- Vegetables: cucurbits
- Crop Production: crop rotation
- Education and Training: workshop
- Pest Management: biological control, biorational pesticides, chemical control, cultural control, genetic resistance, integrated pest management
- Production Systems: general crop production
Pumpkins (Cucurbitae spp.) are grown throughout the world for agricultural purposes (e.g., food and feed) and decoration. Illinois is the leading state in pumpkin production. Bacterial spot, caused by Xanthomonas cucurbitae, has become an important threat to pumpkin production in Illinois. Leaf spots and fruit lesions and rot are major symptoms of this disease, causing up to more than 75% yield losses. This study was conducted to assess host range and seed transmission of X. cucurbitae. To determine incidence of bacterial spot of fruit, 17, 50, and 65 commercial fields were surveyed in 2009, 2010, and 2011, respectively. The symptomatic pumpkins were observed in 100, 80, and 88% of the fields in 2009, 2010, and 2011, respectively. Fifty plants in the family of Amaranthaceae, Brassicaceae, Chenopodiaceae, Cucurbitaceae, Gramineae, Leguminosae, Liliaceae, Malvaceae, Purtulaceae, Solanaceae, and Umbelliferae were tested in a greenhouse for infection by X. cucurbitae. All of the plant species in Cucurbitaceae family developed symptoms and X. cucurbitae was isolated from the lesions. None of the species from other plant families developed symptoms. Seed transmission of X. cucurbitae in pumpkin seeds was tested in the lab and greenhouse. X. cucurbitae was isolated from 12 of 20 seed samples collected from pumpkin fields. Also, X. cucurbitae was detected in kernels of NaClO-surface disinfested seeds. In a greenhouse study, lesions developed on cotyledons of the seedlings grown from naturally-infected pumpkin seeds and X. cucurbitae was isolated from symptomatic leaves.
Pumpkin is a high-value crop grown throughout the United States (US). Approximately 1.5 billion pounds of pumpkins are produced in the US every year. Illinois with about 25,000 acres ranks first in pumpkin production in the US. More than 90% of processing pumpkin are grown and processed in Illinois. Bacterial spot, caused by Xanthomonas cucurbitae has become one of the most economically important diseases on pumpkins and a serious threat to the industry. Leaf spots and fruit lesions and rot are major symptoms of this disease, causing up to more than 75% yield losses. In the past five years, the disease has become more prevalent in Illinois and other Midwestern states and many growers complain about the yield losses and of lack of effective disease management measures. Developing effective management of bacterial spot of pumpkin has not been feasible because of lack of sufficient information on the etiology of the disease. This is proposal for a two-year project to generate necessary information on the etiology of bacterial spot of pumpkin and develop effective methods for management of the disease.
Project objectives:div style="margin-left:1em;">
This is proposal for a two-year project to generate necessary information on the etiology of bacterial spot of pumpkin and develop effective methods for management of the disease. The specific objectives of this research are to: (1) identify the host-range of X. cucurbitae; (2) determine the importance of seed-borne aspect of the pathogen; and (3) develop management of the disease, emphasizing effective seed-treatments and cropping rotations.