Potato Variety Trials 2006

Clinton Shock, Eric Eldredge, and Lamont Saunders

Malheur Experiment Station

Oregon State University

Ontario, OR

Introduction

New potato varieties were evaluated for their productivity and suitability for precessing. Potatoes are grown under contract in Malheur County for processors to make frozen potato products for the food service industry and grocery chain stores. There is very little production for fresh pack or open market, and very few growers store potatoes on their farms. There is also no production of varieties for making potato chips.

The varieties grown for processing in Malheur County, Oregon, are mainly 'Ranger Russet', 'Shepody', and 'Russet Burbank'. Harvest begins in July, providing potatoes to processing plants directly from the field. Yield of harvests later than mid-August may be limited by the "early die" syndrome, which causes early senescence of the vines of susceptible varieties, especially Shepody and Russet Burbank. Early die is caused by a complex of soil pathogens, including bacteria, nematodes, and fungi, particularly Verticillium wilt. Early die is worse when the rotation between potato crops is shorter.

Small acreages of new varieties or advanced selections are sometimes grown under contract to study the feasibility of expanding their use. To displace an existing processing variety, a new potato variety needs to have several outstanding characteristics. The yield should be at least as high as the yield of the currently contracted varieties. The tubers need to have low reducing sugars for light fry color, and high specific gravity. A new variety should be resistant to tuber defects or deformities caused by disease, water stress, or heat. It should begin tuber bulking early and grow rapidly for early harvest. Late harvest varieties should be resistant to early die to continue bulking tubers until harvest.

Potato variety development trials at the Malheur Experiment Station in 2006 included the Western Regional Late Harvest Trial with 21 entries, the Oregon Statewide Trial with 24 entries, the Oregon Preliminary Yield Trial with 140 entries, and a Specialty Trial of 25 colored-flesh potato varieties. Through these trials and active cooperation with other scientists in Idaho, Oregon, and Washington, promising new lines are bred, evaluated, and the best of them may eventually be released as new varieties.

Materials and Methods

The potato variety trials were grown using sprinkler irrigation on Greenleaf silt loam, where winter wheat was the previous crop and potato had not been grown for the past 10 years. A soil test taken on September 12, 2005 showed 24 lb N/acre in the top foot of soil, and 14 ppm P2O5, 362 ppm K2O, 11 ppm SO4, 2,072 ppm Ca, 473 ppm Mg, 2.5 ppm Zn, 6 ppm Fe, 4 ppm Mn, 0.4 ppm Cu, 0.5 ppm B, organic matter 0.92 percent, and pH 7.8. Fertilizer was applied in the fall to supply 200 lb P2O5 /acre, 200 lb S/acre, 4 lb Mg/acre, 2 lb Cu/acre, and 1 lb B/acre. The soil was fumigated in the fall with Telone II® at 25 gal/acre. On April 12 the field was sprayed with Roundup® at 4 pt/acre, and on April 26 the field was bedded on 36-inch row spacing.

Seed of all varieties was hand cut into 2-oz seed pieces and treated with Tops-MZ® plus Gaucho® dust and placed in storage to suberize. Potato seed pieces were planted in single row plots using a two-row assist-feed planter with 9-inch seed spacing in 36-inch rows. Red potatoes were planted at the end of each plot as markers to separate the potato plots at harvest, except in the Specialty Trial where Ranger Russet was used as the marker.

The Western Regional Late Harvest Trial was planted on April 27, 2006. The Statewide Trial, the Specialty Trial, and the Oregon Preliminary Yield Trial were planted on April 28. The Oregon Preliminary Yield Trial and the Specialty Trial plots were 20 seed pieces long with 2 replicates, and the Statewide and Western Regional Late Harvest Trials each had plots 30 seed pieces long with 4 replicates.

After planting, hills were reformed over the rows with a Lilliston rolling cultivator. Prowl® at 1 lb ai/acre plus Dual® at 2 lb ai/acre were applied as a tank mix for weed control on May 10 and were incorporated with the Lilliston. Matrix® herbicide was applied on May 19 and incorporated with 0.375 inch sprinkler irrigation on May 25.

Irrigation was applied 21 times (Fig. 1), from June 7 to September 13, with scheduling based on six Watermark granular matrix sensors (Irrometer Co., Riverside, CA) connected to an AM400 data logger (M.K. Hansen Co., Wenatchee, WA) that recorded soil water potential at seed piece depth every 8 hours (Fig. 1). Irrigations were managed to prevent the soil at the seed piece depth from drying beyond 50 kPa water tension until late in the growing season. Crop evapotranspiration (ETc) was estimated by the U.S. Bureau of Reclamation using data from an AgriMet weather station on the Malheur Experiment Station (Fig. 2). Irrigation water applied was measured using an inline flow meter (McCrometer, Hemet, CA).

Fungicide applications for control of early blight and prevention of late blight infection started with an aerial application of Ridomil Gold® plus Bravo® at 2 lb/acre on June 18. On July 1, Topsin® fungicide at 20 oz product/acre plus Dithane® at 2 lb product/acre were applied. Tanos® at 8 oz product/acre was applied on July 28, and on August 7 ammonium polyphosphate 10-34-0 at 0.18 gal/acre plus Folo Spray 20-20-20 ( J.R. Simplot Co.) at 4 lb/acre plus liquid sulfur at 6 lb S/acre was applied to remedy a nutrient deficiency and to prevent two-spotted spider mite infestation.

Petiole tests were taken every 2 weeks from June 17 and fertilizer was injected into the sprinkler system during irrigation to supply the crop nutrient needs. A total of 185 lb N/acre, 1.5 lb P2O5/acre, 1 lb K2O/acre, 6 lb S/acre, 0.45 lb Zn/acre, 4.2 lb Mn/acre, 2.2 lb Cu/acre, 0.4 lb Fe/acre, and 1.08 lb B/acre were applied through the sprinkler lines and aerial applications.

The vines were flailed on September 18. The vines of most entries were still green. Potatoes in the Specialty Trial were dug on October 2, the Oregon Preliminary Yield Trial on October 3-4, the Statewide Trial on October 4, and the Western Regional Late Harvest Trial was dug on October 5. At each harvest, the potatoes in each plot were lifted with a two-row digger that laid the tubers back onto the soil in each row. Visual evaluations included observations of desirable traits, such as a high yield of large, smooth, uniformly shaped and sized, oblong to long, attractively russetted tubers, with shallow eyes evenly distributed over the tuber length. Notes were also taken of tuber defects such as growth cracks, knobs, curved or irregularly shaped tubers, pointed ends, stem-end decay, attached stolons, heat sprouts and chain tubers, folded bud ends, rough skin due to excessive russetting, pigmented eyes, or any other defect. A note was made for each plot to keep or discard the clone based on the overall appearance of the tubers.

Tubers were placed into burlap sacks and hauled to a barn where they were kept under tarps until grading. Tubers were graded and a 20-tuber sample from each plot was placed into storage. The storage temperature was gradually reduced to 45°F. After 6 weeks, a 20-tuber sample from each plot (except the Specialty Trial) was evaluated for tuber quality traits for processing. Specific gravity was measured using the weight-in-air, weight-in-water method. Ten tubers per plot were cut lengthwise and the 10 center slices were fried for 3.5 min in 375°F soybean oil. Percent light reflectance was measured on the stem and bud ends of each slice using a Photovolt Reflectance Meter model 577 (Seradyn, Inc., Indianapolis, IN), with a green tristimulus filter, calibrated to read 0 percent light reflectance on the black standard cup and 73.6 percent light reflectance on the white porcelain standard plate.

Data from all trials were analyzed with the General Linear Models analysis of variance procedure in NCSS (Number Cruncher Statistical Systems, Kaysville, UT) using Fisher's protected LSD means separation at the 95 percent confidence level.

Results and Discussion

Potato planting at the Malheur Experiment Station in 2006 was delayed by about 1 week by wet spring weather, with 3.57 inch rain in March and 1.76 inch rain in April. No rain was measured in July, and only 0.08 inch in August. In the 145 days between planting and vine destruction there were 81 days with high temperatures of 86°F or above, and 12 days of 100°F or above, with the maximum of 106°F on July 23. No disease, insect, or mite problems were observed in the field.

Soil water potential at the seedpiece depth was allowed to become drier at the end of the growing season, after the vines died on the early maturing entries, by applying frequent sprinkler irrigations of short duration, as shown in Figure 1. This was necessary to avoid swollen lenticels and the associated possibility of rotting tubers of entries maturing early or susceptible to the early die disease syndrome, while continuing to supply a portion of the ETc requirement for entries maturing late or resistant to early die.

Precipitation for May 25 through September 17 was 0.80 inch, the potato crop evapotranspiration (ETc) for the late-harvest trials totaled 29.26 inch, and the trials received 28.45 inch of irrigation plus precipitation (Fig. 2). The incremental increases in the irrigation plus rainfall curve show the 21 sprinkler irrigations applied during the growing season.

Western Regional Late Harvest Trial

Among the highest total yields in the Western Regional Late Harvest Trial were produced by 'MWTX2609-4Ru', with 874 cwt/acre, 'MWTX2609-2Ru', with 845 cwt/acre, and 'CO95172-3Ru' with 803 cwt/acre (Table 1). Those three clones also produced among the highest marketable yield, however, their average fry color as measured by light reflectance was too dark for processing into frozen potato products. The clones MWTX2609-4Ru, and MWTX2609-2Ru also produced 2.5 percent sugar ends in this trial, so they may be unsuitable for processing. The clones 'AO96164-1' and 'AOA95155-7' produced 661 cwt/acre marketable yield, with light fry color, zero percent sugar ends, and high specific gravity. Russet Burbank and 'AO96141-3' produced significantly more U.S. No. 2 tubers than other clones in this trial.

Oregon Statewide Trial

In the Oregon Statewide Trial, the six clones marked with an asterisk were retained by the variety selection committee (Table 2). The clone 'AO96160-3' will graduate from the variety selection program to be released as a named variety. The clone 'AO96141-3' will advance to the Western Regional Trial, and the clones 'AO96305-3' and 'AO96365-2' will advance to the Tri-State Trial. The clones 'AO98282-5', and, 'AO00057-2' will be maintained in the Statewide Trial in 2007.

At this location in 2006, 'AO98104-1', 'AO00024-7', 'AO96364-2', and, AO98282-5 produced among the highest total yields. Russet Burbank and Shepody, two check varieties in this trial, produced significantly more U.S. No. 2 tubers, and significantly more culls than the other entries. The clones 'AO98104-1' and 'AO01012-4' produced significantly more small tubers under 4 oz than other clones in this trial. The clones AO96141-3, 'AO00076-4', 'AO99192-2', Ranger Russet, and AO98282-5 had specific gravity, a measure of tuber solids, among the highest in this trial. The clones AO96160-3, AO96141-3, 'AO96164-1', and AO98282-5 had among the lightest fry color for processing. Russet Burbank produced 25 percent sugar ends, significantly more than any other entry in this trial.

Oregon Preliminary Yield Trial

In the Preliminary Yield Trial, 140 numbered clones were compared to Russet Burbank, Ranger Russet, Shepody, and 'Russet Norkotah' (Table 3). The clones 'AO98281-2', 'OR03050-1', 'AO02045-2', and 'AO02126-3' produced among the highest total yield in this trial but were discarded due to undesirable characteristics.

The Oregon potato variety selection committee kept 12 clones, based on their performance at Hermiston, Klamath Falls, Powell Butte, and Ontario, to advance to the Statewide Trial for 2007. The clones that were advanced were: 'AO98259-5', 'AO98286-4', 'AO01057-5', 'AO02019-2', 'AO02019-3', 'AO02019-8', 'AO02027-6', 'AO02103-1', 'AO02182-1', 'AO02183-2', 'AO02196-5', and 'OR03029-2'. These clones yielded well across the four locations (Hermiston, Klamath Falls, and Powell Butte data are not shown in this report), had a low incidence of undesirable characteristics, had high percent U.S. No. 1 grade tubers, and had high specific gravity, light fry color, and resistance to developing sugar ends in response to stress.

Specialty Potato Trial

This was the second year for a colored-flesh potato variety trial at Malheur Experiment Station. Potato tubers with red to yellow carotinoid or red, blue, and purple anthocyanin pigments are of interest because of the antioxidant properties of those pigments in human nutrition. The performance of the colored clones evaluated at this location is shown in Table 4.The clones 'PA96RR1-193', 'POR00PG4-1', 'POR02PG26-5', and 'POR02PG37-2' will advance to the Regional Specialty Trial, while the clones 'POR01PG45-5', 'OR00068-11', 'POR02PG5-1', 'POR03PG12-2', 'POR03PG23-1' and 'POR03PG80-2' will be retained in the Statewide Specialty Trial for 2007.

The clones 'POR02PG2-4' with 1,029 cwt/acre, 'POR02PG26-6' with 941 cwt/acre, and POR02PG5-1with 932 cwt/acre had the highest yields of the 25 clones, far higher than the check varieties 'Yukon Gold' with 467 cwt/acre and 'All Blue' with 532 cwt/acre. Pigmentation of these specialty potatoes is highly variable. The clone POR02PG2-4 produced tubers that were reddish-purple with a red interior flesh. The clone POR02PG26-6 produced round tubers with a yellow skin with pink eyes and creamy yellow flesh. The clone POR02PG5-1 produced yellow tubers with pink eyes with a light yellow flesh. The clones POR02PG2-4, and POR02PG26-6 had a good size distribution for fresh market, but also had tubers that adhered to the stolons, and were sprouting at harvest. The clone POR02PG5-1 produced 299 cwt/acre of oversized tubers, over 10 oz, which are considered cull tubers in the usual markets for specialty potatoes.

Soil water potential over time.

Figure 1. Soil water potential in the sprinkler-irrigated potato variety trials at Malheur Experiment Station, Oregon State University, Ontario, OR, 2006.

Irrigation accompanied crop evapotranspiration.

Figure 2. Crop evapotranspiration (ETc) and sprinkler irrigation applied (plus rain) to potato variety trials, Malheur Experiment Station, Oregon State University, Ontario, OR, 2006.

Table 1. Western Regional Late Harvest Trial potato yield, grade, and processing quality. Malheur Experiment Station, Oregon State University, Ontario, OR 2006.



U.S. No. 1







Average


Variety

Total

yield

Percent

No. 1

Total

No. 1

>12

oz

6-2

oz

4-6

oz

U.S. No. 2

Marketable

< 4 oz

Cull

Length/ width

Specific

gravity

fry color, light

reflectance

Sugar

ends


cwt/acre

%

---------------------------------cwt/acre------------------------------------

ratio

g cm-3

%

%

Ranger Russet

607

67

402

183

178

41

135

537

30

41

2.02

1.0935

45

0.0

Russet Burbank

648

32

207

44

115

49

260

466

58

123

1.82

1.0704

36

15.0

Russet Norkotah

390

86

338

122

167

49

15

353

28

10

1.90

1.0700

33

5.0

A95074-6

644

80

513

108

272

133

52

566

79

0

1.71

1.0882

45

0.0

A95109-1

571

90

516

304

193

19

42

558

11

2

1.79

1.0830

41

0.0

A95409-1

706

92

648

401

217

31

34

682

16

7

1.93

1.0920

41

0.0

A96104-2

594

81

485

174

244

67

57

543

42

9

1.82

1.0789

43

0.0

AC96052-1RU

596

83

496

93

302

102

22

518

78

0

1.74

1.0827

44

0.0

AO96141-3

665

47

301

57

175

70

302

603

51

11

1.94

1.0925

51

0.0

AO96160-3

627

88

553

117

313

123

21

574

53

1

1.69

1.0940

53

0.0

AO96164-1

698

89

619

218

321

81

42

661

34

4

1.80

1.0941

51

0.0

AOA95154-1

636

84

532

68

332

133

34

566

70

0

1.58

1.0933

47

0.0

AOA95155-7

716

88

627

108

389

131

34

661

51

4

1.68

1.0866

48

0.0

AOTX95265-2ARu

637

76

486

239

207

41

114

600

31

6

1.85

1.0712

35

12.5

AOTX95265-4Ru

654

75

484

231

203

50

133

617

30

7

2.00

1.0710

34

5.0

CO94035-15RU

618

80

496

140

300

57

79

575

40

4

1.58

1.0805

43

0.0

CO95172-3RU

803

80

646

137

407

103

102

748

54

1

1.66

1.0863

35

0.0

CO97137-1W

469

77

362

58

211

94

44

406

62

2

2.16

1.0843

33

7.5

MWTX2609-2Ru

845

78

670

353

274

43

135

805

26

14

1.79

1.0848

34

2.5

MWTX2609-4Ru

874

81

706

340

301

64

122

828

37

9

1.87

1.0856

32

2.5

TXA549-1Ru

589

87

514

253

219

42

50

564

23

2

1.61

1.0821

40

2.5

Mean

647

78

505

178

254

72

87

592

43

12

1.81

1.0840

41

2.5

LSD (0.05)

98

12

109

76

69

27

68

92

17

30

0.21

0.0065

3

6.1


Table 2. Oregon Statewide Trial potato yield, grade, and processing quality. Malheur Experiment Station, Oregon State University, Ontario, OR, 2006.



U.S. No. 1








Average


Variety

Total

yield

Percent

No. 1

Total

>12

oz

6-12

oz

4-6

oz

U.S.

No. 2

Marketable

<4 oz

Cull

Length/

width

Specific

gravity

fry color, light

reflectance

Sugar

ends


cwt/acre

%

------------------------------------cwt/acre---------------------------------------

ratio

g cm-3

%

%

Russet Burbank

565

43

244

44

144

55

235

478

40

47

2.24

1.0706

36

25

Ranger Russet

594

78

463

183

238

42

107

570

22

2

1.94

1.0990

47

0

Shepody

620

48

270

73

151

47

322

592

18

11

1.55

1.0829

42

3

Norkotah

439

88

384

160

171

53

39

422

16

0

1.90

1.0748

35

0

AO96160-3a

534

87

469

44

274

151

22

491

43

0

1.72

1.0951

54

0

AO96164-1

574

89

510

131

307

72

26

535

39

1

1.86

1.0936

52

0

AO96141-3 a

611

65

398

60

237

101

152

550

61

0

1.99

1.1032

52

0

AO96305-3 a

504

76

383

145

196

42

99

482

21

2

2.16

1.0849

51

0

AO96365-2 a

664

77

513

103

308

103

98

611

53

0

1.58

1.0878

43

0

AO98282-5 a

650

81

522

103

305

114

81

604

46

1

1.93

1.0979

52

0

AO98086-1

450

93

419

219

170

30

20

438

12

0

1.80

1.0838

50

0

AO98104-1

746

72

539

86

278

174

113

652

95

0

1.67

1.0838

40

0

AO98129-4

482

71

347

200

126

21

119

465

12

6

1.72

1.0864

46

0

AO98170-4

425

74

315

90

171

54

72

387

37

1

2.02

1.0896

50

0

AO99178-2

603

86

514

119

298

96

45

559

43

0

1.67

1.0888

48

0

AO99179-1

544

83

454

248

176

30

76

530

15

0

2.09

1.0815

47

0

AO99179-4

588

79

463

377

76

11

113

576

11

2

1.97

1.0770

41

3

AO99192-2

598

76

454

42

281

131

81

535

64

0

1.90

1.0994

51

0

AO00018-3

506

88

447

157

233

58

30

478

28

0

1.80

1.0951

48

0

AO00024-7

666

91

603

329

249

25

49

652

14

0

1.74

1.0817

45

0

AO00057-2 a

460

76

350

125

167

58

86

435

25

0

2.03

1.0888

51

0

AO00076-4

544

87

476

95

267

115

16

491

52

0

1.63

1.1023

47

0

AO00088-11

491

89

437

189

212

36

30

467

25

0

1.78

1.0919

48

0

AO01012-4

470

80

378

26

226

126

12

389

81

1

1.88

1.0949

51

0

Mean

555

78

431

139

219

73

85

516

36

3

1.86

1.0889

47

1

LSD (0.05)

114

9

88

69

64

36

89

123

20

17

0.14

0.0069

3

6

aRetained for further testing.

Table 3. Oregon Preliminary Yield Trial potato yield, grade, and processing quality. Malheur Experiment Station, Oregon State University, Ontario, OR, 2006.



U.S. No. 1







Average


Variety

Total

yield

Percent

No. 1

Total

>12

oz

6-12

oz

4-6

oz

U.S.

No. 2

Marketable

<4

oz

Cull

Length/

width

Specific

gravity

fry color, light

reflectance

Sugar

ends


cwt/acre

%

---------------------------------cwt/acre--------------------------------------

ratio

g cm-3

%

%

R. Burbank

631

49

311

49

193

68

221

531

49

51

2.14

1.07879

35.0

30.0

Ranger R.

610

79

484

125

270

89

101

585

20

5

1.94

1.09958

45.0

0.0

Shepody

457

57

260

35

163

62

143

403

37

17

1.58

1.08959

42.6

0.0

Norkotah

466

89

420

142

226

52

20

439

26

0

1.95

1.09137

32.4

20.0

AO98259-5 a

223

79

171

25

105

41

30

202

21

0

1.69

1.09305

47.1

0.0

AO98286-4 a

529

86

460

46

289

125

14

474

54

0

1.63

1.08245

37.1

0.0

AO01057-5 a

497

92

457

53

297

107

10

467

30

0

1.72

1.08525

43.9

0.0

AO02019-2 a

477

92

437

168

239

31

21

459

18

0

2.55

1.08272

48.3

0.0

AO02019-3 a

344

94

325

156

156

12

5

330

14

0

2.23

1.08554

41.6

0.0

AO02019-8 a

655

80

518

200

246

72

93

611

43

0

2.42

1.08272

49.9

0.0

AO02027-6 a

633

95

599

222

303

75

12

612

21

0

1.95

1.0861

45.6

0.0

AO02103-1 a

456

92

418

103

257

58

23

440

15

0

1.68

1.08235

48.3

0.0

AO02182-1 a

514

82

420

88

242

90

33

454

60

0

2.03

1.08096

42.6

0.0

AO02183-2 a

653

90

586

270

287

29

38

623

30

0

1.89

1.09365

55.3

0.0

AO02196-5 a

714

92

658

271

318

69

27

684

29

0

1.79

1.09817

50.2

0.0

OR03029-2 a

391

22

87

0

17

70

2

90

301

0

1.56

1.10348

50.9

0.0

Mean

511.6

81.8

417.4

135.4

212.8

69.2

51.4

468.8

40.3

2.5

1.82

1.08852

44.4

1.5

LSD (0.05)

93.4

9.4

99.9

89.7

69.8

32.1

40.7

92.6

21.0

13.0

0.18

0.00817

3.9

6.8

aRetained for further testing.

Table 4. Specialty Potato Trial yield and grade of colored-flesh clones. Malheur Experiment Station, Oregon State University, Ontario, OR, 2006.

Variety

Total

yield

B-10 oz

4-10 oz

4-6 oz

6-10 oz

Under

4 oz

Over

10 oz

U.S. No. 2

Cull

Twos plus culls

Rotten tubers


----------------------------------------------------------------------- cwt/acre ----------------------------------------------------------------------------------

All Blue

532

457

242

151

91

215

33

42

0

42

0

Yukon Gold

467

224

197

41

155

28

225

3

0

3

1

PA96RR1-193a

598

583

413

248

164

171

11

2

0

2

2

PA97B36-3

640

464

411

123

288

53

169

3

2

5

0

POR00PG4-1a

407

299

231

72

159

69

89

19

0

19

0

POR01PG45-5a

684

597

439

174

266

158

76

9

0

9

1

OR00068-11a

747

653

439

217

221

214

65

29

0

29

1

OR00068-29

343

323

111

85

26

213

15

4

0

4

0

POR02PG2-4

1029

963

487

275

212

476

50

14

0

14

4

POR02PG4-2

220

210

20

17

2

190

5

6

0

6

0

POR02PG5-1a

932

480

363

140

223

118

299

39

0

39

1

POR02PG26-4

549

479

384

162

222

95

57

4

6

10

3

POR02PG26-5a

720

619

498

208

291

121

62

37

0

37

2

POR02PG26-6

941

811

447

267

180

364

34

95

0

95

2

POR02PG26-11

786

626

464

216

248

162

115

23

0

23

4

POR02PG37-2a

527

496

323

173

150

173

26

4

0

4

1

POR03PG12-2a

474

409

319

166

153

90

39

27

0

27

0

POR03PG23-1a

467

383

183

134

50

199

2

76

0

76

7

POR03PG25-2

494

456

146

117

29

310

10

25

0

25

3

POR03PG38-1

583

471

392

137

255

79

109

2

0

2

0

POR03PG43-1

699

614

363

218

146

250

27

58

0

58

0

POR03PG46-1

571

224

199

39

160

25

327

18

0

18

1

POR03PG74-3

625

271

250

49

201

21

278

50

0

50

17

POR03PG74-4

643

502

434

141

292

68

137

1

0

1

0

POR03PG80-2a

519

353

327

76

251

26

159

6

0

6

2

Mean

608

479

323

146

177

155

97

24

0

24

2

LSD (0.05)

99

97

67

57

47

59

88

47

ns

48

7

aRetained for further testing.