Muskmelon Diseases

Our research on cucurbit bacterial wilt is branching into many exciting areas. When we began investigating this pathosystem in 2000, we tried several semiochemical strategies to lure cucumber beetles away from production fields. Next we evaluated using spunbond polypropylene row covers as a barrier against cucumber beetles until anthesis (the start of flowering). In 2007-2009, we suppressed bacterial wilt by delaying the removal of row covers until 10 days after anthesis (Saalau Rojas et al., 2011). 

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Hosta Petiole Rot

Hosta petiole rot (caused by the fungusSclerotium rolfsii var. delphinii) appeared in the northern U.S. within the past decade. Petiole rot is very difficult to control once it appears in a production field or garden, and sclerotia of the pathogen may persist for long periods.  Read more about Hosta Petiole Rot

Japanese Tree Lilac Leaf Spot

Former M.S. student Anne Dombroski (graduated 12/05) investigated etiology and ecology of a newly recognized fungal leaf spot disease of Japanese tree lilac (Syringa reticulata). The disease has caused severe defoliation of Japanese tree lilac in Iowa, Minnesota, Illinois, and Idaho during wet growing seasons. Read more about Japanese Tree Lilac Leaf Spot


I have conducted research on turf diseases for 21 years. Annually, trials are completed to evaluate several fungicides and alternative products for control of brown patch (pictured left), dollar spot, and fairy ring, and other diseases. Results are published in Fungicide and Nematicide Tests.

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