies to determine the presence of the disease and resistance of the genotypes should be carried out with cold plantings, also evaluating the +3 or +5 leaf when the crop is three and five months old. [ABSTRACT FROM AUTHOR]

In Cuba, sugarcane brown rust (Puccinia melanocephala) is one of the most important diseases and orange rust (Puccinia kuehnii) is considered a potentially dangerous disease. The objectives of the present investigation were: to quantify the development of brown and orange rust; to determine the influence of the planting time and age of the plants on the severity of these diseases; and the period in which the levels of both rusts are the highest. It was found that the months of planting have a very similar influence on the manifestation of the symptoms of both rusts with greater affectation in the plantations that were carried out from July to December and in the month of April. The severity of brown rust was significantly higher from three to five months of age after planting, however, in orange rust the severity remained above the average observed until seven months. The severity of orange rust increased with the age of the plants in the plantations that were carried out from January to April. Unlike brown rust, regardless of the age of the plants, the severity of orange rust can be increased when favorable environmental conditions exist. [ABSTRACT FROM AUTHOR]

Sugarcane orange rust (Puccinia kuehnii (W. Krüger) E.J. Butler) is considered an emerging disease in the Western Hemisphere and with high potential for damage. It was detected in Cuba in late 2008, which is why phytosanitary surveillance was established on its dispersion and incidence in the sugarcane plantations of the country. The objective of this work was to update the status of this disease in Cuba from the processing of data from research and surveys conducted in the period 2009-2017. Evaluations were carried out in the risk areas through systematic sampling in germplasm banks, varieties gardens, experimental areas and seed banks, including those established from "in vitro" plants. In addition, surveys were carried out in areas of commercial plantations, validation areas of new cultivars and areas of certified seed production, where 10 stems were randomly evaluated in three sampling stations following the diagonal of the field. P. kuehnii is found in the 13 provinces producing sugarcane in Cuba. Most infected genotypes were found in areas of experimental stations, mainly in the provinces of Mayabeque, Villa Clara and Camagüey. The distribution of this pathogen in the national territory is classified as low prevalence; however, the number of infected commercial cultivars rises to 30. [ABSTRACT FROM AUTHOR]