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  • Author or Editor: Donald Halseth x
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We report field experiments, under N limiting conditions, where applied N was varied between 0 and 252 Kg/ha. Two varieties (Castile and Allegheny) were planted in 1990 and 3 varieties (Katahdin, Monona and Superior) were planted in 1991. A curvilinear tuber yield response to N rate was obtained both years for all varieties with maximum yields at about 168 Kg/ha of N. Weekly field measurements with a hand-held chlorophyll meter (Minolta SPAD 502) were highly correlated to yield, to fresh petiole sap nitrate, to dry petiole nitrate and to the total N of whole leaves, all of which were generally highly correlated to each other and markedly affected by applied N. As plants matured the chlorophyll readings, and concentrations of nitrate and N decreased. In general variety differences or variety × N rate interactions were not significant which encourages the use of such tests to avoid unnecessary N sidedressings.

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Experiments were conducted at Freeville, NY and Riverhead, NY with 0-280 kg/ha of N banded. Tissue samples (both petioles and whole leaves) were taken 5 times starting 32 days from planting. There was a marked increase in yield and specific gravity from the first 112 kg/ha of N and in most cases from an additional 56 kg/ha of N. Both petiole and whole leaf nitrate were sensitive to changes in fertilizer rate that resulted in yield changes. We were encouraged by results obtained with “quick” tests on fresh sap since the pattern paralleled that obtained with traditional lab analysis of dried ground petioles. Although nitrate concentrations did not vary markedly across the varieties used there were substantial differences due to location even when the yield response curve was similar. Rate of N for rate of N, the Freeville samples were substantially higher in nitrate than those from Long Island, except at the 0 N rate, suggesting that the difference is not due to soil residual N.

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Databases are commonly used to coordinate and summarize research from multiple projects. The potato (Solanum tuberosum) research community has invested significant resources in collecting data from multiple states and provinces, and we have developed a web-based database format for the use of researchers, farmers, and consumers. The northeast regional potato variety development project (NE1031) is a U.S. Department of Agriculture, Cooperative State Research, Education, and Extension Service (USDA-CSREES) regional project focused on developing and evaluating the suitability of new varieties and advanced clones from multiple breeding programs for a range of environments. This multistate project and its predecessors have been in existence for more than two decades, and they have resulted in the collection of a significant amount of standardized potato trial data. We have developed an interactive potato variety database that allows researchers and end-users to access and obtain potato variety trial results in one centralized site. The database is populated with the results of potato variety trials conducted in eight states (Florida, Maine, New Jersey, New York, North Carolina, Ohio, Pennsylvania, and Virginia) and two Canadian provinces (Prince Edward Island and Quebec). It currently contains over 35 data features and was developed primarily for scientists interested in potato variety development, growers, and allied industry members. Hypertext mark-up language (HTML) and hypertext preprocessor (PHP) were used to develop the database interface.

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