(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 a group 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 compromise 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

Open Table
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
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
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
Sorgrass1 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
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

1Rhizomatous 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]


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