Malheur Experiment Station
Oregon State University
Information for Sustainable Agriculture

 

2001 ONION VARIETY TRIAL

Clinton C. Shock, Erik B. G. Feibert, and Lamont D. Saunders

Malheur Experiment Station

Oregon State University

Ontario, OR

           

Introduction

The objective of this trial was to evaluate yellow, white, and red onion varieties for bulb yield and quality. Onions were graded out of storage in January 2002. Yellow bulb varieties were rated for single centers.

Methods

The 2001 trial was conducted on an Owyhee silt loam with 2.1 percent organic matter and a pH of 7.2. The field had previously been planted to wheat. In the fall of 2000, the wheat stubble was shredded, and the field was disked, irrigated, ripped, moldboard-plowed, roller-harrowed, fumigated with Telone C-17 at 20 gal/acre, and bedded. Before plowing, 20 lb N/acre, 200 lb P2O5/acre, 28 lb K, 150 lb S/acre, 28 lb Mg/acre, 10 lb Zn/acre, and 5 lb Cu/acre were broadcast.

Beds were knocked down March 21, 2001. On March 22, seed of 51 varieties from 10 companies was planted in plots four rows wide and 27 ft long (Table 1, Fig. 1). The experimental design was a randomized complete block with five replicates. An extra sixth non-randomized replicate was planted for purposes of demonstrating onion variety performance to growers and seed company representatives. The onion seed was planted at 18 seeds per ft of row in single rows on beds spaced 22 inches apart using four Almaco cone seeders mounted on a John Deere Model 71 Flexi Planter equipped with disc openers. The onion rows received 3.7 oz of Lorsban 15G per 1,000 ft of row (0.82 lb ai/acre), and the soil surface was rolled on March 25. On May 11, alleys 4 ft wide were cut between plots, leaving plots 23 ft long. From May 11 through 14, the seedlings were hand thinned to a plant population of four plants per ft of row (3-inch spacing between individual onion plants, or 95,000 plants/acre). The field was sidedressed with 100 lb N/acre, 10 lb Zn/acre, 1 lb Cu/acre, and 1 lb B/acre on May 21. On June 21, 100 lb N/acre was water run as urea ammonium nitrate solution (uran).

The trial was managed to avoid yield reductions from weeds, pests, and diseases with moderate amounts of control. Weeds were controlled with cultivations on May 20 and June 19, and with low-rate herbicide applications as needed until lay-by (Goal at 0.031 lb ai/acre, Buctril at 0.16 lb ai/acre, and Poast at 0.26 lb ai/acre on May 19 and Prowl at 0.83 lb ai/acre on May 30). After lay-by the field was hand weeded as necessary. Thrips were controlled with four aerial applications of Warrior and Lannate (June 30, July 20, August 1, and August 18) and one aerial application of Warrior on June 11. Warrior was applied at 0.03 lb ai/acre and Lannate was applied at 0.26 lb ai/acre.

The trial was furrow irrigated when the soil water potential at 8-inch depth reached -25 kPa. Soil water potential was monitored by six granular matrix sensors (GMS, Watermark Soil Moisture Sensors Model 200SS, Irrometer Co. Inc., Riverside, CA) installed on June 7 below the onion row at 8-inch depth. Sensors were automatically read three times a day with an AM-400 meter (Mike Hansen, East Wenatchee, WA). The last irrigation was on August 31.

The onions were lifted on September 10 to field dry. Onions from the middle two rows of every plot were topped, and bagged by hand on September 17. The onions were placed into storage on September 21. The storage shed was managed to maintain an air temperature of approximately 34°F.

In early September bulbs from one of the border rows in each plot of yellow onions were rated for single centers. Twenty-five consecutive onions ranging in diameter from 3.5 to 4.25 inches were rated. The onions were cut equatorially through the bulb middle and, if multiple centered, the long axis of the inside diameter of the first single ring was measured. These multiple-centered onions were ranked according to the diameter of the first single ring: "small double" had diameters <1½ inch, "intermediate double" had diameters from 1½ to 2¼ inch, and "blowout" had diameters >2 ¼ inch Single-centered onions were classed as a "bullet". Onions were considered functionally single centered for processing if they were a "bullet" or "small double."

Onions were graded out of storage in early January 2002. Bulbs were separated according to quality: bulbs without blemishes (No. 1s), double bulbs (No. 2s), neck rot (bulbs infected with the fungus Botrytisallii in the neck or side), plate rot (bulbs infected with the fungus Fusarium oxysporum), and black mold (bulbs infected with the fungus Aspergillus niger). The No. 1 bulbs were graded according to diameter: small (< 2¼ inch), medium (2¼ to 3 inch), jumbo (3 to 4 inch), colossal (4 to inch), and supercolossal (>4¼ inch). Bulb counts per 50 lb of supercolossal onions were determined for each plot of every variety by weighing and counting all supercolossal bulbs during grading. Varietal differences were compared using ANOVA and least significant differences at the 5 percent probability level, LSD (0.05).

Results and Discussion

Varieties are listed by company in alphabetical order. The LSD (0.05) values at the bottom of each table should be considered when comparisons are made between varieties for significant differences in performance characteristics. Differences between varieties equal to or greater than the LSD (0.05) value for a characteristic should exist before any variety is considered different from any other variety in that characteristic.

The percentage of "bullet" single centers averaged 28.5 percent and ranged from 6.7 percent for 'Delgado' to 70 percent for 'Vaquero' (Table 1). 'Vaquero', 'Sabroso', and 'Granero' were among the highest in percentage of "bullet" single centers. The percentage of onions that were functionally single centered averaged 53 percent and ranged from 24.7 percent for 'T-434' to 91.3 percent for 'Sabroso'. 'Sabroso', 'Vaquero', 'Granero', and 'Gunnison' were among the highest varieties in percentage of functionally single-centered bulbs.

Total yield out of storage in January, 2002 averaged 851.1 cwt/acre and ranged from 477.9 cwt/acre for 'Sabroso' to 1191.6 cwt/acre for 'T-433' (Table 2). 'T-433', 'Quest', 'T-434', 'Torero', and 'Superstar' were among the highest varieties in total yield. Supercolossal-size onion yield averaged 173 cwt/acre and ranged from 0 cwt/acre for 'T-441', 'Gunnison', 'Redwing', 'Flamenco', and 'Tango' to 483 cwt/acre for 'Quest'. 'Quest' was the highest yielding variety of supercolossal bulbs. The number of bulbs per 50 lb of supercolossal onions averaged 31 and ranged from 24 for 'Vaquero' to 59 for 'Red October'. Yellow bulb varieties that had supercolossal counts above the acceptable range (averaged too small) for marketing (28-36 count per 50 lb) were 'Daytona', 'Delgado', 'Legend', 'Sabroso', and 'Valiant'. 'Vaquero' had a supercolossal count below the acceptable range for marketing (averaged too big). Colossal-size onion yield averaged 258.1 cwt/acre and ranged from 18.6 cwt/acre for 'Red October' to 478.3 cwt/acre for 'Torero'. 'Torero', 'Vaquero', 'T-433', 'Santa Fe', 'Granero', 'Ranchero', 'Superstar', and 'Tequila' had colossal bulb yields greater than 400 cwt/acre.

Decomposition in storage averaged 10.5 percent and ranged from 3.6 percent for 'Daytona' to 26.6 percent for 'Red October'. No. 2 bulbs averaged 65.7 cwt/acre and ranged from 0 cwt/acre for 'Sweet Perfection' to 381.3 cwt/acre for 'T-434'. Bolting averaged 0.5 bolted onions out of approximately 368 onions in each 4-row plot. Bolting ranged from 0 bolted onions per plot for many varieties to only 2.4 bolted onions per plot for 'Zorro'.

Table 1. Yellow onion multiple center rating. Malheur Experiment Station, Oregon State University, Ontario, OR, 2001.
Seed company Variety "Blowout" "Intermediate double" "Small double" "Bullet" Functionally single centered "Bullet + small double"
    ------------------------------------- % ---------------------------------------
American Takii Eagle 18.8 34.3 36.9 10.1 47.0
  T-433 31.4 30.5 17.4 20.7 38.1
  T-434 49.3 26.0 14.0 10.7 24.7
  T-439 33.3 24.7 24.0 18.0 42.0
  T-441 6.0 31.3 38.0 24.7 62.7
Asgrow Cannon Ball 29.3 24.0 18.7 28.0 46.7
  Santa Fe 13.3 16.0 36.7 34.0 70.7
  EX77031 19.5 31.4 22.1 26.9 49.0
  EX15120 19.6 29.6 23.4 27.5 50.9
Bejo Daytona 30.5 34.4 22.8 12.3 35.1
  Delgado 42.0 30.0 21.3 6.7 28.0
  Gunnison 6.0 15.3 35.3 43.3 78.7
  Legend 38.0 34.7 19.4 7.9 27.3
Crookham Sweet Perfection 13.8 23.7 21.0 41.5 62.5
  Zorro 23.8 19.8 23.9 32.5 56.4
  XPH97H33 21.3 30.7 21.3 26.7 48.0
  XPH95345 41.8 27.8 21.9 8.5 30.4
D. Palmer Mesquite 28.7 35.3 21.3 14.7 36.0
  Tequila 21.6 18.0 25.5 34.9 60.4
Dorsing Harvest Moon 22.9 28.6 23.4 25.1 48.6
Petoseed Pinnacle 21.5 33.6 23.4 21.5 44.9
  Quest 19.3 24.0 28.0 28.7 56.7
  Tioga 21.3 34.0 26.0 18.7 44.7
  Vision  16.0 17.3 25.3 41.3 66.7
Rispens Golden Security 37.5 27.6 18.1 16.8 34.8
  Ringstar 25.3 29.3 19.3 26.0 45.3
  Superstar 10.7 24.7 34.7 30.0 64.7
Seed Works Pathfinder 45.4 22.8 18.2 13.5 31.7
  Raptor 30.0 23.3 20.0 26.7 46.7
  SWO 7102 8.0 16.0 30.0 46.0 76.0
  SWO 7254 18.7 25.3 28.0 28.0 56.0
  SWO 12028 21.5 22.2 22.1 34.2 56.3
Sunseeds Granero 8.0 12.0 25.3 54.7 80.0
  Ranchero 8.0 20.7 22.0 49.3 71.3
  Sabroso 1.3 7.3 30.0 61.3 91.3
  Tesoro 33.3 28.7 20.7 17.3 38.0
  Torero 12.1 28.9 31.4 27.6 59.0
  Valiant 9.3 14.5 29.9 46.3 76.2
  Vaquero 8.7 8.0 13.3 70.0 83.3
Mean
22.2 24.8 24.5 28.5 53.0
LSD (0.05)   9.7 11.1 11.4 12.0 13.2
Table 2. 2001 performance data for experimental and commercial onion varieties graded out of storage, January, 2002, Malheur Experiment Station, Oregon State University, Ontario, OR.



  Marketable yield by grade
Non-marketable yield
Maturity
Bolters
Company  Entry name Bulb color Total yield Total >4¼ in >4¼ in 4-4¼ in 3-4 in 2¼-3 in   Total rot Neck rot Plate rot Black mold No. 2s Small   Aug. 20 Sept. 7   Sept. 7
      --- cwt/acre --- #/50 lb ------------ cwt/acre ------------   ----- % of total yield -----  -- cwt/acre --   ---- % ----   #/plot
American Takii Eagle Y 731.9 636.1 33 17.1 242.0 367.5 9.6   9.0 7.1 1.9 0.0 28.5 1.4   26.0 71.0   0.0
  T-433 Y 1191.6 980.2 29 316.0 446.0 211.4 6.8   9.7 5.6 4.0 0.2 94.9 0.8   10.0 34.0   0.8
  T-434 Y 1132.2 645.9 30 141.8 307.0 190.1 7.0   8.4 6.7 1.6 0.2 381.3 1.5   12.0 52.0   0.0
  T-439 Y 893.0 732.6 31 80.3 378.0 265.4 8.9   8.9 4.4 4.5 0.0 78.4 2.7   52.0 87.5   0.6
  T-441 Y 645.3 588.9   0.0 45.7 521.4 21.8   7.1 4.7 2.3 0.1 1.3 8.5   67.0 96.5   0.2
Asgrow Cannon Ball Y 1036.2 825.3 30 200.8 393.3 226.0 5.2   12.5 9.6 2.8 0.1 78.2 1.7   9.0 44.0   2.2
  Red Zepplin R 631.3 421.2 54 1.0 53.1 341.0 26.1   12.4 11.1 1.3 0.0 126.8 5.4   55.0 85.5   0.0
  Santa Fe Y 1013.6 866.4 31 143.5 442.1 267.4 13.5   9.5 7.3 2.2 0.0 47.8 3.1   16.0 51.0   1.4
  EX77031 Y 943.9 801.2 32 135.7 390.1 268.3 7.1   9.9 7.4 2.1 0.3 47.6 0.9   24.0 54.0   1.2
  EX15120 Y 889.5 785.8 33 55.1 326.9 397.9 5.9   6.9 5.2 1.7 0.0 39.6 2.9   28.0 62.0   0.2
Bejo Daytona Y 765.1 686.2 45 10.7 195.1 455.1 25.3   3.6 2.4 1.2 0.0 36.6 14.7   20.0 60.0   0.0
  Delgado Y 815.5 700.0 38 16.8 211.9 460.0 11.3   9.0 5.9 3.0 0.1 38.7 3.3   31.0 69.0   0.0
  Gladstone W 783.4 603.3 37 24.8 171.1 393.9 13.5   17.9 16.2 1.7 0.0 34.6 5.0   27.0 66.0   0.6
  Gunnison Y 619.3 567.9   0.0 27.6 515.9 24.4   7.0 3.6 3.3 0.0 2.4 5.5   71.0 99.0   0.0
  Legend Y 866.9 770.1 38 19.8 201.1 526.8 22.4   5.1 3.7 1.4 0.0 43.4 9.4   23.3 66.7   0.0
  Redwing R 728.8 654.8   0.0 87.1 547.3 20.4   8.5 6.9 1.5 0.0 5.5 7.8   22.0 62.0   0.0
Crookham Sweet Perfection Y 983.5 726.8 31 234.8 334.6 148.7 8.8   22.6 20.0 2.5 0.0 29.2 1.3   16.0 53.0   1.0
  Zorro Y 969.8 802.4 31 235.2 362.2 195.9 9.2   10.3 8.8 1.6 0.0 68.1 2.1   13.0 50.0   2.4
  XPH97H33 Y 966.4 754.7 32 157.2 366.8 222.8 8.0   12.5 10.5 2.1 0.0 88.8 1.2   18.0 49.0   0.6
  XPH95345 Y 893.3 703.3 32 86.9 279.2 327.8 9.5   9.4 8.6 0.9 0.0 104.7 2.0   12.0 48.0   0.4
D. Palmer Frosty W 733.7 493.6 35 7.4 159.2 319.1 7.8   25.0 19.9 5.1 0.0 53.2 2.8   31.0 68.0   0.6
  Mesquite Y 1008.7 766.9 32 217.4 319.8 218.6 11.1   17.5 15.6 1.9 0.0 62.1 2.1   7.5 37.0   1.6
  Tequila Y 1043.3 884.9 31 217.0 404.8 253.9 9.2   7.9 6.8 1.2 0.0 74.6 1.3   8.5 41.0   0.8
Dorsing Harvest Moon Y 684.5 540.6 31 173.0 226.0 133.1 8.5   10.5 9.2 1.3 0.0 70.5 3.1   15.8 51.7   1.0
  Red October R 522.4 303.6 59 3.7 18.6 251.4 29.9   26.6 23.6 3.1 0.0 74.3 7.4   72.0 100.0   0.0
Petoseed Flare R 786.7 569.4 30 31.3 178.0 345.3 14.8   7.4 5.9 1.5 0.0 158.0 1.7   36.0 76.5   0.0
  Mercury R 679.6 464.6 33 6.4 110.1 327.7 20.5   16.6 13.2 3.4 0.0 100.2 4.5   56.0 92.5   0.0
  Pinnacle Y 878.4 735.5 34 32.1 296.9 394.1 12.3   11.1 8.6 2.6 0.0 43.6 2.4   41.0 74.5   0.0
  Quest Y 1138.6 961.6 29 483.2 375.4 96.7 6.3   12.2 9.3 3.0 0.0 27.6 0.0   7.5 45.0   0.4
  Tioga Y 974.7 915.4 31 54.3 388.9 462.4 9.8   4.8 2.6 2.2 0.0 9.0 2.7   34.0 66.0   0.2
  Vision  Y 986.8 836.8 31 197.3 385.6 245.6 8.3   11.9 8.6 3.2 0.2 31.7 1.6   19.0 56.0   0.2
Rispens Golden Security Y 817.6 636.3 33 56.0 272.3 292.6 15.4   8.4 6.7 1.8 0.0 110.8 2.8   17.0 57.0   1.4
  Red Fortress R 660.4 443.6 48 2.2 67.6 359.5 14.3   10.4 8.1 2.3 0.0 141.6 6.9   19.5 62.0   0.4
  Red Rider R 644.0 319.7 41 2.5 44.6 252.3 20.2   7.8 5.9 1.8 0.1 271.0 3.9   24.0 62.0   0.0
  Ringstar Y 995.4 786.2 31 219.2 350.0 212.0 5.0   12.1 10.7 1.3 0.0 88.0 1.7   13.0 47.0   0.6
  Superstar Y 1058.9 881.2 31 228.6 416.5 230.4 5.7   9.8 8.2 1.6 0.0 73.6 0.8   9.5 45.0   1.4
Seed Works Pathfinder Y 815.2 636.4 33 15.8 198.6 415.1 6.9   11.3 10.2 1.1 0.0 85.2 1.4   49.0 73.5   0.4
  Raptor Y 971.0 690.3 32 131.3 291.7 260.2 7.1   19.2 15.1 4.1 0.0 94.8 1.8   16.0 49.0   1.2
  SWO 7102 Y 728.5 661.7 33 11.0 196.6 441.4 12.7   7.5 5.5 2.0 0.0 8.6 4.2   48.0 81.0   0.0
  SWO 7254 Y 883.2 740.9 31 108.9 330.2 290.9 11.0   9.5 7.5 2.0 0.0 53.1 3.5   22.0 56.0   0.2
  SWO 12028 Y 903.0 702.6 30 197.1 258.5 230.0 17.1   14.9 12.8 2.2 0.0 62.7 2.6   26.0 60.0   1.4
Sunseeds Flamenco R 541.4 437.4   0.0 11.8 385.4 40.2   11.6 9.0 2.6 0.0 33.5 7.0   70.0 100.0   0.0
  Granero Y 904.9 840.5 32 120.0 437.5 279.0 4.0   6.2 4.0 1.9 0.3 6.2 2.2   13.0 53.0   0.8
  Ranchero Y 998.3 915.0 30 183.2 419.1 300.5 12.2   5.8 3.7 2.1 0.0 23.2 2.4   21.0 63.0   0.2
  Sabroso Y 477.9 430.2 54 1.0 51.1 361.4 16.8   7.7 5.1 2.6 0.0 4.2 6.8   34.0 79.0   0.0
  Tango  R 542.2 421.6   0.0 20.3 376.8 24.6   13.5 10.3 3.1 0.0 40.5 6.9   64.0 99.0   0.0
  Tesoro Y 888.1 746.6 31 16.6 227.5 485.0 17.5   8.5 7.3 0.9 0.3 59.8 6.9   39.0 74.0   0.6
  Torero Y 1066.9 929.8 31 219.5 478.3 226.1 5.9   10.2 7.4 2.7 0.1 24.9 2.5   14.0 61.0   0.0
  Valiant Y 740.4 613.8 37 26.9 253.8 319.6 13.5   14.4 8.0 5.9 0.4 16.2 1.5   34.0 80.5   1.8
  Vaquero Y 980.7 909.0 24 130.9 454.8 314.2 9.1   6.3 5.2 1.1<