Author
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BRODIE, BILL |
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Submitted to: Journal of Nematology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/22/1996 Publication Date: N/A Citation: N/A Interpretive Summary: The golden nematode is a serious threat to the potato industry of the United States. If left uncontrolled, this nematode can cause up to 80% loss of potato yields. A strict quarantine together with an aggressive regula- tory and control program has limited the golden nematode in the United States to 6 counties in New York State. Environmental and human health concerns forced the decision to eliminate the use of pesticides in the golden nematode control program. This decision focused attention on the development of nonchemical means of controlling the golden nematode. The present study explored the feasibility of using host resistance to control the golden nematode. The objective of the study was to determine how often resistant potato varieties must be grown in cropping systems involving nonhost crops & susceptible potato varieties to manage the golden nematode at population densities that prevents its spread. The results indicate that twhen nematode population densities reach levels that are detectable by a regulatory survey, two successive years of a resistant variety followed by one year of a nonhost with a susceptible variety grown only once in four years manage the nematode at the desired population density. When nematode populations were below the detection level, two successive years of a resistant variety followed by a susceptible variety every third year of production without a nonhost crop successfully managed the golden nematode. These nematodes management strategies have been implemented by regulatory agencies to manage the golden nematode in both infested and exposed lands. Technical Abstract: Cropping systems in which resistant potato cultivars were grown at different frequencies in rotation with susceptible cultivars and a nonhost (oats), were evaluated at four initial nematode population densitites (Pi) for their ability to manage Globodera rostochiensis at a target level of <0.2 egg/cm3 of soil. At a Pi of 0.1-1 egg/cm3 of soil, cropping systems with two successive years of a resistant cultivar every 3 years of potato production reduced and maintained G. rostochiensis at <0.2 egg/cm3 of soil. At a Pi of 1-4 eggs/cm3 of soil, two successive years of a resistant cultivar followed by one year of oats for every four years of production were necessary to reduce and maintain G. rostochiensis populations at <0.2 egg/cm3 of soil. At a Pi greater than 4 eggs/cm3 of soil, two successive years of a resistant cultivar plus one year of oats reduced G. rostochiensis densitites to <0.2 eggs/cm3 of soil but did not maintain them at that density after cropping one year to a susceptible cultivar. The numbers of cysts and eggs/cst in the final population (Pf) of G. rostochiensis was influenced by initial density and the frequency of growing a susceptible cultivar in a cropping system. The fewest number of cysts and eggs/cst in the final G. rostochiensis population occurred with a cropping system consisting of two successive years of a resistant cultivar followed by oats with a susceptible cultivar grown the fourth year of production. |
