Potato yield loss prediction and discrimination using preplant population densities of Verticillium dahliae and Pratylenchus penetrans
Reduced yield of potato, Solanum tuberosum, attributable to preplant population densities of Verticillium dahliae and Pratylenchus penetrans, pathogens involved in potato early dying disease, were quantified with linear regression models. Experimental microplot data consisted of controlled, factorial, pathogen inoculum levels in fumigated soil and resulting yields of potato cultivar Superior at two locations over a 5-6 yr period. Variation in yield relative to controls was explained best by regressions on the natural log of V. dahliae x P. penetrans. Population densities of pathogens at planting also were used in a discriminant analysis to predict yields above or below 90 percent of the control yield. A discriminant function correctly classified 86 percent of the yields from a 3-yr subset of data from one location. The rate of correct classification was 70 percent when the same discriminant function was validated on data not used in model development. Erection of a third category, "between 80-90 percent of the control yield," resulted in an overall 6 percent misclassification rate for the "below 80 percent relative yield" category as "above 90 percent relative yield," and a 23 percent misclassification rate for "above 90 percent relative yield" as "below 80 percent relative yield." Discriminant models intentionally minimized "below 80 percent relative yield" misclassification in order to promote confidence in the management of potato early dying
| Main Authors: | , , , |
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| Format: | biblioteca |
| Published: |
1987
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| Subjects: | HORTALIZAS DE RAIZ, SOLANUM TUBEROSUM, VERTICILLIUM DAHLIAE, PRATYLENCHUS PENETRANS, RENDIMIENTO, PERDIDAS, DENSIDAD DE LA POBLACION, NEMATODOS DE LAS PLANTAS, MODELOS, CONTROL DE PLAGAS, |
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| Summary: | Reduced yield of potato, Solanum tuberosum, attributable to preplant population densities of Verticillium dahliae and Pratylenchus penetrans, pathogens involved in potato early dying disease, were quantified with linear regression models. Experimental microplot data consisted of controlled, factorial, pathogen inoculum levels in fumigated soil and resulting yields of potato cultivar Superior at two locations over a 5-6 yr period. Variation in yield relative to controls was explained best by regressions on the natural log of V. dahliae x P. penetrans. Population densities of pathogens at planting also were used in a discriminant analysis to predict yields above or below 90 percent of the control yield. A discriminant function correctly classified 86 percent of the yields from a 3-yr subset of data from one location. The rate of correct classification was 70 percent when the same discriminant function was validated on data not used in model development. Erection of a third category, "between 80-90 percent of the control yield," resulted in an overall 6 percent misclassification rate for the "below 80 percent relative yield" category as "above 90 percent relative yield," and a 23 percent misclassification rate for "above 90 percent relative yield" as "below 80 percent relative yield." Discriminant models intentionally minimized "below 80 percent relative yield" misclassification in order to promote confidence in the management of potato early dying |
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