Weight of working sample.

(a) Unmixed seed. The working samples for purity analysis and noxiousweed seed examination of unmixed seed shall be at least the weights set forth in table 1. (b) Mixtures consisting of one predominant kind of seed or groups of kinds of similar size. The weights of the purity and noxious-weed seed working samples in this category shall be determined by the kind or group of kinds which comprise more than 50 percent of the sample. (c) Mixtures consisting of two or more kinds or groups of kinds of different sizes, none of which comprise over 50 percent of the sample. The weights of the purity working samples in this category shall be the weighted averages (to the nearest half gram) of the weights listed in table 1 for each of the kinds which comprise the sample determined by the following method: (1) Multiply the percentage of each component in the mixture (rounded off to the nearest whole number) by the sample sizes specified in column 2, table 1, (2) add all these products, (3) total the percentages of all components of the mixtures, and (4) divide the sum in paragraph (c)(2) of this section by the total in paragraph (c)(3) of this section. If the approximate percentage of the components of a mixture are not known they may be estimated. The weight of the noxious-weed seed working sample shall be determined by multiplying the weight of the purity working sample by 10 or by calculating the weighted average in the same manner described above for the purity working sample. (d) Coated seed. (1) Unmixed coated seed. Due to variation in the weight of coating materials, the size or weight of the working sample shall be determined separately for each lot. The weight of the working sample shall be determined by weighing 100 completely coated units and calculating the weight of 2,500 coated units for the purity analysis and 25,000 coated units for the noxious-weed seed examination. (2) Mixtures of coated seed. The working weight shall be determined in the following manner: (i) Calculate the weight of the working sample to be used for the mixture under consideration as though the sample were not coated by following paragraph (b) or (c) of this section. (ii) Determine the amount of coating material on 100 coated units by weighing the coated units. Remove the coating material using the methods described in §§ 201.51b (c) and (d). Calculate the percentage of coating material using the following formulas: Weight of coating material = weight of 100 coated units − weight of 100 de-coated units; The percentage of coating material = weight of the coating material divided by the weight of 100 coated units × 100%. (iii) The weight of the working sample shall be the product of the weight calculated in paragraph (d)(2)(i) of this section multiplied by 100 percent, divided by 100 percent minus the percentage of coating material calculated in paragraph (d)(2)(ii) of this section. Table 1—Weight of Working Sample Name of seed Minimum weight for purity analysis (grams) Minimum weight for noxious-weed seed examination (grams) Approximate number of seeds per gram Agricultural Seed Agrotricum 65 500 39 Alfalfa 5 50 500 Alfilaria 5 50 440 Alyceclover 5 50 665 Bahiagrass: Var. Pensacola 5 50 600 All other vars. 7 50 365 Barley 100 500 30 Barrelclover 10 100 250 Bean: Adzuki 200 500 11 Field 500 500 4 Mung 100 500 24 Beet, field 50 500 55 Beet, sugar 50 500 55 Beggarweed, Florida 5 50 440 Bentgrass: Colonial 0.25 2.5 13,000 Creeping 0.25 2.5 13,515 Velvet 0.25 2.5 18,180 Bermudagrass 1 10 3,930 Bermudagrass, giant 1 10 2,950 Bluegrass: Annual 1 10 2,635 Bulbous 4 40 585 Canada 0.5 5 5,050 Glaucantha 1 10 Kentucky 1 10 3,060 Nevada 1 10 2,305 Rough 0.5 5 4,610 Texas 1 10 2,500 Wood 0.5 5 4,330 Bluejoint 0.5 5 8,461 Bluestem: Big 7 70 320 Little 5 50 525 Sand 10 100 215 Yellow 1 10 1,945 Bottlebrush-squirreltail 9 90 300 Brome: Field 5 50 465 Meadow 13 130 190 Mountain 20 200 140 Smooth 7 70 315 Broomcorn 40 400 60 Buckwheat 50 500 45 Buffalograss: (Burs) 20 200 110 (Caryopses) 3 30 740 Buffelgrass: (Fascicles) 6 66 365 (Caryopses) 2 20 1,940 Burclover, California: (in bur) 50 500 (out of bur) 7 70 375 Burclover, spotted (in bur) 50 500 50 (out of bur) 5 50 550 Burnet, little 25 250 110 Buttonclover 7 70 365 Camelina 4 40 880 Canarygrass 20 200 150 Canarygrass, reed 2 20 1,185 Carpetgrass 1 10 2,230 Castorbean 500 500 5 Chess, soft 5 50 555 Chickpea 500 500 2 Clover: Alsike 2 20 1,500 Arrowleaf 4 40 705 Berseem 5 50 455 Cluster 1 10 2,925 Crimson 10 100 330 Kenya 2 20 Ladino 2 20 1,935 Lappa 2 20 1,500 Large hop 1 10 5,435 Persian 2 20 1,415 Red 5 50 600 Rose 7 70 360 Small hop 2 20 1,950 Strawberry 5 50 635 Sub 25 250 120 White 2 20 1,500 Corn: Field 500 500 3 Pop 500 500 3 Cotton 300 500 8 Cowpea 300 500 8 Crambe 25 250 Crested dogtail 2 20 1,900 Crotalaria: Lance 7 70 375 Showy 25 250 80 Slenderleaf 10 100 205 Striped 10 100 215 Sunn 75 500 35 Crownvetch 10 100 305 Dallisgrass 4 40 620 Dichondra 5 50 470 Dropseed, sand 0.25 2.5 12,345 Emmer 100 500 25 Fescue: Chewings 3 30 900 Hair 1 10 Hard 2 20 1,305 Meadow 5 50 495 Red 3 30 900 Sheep 2 20 1,165 Tall 5 50 455 Flatpea 100 500 25 Flax 15 150 180 Foxtail, creeping 1.5 15 1,736 Foxtail, meadow 3 30 893 Galletagrass: (Other than caryopses) 10 100 260 (Caryopses) 5 50 580 Grama: Blue 2 20 1,595 Side-oats: (Other than caryopses) 6 60 350 (Caryopses) 2 20 1,605 Guar 75 500 35 Guineagrass 2 20 2,205 Hardinggrass 3 30 750 Hemp 50 500 45 Indiangrass, yellow 7 70 395 Indigo, hairy 7 70 435 Japanese lawngrass 2 20 1,325 Johnsongrass 10 100 265 Kenaf 50 500 Kochia, forage 2 20 1,070 Kudzu 25 250 80 Lentil 120 500 14-23 Lespedeza: Korean 5 50 525 Sericea 3 30 820 Siberian 3 30 820 Striate 5 50 750 Lovegrass, sand 1 10 3,585 Lovegrass, weeping 1 10 3,270 Lupine: Blue 500 500 7 White 500 500 7 Yellow 300 500 9 Manilagrass 2 20 Medic, black 5 50 585 Milkvetch 9 90 270 Millet: Browntop 8 80 315 Foxtail 5 50 480 Japanese 9 90 315 Pearl 15 150 180 Proso 15 150 185 Molassesgrass 0.5 5 7,750 Mustard: Black 2 20 1,255 India 5 50 625 White 15 150 160 Napiergrass 5 50 Needlegrass, green 7 70 370 Oat 75 500 35-50 Oatgrass, tall 6 60 417 Orchardgrass 3 30 945 Panicgrass, blue 2 20 1,370 Panicgrass, green 2 20 1,305 Pea, field 500 500 4 Peanut 500 500 1-3 Radish 30 300 75 Rape: Annual 7 70 345 Bird 7 70 425 Turnip 5 50 535 Winter 10 100 230 Redtop 0.25 2.5 10,695 Rescuegrass 20 200 115 Rhodesgrass 1 10 4,725 Rice 50 500 65 Ricegrass, Indian 7 70 355 Roughpea 75 500 40 Rye 75 500 40 Rye, mountain 28 280 90 Ryegrass: Annual 5 50 420 Intermediate 8 80 338 Perennial 5 50 530 Wimmera 5 50 Safflower 100 500 30 Sagewort, Louisiana 0.5 5 8,900 Sainfoin 50 500 50 Saltbush, fourwing 15 150 165 Sesame 7 70 360 Sesbania 25 250 105 Smilo 2 20 2,010 Sorghum 50 500 55 Sorghum almum 15 150 150 Sorghum-sudangrass 65 500 38 Sorgrass 1 15 150 135 Sourclover 5 50 660 Soybean 500 500 6-13 Spelt 100 500 25 Sudangrass 25 250 100 Sunflower 100 500 Sweetclover: White 5 50 570 Yellow 5 50 570 Sweet vernalgrass 2 20 1,600 Sweetvetch, northern 19 190 130 Switchgrass 4 40 570 Teff 1 10 3,288 Timothy 1 10 2,565 Timothy, turf 1 10 2,565 Tobacco 0.5 5 15,625 Trefoil: Big 2 20 1,945 Birdsfoot 3 30 815 Triticale 100 500 Vaseygrass 3 30 970 Veldtgrass 4 40 655 Velvetbean 500 500 2 Velvetgrass 1 10 3,360 Vetch: Common 150 500 19 Hairy 75 500 35 Hungarian 100 500 24 Monantha 100 500 Narrowleaf 50 500 60 Purple 100 500 22 Woollypod 100 500 25 Wheat: Common 100 500 25 Club 100 500 25 Durum 100 500 25 Polish 100 500 25 Poulard 100 500 25 Wheat × Agrotricum 65 500 38 Wheatgrass: Beardless 8 80 275 Fairway crested 4 40 685 Standard crested 5 50 425 Intermediate 15 150 175 Pubescent 15 150 180 Siberian 5 50 Slender 7 70 295 Streambank 10 50 370 Tall 15 150 165 Western 10 100 250 Wildrye: Basin 8 80 317 Canada 11 110 190 Russian 6 60 360 Vegetable Seed Artichoke 100 500 24 Asparagus 100 500 25 Asparagusbean 300 500 8 Bean: Garden 500 500 4 Lima 500 500 2 Runner 500 500 1 Beet 50 300 60 Broadbean 500 500 Broccoli 10 50 315 Brussels sprouts 10 50 315 Burdock, great 15 150 Cabbage 10 50 315 Cabbage, Chinese 5 50 635 Cabbage, tronchuda 10 100 Cardoon 100 500 Carrot 3 50 825 Cauliflower 10 50 315 Celeriac 1 25 2,520 Celery 1 25 2,520 Chard, Swiss 50 300 60 Chicory 3 50 940 Chives 5 50 Citron 200 500 11 Collards 10 50 315 Corn, sweet 500 500 Cornsalad: Vars. Fullhearted and Dark Green Fullhearted 5 50 All other vars 10 50 380 Cowpea 300 500 8 Cress: Garden 5 50 425 Upland 2 35 1,160 Water 1 25 5,170 Cucumber 75 500 40 Dandelion 2 35 1,240 Dill 3 50 800 Eggplant 10 50 230 Endive 3 50 940 Gherkin, West India 16 160 153 Kale 10 50 315 Kale, Chinese 10 50 Kale, Siberian 8 80 325 Kohlrabi 10 50 315 Leek 7 50 395 Lettuce 3 50 890 Melon 50 500 45 Mustard, India 5 50 625 Mustard, spinach 5 50 535 Okra 100 500 19 Onion 7 50 340 Onion, Welsh 10 50 Pak-choi 5 50 635 Parsley 5 50 650 Parsnip 5 50 430 Pea 500 500 3 Pepper 15 150 165 Pumpkin 500 500 5 Radish 30 300 75 Rhubarb 50 300 60 Rutabaga 5 50 430 Sage 25 150 120 Salsify 50 300 65 Savory, summer 2 35 1,750 Sorrel 2 35 1,080 Soybean 500 500 6-13 Spinach 25 150 100 Spinach, New Zealand 200 500 13 Squash 200 500 14 Tomato 5 50 405 Tomato, husk 2 35 1,240 Turnip 5 50 535 Watermelon 200 500 11 1 Rhizomatous derivatives of a johnsongrass × sorghum cross or a johnsongrass × sudangrass cross. [25 FR 8769, Sept. 13, 1960, as amended at 30 FR 7888, June 18, 1965; 32 FR 12780, Sept. 6, 1967; 35 FR 6108, Apr. 15, 1970; 41 FR 20156, May 17, 1976; 46 FR 53635, Oct. 29, 1981; 59 FR 64492, Dec. 14, 1994; 65 FR 1707, Jan. 11, 2000; 85 FR 40580, July 7, 2020]