NAC587.428. Inspection of planting; frequency; conditions preventing adequate inspection; standards for disease tolerance levels.  


Latest version.
  •      1. The Department may inspect a planting at any time.

         2. The Department will make at least two field inspections during the growing stage of the planting. The Department may make additional inspections, but not for the purpose of allowing a grower to rogue a planting that will not pass inspection.

         3. The Department may disqualify a planting from certification if any condition prevents adequate inspection of the planting. Such conditions include, without limitation:

         (a) Excessive weed growth.

         (b) Disease.

         (c) Weather.

         (d) Chemical damage.

         (e) Another environmental condition.

         4. To be eligible to produce certified seed potatoes, a planting must not exceed the maximum percentage of disease tolerance for each factor for the generation of seed potato produced.

         5. Disease tolerances are established only for diseased plants showing visible symptoms, but serological tests such as ELISA may be used to confirm the presence of disease on plant samples taken from the planting. Disease tolerances are based on the following symptoms:

         (a) Visual symptoms at the time of field inspections.

         (b) For blackleg, the presence of a typical, inky black stem originating from the tuber.

         (c) For bacterial ring rot, visual symptoms that are confirmed by laboratory diagnosis.

         6. During the first field inspection, a planting must not exceed the following maximum percentages of disease tolerances for the generation of seed potatoes produced:

    Factor

                                 Percent for Each Generation

      Nuclear

        Gen 1

         Gen 2

        Gen 3

         Gen 4

        Gen 5

    Potato leaf roll virus

         0.00

          0.00

         0.03

          0.05

         0.10

          0.20

    Well-defined mosaic

         0.00

          0.00

         0.10

          0.50

         0.80

          2.00

    Total visible viruses

         0.00

          0.00

         0.10

          0.50

         1.00

          2.00

    Spindle tuber viroid

         0.00

          0.00

         0.00

          0.00

         0.00

          0.00

    Blackleg

         0.00

          0.10

         0.50

          1.00

         2.00

          3.00

    Bacterial ring rot

         0.00

          0.00

         0.00

          0.00

         0.00

          0.00

    Root-knot nematode

         0.00

          0.00

         0.00

          0.00

         0.00

          0.00

    Other varieties

         0.00

          0.00

         0.02

          0.10

         0.25

          0.50

         7. During the second field inspection, a planting must not exceed the following maximum percentages of disease tolerances for the generation of seed potatoes produced:

    Factor

                                 Percent for Each Generation

      Nuclear

        Gen 1

         Gen 2

        Gen 3

         Gen 4

        Gen 5

    Potato leaf roll virus

         0.00

          0.00

         0.01

          0.05

         0.10

          0.20

    Well-defined mosaic

         0.00

          0.00

         0.05

          0.25

         0.50

          1.00

    Total visible viruses

         0.00

          0.00

         0.05

          0.25

         0.50

          1.00

    Spindle tuber viroid

         0.00

          0.00

         0.00

          0.00

         0.00

          0.00

    Blackleg

         0.00

          0.10

         0.50

          1.00

         2.00

          3.00

    Bacterial ring rot

         0.00

          0.00

         0.00

          0.00

         0.00

          0.00

    Root-knot nematode

         0.00

          0.00

         0.00

          0.00

         0.00

          0.00

    Other varieties

         0.00

          0.00

         0.01

          0.05

         0.10

          0.20

         8. A finding of 0.00 percent of disease tolerance means that none must be found during normal inspection procedures, but such a finding does not guarantee that all plants in the planting are free from the disease.

         9. When a planting exceeds the disease tolerances for the generation of seed potatoes produced, the Department will classify the seed potatoes as the next higher generation for which the seed potatoes do not exceed the disease tolerances.

         10. As used in this section:

         (a) “ELISA” means enzyme linked immunosorbent assay.

         (b) “Total visible viruses” means the combined percentages of disease tolerances of potato leaf roll virus, well-defined mosaic, calico and all other viral, viroid and mycoplasma-like diseases, including haywire, witches’ broom and aster yellows.

     (Added to NAC by Dep’t of Agriculture by R036-01, eff. 10-17-2001)