2003 ONION VARIETY TRIALS

Clinton C. Shock, Erik B. G. Feibert, and Lamont D. Saunders
Malheur Experiment Station
Oregon State University
Ontario, OR

Introduction


The objective of the onion variety trials was to evaluate yellow, white, and red onion varieties for bulb yield, quality, and single centers. Six early season yellow varieties were planted in March and were harvested and graded in August. Forty-two full season varieties (33 yellow, 8 red, and 1 white) were planted in March, harvested in September 2003, and evaluated in January 2004.

Methods


The onions were grown on a Greenleaf silt loam previously planted to wheat. Soil analysis indicated the need for 100 lb P2O5/acre, 150 lb K /acre, 6 lb Mn/acre, 2 lb Cu/acre, and 1 lb B/acre that was broadcast in the fall. In the fall of 2002, 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. A soil sample taken on May 9 showed a pH of 7.4, 1.2 percent organic matter, 11 ppm nitrate-N, 30 ppm P, and 185 ppm K.

A full season trial and an early maturing trial were conducted adjacent to each other. The early maturing trial was planted on March 12 and the full season trial was planted on March 13. Both trials were planted in plots four double rows wide and 27 ft long. The early maturing trial had 6 varieties from 4 companies (Table 1) and the full season trial had 42 varieties from 10 companies (Table 2). The experimental design for both trials was a randomized complete block with five replicates. A sixth nonrandomized replicate was planted for demonstrating onion variety performance to growers and seed company representatives.

Seed was planted in double rows spaced 3 inches apart at nine seeds/ft of single row. Each double row was planted on beds spaced 22 inches apart with a customized planter using John Deere Flexi Planter units 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 14. On March 28 the field was sprayed with Roundup at 24 oz/acre. Onion emergence started on April 2. On May 13, alleys 4 ft wide were cut between plots, leaving plots 23 ft long. From May 15 through 17, the seedlings were hand thinned to a plant population of two plants/ft of single row (6-inch spacing between individual onion plants, or 95,000 plants/acre). The field was sidedressed with 44 lb of N/acre as ammonium sulfate, 56 lb N/acre as urea, and 1 lb of B/acre on May 21. On June 9 the field was sidedressed with 100 lb N/acre as urea.

The onions were managed to avoid yield reductions from weeds, pests, and diseases. Weeds were controlled with an application of Buctril at 0.12 lb ai/acre and Poast at 0.38 lb ai/acre on April 16, and an application of Goal at 0.12 lb ai/acre, Buctril at 0.12 lb ai/acre, Poast at 0.28 lb ai/acre, and Prowl at 0.83 lb ai/acre on May 22, and an application of Goal at 0.12 lb ai/acre, Buctril at 0.12 lb ai/acre, and Poast at 0.28 lb ai/acre on May 28. After lay-by the field was hand weeded as necessary. Thrips were controlled with one aerial application of Warrior on June 5 and two aerial applications of Warrior (0.03 lb ai/acre) plus Lannate (0.4 lb ai/acre) on July 16 and August 4.

The trial was furrow irrigated when the soil water potential at 8-inch depth reached -20 kPa. Soil water potential was monitored by six granular matrix sensors (GMS, Watermark Soil Moisture Sensors Model 200SS, Irrometer Co., Riverside, CA) installed in mid-June below the onion row at 8-inch depth. Sensors were automatically read three times a day with an AM-400 meter (Mike Hansen Co., East Wenatchee, WA). The last irrigation was on August 26.

Onions in each plot were evaluated subjectively for maturity by visually rating the percentage of onions with the tops down and the percent dryness of the foliage. The percent maturity was calculated as the average of the percentage of onion with tops down and the percent dryness. The early maturing trial was evaluated for maturity on July 30 and the full season trial on August 22.

Onions from the middle two rows in each plot in the early maturity trial were lifted, topped by hand, and bagged on August 12. The onion bags were hauled to a barn on August 15. On August 18 the onions were graded. The onions in the full season trial were lifted on September 12 to field cure. Onions from the middle two rows in each plot of the full season trial were topped by hand and bagged on September 17. The bags were put in storage on October 1. The storage shed was managed to maintain an air temperature of approximately 34°F. Onions from the full season trial were graded out of storage on January 14, 2004.

During grading, bulbs were separated according to quality: bulbs without blemishes (No. 1s), split bulbs (No. 2s), neck rot (bulbs infected with the fungus Botrytis allii 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 inches), medium (2¼-3 inches), jumbo (3-4 inches), colossal (4-4¼ inches), and supercolossal (>4¼ inches). 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. The red varieties were evaluated subjectively during grading for exterior thrips damage during storage. The bulbs in each red variety plot were rated for the damage that was apparent on the bulb surface, without removing the outer scales (0 = no damage, 10 = most damage).

In early September bulbs from one of the border rows in each plot of both trials were rated for single centers. Twenty-five consecutive onions ranging in diameter from 3.5-4.25 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 inches, "intermediate double" had diameters from 1½-2¼ inches, and "blowout" had diameters >2¼ inches. Single-centered onions were classed as a "bullet". Onions were considered functionally single centered for processing if they were a "bullet" or "small double."

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. 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.

Early Maturity Trial, Six Yellow Varieties

The percentage of "bullet" single centers averaged 6.6 percent and ranged from 1.6 percent for 'XON-0101' and 'Renegade' to 19.1 percent for 'Kodiak' (Table 1). Kodiak was the highest in percentage of "bullet" single centers. The percentage of onions that were functionally single centered averaged 24.8 percent and ranged from 12.8 percent for Renegade to 39.2 percent for Kodiak. Kodiak, 'DPSX 1170' and 'Madero' were among those with the highest percentage of functionally single-centered bulbs.

Total yield averaged 716 cwt/acre and ranged from 536 cwt/acre for DPSX 1170 to 974 cwt/acre for Renegade (Table 3). Renegade and XON-0101 had the highest total yield. Super colossal-size onion yield averaged 25.1 cwt/acre and ranged from 0 cwt/acre for DPSX 1170 to 75.3 cwt/acre for Renegade. Renegade and XON-0101 had the highest yield of super colossal bulbs. Not considering super colossals, colossal-size onion yield averaged 173.5 cwt/acre and ranged from 9.8 cwt/acre for DPSX 1170 to 463.7 cwt/acre for Renegade. Renegade and XON-0101 had the highest colossal bulb yields.

Full Season Trial, 33 Yellow Varieties

The percentage of "bullet" single centers averaged 22.3 percent and ranged from 2 percent for 'Delgado' to 72.7 percent for '6011' (Table 2). Varieties 6011 and 'SR 7004 ON' were among the highest in percentage of onions with "bullet" single centers. Varieties 6011, SR 7004 ON, 'Bandolero', and 'SR 7003 ON' were among the highest in percentage of onions that were functionally single centered.

Marketable yield out of storage in January 2004 averaged 951.2 cwt/acre and ranged from 644.4 cwt/acre for 'Milestone' to 1198.9 cwt/acre for 'Ranchero' (Table 4). Ranchero, 'Santa Fe', 'Granero', '6001', SR 7004 ON, 'Torero', and 6011 were among the varieties with the highest marketable yield. Super colossal-size onion yield averaged 228.3 cwt/acre and ranged from 0 cwt/acre for Milestone to 501 cwt/acre for 'Mesquite'. Mesquite and Ranchero were among the varieties with the highest super colossal yield. The number of bulbs per 50 lb of super colossal onions averaged 32 and ranged from 26.3 for 'Tequila' to 37.5 for 'Sabroso'. Only Sabroso had super colossal counts above the acceptable range (averaged too small, because they are almost all at the small end of the size range) for marketing as super colossals (28-36 count per 50 lb). Tequila, 'T-433', and Ranchero had super colossal counts below the acceptable range (averaged too big) for marketing as super colossal. Not considering super colossals, colossal-size onion yield averaged 402.1 cwt/acre and ranged from 56 cwt/acre for Milestone to 607.6 cwt/acre for Granero. Granero, SR 7004 ON, and 'Vaquero' were among the highest in colossal bulb yields.

Decomposition in storage averaged 4.4 percent and ranged from 1.3 percent for Granero to 17.6 percent for T-433. No. 2 bulbs averaged 43.8 cwt/acre and ranged from 1.4 cwt/acre for Milestone to 135.5 cwt/acre for 'XPH95345". Bolting was not observed in any plot in 2003.

Full Season Trial, Eight Red Varieties

The percentage of "bullet" single centers averaged 11 percent and ranged from 2.7 percent for 'Mercury' to 20 percent for 'Redwing' (Table 2). The percentage of functionally single-centered onions averaged 40.8 percent and ranged from 24 percent for 'Red Zepelin' to 60.7 percent for Redwing.

Marketable yield out of storage in January 2004 averaged 537.7 cwt/acre and ranged from 376.4 cwt/acre for 'Red October' to 730.7 cwt/acre for Redwing (Table 4). Super colossal-size onion yield averaged 4.2 cwt/acre and ranged from 0 cwt/acre for Red Zepelin to 17.3 cwt/acre for 'Red Fortress'. The number of bulbs per 50 lb of super colossal onions averaged 30.5 and ranged from 32.5 for Mercury to 54.2 for 'EXP Red 440'. Not considering super colossals, colossal-size onion yield averaged 86.9 cwt/acre and ranged from 49.1 cwt/acre for Red Zepelin to 135.9 cwt/acre for Redwing. Decomposition in storage averaged 4.4 percent and ranged from 1 percent for Red Fortress to 14.4 percent for Red October.

Subjective evaluation of thrips damage to red onions in storage ranged from 1.6 for Red Fortress to 6.7 for Red October. Red Fortress, EXP Red 440, and Redwing were among the lowest in thrips damage.

Table 1. Onion multiple center rating for early maturing varieties, Malheur Experiment Station, Oregon State University, Ontario, OR, 2003.


Seed company Variety Blowout Intermediate double Small double Bullet Functionally single centered
"Bullet + small double"


% % % % %
D. Palmer DPSX 1170 36 36.8 22.4 4.8 27.2
D. Palmer Kodiak 33.5 27.3 20.1 19.1 39.2
Sakata XON-0101 48 33.6 16.8 1.6 18.4
Scottseed Dawn 50.7 26.9 20 2.4 22.4
Sunseeds Madero 45.6 25.6 18.4 10.4 28.8
Sunseeds Renegade 56 31.2 11.2 1.6 12.8
Average
45 30.2 18.2 6.6 24.8
LSD (0.05)
NS NS NS 8.2 14.4

Table 2. Onion multiple center rating for long season varieties, Malheur Experiment Station, Oregon State University, Ontario, OR, 2003.

Seed company Variety Blowout Intermediate double Small double Bullet Functionally single centered
"Bullet + small double"


%
%
%
%
%
A. Takii Milestone (T-441) 8.0 25.3 62.0 4.7 66.7

T-433 57.3 27.3 12.7 2.7 15.3

T-439 34.7 30.7 30.0 4.7 34.7
Bejo Daytona 58.9 26.3 12.1 2.7 14.8

Delgado 40.7 36.0 21.3 2.0 23.3

Gladstone 32.7 29.3 30.7 7.3 38.0

Redwing 10.0 29.3 40.7 20.0 60.7

BGS 167 36.7 19.3 27.3 16.7 44.0
Crookham Harmony 30.5 28.5 14.4 26.6 41.0

Sweet Perfection 34.7 27.3 18.0 20.0 38.0

OLYS97-24 43.3 21.3 18.0 17.3 35.3

OLYS97-27 48.7 17.3 22.0 12.0 34.0

XPH95345 50.7 25.3 18.7 5.3 24.0
Dorsing Harvest Moon 48.0 12.0 20.0 20.0 40.0

Red October 20.0 24.0 37.3 18.7 56.0
D. Palmer DPSX 1171 40.0 24.7 24.0 11.3 35.3

DPSX 1172 46.0 20.0 14.7 19.3 34.0

Mesquite 45.3 20.0 18.0 16.7 34.7

Tequila 29.3 20.7 19.3 30.7 50.0
Rispens Red Fortress 37.3 20.0 24.0 18.7 42.7

Vivacious Red 50.0 17.3 23.3 9.3 32.7

EXP Red 440 49.3 17.3 21.3 12.0 33.3
Scottseed Red Marksman 42.7 23.3 30.7 3.3 34.0
Seedworks
Varsity 14.0 16.7 26.7 42.7 69.3

4001 14.7 28.7 32.7 24.0 56.7

6001 40.7 14.0 23.3 22.0 45.3

6005 14.7 24.0 22.7 38.7 61.3

6011 2.0 4.7 20.7 72.7 93.3
Seminis Mercury 31.3 26.0 40.0 2.7 42.7

Red Zepelin 44.7 31.3 20.7 3.3 24.0

Sea Hawk 22.7 38.7 32.0 6.7 38.7

Santa Fe 24.0 32.0 23.3 20.7 44.0
Sunseeds Granero 16.0 24.0 18.7 41.3 60.0

Pandero 24.0 18.7 26.7 30.7 57.3

Ranchero 18.0 30.7 22.7 28.7 51.3

Sabroso 10.7 14.0 44.0 31.3 75.3

Torero 30.0 22.7 29.3 18.0 47.3

Vaquero 16.0 28.0 17.3 38.7 56.0

SR7003 ON 10.0 10.0 23.3 56.7 80.0

SR7004 ON 4.7 6.0 28.7 60.7 89.3

Bandolero 0.0 11.3 31.3 57.3 88.7

SX7002 ON 6.7 17.3 37.3 38.7 76.0
Average
29.5 22.4 25.8 22.3 48.1
LSD (0.05)

13.6
13.2
10.9
12.4
14.3


Table 3. Performance data for early maturing onion varieties harvested on August 12 and graded on August 18, Malheur Experiment Station, Oregon State University, Ontario, OR, 2003.





Marketable yield by grade Marketable yield by grade Marketable yield by grade Marketable yield by grade Marketable yield by grade Marketable yield by grade Non-marketable yield Non-marketable yield Non-marketable yield Non-marketable yield
Maturity
Company Entry-name Total-yield
Total >4¼ in >4¼ in 4-4¼ in 3-4 in 2¼-3 in Total rot Sun scald No. 2s
Small 30-Jul


cwt/acre cwt/acre #/50 lb.
cwt/acre cwt/acre cwt/acre cwt/acre %
cwt/acre cwt/acre cwt/acre %
D.Palmer DPSX-1170
536.0
494.8

0.0
9.8
432.2
52.7
1.5
7.2
21.3
4.6
62

Kodiak
667.2
548.4
33.3
8.2
99.3
421.5
19.4
2.6
20.8
73.8
7.1
13
Sakata
XON-0101
942.0
819.7
29.0
72.1
346.5
393.9
7.3 5.8
36.7
31.2
1.6
53
Scottseed Dawn
757.1
666.2
30.5
16.4
167.4
468.0
14.5
5.7
23.9
22.1
1.4
56
Sunseeds Madero
789.2
725.6
29.5
3.5
123.8
586.5
11.8
2.1
5.5
36.1
5.5
49

Renegade
974.0
859.7
29.7
75.3
463.7
312.1
8.6
2.5
48.1
41.2
0.9
46
Average

715.7
625.7
30.4
25.1
173.5
395.5
31.6
4.9
20.3
34.0
5.7
51
LSD(0.05)
41.4
67.6
15.6
29.6
51.1
56.7
13.5
4.3
28.6
23.1
6.0
6.1

Table 4. 2003 performance data for experimental and commercial onion varieties graded out of storage in January 2004 Malheur Experiment Station, Oregon State University, Ontario, OR.






Marketable yield by grade Marketable yield by grade Marketable yield by grade Marketable yield by grade Marketable yield by grade Marketable yield by grade Non-marketable yield Non-marketable yield Non-marketable yield Non-marketable yield Non-marketable yield Non-marketable yield Maturity Thrips damage*
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. 22



cwt/acre cwt/acre #/50 lb cwt/acre cwt/acre cwt/acre cwt/acre  % of total yield  % of total yield  % of total yield  % of total yield cwt/acre cwt/acre %

A. Takii  Milestone(T-441)
Y 660.5
644.4

0.0
56.0
566.8
21.6
1.8
0.9
0.7
0.3
1.4
2.6
86.0

T-433  1289.7 979.5 27.3 324.9 451.2 199.1 4.4 17.6 13.8 3.7 0.1 83.0 0.9 31.0

T-439 Y 960.5 890.3 31.0 89.1 381.8 412.8 6.6 4.5 2.9 1.4 0.3 25.7 1.2 75.0
Bejo Daytona Y 868.0 795.9 32.5 13.7 258.9 512.9 10.4 1.4 1.0 0.4 0.0 58.2 2.1 49.0

Delgado Y 933.6 869.4 33.8 15.3 315.5 531.7 6.9 2.1 0.6 1.0 0.5 44.1 1.0 70.0

Gladstone W 773.9 640.6 33.1 33.5 207.2 383.2 16.7 11.0 9.1 1.3 0.6 41.3 3.1 52.0

Redwing R 743.5 730.7 38.4 1.3 135.9
587.4 6.1 1.2 0.7 0.6 0.0 2.4 1.5 58.0 2.6

BGS 167 Y 925.8 854.5 33.4 23.4 308.0 515.2 7.9 2.1 1.4 0.4 0.3 50.4 2.0 58.0
Crookham Harmony Y 1198.3 1063.6 28.6 422.9 475.8 161.0 3.8 7.0 4.1 1.7 1.3 51.7 0.5 35.5

Sweet Perfection Y 1186.0 1037.1 29.5 343.6 451.2 239.1 3.2 7.2 4.8 1.4 1.0 62.5 1.6 52.0

OLYS97-24 Y 1217.8 1043.3 28.7 432.6 437.8 165.9 7.0 5.7 3.9 1.5 0.3 104.2 1.0 27.0

OLYS97-27 Y 1201.5 1058.1 28.1 418.8 428.0 207.8 3.5 5.0 3.2 1.2 0.7 81.0 1.8 26.0

XPH95345 Y 1021.9 816.6 31.0 125.6 362.2 319.0 9.9 6.8 5.6 0.9 0.3 135.5 0.5 37.0
Dorsing Harvest Moon Y 1083.0 885.4 29.0 371.9 351.7 157.1 4.6 8.9 6.0 2.3 0.5 100.8 1.9 40.0

Red October R 500.5 376.4 34.7 4.4 49.8 308.4 13.8 14.9 11.3 3.6 0.0 48.0 1.6 93.0 6.7
D. Palmer DPSX 1171 Y 1036.9 863.8 29.4 128.8 355.6 372.1 7.3 8.0 6.0 1.1 0.9 86.7 3.5 56.0

DPSX 1172 Y 1018.2 842.5 30.0 148.1 318.2 373.7 2.5 5.5 3.1 1.6 0.9 118.7 2.3 55.0

Mesquite Y 1134.1 982.5 28.7 501.0 354.8 122.0 4.7 3.4 2.0 0.8 0.5 113.4 0.8 12.5

Tequila Y 1064.5 964.3 26.3 407.2 380.2 172.1 4.8 4.6 3.0 1.1 0.5 48.6 2.8 26.5
Rispens Red Fortress R 736.2 573.1 38.4 17.3 115.0 425.5 15.2 1.0 0.5 0.5 0.0 153.7 2.4 42.0 1.6

Vivacious Red R 710.6 451.1 45.4 1.1 79.8 351.1 19.0 1.9 1.2 0.7 0.0 241.4 5.7 47.0 3.0

EXP Red 440 R 753.6 578.2 54.2 2.8 128.5 431.0 15.9 1.1 0.9 0.2 0.0 165.8 1.3 37.0 2.1
Scottseed  Red Marksman R 529.6 386.7 
0.0 18.3 330.5 38.0 8.0 4.2 3.7 0.0 98.1 3.5 81.0 6.0
Seedworks Varsity Y 854.2 826.4 35.5 39.0 362.7 416.1 8.6 2.2 1.2 1.0 0.0 8.9 0.3 71.0

4001 Y 851.0 810.8 34.7 51.1 309.6 443.2 6.9 2.3 0.8 1.3 0.2 17.7 2.6 68.0

6001 Y 1178.8 1105.9 28.4 499.9 453.8 146.8 5.4 2.6 1.6 1.0 0.0 40.7 3.3 33.0

6005 Y 942.3 888.6 27.7 377.8 405.4 103.4 2.0 3.7 2.2 1.3 0.2 18.2 1.5 41.0

6011 Y 1151.2 1089.4 28.9 312.9 532.2 240.9 3.4 3.1 1.3 1.8 0.0 25.1 1.6 53.0
Seminis Mercury R 696.4 624.4 32.5 6.3 118.7 487.2 12.2 5.2 3.5 1.1 0.6 34.0 1.3 81.0 6.5

Red Zepelin R 689.4 580.8
0.0 49.1 496.7 35.0 1.8 1.2 0.5 0.0 90.6 4.3
72.0 3.7

Sea Hawk Y 786.7 737.2 30.6 8.2 230.8 472.7 25.5 2.6 2.0 0.6 0.0 24.9 4.1 71.0

Santa Fe Y 1247.6 1133.5 28.1 320.8 522.7 285.8 4.2 5.5 3.4 1.4 0.7 43.7 3.0 39.0
Sunseeds Granero Y 1153.5 1130.4 29.6 295.7 607.6 221.3 5.8 1.3 0.4 0.7 0.2 7.8 0.4 48.0

Pandero  Y 1133.6 1070.7 29.1 262.5 522.5 280.2 5.6 3.8 1.8 1.1 0.8 21.4 0.7 27.0

Ranchero Y 1264.3 1198.9 27.6 443.3 529.8 222.0 3.8 3.5 2.6 0.8 0.1 20.0 2.8 53.0

Sabroso Y 831.9 809.9 37.5 18.7 283.8 494.9 12.6 1.7 0.6 0.9 0.2 3.0 4.2 68.0

Torero Y 1169.5 1090.1 28.3 384.9 474.4 222.3 8.5 5.2 3.4 0.9 0.9 16.3 2.8 40.0

Vaquero Y 1111.4 1052.0 29.5 263.4 537.7 245.9 4.9 3.9 2.6 0.8 0.4 16.3 2.3 50.0

SR7003 ON Y 1045.1 1020.0 31.0 181.6 525.9 307.3 5.1 2.2 1.2 0.7 0.2 1.7 0.7 46.0

SR7004 ON Y 1125.3 1093.0 31.3 163.4 577.4 349.8 2.3 2.2 1.0 1.0 0.2 6.1 0.6 53.0

Bandolero Y 778.3 752.6 34.0 4.5 260.5 471.3 16.3 2.6 1.3 1.3 0.0 3.6 3.0 71.0

SX7002 ON
Y 1051.8 988.0 32.6 137.8 446.6 396.0 7.6 5.3 3.3 1.9 0.2 5.4 3.0 74.0
Average

966.9 865.0 32.0 180.9 337.4 336.9 9.8 4.6 3.0 1.2 0.3
55.3
2.1 52.5 3.8
LSD(0.05)

115.4 120.1 2.9 64.2 76.3 94.4 9.7 3.0 2.7 1.8 NS 29.0 2.7 7.0 1.4

* Thrips damage: 0 = least damage, 10 = most damage.