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California Crop Improvement Association
University of California
California Crop Improvement Association

Certified Blends and Mixtures

Section 22. Certified Blends and Mixtures

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Blending  is considered part of the conditioning process. Only those conditioners capable of uniform blending shall be accepted into this program. Permission to blend  seed lots together must be obtained in advance. The specific ‘Certified Seed Blending Permit’,  available from the CCIA web site, must be completed, submitted, and approved by  the CCIA for each blend or blend type prior to blending. The number on the ‘Certified  Seed Blending Permit’ becomes the new certification number for the seed lot. This  new certification number is not preceded by any other designation but may have lot  identification added.  If seed lots of  different certified seed classes are blended the resulting blended lot shall be  equal to the lowest class of the components except as noted.


22.1   In-Dirt Blend. An  in-dirt blend is the comingling of harvested seed of a single variety from  fields that have been inspected and passed as a class of certified seed but  were assigned different certification numbers. The in-dirt blend is done to  establish a single identifying number for handling, storage and conditioning of  the same variety and kind of seed eligible for certification.  A completed “Blend Permit - InDirt” (Excel spreadsheet) listing  all application numbers and their certification numbers must be approved by the  CCIA prior to blending. The  entire production from an application/field will be used in the blend. The number on the “In-Dirt Certified  Seed Blending Permit” form becomes the new certification number and is preceded  by the letters CA-D; example: CA-D12345. This new certification number may  be followed by lot designations. In-dirt blends can be prepared for any class  of certified seed, however, if lots of different certified classes are blended,  the resulting lot shall be equal to the lowest class of the components.


22.2  Lot Blend. A lot blend is made by blending different lots of  the same variety. This  blend is often desirable to combine numerous small lots of seed to create one  larger uniform lot and to establish a single certification number for handling,  storage and marketing. Blending of seed lots which have failed to meet  certification standards is also permitted so long as the reason for failure was  not for genetic purity, prohibited or restricted noxious weeds, or of poor quality  and appearance. A completed “Blend Permit - Lots” (Excel spreadsheet) for lot blends (listing all  component lots, seed identification numbers, and certification numbers) must be  approved by the CCIA prior to blending. The calculated weighted average of lots  within the certified blend must meet minimum standards for the crop or after  blending a seed sample must be taken and submitted for testing. The Laboratory  Report of Analysis for the blend must meet crop standards. Blends  can be prepared for any class of certified seed however if lots of different  certified classes are blended, the resulting lot shall be equal to the lowest  class of the components. The  number on the “Lot Blend - Certified Seed Blending Permit” form becomes the new  certification number and is preceded by the letters CA-L; example CA-L12345.  This new certification number may be followed  by lot designations. 


22.3   Varietal Blend. A varietal blend is  made by  blending seed lots of different varieties of the same kind of seed and marketed  as a “Named Varietal Blend” of certified seed. For detailed information about  the approval and labeling of varietal blends check the CCIA web site at Seed Lot Blend Information.

  1. The conditioner will submit a completed “Blend Permit - Varietal” (Excel spreadsheet) which identifies each individual lot and variety along  with calculated analyses. The CCIA will verify information submitted and issue  written conditional approval.

  2. The certification number on the “Varietal Blend  - Certified Seed Blending Permit” form is comprised of the letters CA-V and a 5  digit number: example CA-V12345.  This  new certification number may be followed by lot designations.

  3. After blending, bagging, and tagging the  varietal blend, a representative seed sample will be sent for laboratory  analysis and the results forwarded to the CCIA. In addition, a 1,000 gram seed  sample will be sent to the CCIA for audit or verification purposes. The blend  must be held on the premises until the final written approval from the CCIA is  received.

  4. If the blend lot fails to meet certification  standards, the certification tags must be removed and returned to the CCIA.

  5. If the blend lot  passes certification standards, the CCIA will issue a written final approval  and the seed may be moved.


22.4   Mixture. A mixture is a combination of seed lots from two or more kinds (species) of seed and marketed as a "Mixture of certified seed". The mixture may contain two or more varieties of the same species. Example of a pasture mixture may contain several seed lots of clover, vetch, and grasses. All component varieties of a "Mixture of certified seed" shall have been approved for certification by the CCIA. Permission to use a protected or proprietary variety in a "Mixture of certified seed" must be obtained from the owner of that variety and presented in writing to the CCIA prior to acceptance of the mixture. Only the Foundation, Registered or Certified classes of certified seed are eligible to be a component in a "Mixture of certified seed", however, a mixture can only be labeled as the Certified class of seed. A completed "Blend Permit - Mixtures" (Excel spreadsheet) naming all component lots and their certification numbers and related information must be approved by the CCIA prior to the combination of the mixture. The certification number on the "Mixture - Certified Seed Permit" form is comprised of the letters CA-M and a 5 digit number: example CA-M12345.  This new certification number may be followed by lot designations.

Go to Section 23. Seed Laboratory

Updated: November 2010

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