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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Mycology and Nematology Genetic Diversity and Biology Laboratory » Research » Publications at this Location » Publication #393980
Research Project: Plant-associated Nematode Management and Systematics and USDA Nematode Collection Curation

Location: Mycology and Nematology Genetic Diversity and Biology Laboratory

Title: Pathogenicity and control of the citrus nematode Tylenchulus semipenetrans on some citrus, grape, olive, loquat, and persimmon species and cultivars

Author
item IBRAHIM, IBRAHIM - Agricultural Research Center Of Egypt
item ABU HABIB, ALAA HABIB - Agricultural Research Center Of Egypt
item KANTOR, MIHAIL - Oak Ridge Institute For Science And Education (ORISE)
item Handoo, Zafar

Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/8/2022
Publication Date: 12/1/2022
Citation: Ibrahim, I.K.A., Abu Habib, A.A., Kantor, M., Handoo, Z.A. 2022. Pathogenicity and control of the citrus nematode Tylenchulus semipenetrans on some citrus, grape, olive, loquat, and persimmon species and cultivars. Nematropica. 52:79-84.

Interpretive Summary: Plant-parasitic nematodes are microscopic worms that feed on plants and cause an estimated ten billion dollars of crop losses each year in the United States and 100 billion dollars globally. Citrus nematodes are one of the most economically important groups of plant-parasitic that cause important crop losses in citrus crops and are the causal agent of slow decline of citrus. This semiendoparasitic nematode has a narrow host range that includes olive, grape and citrus. In the present study, ARS and Alexandria University scientists examined the reactions of some citrus, grape, olive, loquat and persimmon species and cultivars to the citrus nematodes, Tylenchulus semipenetrans in the greenhouse. The results show that T. semipenetrans infected and reproduced successfully on all the tested fruit species and cultivars. Soil amendments with dried plant materials of horseradish tree, blue gum tree, lime, crude culture suspensions of Bacillus subtilis and B. thuringiensis, Vertimec (abamectin), and Nemacur (fenamiphos) were effective in suppressing T. semipenetrans infection and reproduction on sour orange roots. The results are significant because they provide the first evidence on the pathogenicity of T. semipenetrans on loquat from Egypt. This research will be of use to scientists, growers and extension agencies involved in citrus nematode research and control.

Technical Abstract: The pathogenicity of the citrus nematode Tylenchulus semipenetrans on some citrus, grape, olive, loquat and persimmon species and cultivars was determined in several greenhouse tests. The results show that T. semipenetrans infected and reproduced successfully on all the tested fruit species and cultivars. The citrus ("lime", "mandarin", "sour orange"), red seedless grape ("Crimson"), olive ("Pikwal", "Spanish"), loquat ("Premier"), and persimmon ("Balady") trees were highly susceptible to T. semipenetrans, while green seedless grape ("Thompson") and olive ("Ogeizi") trees were susceptible to this nematode species. Soil amendments with dried plant materials of horseradish tree, blue gum tree, lime, crude culture suspensions of Bacillus subtilis and B. thuringiensis, Vertimec (abamectin), and Nemacur (fenamiphos) were effective in suppressing T. semipenetrans infection and reproduction on sour orange roots. The highest reductions (90.2-94.2%) of nematode reproduction (numbers of 2nd stage juveniles, J2's) were recorded with treatments of horseradish tree dried leaves, Vertemic and Nemacur. Treatments with lime peel fruits, S. subtilis and B. thuringiensis showed 76.5-86.4% reduction in T. semipenetrans J2's. On the other hand, amendments with blue gum tree leaves resulted in 61.6-62.4% reduction in T. semipenetrans J2's. This represents the first study in Egypt on the pathogenicity of T. semipenetrans on loquat.