Severe Outbreak of Stemphylium Leaf Blight, a New Disease of Cotton in Brazil
Open Access
- 1 March 1998
- journal article
- Published by Scientific Societies in Plant Disease
- Vol. 82 (3), 333-336
- https://doi.org/10.1094/pdis.1998.82.3.333
Abstract
A severe epidemic of a leaf blight of cotton occurred in the state of Paraná, Brazil, during 1994 and 1995, causing up to 100% yield losses in some commercial fields of cultivar Paraná 3. The severity of the disease among fields was variable and cultivar-dependent. Attempts were made to identify the organism causing the leaf blight symptoms, which were characterized as circular to irregular dark brown to black spots turning reddish brown with age and varying between 2 and 10 mm in diameter. The older lesions showed cracks and/or holes in the center. Severely diseased leaves dried rapidly and abscised. Fructifications of a fungus in the genus Stemphylium were observed on young, as well as on old, lesions. The Stemphylium sp. was consistently isolated on potato dextrose agar from disease samples collected from five cultivars in 14 locations. In inoculation tests, the Stemphylium isolates from cotton were highly aggressive to cotton, tomato, potato, and blue lupines; whereas an isolate of S. solani from tomato was highly aggressive on tomato and potato but less aggressive on cotton. On the basis of its morphological, cultural, and pathogenic characteristics, the principal pathogen causing leaf blight symptoms was identified as Stemphylium solani. Epidemics caused by S. solani on cotton have not been reported previously in commercial cotton cultivation.Keywords
This publication has 6 references indexed in Scilit:
- The relationship between Alternaria leaf spot and potassium deficiency causing premature defoliation of cottonPlant Pathology, 1989
- Alternaria alternata in cotton (Gossypium hirsutum) cv. Acala: Effects on gas exchange, yield components and yield accumulationEuropean Journal of Plant Pathology, 1989
- Evaluation of Cotton Cultivar Susceptibility to Alternaria Leaf SpotPlant Disease, 1987
- Phenols in Cotton Seedlings Resistant and Susceptible to Alternaria macrosporaJournal of Phytopathology, 1986
- Influence of Controlled Environment and Age on Development ofAlternaria macrosporaand on Shedding of Leaves in CottonPhytopathology®, 1983
- Negro Population in the United StatesThe Annals of the American Academy of Political and Social Science, 1913