Storage Inspections

PCAN personnel perform storage inspections between harvest and shipping. The purpose of these inspections is to assess the storability, health, and quality of seed during the storage season. Additionally, these inspections aid PCAN personnel and growers in identifying potential issues before the shipping season is underway, allowing growers to make informed decisions concerning their seed. In most cases storage inspections are conducted on site (Figure 1). However, seed may be delivered to the PCAN office for inspections as well (Figure 2).


Storage Inspection Rules

  • Bins need to be approved by PCAN in advance of their use.
  • Potatoes eligible for storage inspection and tagging as certified potatoes cannot be stored, graded, or handled in storages containing unidentified potatoes (which were not field inspected for certification), or lots rejected for the presence of Bacterial Ring Rot.
  • Separation of seed lots should be easily identifiable.
  • A written notification shall be filled with the PCAN office if certified seed stocks are moved in bulk from one storage to another.

Figure 1. Storage inspection conducted on site.

Figure 2. Storage inspection conducted at PCAN office.

Commonly Asked Questions Regarding Storage

  • When are storage inspections normally conducted?
    As soon as possible after harvest.
  • How much do storage inspections costs?
    The cost of storage inspections is 7 cents per cwt per lot.
  • Does the procedure for inspecting Nuclear and G1 lots differ from inspecting G2-G5 lots?
    Seed lots from Nuclear and G1 will be visibly examined, unless otherwise requested by the seed grower. G1 lots will be inspected if they exceed 250 hundredweight.
  • If a lot meets all disease tolerances specified within a designated grade during a storage inspection, is it considered certified?
    If a lot meets all disease tolerances specified, it is considered as certified subject to grading before final sale.
  • If a lot fails to meet disease tolerances or any other special requirements, is it rejected for certification?
    It is rejected for certification, except for factors that can be removed. In other words, a lot may be rejected if there is significant breakdown from leak or water rot such that affected potatoes cannot be removed at or prior to grading  The presence of debris, damaged potatoes, or off types will not result in a rejection for certification, since these factors can be removed.  Once these disqualifying factors are removed, the lots are then eligible for re-inspection and final certification.
  • What are maximum disease tolerances allowed during storage inspections?
    Maximum disease tolerances for storage inspections are listed in Figure 3.
Figure 3. Maximum disease tolerances allowed during storage inspections.
Disease Generation N – 3 Generation 4 & 5
Stem End Discoloration 2.5% 5.0%
Variety Mixture 0.1% 0.5%
Other Diseases 0.1% 0.5%
  • When is the presence of stem end discoloration scored against a lot?
    Stem End Discoloration is considered as a grading factor and is scored if it causes damage.
  • When will varietal mix be scored against a lot?
    If it is removable at grading.