ONION VARIETY TRIALS

Clint Shock, Joey Ishida, and Eric P. Eldredge

Malheur Experiment Station
Oregon State University
Ontario, Oregon, 1996
 

Purpose

This trial compared commercial varieties and experimental lines of yellow, white, and red onions for yield and grade. Field observations were made for relative maturity, incidence of plate rot, and bolting.
 


Procedures

The 1996 trials were conducted on a Owyhee silt loam soil with 1.2 percent organic matter and a pH of 7.3. The field had previously been planted to wheat. Before plowing, 100 lbs/ac of P2O5, and 60 lbs N/ac were broadcast. The wheat stubble was shredded and the field deep-chiseled, disked, irrigated, moldboard-plowed, roller- harrowed, and bedded in the fall. After bedding, the field was left until spring without further tillage.

Onion seed for entry in the trial was received from 15 companies: American Takii, Aristogene, Asgrow, Bejo, Champion, Crookham, Ferry Morse, Harris Moran, Petoseed, Rio Colorado, Rispens Seed, Scott Seeds, Shamrock, Sunseeds, and Waldow Seed. Seventy-one onion varieties were planted April 9 in plots four rows wide and 27 feet long. The onions were planted on 22-inch single-row beds. Each variety was planted with five replications. Seed for each row was prepackaged using enough seed for a planting rate of 12 viable seeds per foot of row. Seed was planted using four cone-seeders mounted on John Deere Model 71 Flexi-planter units equipped with disc openers.

The onions were furrow-irrigated during the growing season. The first irrigation was applied on April 13 to supply the soil with moisture for seed germination. On May 8, alleys 3 ft wide were cut between plots, leaving plots 24 ft long. On May 28 through June 1 the seedling onion plants were thinned by hand to a plant population of four plants per foot of row (3-inch spacing between individual onion plants). On June 3, 100 lb N/ac as Urea was sidedressed on each side of every row. On June 15, a second sidedressed application of 100 lb N/ac as Urea was applied.

The trial was managed to avoid yield reductions from pests. Dacthal was applied on May 4, and Lorsban 15G was applied for onion maggot control on May 11. Weeds were controlled with cultivations and low-rate herbicide applications as needed until layby. On July 5, layby herbicides Buctril, Goal, Poast, and Prowl were applied, along with Warrior insecticide for thrips control. On August 7, Lannate was applied by airplane.

Bulb maturity ratings for each plot were recorded on August 22, 30, and September 9, as visual estimates of percent dry leaf material in each plot, and percent of bulbs with necks collapsed and leaves on the ground. Those percentages for each date were averaged for the reported maturity ratings. Plate rot was counted on bulbs in the two center rows of each plot on September 4-6, and the number of bolters in the two center rows of each plot was recorded on September 9.

The onion bulbs were lifted on September 11 to field-dry. On September 15, 0.10 inch of rain fell, followed by 0.44 inch of rain on September 16. On September 25-26 the onions were hand-topped and placed into slatted wooden crates. The crates were placed into wooden bins (4 x 4 x 6 feet) on September 27, and the bins were moved into storage on September 30 and October 1.

The onion bulbs were removed from storage and graded from January 2-8, 1997. Bulbs were graded according to their diameter and quality. Size categories were 2¼ to 3-inch (medium), 3 to 4-inch (jumbo), and 4-inch and larger (colossal). Split bulbs and bulbs smaller than 2¼ inches were graded as No. 2s. Bulbs rotted by Botrytis neckrot, plate rot, and bacterial decay during storage were weighed and the percent of storage rot was calculated.

Varietal differences were compared using ANOVA and least significant differences at the 5 percent probability level, LSD (0.05).
 
 

Results

Varieties are listed by company in alphabetical order and ranked by marketable bulb yield for each company's varieties (Table 1). Average marketable yield was 806 cwt/ac with 27 percent colossal-sized bulbs, 72 percent jumbo, and 1 percent medium. Average cullage for No. 2's (3 percent) and storage rot (4 percent) are expressed in percentage above the total marketable yield. Bulbs smaller than 2¼ inches were included in the No. 2s category, which represents mostly split double bulbs. Small onions were less than 1 percent of yield for all varieties, and many varieties produced no small bulbs.

The LSD (0.05) values at the bottom of Table 1 should be considered when comparisons are made between varieties for yield and grade. Differences equal to or greater than the LSD (0.05) value for a column should exist before any variety is considered different from any other variety in the category compared in that column.
 

Table 1. Yield and grade of experimental and commercial onion varieties evaluated in 1996.
Malheur Experiment Station, Oregon State University, Ontario, Oregon, 1996.
 
Seed Onion Bulb Marketable yield by grade Non-marketable Maturity rating Plate rot Bolters
company variety color Total > 4 inch 3 - 4 inch 2 1/4 - 3 inch Storage rot No. 2's 8/22 8/30 9/6 9/4 9/9
      cwt/ac cwt/ac % cwt/ac % cwtac % % cwt/ac %  % 
American Takii 9003-C yellow 1131 630 55.1 499 44.8 1.5 0.1 4.8 73 6.4 0 3 19 2.9 1.1
  9003 yellow 988 377 38.6 606 60.9 5.7 0.6 9.4 43 4.4 0 1 5 3.1 0.3
  ATX 596 yellow 893 309 34.6 582 65.1 2.8 0.3 2.1 22 2.5 2 6 16 3.5 0.2
  ATX 589 yellow 869 351 40.8 514 58.8 3.5 0.4 3.2 28 3.3 2 3 13 4.9 0.8
  Condor yellow 818 225 27.8 591 72.0 1.2 0.1 4.4 13 1.6 14 22 44 10.3 0.4
  T-406 yellow 800 177 22.0 622 77.8 1.0 0.1 2.1 20 2.5 3 6 24 5.3 1.3
  T-432 yellow 699 295 42.8 399 56.6 4.1 0.6 5.7 21 3.2 2 11 20 5.1 0.0
  Frontier yellow 503 18 3.2 467 93.2 12.7 2.5 3.5 8 1.7 64 75 89 5.6 0.0
Aristogene Seville yellow 1093 493 45.1 597 54.6 2.4 0.2 3.7 13 1.2 6 12 30 2.3 1.9
  El Charro yellow 1071 467 43.6 601 56.1 2.9 0.3 5.5 11 1.0 4 9 21 4.5 1.5
  El Padre yellow 1040 479 46.3 559 53.4 1.8 0.2 2.3 10 1.0 1 3 16 3.4 1.5
  Bravo yellow 1015 460 45.2 552 54.5 1.3 0.1 3.8 29 3.0 6 10 21 4.8 1.9
  Maritime yellow 910 199 21.7 707 77.8 2.3 0.2 2.9 11 1.2 25 40 53 6.9 0.8
  Envoy yellow 881 249 28.3 628 71.3 3.7 0.4 2.8 25 2.9 33 43 52 5.3 0.9
Asgrow Viper yellow 885 242 27.3 640 72.4 2.8 0.3 5.8 28 3.2 29 40 50 4.5 2.2
  Viceroy yellow 807 155 19.2 645 80.1 5.8 0.7 1.9 19 2.3 22 38 52 3.4 0.0
  Regiment yellow 775 241 30.7 534 69.3 0.4 0.1 4.1 16 2.1 37 48 51 9.9 1.1
  Fury yellow 638 96 15.5 536 83.6 4.7 0.7 2.4 39 6.3 27 35 50 7.8 0.0
Bejo Seeds Gladstone white 766 102 13.3 654 85.4 9.6 1.2 2.0 19 2.5 1 3 13 4.0 0.3
  BGS 77F1 yellow 706 90 12.6 608 86.2 5.7 0.8 1.1 19 2.7 2 9 20 3.4 0.1
  Daytona yellow 704 93 13.1 603 85.7 6.7 1.0 1.1 21 3.0 2 5 11 4.9 0.3
  Redwing red 656 75 11.6 580 88.2 1.6 0.2 1.9 4 0.7 3 11 22 10.0 0.0
  Tamara F1 yellow 609 17 2.6 585 96.1 5.5 1.0 4.1 2 0.4 23 47 60 8.8 0.0
  Santana yellow 534 34 6.4 493 92.4 6.3 1.1 4.0 8 1.5 23 40 55 14.6 0.0
Champion PX 81892 red 498 121 24.6 368 73.6 5.4 1.1 6.3 16 3.1 11 13 19 8.3 0.0
Crookham Sweet Amber yellow 990 342 35.1 644 64.5 3.4 0.3 4.5 39 4.0 13 27 42 3.6 0.8
  Celebrity yellow 985 426 43.4 553 56.0 4.5 0.5 4.4 39 4.0 1 6 18 3.5 1.6
  Sweet Perfection yellow 970 439 45.3 528 54.4 1.8 0.2 3.0 42 4.3 12 18 30 3.8 0.8
  XPH 93386 yellow 708 118 16.9 581 81.9 7.1 1.0 3.2 21 3.0 10 22 43 5.2 1.5
Ferry Morse FMX 2074 yellow 886 322 35.9 561 63.7 3.0 0.3 3.0 11 1.3 7 22 35 5.8 1.0
  Caesar yellow 885 231 26.2 651 73.4 3.5 0.4 2.5 7 1.1 3 11 32 4.4 0.8
  Oro Grande yellow 857 270 31.2 582 68.4 2.4 0.3 3.2 8 1.0 5 11 30 4.5 1.0
  Augustus yellow 838 249 30.3 588 69.6 1.0 0.1 4.8 14 1.8 2 6 14 3.4 1.2
  Fabius yellow 830 175 21.0 652 78.5 2.7 0.3 2.7 16 1.9 22 36 52 7.0 2.1
Harris Moran Impact yellow 598 26 4.7 566 94.3 5.5 1.0 1.8 22 3.7 47 54 67 3.8 0.6
  White Ivory white 492 7 1.4 469 95.2 14.6 2.9 1.4 66 13.4 12 17 35 6.3 0.1
  Squire yellow 478 36 7.8 431 89.9 10.2 2.1 5.4 16 3.3 35 49 57 11.1 0.0
Seed Onion Bulb Marketable yield by grade Non-marketable Maturity rating Plate rot Bolters
company variety color Total > 4 inch 3 - 4 inch 2 1/4 - 3 inch Storage rot No. 2's 8/22 8/30 9/6 9/4 9/9
      cwt/ac cwt/ac % cwt/ac % cwtac % % cwt/ac %  % 
Petoseed Quest yellow 939 579 62.1 359 37.8 0.8 0.1 4.6 14 1.5 2 5 20 9.1 0.6
  Atlas yellow 925 627 68.0 296 31.8 1.3 0.2 5. 0 37 4.2 6 17 31 9.3 0.8
  Vision yellow 917 430 47.2 485 52.6 1. 0 0.1 4.3 22 2.5 2 5 21 7.2 0.6
  Pinnacle yellow 855 191 22.4 661 77.1 2.4 0.3 1.4 3 0.4 6 15 40 5.1 0.0
  Apex yellow 828 157 18.8 667 80.9 2.6 0.3 1.4 16 2.0 3 6 24 3.3 0.0
  Teton yellow 778 188 24.3 589 75.6 0.6 0.1 3.9 15 2.0 15 27 48 8.9 1.9
Rio Colorado 6077 yellow 851 277 32.8 571 66.9 2.3 0.3 2.2 65 7.7 13 23 36 5.3 0.6
  Challenge yellow 846 262 31. 0 581 68.8 2.1 0.3 3.5 42 4.9 14 22 40 5.8 1. 0
  Rio Seco yellow 801 112 13.9 683 85.5 3.4 0.4 4.5 19 2.4 50 53 55 7.6 0.2
  Discovery yellow 733 156 21.4 567 77.2 9.8 1.3 4. 0 28 3.8 27 38 45 5.6 0.3
  RNX 10090 yellow 670 71 10.6 598 89.2 1.2 0.2 4.2 8 1.2 36 45 53 8.3 0.6
  RCS 6171 yellow 655 113 17.4 536 81.7 3.7 0.6 6.3 37 5.8 44 47 52 10.2 0.6
  RNX-10001 white 550 28 5.1 509 92.3 11.9 2.2 2.8 12 2.3 20 26 43 3.7 0.1
Rispen Seeds Golden Security yellow 1022 467 45.5 553 54.3 2.3 0.2 3.7 48 4.7 2 3 17 1.5 1.1
  Victory yellow 982 438 44.7 540 55. 0 2. 0 0.2 3.4 43 4.3 8 19 33 3.6 0.2
  Wrangler yellow 786 161 20.9 586 74.6 36.0 4.1 2.2 24 3.0 3 12 29 3.8 0.2
Scottseed Great Scott yellow 900 404 45.2 495 54.6 0.3 0.03 3.9 62 7.0 3 8 25 2.8 0.2
Shamrock 55C 1992 yellow 788 165 20.7 614 78.2 7.3 0.9 3. 0 40 5.1 8 18 28 5.2 0.3
  Impala yellow 751 109 14.0 636 85.1 4.4 0.7 4.5 73 10.0 47 52 57 4.2 0.0
  SSC 3359 yellow 697 149 21.3 544 78.0 4.5 0.7 3.6 46 6.6 14 26 38 2.9 0.0
  SSC 9983 yellow 629 101 16.1 525 83.5 2.8 0.5 3.4 17 2.8 20 37 51 9.3 1.2
Sunseeds Sunre 1430 yellow 1061 449 42.2 611 57.7 1.1 0.1 0.9 8 0.7 16 36 46 1.8 0.2
  Vaquero yellow 996 336 33.9 657 65.7 3.2 0.3 2.9 2 0.2 3 6 27 2.4 0.3
  Snow White white 853 364 42.5 485 56.9 3. 0 0.4 7.2 41 4.8 0 3 5 3.1 0.8
  Bullring yellow 834 171 19.9 661 79.7 2.4 0.3 5.9 5 0.6 33 49 54 8.4 3.5
  Winner yellow 779 386 49.5 389 50. 0 3.3 0.4 9.4 10 1.3 19 33 42 17.1 2.8
  Tesoro yellow 764 155 20.1 606 79.4 3.5 0.5 1.6 15 2. 0 15 27 45 2.9 1.0
  Sunex 1440 yellow 744 99 13.4 639 85.8 4.5 0.6 2.2 15 2.1 6 22 46 6.9 0.0
  Valiant yellow 721 122 16.8 593 82.3 5.1 0.7 4.1 11 1.5 11 22 49 10.0 1.5
  Blanco Duro PVP white 691 116 17.3 572 82.2 2.6 0.4 6.2 13 2.1 1 3 12 3.9 0.4
  Mambo red 604 69 11.2 525 87.1 8.1 1.3 3. 0 29 4.8 2 8 16 7.6 0.0
  Tango red 493 18 3.5 465 94.5 7.1 1.4 3.7 9 1.8 13 24 40 11.1 0.0
Waldow Seeds X202 yellow 1004 385 38.3 615 61.4 3.5 0.3 9.6 24 2.4 1 2 12 3.7 1.6
  X201 yellow 949 402 42.7 546 57.1 1.1 0.1 12.3 33 3.7 2 9 19 4.6 1.6
Mean     805.6 237.9 27.13 562.5 72.12 4.4 0 0.63 3.87 24.1 3.1 13.5 21.7 34.7 5.9 0.7
LSD (0.05)     73.5 81. 0 9.46 101.47 9.34 10.27 1.21 3.85 19.38 2.4 8.12 8.73 9.17 3.3 0.8
5 non-marketable percents and cwt/ac are over and above total marketable yield