Corn Crop Standards

(Zea mays)

GENERAL STANDARDS -- The standards on this sheet are in part condensed and apply to open-pollinated corn (except for open-pollinated inbred lines used in hybrid production). For greater detail and additional provisions, see the General Standards.

PLANTING STOCK -- Breeder seed must be planted to produce Foundation seed. Foundation seed must be planted to produce Registered seed. Registered seed must be planted to produce Certified seed. In varieties where there is no Registered class, Foundation seed must be planted to produce Certified seed.

APPLICATION -- Applications should be submitted electronically on CCIA’s website (Application to grow and certify seed) as soon as possible and no later than three (3) weeks after planting. New applicants should contact the CCIA office for instructions on obtaining access to the online application system.

FIELD ELIGIBILITY -- Corn may be grown for certification only on land where no other corn of the same color or endosperm type has been grown in the preceding crop year.

ISOLATION -- All fields or portions of fields of any class must be isolated from other varieties of corn with the same color or texture by a minimum of 660’ and 1320’ from varieties that have a different color or texture. If the corn is the same variety, only a definite separation is required.

FIELD INSPECTION -- For all classes of certified seed there shall be at least one (1) field inspection. When the seed crop follows another corn crop either the preceding year or the current year, at least one (1) additional inspection must be made.

Off-types -- Every field should be rogued to completely destroy any plants of other varieties of corn prior to pollen dispersal. Varieties cannot always be differentiated at field inspection. When differences can be distinguished, the maximum mixture of other varieties, distinct off-types, and inseparable other crops permitted is as follows:

Foundation - 1:500
Certified - 1:200

Weeds -- Fields must be free of any prohibited noxious weeds. Restricted noxious weeds, and common weeds difficult to separate must be controlled. Prohibited and Restricted noxious weeds are listed in the California Seed Law/CA Code of Regulations/Sections 3854 and 3855. See California Seed Law - Prohibited and Restricted Noxious Weed List.

Fields may be refused certification due to unsatisfactory appearance caused by weeds, poor growth, poor stand, disease, insect damage, and any other condition which prevents accurate inspection or creates doubt as to identity of the variety.

A Field Inspection Report will be available to the applicant online. If the field is approved, a certification number will be assigned. This number must be on all containers of seed before they leave the field. It is the responsibility of the applicant to make sure his field has been inspected before it is harvested.

HARVESTING -- Harvesting is subject to the supervision of the local County Agricultural Commissioner who must be contacted prior to harvest. Any seed moved out of the county must be accompanied by an Inter-County Permit or Interstate Transfer of Seed Certificate issued by the Commissioner.

CONDITIONING AND SAMPLING -- Conditioning of seed for certification may be done only in facilities approved for this purpose by the California Crop Improvement Association. It is the responsibility of the applicant to determine if the facility is eligible before delivering seed for conditioning. Conditioning, sampling, reconditioning, and blending must be supervised by the County Agricultural Commissioner. Conditioning equipment must be free from contaminating seed to the satisfaction of the supervising inspector.

SEED INSPECTION - All seed must be sampled and tested after conditioning and the seed lot must meet or exceed seed certification standards for that crop. A seed lab using the Association of Official Seed Analyst “Rules for Testing” must test the sample. A Registered Seed Technologist must sign each lab analysis. In addition to AOSA rules, specific seed testing may be required to meet CCIA seed certification standards.

The conditioner is required to submit a 1,000 gram sample to the laboratory (Submitted Sample Sizes for Certification) for analysis. In some instances, varietal identity cannot be determined by visual seed inspections. Seed must be well screened and graded, bright in color, of good appearance and meet the following standards:

Pure Seed

   99.00% (Minimum)

Inert Matter

   1.0% (Maximum)

Other Varieties


- Foundation


- Certified

   0.5% (Maximum)

Other Crop

   0.5% (Maximum)

- Castor Bean seed


Weed Seed


Noxious Weed Seed



   14% (Maximum)


   90.00% (Minimum)

The CCIA requires Reports of Analysis for initial certification to be dated no more than a maximum of six (6) months prior to the request for seed certification. The 'Purity Analysis' and 'Germination' must be conducted on the same laboratory seed sample and those results must be presented in a single Report of Analysis.

FINAL CERTIFICATION AND TAGGING -- If the seed sample meets all standards a Seed Inspection Report is issued. Before certification is complete, however, each container must have an official tag or label attached. Certified seed may be sold to a grower in bulk without tagging if a properly filled out Bulk Sale Certificate accompanies the shipment. The tags and Bulk Sale Certificates are issued by the California Crop Improvement Association.

Updated November 2019