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During the past years there has been an increase in the number of tomato greenhouse facilities in Michoacan. The expected high yield for some of these greenhouses has not been attained due mainly to the presence of tomato diseases, which in many cases, the identity of the pathogen is unknown. The objectives of this research were to determine the incidence and the etiology of the main diseases affecting greenhouse grown tomato in central Michoacan. Sampling was carried out in six commercial tomato greenhouses located in four municipalities from March to October 2007. The main diseases detected were wilting of young and mature plants, late blight, bacterial speck and powdery mildew. The identified pathogens were Phytophthora infestans, Oidiopsis taurica, Rhizoctonia spp., Fusarium oxysporum, Oidium neolycopersici and Pseudomonas syringae pv. tomato. Late blight caused by P. infestans and mildew caused by O. neolycopersici were the most important diseases detected due to the high disease incidence and severity. [ABSTRACT FROM AUTHOR]

Tamarind (Tamarindus indica) is an important crop in the dry tropic region of Mexico. Powdery mildew (Oidium sp.) is a disease that affects this leguminous crop, and causes up to 60% reduction in fruit production. Lesions on leaves are powdery; there is production of a white mycelium with a hyphal net on the foliar surface. Hyphae are hyaline with smooth cell wall, and produce short and erect conidiophores. Conidia are hyaline, unicellular, cylindrical, in chains or singly, with an average length of 27 μm × 14 μm width. Powdery mildew has a strong relationship with the rainy season, the presence of young plant shoots, and dry days; therefore, the highest disease severity occurs during August-October. The damage caused by this disease increases in orchards that have poor agronomic management practices. The current control of the disease is mainly based on the continuous application of systemic fungicides. [ABSTRACT FROM AUTHOR]

The article presents a study on the appearance of the Podosphaera, a section of the Sphaerotheca xanthii, on the cucurbits in northern Sinaloa, Mexico. It is stated that the powdery mildew is one of the most important diseases in the cucurbits in the region. The literature notes of the Golovinomyces cichoracearum as the causal agent of the disease. The aim of the study is to identify and confirm the real cause of the disease. Results show that there is no occurrence of the Golovinomyces cichoracearum among the tested samples of the powdery mildew.