An Algorithm for Optimizing Rotational Control of Globodera rostochiensis on Potato Crops in Bolivia
Keywords:bolivia, decline rate, dormancy, fecundity, globodera rostochiensis, lipid use, nematode, pest management, population models, potato, potato cyst nematode, rotation
AbstractThe outline area of new cysts of Globodera rostochiensis was measured by image analysis. A linear regression of this value against egg content provided a basis for adjusting the egg number for cyst size. This adjusted egg content provides an estimate of the relative fullness of a cyst with eggs. This value showed an exponential decline in eggs over 3.5 years since the last potato crop. It corresponds to an average loss in the dormant egg population of 32.8 ± 5.6%/year for 26 fields at Toralapa, Bolivia. This value compared well with a mean decline of 40 ± 4%/year for 42 fields after measuring viable eggs/100 g soil on two occasions one year apart. The new approach allows declines to be estimated at one time point. The decline in lipid content of the dormant, unhatched second-stage juveniles (J2) was 17 ± 6% per annum as measured by image analysis after Oil red O staining. This may be sufficient to compromise infectivity after 3 to 4 years of dormancy. A standard model was modified to consider the effect of both lipid depletion during dormancy and choice of susceptible potato on the population dynamics of G. rostochiensis under rotational control. It is concluded that a few cultivars may impose lower populations on G. rostochiensis in 3 to 4-year rotations than the majority used in Bolivia.
Copyright and Permissions
All material published by the Society of Nematologists (SON), except for papers prepared by United States and Canadian government employees, is copyrighted and protected under the U.S. copyright law. Under the Copyright Act of 1976, the term of copyright for materials registered by an organization is 75 years from the date first published. Before publishing any manuscript, SON requires that authors transfer full and complete ownership of any copyright to SON by signing a JON Page Charge/Copyright Form (.pdf). SON then registers the copyright. Subsequent use of published materials requires written permission from the SON and may be obtained by contacting the current Editor-in-Chief and state where and how the material will be used.
The author warrants that the article is an original work not published elsewhere in whole or in part, except in abstract form, and that the author has full power to make this grant. If portions of the article have been published previously, then the author warrants that permission has been obtained from the copyright holder and the author will submit a copy of the permission release with this copyright transfer form.
SON shall claim no proprietary right other than copyright. Authors and coauthors retain the right to revise, adapt, modify, or otherwise use all or part of the article in future works of the author(s), such as press releases, lectures, and reviews, provided that all such use is for the personal noncommercial benefit of the author(s). All patent rights are retained by the author(s).