Potato Variety Trials 2000

Clinton C. Shock, Eric P. Eldredge, and Lamont D. Saunders

Malheur Experiment Station

Oregon State University

Ontario, OR 2000

Introduction

Oregon's Malheur County currently grows about 10,500 acres of potato, under contract with potato processors for frozen fries for the fast food industry. There is virtually no production for fresh pack, open market, or storage on the grower's farm. There is also no production of varieties for making potato chips. Because of severe aphid pressure leading to virus infection, there is no potato seed production in the irrigated northeastern part of Malheur County. Harvest begins in late July, to provide potatoes to processing plants straight from the field. The early harvested fields, about 4,700 acres, are mostly furrow irrigated. For late harvest, September through October, about 5,800 acres are mostly sprinkler irrigated. Average yield is 425 100-lb sacks (or cwt) per acre, and the varieties grown are mainly 'Russet Burbank', 'Shepody', and 'Ranger Russet'.

Small acreages of some newer varieties are contracted by processors each year to study the profitability of writing contracts for more acres of the newer varieties. To replace an existing processing variety, a new potato variety needs to have several outstanding characteristics. Total yield should be at least as high as the yield of 'Russet Burbank'. The percentage of USDA No. One tubers must be high, and the tubers need to have low sugars and high specific gravity for light, uniform fry color. A new variety should be resistant to tuber defects or deformities caused by diseases and heat. It should begin to bulk its tubers early if it is a variety for early harvest. Or, if it is a late harvest variety, it should be resistant to early vine death, known as "early die." Early die is caused by a disease complex of common soil fungi, mainly Verticillium and Fusarium. A late harvest variety should continue to bulk its tubers late in the growing season.

Potato variety development at Malheur Experiment Station in 2000 included an 8-Hill trial of 53 long russet clones from the USDA Agricultural Research Service potato breeding program at Aberdeen, Idaho, the Oregon Preliminary Yield and Oregon Statewide trials, and the Western Regional Early and Late Harvest russet trials.

Materials and Methods

The five furrow-irrigated potato variety trials were grown in a field of Owyhee silt loam where winter wheat was the previous crop. The wheat stubble was flailed, the field was irrigated, and disked, then 100 lb P/acre and 20 lb N/acre were broadcast. On October 12, 1999, the field was ripped with Telone II injected at 22 gal/acre, and the field was bedded on 36-inch row spacing on November 16. A soil test March 30, 2000 showed available nitrate plus ammonia nitrogen totaled 106 lb N/acre in the top 2 ft of soil, 41 ppm extractable P, 484 ppm K, organic matter 1.7 percent, and pH 6.7.

Seed of all varieties was hand cut into 2 oz seed pieces and treated with Tops MZ dust. The Western Regional Early trial was planted April 20, 2000, and the other trials were planted May 1, 2000. The 8-Hill trial was unreplicated, the Preliminary Yield Trial had two replicates, and the Statewide, Western Regional Early Harvest, and Western Regional Late Harvest trials each had four replicates. Plots were planted using a two-row cup planter with seed spacing 9 inches in the row, with rows 36 inches apart, and Thimet 20G was metered into the seed furrow at planting at 1.7 oz/100 ft of row. The potato rows were sidedressed to provide 102 lb N/acre, 10 lb Zn/acre, 6 lb Mn/acre, and 2 lb B/acre. After planting, hills were formed over the rows with a Lilliston rolling cultivator. Prowl at 1 lb ai/acre plus Dual at 2 lb ai/acre, in 30 gal/acre spray mix, was applied and incorporated with the Lilliston on May 4, 2000.

Potatoes in all the trials had emerged by May 26. Fungicide applications to prevent late blight infection started with an aerial application of Bravo at 1.5 pint/acre on the evening of June 6, and then with Dithane at 4 pint/acre on June 16. Powdered sulfur was applied at 30 lb/acre by airplane July 11, and again on August 3, to control powdery mildew. Vines were flailed off the plants in the early harvest trials on August 21. Western Regional Early Harvest potatoes were lifted August 23 and 24 with a two-row digger that laid the tubers back onto the soil in each row, and potatoes were visually evaluated in the plots. Visual evaluations included observations on desirable traits, such as a high yield of large, smooth, uniformly shaped and sized, oblong (or blocky) to long, attractively russetted tubers, with shallow eyes evenly distributed. Notes were also made of tuber defects such as growth cracks, knobs, curved or irregularly shaped tubers, pointed ends, stem-end decay, stolons that remained attached, folded bud ends, rough skin due to excessive russetting, pigmented eyes, or any other defect, and a note to keep or discard the line based on tuber appearance. Plots with excessive water rot were also noted, to be excluded from the statistical analysis. Tubers were placed into burlap sacks and hauled to a barn where they were kept under tarps until grading, on August 29 and 30. At grading, a 20-tuber sample from each plot was placed into refrigerated storage for processing quality tests.

Vines were flailed off the Western Regional Late, Statewide, Preliminary Yield, and 8-Hill trials on August 29. The potatoes were lifted on September 5 and 7 with a two-row digger that laid the tubers back onto the soil in each row. At harvest, the potatoes in each plot were visually evaluated and plots with excessive water rot were excluded from the statistical analysis. Tubers were graded September 8, 11, and 12, and samples from each plot placed into storage. The storage was kept near 100 percent relative humidity and the temperature was gradually reduced to 45°F. Tubers were removed from storage November 14 through 30 and evaluated for tuber quality traits, specific gravity was measured, and ten tubers per plot were cut lengthwise and examined for internal defects. Center slices from ten tubers were fried for 3.5 minutes in 375oF soybean oil. Percent light reflectance was measured on the stem and bud ends of each slice using a model 577 Photovolt Reflectance Meter (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.

Results and Discussion

The summer of 2000 was not intensely hot, with the highest temperature 102°F on August 2. The heat was prolonged, however. During June, July, and August, there were 7 days 100°F or higher, and 56 days 90°F or hotter. Daytime high temperatures over 86°F are stressful for potato, and 70 days between June 1 and August 31 had high temperatures of 86°F or above. Powdery mildew was found on the foliage of potatoes in the trial on July 6. Powdery mildew is often a problem on potato in Malheur County, and was widespread in 2000. The unusually hot, dry weather in June allowed the pathogen to infect the crop, and the prolonged hot, dry weather in July and August favored the spread of powdery mildew and made control difficult in potato and other crops. Dry weather prevented late blight from developing in 2000.

Hot weather also increases evapotranspiration. The monthly total pan evaporation in 2000 measured at the U.S. Weather Bureau Class A pan at Malheur Experiment Station exceeded the 52-year average for the month of June by 21 percent, July by 14 percent, and August by 25 percent. To prevent tuber defects associated with water stress, irrigations were applied when Watermark soil moisture sensors in the crop root zone indicated that the soil water potential would fall below -60 centibar the following day if an irrigation was not applied. The more frequent irrigations, the higher than normal soil temperature due to the prolonged heat, and frequent crops of potato in the field's rotational history, led to the development of water rot, especially in a low spot in the field. Water rot reduced the yield of all the furrow-irrigated potato variety trials in 2000.

8-Hill Trial

In the 8-Hill trial of early selections of long, russeted varieties, 53 clones were tested (Table 1). The line 'A96003-23' yielded a total of 647 cwt, with 90 percent No. 1 grade tubers, with high specific gravity of 1.099 g/cm-3 and average fry color of 50.3 percent light reflectance. The line 'A96079-2' yielded 426 cwt total, with 79 percent No. 1 grade, with acceptable fry color and specific gravity, but did produce some tubers with knobs. Only 'A96003-23' and 'A96079-2' had high enough yield and were sufficiently free from defects to warrant growing them at this site again.

Preliminary Yield Trial

In the Preliminary Yield Trial, 76 lines were compared to 'Russet Burbank', 'Ranger Russet', 'Shepody', 'Norkotah', and 'Atlantic' (Table 2). The Oregon potato variety selection committee kept 12 lines for another year, advancing them to the Statewide trial for 2001. Six of the lines, 'AO92019-4', 'AO94004-3', 'AO96160-3', 'AO96165-2', 'AO96165-9', and 'AO96262-1', appear in the entry list. The other six had excessive water rot at this location and data are not shown. Of the six lines with data for this location, 'AO92019-4', 'AO96125-9', 'AO96165-2', and 'AO96165-9' had mediocre total yield and/or dark fry color. The lines 'AO94004-3' and 'AO96160-3' both yielded over 400 cwt, produced over 80 percent No. 1 grade tubers, and had high specific gravity and light fry color.

Oregon Statewide Trial

In the Oregon Statewide Trial, the lines 'AO87277-6', and 'AO91812-1' graduated out (Table 3).The line 'AO87277-6' will move into the variety release procedure as a fresh market variety named 'Wallowa Russet'. 'AO92017-6' graduated to the Western Regional Early and Late Harvest trials for 2001, and 'AO94110-203' was retained for another year in the Statewide trial. The line 'AO94110-203' produced a total yield of 488 cwt, with 74 percent No. 1 grade, good specific gravity of 1.095 g/cm-3, and an average fry color reading of 45 percent light reflectance. 'Zolushka' and 'Catalina' tubers were so irregular that they would have been discarded, but they are of interest because they are varieties that can be grown from true potato seed. They are proprietary varieties that were entered by Bejoseeds, and will be grown from cut seed again in the 2001 Oregon Statewide Trial. All of the other clones were discarded following this trial.

Western Regional Early Harvest Trial

In the Western Regional Early Harvest trial, 'ATX9202-3RU' had 436 cwt total yield, which was significantly higher than the check varieties 'Ranger Russet' and 'Shepody' (Table 4). The line 'ATX9202-3RU' had acceptable specific gravity and fry color, and no dark ends. All of the other varieties produced unacceptable dark fry color, or had dark ends. In the Western Regional Late Harvest trial, none of the entries matched 'Russet Burbank' for total yield, except 'A9045-7', with 459 cwt total yield (Table 5). The line 'A9045-7' produced 80 percent U.S. No. 1 grade tubers, and appeared to be a productive variety without excessive tuber defects. In the Western Regional Early and Late Harvest trials, 'A8792-1', 'PORTGNP3-138', 'PORTGS124-1', and 'PORTGS129-1' were advanced out of the trial, and all of the other entries will remain in the trials for 2001 to be evaluated an additional year.

Table 1. 8-Hill Trial early selection 'Aberdeen' clones: yield, grade, and processing quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2000.

    U.S. No. 1         Average  
Variety Total

yield

Percent

No. 1

Total >12

oz

4 to 12

oz

<4

oz

U.S.

No. 2

Cull Length-to-

width ratio

Specific

gravity

fry color, light

reflectance

Sugar

ends

  cwt/acre % -----------------------------cwt/acre---------------------------------     %  
Russet Burbank 373 51 189 41 148 32 107 44 2.32 1.079 32.9 30
A96002-1 416 72 299 18 281 89 28 0 1.68 1.092 47.3 0
A96002-3 325 75 242 0 242 47 15 21 1.80 1.077 51.6 0
A96002-8 525 74 389 0 389 60 70 6        
A96002-9 446 67 300 122 178 23 113 11 2.52 1.082 45.1 0
A96002-12 435 75 328 0 328 90 17 0 1.87 1.091 51.2 10
A96002-16 286 91 259 52 207 3 21 3 2.00 1.097 54.7 0
A96003-9 408 95 389 177 212 12 7 0 2.00 1.091 39.2 10
A96003-20 356 89 318 173 145 23 0 15 1.70 1.081 44.1 0
A96003-23* 647 90 585 350 234 37 25 0 1.79 1.099 50.3 0
A96005-3 422 84 356 45 310 24 42 0 1.85 1.085 37.1 0
A96005-4 371 63 233 78 156 23 110 5 1.96 1.087 40.6 0
A96005-6 387 75 290 173 117 4 93 0 1.93 1.087 38.1 0
A96006-2 202 80 161 19 142 36 0 5 2.09 1.086 46.6 0
A96010-6 209 88 183 18 165 26 0 0 1.91 1.102 56.0 0
A96011-10 378 81 308 25 282 65 0 6 2.00 1.087 46.4 0
A96014-5 337 56 188 19 168 31 99 20 1.78 1.077 43.7 0
A96014-6 571 73 415 20 394 70 74 12 1.63 1.085 40.1 10
A96023-1 301 76 229 19 210 49 0 23 1.72 1.091 49.1 0
A96023-6 264 73 192 38 154 21 14 37 1.58 1.094 51.3 0
A96027-1 419 76 317 107 210 94 8 0 1.88 1.088 46.1 0
A96028-3 181 59 107 0 107 45 0 29 1.90 1.094 46.1 0
A96031-2 169 40 68 52 16 24 0 77 2.33 1.093 44.6 0
A96031-3 302 70 211 22 189 20 70 0 1.77 1.088 43.6 0
A96032-1 424 66 281 232 49 7 44 93 2.04 1.085 36.1 0
A96032-2 98 50 49 22 27 7 0 42 2.00 1.071 42.9 10
A96044-3 394 73 289 90 199 33 45 26 2.16 1.086 42.6 0
                         
Table 1. 8-Hill Trial early selection 'Aberdeen' clones: yield, grade, and processing quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2000 (continued).
    U.S. No. 1         Average  
Variety Total 

yield

Percent

No. 1

Total >12

oz

4 to 12

oz

<4

oz

U.S.

No. 2

Cull Length-to-

width ratio

Specific

gravity

fry color, light

reflectance

Sugar

ends

  cwt/acre % -----------------------------cwt/acre---------------------------------     % %
A96049-5 361 42 150 81 69 54 144 14 2.09 1.088 45.4 0
A96052-8 263 71 187 0 187 31 30 14 2.00 1.071 47.9 0
A96057-2 194 67 130 0 130 32 0 32        
A96058-1 153 81 124 24 100 24 0 5 1.90 1.075 56.5 0
A96062-5 137 58 80 0 80 51 0 7 1.84 1.091 46.7 0
A96065-5 208 73 151 19 133 22 0 35 2.00 1.071 44.3 10
A96067-4 36 72 26 0 26 4 0 6        
A96068-4 371 70 261 205 56 58 36 16 2.00 1.085 42.5 0
A96070-1 173 60 103 52 52 39 0 31 2.33 1.085 44.5 0
A96076-4 54 45 24 24 0 0 0 30        
A96079-2* 426 79 337 242 95 30 42 17 1.93 1.092 52.9 0
A96085-3 329 66 218 45 173 77 18 16 2.05 1.083 41.3 0
A96095-1 153 17 26 0 26 1 0 125 2.17 1.078 46.8 0
A96095-3 318 53 168 69 99 17 48 85 1.84 1.081 42.1 10
A96104-2 298 43 128 0 128 53 19 98 1.70 1.081 49.9 0
A96319-3 334 47 156 61 95 56 62 60 1.91 1.087 34.2 10
A96321-1 228 54 122 35 87 14 0 91 2.00 1.086 45.3 10
A96323-11 289 55 159 49 109 60 0 70 2.04 1.095 44.4 0
A96323-13 289 75 218 39 180 56 0 15 1.88 1.092 37.6 0
A96324-1 379 68 257 119 138 34 88 0 2.08 1.094 43.9 0
A96324-2 284 71 201 0 201 45 33 5 1.79 1.087 41.4 0
COA96054-3 117 43 51 0 51 9 0 57 1.80 1.083 42.3 0
COA96072-1 51 53 27 20 7 24 0 0 2.25 1.072 38.6 0
COA96072-4 71 82 58 0 58 13 0 0 2.17 1.079 33.0 10
COA96272-1 155 49 75 18 57 7 0 72 1.92 1.070 38.1 0
A96017-8 397 70 277 171 106 12 45 64 1.73 1.072 50.9 0
A96065-7 224 27 60 44 16 29 8 127 2.17 1.070 35.6 10
*acceptable lines

Table 2. Preliminary Yield Trial: yield, grade, and processing quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2000.

    U.S. No. 1         Average  
Variety Total 

yield

Percent

No. 1

Total >12

oz

4 to 12

oz

<4

oz

U.S.

No. 2

Cull Length-to-

width ratio

Specific

gravity

fry color, light

reflectance

Sugar

ends

  cwt/acre % ---------------------------cwt/acre--------------------------------     % %
Russet Burbank 373 51 189 41 148 32 107 44 2.3 1.0787 32.9 30
Ranger Russet 342 72 247 47 200 21 69 6 2.3 1.0947 39.9 0
Shepody 362 79 288 101 187 27 45 3 1.8 1.0901 43.8 0
Norkotah 328 86 283 52 231 36 6 3 1.7 1.0757 18.6 0
Atlantic 425 89 380 149 230 12 28 5 1.1 1.1005 47.6 0
AO88118-1 371 66 245 24 221 41 76 9 1.6 1.0755 27.4 0
AO92016-2 355 83 295 34 261 33 22 6 1.8 1.0930 46.0 10
AO92016-3 300 81 242 0 242 40 0 17 1.8 1.0915 39.2 10
AO92016-4 341 62 213 82 131 9 59 60 2.2 1.0735 36.1 0
AO92016-5 261 78 205 29 176 39 9 8 1.7 1.0895 41.8 10
AO92019-2 421 75 316 61 255 13 79 13 2.1 1.1037 40.6 0
AO92019-4* 328 82 269 54 214 30 28 1 2.0 1.0801 27.2 10
AO94002-3 251 72 182 93 88 21 32 16 1.7 1.0862 33.7 0
AO94004-3* 412 87 359 25 334 43 9 1 1.6 1.0946 41.6 0
AO94004-4 238 58 137 0 137 52 44 4 2.3 1.0927 33.1 0
AO94012-2 361 84 303 43 260 24 33 0 1.8 1.1085 47.9 10
AO94012-8 314 76 240 7 233 36 32 6 1.8 1.1013 35.8 0
AO94014-3 447 59 264 82 182 19 164 0 2.2 1.0839 29.9 10
AO94201-1 396 78 310 81 229 37 17 32 1.9 1.1045 49.9 0
AO94246-1 339 81 276 16 260 59 0 4 1.6 1.0986 53.7 0
AO94248-5 512 79 407 291 116 23 64 19 1.7 1.0804 25.9 0
AO94248-7 276 74 205 60 145 10 56 5 1.6 1.0778 25.7 20
AO94348-2 466 70 328 0 328 72 57 9 2.1 1.0757 24.2 0
AO94363-2 431 76 329 0 329 34 68 0 2.2 1.0804 31.5 20
AO96003-1 493 73 362 98 264 40 87 5 1.8 1.0900 33.9 0
AO96003-2 402 69 277 112 165 6 109 11 1.6 1.0936 29.7 0
AO96003-3 289 72 208 16 192 21 58 3 1.7 1.0974 48.0 0
AO96004-2 390 85 332 49 283 31 0 27 1.6 1.0926 34.2 0
AO96005-1 268 76 206 20 186 21 28 13 1.9 1.08 40.5 0
AO96008-1 489 60 291 0 291 61 135 1 2.2 1.09 40.8 0
Table 2. Preliminary Yield Trial: yield, grade, and processing quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2000 (continued).
    U.S. No. 1         Average  
Variety Total 

yield

Percent

No. 1

Total >12

oz

4 to 12

oz

<4

oz

U.S.

No. 2

Cull Length-to-

width ratio

Specific

gravity

fry color, light

reflectance

Sugar

ends

  cwt/acre % ---------------------------cwt/acre--------------------------------     % %
AO96008-5 418 71 298 7 290 36 49 36 2.0 1.0816 32.3 10
AO96008-7 354 72 257 0 257 14 75 8 2.0 1.0937 42.3 0
AO96009-2 438 71 311 24 287 32 72 23 1.7 1.0858 29.9 20
AO96013-1 423 76 321 64 257 34 60 9 1.7 1.0911 33.3 10
AO96014-5 410 79 325 43 282 35 45 4 1.7 1.0833 32.4 0
AO96016-2 350 75 261 0 261 42 33 14 2.0 1.0794 39.0 0
AO96023-5 465 62 287 24 263 42 125 11 2.0 1.0871 37.3 0
AO96032-7 251 61 152 18 135 8 55 36 1.7 1.0893 39.9 0
AO96034-1 232 83 192 41 152 33 0 7 1.7 1.0843 48.1 0
AO96051-1 494 79 391 15 377 52 39 13 1.6 1.0997 49.3 0
AO96052-2 397 80 317 41 276 54 18 8 1.8 1.0851 50.0 0
AO96063-1 295 86 253 81 172 14 3 25 2.0 1.0797 40.2 0
AO96082-4 264 93 245 40 205 11 0 7 2.0 1.0833 38.4 0
AO96086-2 265 64 169 85 84 27 29 41 2.0 1.0794 40.3 0
AO96121-2 319 80 254 125 129 18 14 33 1.7 1.0878 30.1 20
AO96160-3* 427 78 332 32 299 39 0 56 2.0 1.1019 54.1 0
AO96160-4 382 76 290 51 239 37 30 26 1.9 1.0748 33.1 10
AO96165-2* 348 58 202 0 202 36 37 73 1.9 1.0874 37.5 0
AO96165-9* 302 76 229 52 176 20 24 29 2.1 1.0875 33.0 0
AO96262-1* 411 81 331 96 235 31 37 12 2.0 1.0889 36.4 0
AO96264-1 358 88 317 50 266 22 0 19 1.8 1.0841 31.8 0
AO96437-6 433 72 310 127 183 18 52 53 2.3 1.0849 36.2 10
AO96437-8 366 80 292 88 204 8 54 12 2.1 1.0866 40.1 10
AO96440-1 405 77 311 155 156 14 55 25 1.9 1.0933 39.1 10
AO96440-2 352 76 267 67 200 15 8 62 1.7 1.0810 33.6 10
AO96440-3 347 73 252 71 181 24 58 13 2.0 1.0875 40.7 0
AO96445-6 429 80 344 186 158 15 55 15 1.9 1.0780 36.7 0
AO96448-1 494 83 410 100 310 48 18 17 1.9 1.0804 32.6 10
Mean 369 75 278 58 220 30 44 18 1.9 1.0877 37.4 4

*advanced to Statewide, also advanced were AO96060-1, AO96065-7, AO96164-1, AO96176-3, AO96177-6, and AO96272-1.

Table 3. Oregon Statewide Trial: yield, grade, and processing quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2000.
    U.S. No. 1         Average  
Variety Total 

yield

Percent

No. 1

Total >12

oz

4 to 12

oz

<4

oz

U.S.

No. 2

Cull Length-to-

width ratio

Specific

gravity

fry color, light

reflectance

Sugar 

ends

  cwt/acre % --------------------------cwt/acre------------------------------     % %
Russet Burbank 448 42 186 29 157 98 140 19 2.43 1.078 34.3 33
Ranger Russet 377 62 235 79 156 38 94 8 1.99 1.095 45.3 0
Shepody 388 59 228 102 126 48 103 8 1.72 1.084 42.4 26
Norkotah 373 73 274 46 228 24 58 9 1.88 1.067 19.7 3
Atlantic 502 82 411 194 216 49 17 23 1.06 1.095 49.1 0
AO87277-6 359 65 234 36 198 64 49 13 2.04 1.090 45.7 0
AO89128-4.1 416 58 247 77 170 34 118 17 2.11 1.093 49.0 1
AO89128-4.2 434 44 190 2 194 159 79 6 2.26 1.092 52.5 0
AO91812-1 428 70 299 18 281 93 17 18 1.00 1.088 48.4 0
AO92007-2 415 65 271 79 192 72 58 14 2.15 1.083 35.2 5
AO92017-6 398 58 231 40 191 74 87 5 2.03 1.083 41.9 5
COO93031-3 455 73 336 172 164 39 61 19 2.39 1.075 32.6 10
AO92252-1 353 67 237 28 209 53 56 6 2.13 1.097 44.7 3
AO94110-203 488 74 361 92 268 47 66 14 1.88 1.095 45.0 0
AO94117-201 509 60 320 155 165 48 106 34 1.78 1.087 42.9 4
AO94171-2 412 64 265 46 219 57 76 13 1.92 1.087 35.7 0
AO95115-3 338 62 215 28 187 83 25 14 2.05 1.089 44.8 3
AO95115-6 347 72 251 58 193 47 9 40 1.90 1.068 32.0 6
AO95135-5 502 73 369 141 229 40 68 25 1.76 1.080 40.6 3
Zolushka 458 58 268 50 217 151 31 9 1.40 1.083 33.6 5
Catalina 451 55 249 37 212 143 53 6 1.40 1.078 34.9 10
Mean 421 64 270 72 199 70 65 15 1.87 1.085 40.5 6
LSD (0.05) 78 10 81 49 56 35 32 NS 0.17 0.007 6.0 15

Table 4. Western Regional Early Harvest Trial: yield, grade, and processing quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2000.

    U.S. No. 1         Average  
Variety Total 

yield

Percent

No. 1

Total >12

oz

4 to 12

oz

<4

oz

U.S.

No. 2

Cull Length-to-

width ratio

Specific

gravity

fry color, light

reflectance

Sugar 

ends

  cwt/acre % --------------------------cwt/acre-----------------------------     % %
Russet Burbank 420 48 204 34 171 18 173 25 2.40 1.082 33.5 60.0
Ranger  341 58 199 63 135 10 119 14 2.13 1.088 43.4 2.5
Norkotah 363 81 292 87 205 8 52 12 1.83 1.073 22.5 2.5
Shepody 292 66 192 80 112 14 60 26 1.66 1.076 37.0 7.5
A8792-1 391 70 274 94 180 20 84 13 1.75 1.090 49.9 5.0
A8893-1 536 65 358 182 177 9 140 29 2.00 1.078 40.3 2.5
A9014-2 326 71 228 90 138 5 61 31 1.78 1.089 52.5 0.0
A9045-7 433 71 308 152 156 8 110 7 2.00 1.088 35.5 2.5
A90586-11 402 72 292 68 224 14 82 13 1.83 1.095 39.6 10.0
AC87138-4 289 62 178 61 117 20 53 38 2.03 1.082 32.8 7.5
AC89536-5 433 74 321 63 258 18 73 21 2.00 1.092 43.4 2.5
ATX9202-3RU 436 74 319 100 219 14 84 19 1.98 1.084 45.2 0.0
TXNS102 378 66 253 81 172 7 98 20 1.95 1.078 30.9 2.5
TXNS296 442 67 300 163 137 10 115 18 2.03 1.079 25.9 2.5
PORTGNP3-138 322 47 155 34 122 14 70 82 1.96 1.069 24.5 2.5
PORTGS124-1 301 48 148 63 85 21 68 63 1.95 1.071 39.1 12.5
PORTGS129-1 330 40 142 39 103 19 98 71 1.75 1.073 38.4 10.0
Mean 378 64 245 85 159 13 91 30        
LSD (0.05) 90 11 72 43 39 8 42 23        

Table 5. Western Regional Late Harvest Trial: yield, grade, and processing quality, Malheur Experiment Station, Oregon State University, Ontario, OR, 2000.
    U.S. No. 1         Average  
Variety Total 

yield

Percent

No. 1

Total >12

oz

4 to 2

oz

<4

oz

U.S.

No. 2

Cull Length-to-

width ratio

Specific

gravity

fry color, light

reflectance

Sugar 

ends

  cwt/acre % --------------------------cwt/acre-----------------------------     % %
Russet Burbank 466 41 187 28 159 9 184 33 2.88 1.0774 31.3 91
Ranger  335 63 207 55 151 5 71 21 2.23 1.0909 41.7 3
Norkotah 327 79 260 56 204 4 23 19 1.93 1.0703 19.9 3
A8792-1 343 67 228 49 180 7 51 16 1.78 1.0837 42.2 5
A8893-1 350 69 241 121 120 5 55 19 2.16 1.0730 34.0 6
A9014-2 300 71 211 111 101 4 50 13 2.03 1.0874 54.0 1
A9045-7 459 80 368 98 270 6 45 10 1.93 1.0898 38.3 0
AC87079-3 274 69 185 76 110 3 41 27 2.12 1.0890 36.4 16
A90586-11 319 63 197 1 196 13 24 12 1.89 1.0876 34.1 11
AC87138-4 384 69 265 50 215 10 38 13 1.99 1.0853 37.1 1
AC89536-5 271 71 195 31 164 7 25 8 2.05 1.0898 40.3 3
ATX9202-3RU 381 69 265 44 220 9 39 19 1.85 1.0780 42.2 1
Mean 351 68 234 60 174 7 54 18 2.07 1.0835 37.6 12
LSD (0.05) 72 8 57 48 46 NS 40 NS 0.21 0.0031 3.5 8