Field standards

1. Isolation. a. Seed parent increases (AxB). Fields or parts of fields acceptable for production of seed parents to be used for the production of commercial hybrid seed must be so located that the seed parent is not less than two thousand six hundred forty feet [804.67 meters] from fields of other kinds or varieties that could provide a source of contamination, or from fields of the same variety that do not meet varietal purity requirements for certification. The A-line and B-line must be separated by an unplanted strip of ground adequate to prevent mechanical mixture. b. Maintainer and restorer increases. Fields or parts of fields acceptable for production of pollinator lines must be so located that the line is not less than thirty feet [9 meters] from fields of other kinds or varieties which could provide a source of contamination, or from fields of the same variety that do not meet varietal purity requirements for certification. Before inspection, the field must be isolated from inseparable crops by a strip at least five feet [1.52 meters] wide to prevent mechanical contamination. c. Commercial hybrids. Fields or parts of fields acceptable for production of commercial hybrid seed must be no less than three hundred thirty feet [100.58 meters] from fields of other kinds or varieties that would provide a source of contamination, or from fields of the same variety that do not meet varietal purity requirements for certification. Seed parent and restorer lines must be separated from each other by an unplanted strip of ground adequate to prevent mechanical mixture. 2. Specific field standards. Factor A-Line Foundation B- and R-Lines Foundation Commercial Hybrid Certified Pollen shedders 1:3,000 N/A N/A Other varieties * 1:3,000 1:3,000 1:3,000 Inseparable other crops 1:30,000 1:30,000 1:5,000 Prohibited noxious weed seeds ** none none none *Other varieties include plants that can be differentiated from the variety being inspected, but may not include variants that are characteristic of the variety. **The tolerance for prohibited or objectionable weeds, or both, in the field will be determined by the inspector.