Oakes Irrigation Research Site
Carrington Research Extension Center * North Dakota State University
P.O. Box 531, Oakes, ND 58474-0531, Voice: (701) 742-2189, FAX: (701) 742-2700, email: rgreenla@ndsuext.nodak.edu

CARROT TILLAGE STUDY, 2000

Richard Greenland

Introduction

Materials and methods

Results summary

Table 51. List of treatments

Table 52. Quantity and yield of carrots on beds - late July harvest.

Table 53. Quality characteristics of carrots on beds - late July harvest.

Table 54. Quantity and yield of carrots on beds - late August harvest.

Table 55. Quality characteristics of carrots on beds - late August harvest.

Table 56. Quantity and yield of carrots on beds - late September harvest.

Table 57. Quality characteristics of carrots on beds - late September harvest.

Table 58. Quantities and yields of carrots planted flat (no beds) - late July harvest.

Table 59. Quality of carrots planted flat (no beds) - late July harvest.

Table 60. Quantities and yields of carrots planted flat (no beds) - late August harvest.

Table 61. Quality of carrots planted flat (no beds) - late August harvest.

Table 62. Quantities and yields of carrots planted flat (no beds) - late September harvest.

Table 63. Quality of carrots planted flat (no beds) - late September harvest.

Table 64. Quantities of carrots in tillage by seeding rate study - late July harvest.

Table 65. Quality of carrots in tillage by seeding rate study - late July harvest.

Table 66. Quantities of carrots in tillage by seeding rate study - late August harvest.

Table 67. Quality of carrots in tillage by seeding rate study - late August harvest.

Table 68. Quantities of carrots in tillage by seeding rate study - late September harvest.

Table 69. Quality of carrots in tillage by seeding rate study - late September harvest.

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INTRODUCTION

Carrots are usually planted on raised beds. The raised beds have loose soil which allow the carrots to grow long and straight. Carrots planted on flat ground usually are more crooked and shorter because of compacted soil and plow pans. But making raised beds reduces the surface area for planting carrots, so carrots are crowded together on top of the beds. Also during the growing season the sides of the beds erode away leaving some carrot tops exposed which causes green or red colored root tops, which in turn reduce carrot quality. Planting carrots on flat ground would solve these last two problems, but the soil needs to be loosened. We tried two methods to loosen the soil. We used a chisel plow to rip the soil about 12 inches deep or a soil spader to till the soil 12 inches deep. We compared these two treatments to carrots planted on beds. We also included a population study with the tillage study, and included two carrot hybrids, Bolero and Prime Cut.

MATERIALS AND METHODS

Soil: Maddock sandy loam; pH=7.4; 2.0% organic matter; soil-P and soil-K was very high; soil-S was low.
Previous crop: 1999 - sweet corn; 1998 - cabbage, broccoli, and cauliflower; 1997 - potato.
Seedbed Preparation: Disked entire study on 29 October 1999. Multiweeded (field cultivated) April 5. See Table 51 for tillage treatments. Depth the soil was worked: Soil spader 12", chisel plow 12", disk 5 to 6", field cultivater 3 to 5". Beds were 36 inches wide on 54 inch centers and 9" tall (5" above ground level with a 4" deep furrow). Beds were lightly rototilled once and flat planted areas were field cultivated shallow twice to incorporated herbicides just before planting.
Planting: Direct seeded on May 12 or May 15 with a Stanhay vegetable planter. Planting pattern for all carrots was paired rows (3 inches between rows (lines) in the pair). See Table 51 for number of paired rows, spacing and seeding rates.
Plot layout: This study was laid out in a split plot in strips design with subplots arranged in a randomized complete block design. Main plots were hybrid (80 by 54 ft) and tillage (160 by 13.5 ft). Subplots were seeding rate (flat planted) or rows per bed by seeding rate (planted in beds). Subplots were 17 ft long by 13.5 ft wide. There were 4 reps.
Fertilizer: On April 4, broadcast 18 lbs N/acre and 20 lbs S/acre as 21-0-0-24. Fertigated 35 lbs N/acre as 28-0-0 on June 27 and July 14.
Irrigation: Sprinkler irrigation as needed.
Pest control: Weeds were controlled using Treflan (1.5 pt/acre on May 11) and Lorox (1 lb/acre on May 15 and 2 lb/acre on June 22). We sprayed Sevin (1 qt/acre on July 27, Aug 10, Aug 26, and Aug 31) and Asana (8 oz/acre on June 29, July 6, July 14, Jul 20, and Aug 3) to control leafhopper.
Harvest: Plots were harvested three times. Harvest area was a three foot section in the center of each plot (two center rows of the flat planted plots and the center bed on the plots that were bedded). Carrots were harvested from July 28 through September 28.

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RESULTS

The Bolero carrots were much more vigorous than the Prime Cut carrots. This was amplified when our irrigation system went down when carrots were about one inch tall. We applied irrigation through a replacement system, but the distribution, etc. was not completely adequate and the carrots were stressed for one to two days. The Prime Cut was hurt the most by this stress. As a result, numbers, yields, and quality of Bolero carrots were higher than Prime Cut carrots.

Planting three rows per bed did not increase quality or yield as compared to two rows per bed, except that root size was increased slightly at the early harvest.

When planting on beds, increasing the seeding rate from 1 to 1.5 million increased both carrot yield and quality, but decreased average carrot size. When planting on flat ground, higher planting rates increased small carrot yield and decreased large carrot yield. Overall US #1 carrot yield was not improved by planting more than 1 million seeds per acre.

Using the chisel plow before bedding increased carrot length and decreased the percent of carrots with multiple roots, but did not affect yield or other quality factors as compared to only disking before bedding. On flat planting, carrots were longer and more carrots had multiple roots when the soil was worked with a soil spader vs. when the soil was worked with a chisel plow. Yields, numbers, and other quality characteristics were not affected by primary tillage method.

Yield and quality were generally lower when carrots were planted flat vs. being planted on beds. One possible reason for this is that the chisel plow left a rougher seedbed (lowering stand establishment) and the soil spader left too fine a seedbed that crusted very easily (also lowering stand establishment). Carrots grew longer when planted on beds after a chisel plow tillage or planted flat after tilling with the soil spader. Disking plus bedding or planting flat after tillage with the chisel plow produced shorter carrots.

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Table 51. List of treatments for the carrot tillage/population study.
Primary tillage Bed vs. flat No. of paired rows per bed Row spacing Plant populations
inches millions/acre
Disk bed 2 or 3 16 or 8 1 or 1.5
Chisel plow bed 2 or 3 16 or 8 1 or 1.5
Chisel plow flat - 16 0.5, 1, 1.5, or 2.0
Soil spader flat - 16 0.5, 1, 1.5, or 2.0

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Table 52. Quantity and yield of carrots in a bedded carrot study at the Oakes Irrigation Research Site - late July harvest.
Treatment Number of US #1 carrots US #1 carrot yield Total yield
> ¾" 3/8 to ¾" total > ¾" 3/8 to ¾" total
----- 1000s of roots/acre ----- -------------- tons/acre --------------
Hybrid
Bolero 237 252 489 12.7 5.6 18.4 20.0
Prime Cut 60 215 275 3.4 5.5 8.9 12.5
Probability1 0.0002 0.049 0.0003 0.001 0.67 0.002 0.002
Seeding rate
1 million 139 153 292 8.3 4.2 12.4 15.3
1.5 million 158 314 472 7.9 7.0 14.8 17.2
Probability1 0.015 <.0001 <.0001 0.27 <.0001 <.0001 0.0001
Rows per bed
Two 138 253 392 7.6 5.9 13.5 16.3
Three 159 215 372 8.6 5.3 13.8 16.3
Probability1 0.01 0.06 0.41 0.014 0.16 0.44 0.92
Tillage
Disked 153 244 398 8.2 5.6 13.8 17.0
Chisel plow 143 223 366 8.0 5.5 13.5 15.6
Probability1 0.45 0.42 0.28 0.78 0.87 0.72 0.08
C. V. (%) 20 35 25 19 30 14 11

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

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Table 53. Quality characteristics of carrots in a bedded carrot study at the Oakes Irrigation Research Site - late July harvest.
Treatment US #1 > ¾" Total US #1 Multiple root Straight score1 Root size Root length Root diameter
-------- % of total yield --------- 1 to 10 oz/root ----- inches ------
Hybrid
Bolero 64 91 5 4.8 1.3 8.7 1.01
Prime Cut 28 71 19 4.5 1.1 9.8 0.84
Probability2 0.0005 0.002 0.006 0.17 0.0153 0.005 0.004
Seeding rate
1 million 49 78 15 4.6 1.4 9.4 0.93
1.5 million 42 84 9 4.8 1.0 9.1 0.92
Probability2 0.004 0.005† 0.0005† 0.31 <.0001 0.26 0.54
Rows per bed
Two 42 80 13 4.6 1.1 9.3 0.93
Three 49 82 11 4.7 1.2 9.1 0.92
Probability2 0.005 0.28 0.15 0.56 0.02 0.44 0.63
Tillage
Disked 44 78 15 4.6 1.2 8.7 0.91
Chisel plow 47 85 9 4.8 1.2 9.7 0.94
Probability2 0.23 0.03† 0.04† 0.21 0.34 0.004 0.10
C. V. (%) 20 10 49 18 16 12 8

1The higher the score the straighter the carrot.

2If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

†Seeding rate by tillage interaction (tillage effect seen only at low seeding rate; seeding rate effect seen with disked but not with chisel plow treatments).

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Table 54. Quantity and yield of carrots in a bedded carrot study at the Oakes Irrigation Research Site - late August harvest.
Treatment Number of US #1 carrots US #1 carrot yield Total yield
> ¾" 3/8 to ¾" total > ¾" 3/8 to ¾" total
----- 1000s of roots/acre ----- --------------- tons/acre ---------------
Hybrid
Bolero 318 119 438 24.3 3.2 27.5 31.5
Prime Cut 165 159 324 13.1 4.5 17.6 24.2
Probability1 0.004 0.04† 0.02 0.002‡ 0.008† 0.003 0.004
Seeding rate
1 million 223 85 308 19.0 2.5 21.5 27.3
1.5 million 261 193 454 18.4 5.1 23.6 28.4
Probability1 0.006 <.0001† <.0001 0.43 <.0001† 0.014 0.17
Rows per bed
Two 233 161 394 18.0 4.4 22.4 28.3
Three 250 117 368 19.5 3.2 22.7 27.4
Probability1 0.18 0.002 0.26 0.05‡ 0.002 0.66 0.26
Tillage
Disked 251 155 406 18.8 4.1 22.9 28.5
Chisel plow 232 123 356 18.7 3.6 22.2 27.2
Probability1 0.07 0.17 0.04 0.90 0.27 0.26 0.09
C. V. (%) 22 37 24 16 36 14 12

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

†Hybrid by seeding rate interaction (Prime Cut had more small numbers and yield than Bolero at the 1.5 million rate, but at the 1million rate both hybrids were the same).

‡Hybrid by row interaction (three row yield is higher than two row yield for Bolero but not for Prime Cut).

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Table 55. Quality characteristics of carrots in a bedded carrot study at the Oakes Irrigation Research Site - late August harvest.
Treatment US #1 > ¾" Total US #1 Multiple root Straight score1 Root size Root length Root diameter
-------- % of total yield --------- 1 to 10 oz/root ----- inches ------
Hybrid
Bolero 77 87 7 5.5 2.1 9.3 1.19
Prime Cut 54 73 18 5.6 1.9 10.3 1.07
Probability2 0.001 0.005 0.007 0.46 0.17 0.057 0.07
Seeding rate
1 million 68 78 16 5.5 2.3 10.0 1.15
1.5 million 63 82 10 5.6 1.7 9.6 1.10
Probability2 0.004 0.02 0.0004 0.59 <.0001 0.14 0.16
Rows per bed
Two 62 78 13 5.5 1.9 9.8 1.12
Three 69 82 13 5.7 2.1 9.8 1.13
Probability2 0.0004 0.03 0.82 0.24 0.07 0.96 0.71
Tillage
Disked 64 79 15 5.6 1.9 9.2 1.13
Chisel plow 67 81 11 5.5 2.1 10.4 1.12
Probability2 0.22 0.08 0.005 0.72 0.19 0.003 0.65
C. V. (%) 11 8 46 10 17 9 12

1The higher the score the straighter the carrot.

2If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

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Table 56. Quantity and yield of carrots in a bedded carrot study at the Oakes Irrigation Research Site - late September harvest.
Treatment Number of US #1 carrots US #1 carrot yield Total yield
> 1.5" ¾ to 1.5" total > 1.5" ¾ to 1.5" total
----- 1000s of roots/acre ----- --------------- tons/acre ---------------
Hybrid
Bolero 36 378 462 6.2 27.4 34.5 40.8
Prime Cut 13 278 365 2.7 20.6 24.7 33.3
Probability1 0.02 0.0018 0.017 0.03‡ 0.0002‡ 0.002 0.006
Seeding rate
1 million 29 266 323 5.5 21.7 27.8 35.3
1.5 million 20 391 504 3.3 26.3 31.4 38.8
Probability1 0.0015 <.0001 <.0001 0.0002 <.0001 0.0002 0.0003
Rows per bed
Two 27 327 425 4.9 23.1 29.3 37.3
Three 22 329 402 3.9 24.9 29.9 36.7
Probability1 0.12 0.91 0.41 0.04‡ 0.07‡ 0.53 0.50
Tillage
Disked 23 342 429 4.0 25.0 30.2 38.4
Chisel plow 26 314 398 4.8 23.0 29.0 35.7
Probability1 0.49 0.24 0.31 0.22 0.08 0.12 0.014
C. V. (%) 43 25 26 48 17 11 9

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

‡Hybrid by rows/bed interaction (effect of rows/bed seen only with Bolero).

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Table 57. Quality characteristics of carrots in a bedded carrot study at the Oakes Irrigation Research Site - late September harvest.
Treatment US # 1 Multiple root Straight score1 Root size Root length Root diameter
> 1.5" ¾ to 1.5" Total
-------- % of total yield --------- 1 to 10 oz/root ----- inches ------
Hybrid
Bolero 15 67 85 7 5.1 2.5 9.6 1.18
Prime Cut 8 61 74 18 5.3 2.5 10.3 1.03
Probability2 0.06‡ 0.09‡ 0.0009† 0.002† 0.09 0.59 0.10 0.03
Seeding rate
1 million 15 61 78 15 5.2 2.9 10.0 1.11
1.5 million 8 68 81 10 5.3 2.1 9.9 1.10
Probability2 <.0001 0.003 0.09† <.0001† 0.64 <.0001 0.50 0.73
Rows per bed
Two 13 61 78 12 5.2 2.4 9.9 1.10
Three 11 67 81 13 5.2 2.6 9.9 1.12
Probability2 0.15‡ 0.008‡ 0.10 0.39 0.78 0.07 0.95 0.48
Tillage
Disked 10 65 78 15 5.3 2.4 9.3 1.10
Chisel plow 14 64 81 10 5.1 2.6 10.6 1.12
Probability2 0.06 0.90 0.28 0.02 0.48 0.23 0.003 0.35
C. V. (%) 52 13 7 32 13 19 8 10

1The higher the score the straighter the carrot.

2If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

†Hybrid by seeding rate interaction (effect of seeding rate significant with Prime Cut but not with Bolero).

‡Hybrid by rows/bed interaction (effect of rows/bed significant with Bolero but not with Prime Cut).

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Table 58. Quantities and yields of carrots in a flat planted carrot study at the Oakes Irrigation Research Site - late July harvest.
Treatment Number of US #1 carrots Total roots US #1 carrot yield Total yield
> ¾" 3/8 to ¾" total > ¾" 3/8 to ¾" total
----------- 1000s of roots/acre ----------- ----------------- tons/acre -----------------

BOLERO AND PRIME CUT
Hybrid
Bolero 221 145 365 423 12.1 3.2 15.3 17.6
Prime Cut 66 64 130 212 4.1 1.9 6.0 9.5
Probability1 0.002 0.008 0.0002 0.0005 0.006† 0.0006 0.004 0.01
Seeding rate
1.0 million 142 61 203 259 8.9 1.8 10.6 13.5
1.5 million 145 147 292 375 7.4 3.3 10.7 13.7
Probability1 0.89 0.009 0.047 0.017 0.014† 0.011 0.91 0.83
Tillage
Chisel plow 153 110 263 319 8.5 2.7 11.2 13.7
Soil Spader 134 98 233 315 7.7 2.4 10.2 13.5
Probability1 0.11 0.53 0.18 0.80 0.07 0.65 0.16 0.77
C. V. (%) 29 76 46 37 18 59 25 19

BOLERO ONLY
Seeding rate
0.5 million 71 b2 8 b 79 c 129 d 7.1 c 0.3 c 7.3 b 11.8 b
1.0 million 225 a 82 b 307 b 352 c 13.5 a 2.2 b 15.7 a 17.9 a
1.5 million 217 a 208 a 424 a 494 b 10.7 b 4.3 a 15.0 a 17.3 a
2.0 million 260 a 265 a 525 a 615 a 11.9 ab 5.2 a 17.1 a 19.3 a
Probability <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001
C. V. (%) 23 52 31 26 16 45 18 14

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the Bolero seeding rate section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

†Hybrid by seeding rate interaction (effect of seeding rate significant with Bolero but not with Prime Cut).

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Table 59. Quality of carrots in a flat planted carrot study at the Oakes Irrigation Research Site - late July harvest.
Treatment US #1 > ¾" Total US #1 Multiple root Root size Root length Root diameter
-------- % of total yield --------- oz/root ----- inches ------

BOLERO AND PRIME CUT
Hybrid
Bolero 68 87 10 1.5 8.2 1.06
Prime Cut 45 64 28 1.6 10.3 0.95
Probability1 0.0004 0.0015 0.009 0.10 0.03 0.03
Seeding rate
1.0 million 62 75 19 1.8 9.1 1.01
1.5 million 51 75 19 1.3 9.5 1.00
Probability1 0.005 0.96 0.99 0.003 0.14 0.81
Tillage
Chisel plow 60 79 15 1.5 8.9 1.00
Soil Spader 53 71 23 1.6 9.6 1.01
Probability1 0.07 0.03 0.02 0.22 0.03 0.68
C. V. (%) 16 10 48 23 8 8

BOLERO ONLY
Seeding rate
0.5 million 60 b2 63 b 34 b 3.0 a 9.5 a 1.14 a
1.0 million 75 a 88 a 9 a 1.7 b 8.2 b 1.06 b
1.5 million 62 b 86 a 10 a 1.2 c 8.3 b 1.06 b
2.0 million 61 b 88 a 6 a 1.1 c 8.2 b 1.01 b
Probability 0.0005 <.0001 <.0001 <.0001 0.018 0.013
C. V. (%) 10 9 45 19 11 7

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the Bolero seeding rate section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

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Table 60. Quantities and yields of carrots in a flat planted carrot study at the Oakes Irrigation Research Site - late August harvest.
Treatment Number of US #1 carrots Total roots US #1 carrot yield Total yield
> ¾" 3/8 to ¾" total > ¾" 3/8 to ¾" total
----------- 1000s of roots/acre ----------- ----------------- tons/acre -----------------

BOLERO AND PRIME CUT
Hybrid
Bolero 275 56 331 412 22.5 1.4 23.9 30.1
Prime Cut 100 25 125 224 10.7 0.8 11.5 21.1
Probability1 0.0006 0.03 0.0009 0.005 0.0025 0.04 0.0015 0.004
Seeding rate
1.0 million 162 28 190 274 15.9 0.7 16.6 25.2
1.5 million 212 54 266 361 17.3 1.5 18.8 26.0
Probability1 0.009 0.02 0.009 0.007 0.28 0.02 0.13 0.47
Tillage
Chisel plow 210 42 252 338 18.6 1.1 19.8 26.8
Soil Spader 165 39 204 298 14.6 1.1 15.6 24.4
Probability1 0.04 0.69 0.07 0.15 0.07 0.70 0.08 0.18
C. V. (%) 24 70 30 24 22 68 21 12

BOLERO ONLY
Seeding rate
0.5 million 93 c2 2 b 95 c 162 c 14.9 b 0.1 c 15.0 b 28.0 a
1.0 million 255 b 47 b 303 b 387 b 22.4 a 1.2 bc 23.6 a 30.1 a
1.5 million 294 ab 65 b 359 b 437 b 22.6 a 1.6 b 24.2 a 30.1 a
2.0 million 365 a 192 a 557 a 640 a 22.2 a 3.8 a 26.0 a 30.5 a
Probability <.0001 0.0002 <.0001 <.0001 0.002 0.0002 0.0001 0.51
C. V. (%) 29 88 35 28 19 76 18 12

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the Bolero seeding rate section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

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Table 61. Quality of carrots in a flat planted carrot study at the Oakes Irrigation Research Site - late August harvest.
Treatment US #1 > ¾" Total US #1 Multiple root Root size Root length Root diameter
-------- % of total yield --------- oz/root ----- inches ------

BOLERO AND PRIME CUT
Hybrid
Bolero 74 79 14 2.4 9.1 1.19
Prime Cut 48 52 38 3.3 10.7 1.15
Probability1 0.004 0.002 0.005 0.015 0.03 0.61
Seeding rate
1.0 million 59 62 29 3.4 10.0 1.20
1.5 million 64 69 23 2.4 9.8 1.14
Probability1 0.19 0.06 0.11 0.0002 0.55 0.13
Tillage
Chisel plow 67 72 19 2.8 9.2 1.17
Soil Spader 55 59 33 2.9 10.6 1.17
Probability1 0.06 0.07 0.02 0.53 0.013 0.61
C. V. (%) 16 16 39 18 11 10

BOLERO ONLY
Seeding rate
0.5 million 52 b2 52 b 44 c 5.2 a 10.0 a 1.46 a
1.0 million 74 a 78 a 15 b 2.6 b 9.4 a 1.26 b
1.5 million 75 a 80 a 12 ab 2.2 bc 8.7 a 1.12 c
2.0 million 73 a 85 a 8 a 1.7 c 8.6 a 1.18 bc
Probability 0.0001 <.0001 <.0001 <.0001 0.08 0.0001
C. V. (%) 13 11 30 20 13 10

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the Bolero seeding rate section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

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Table 62. Quantities and yields of carrots in a flat planted carrot study at the Oakes Irrigation Research Site - late September harvest.
Treatment Number of US #1 carrots Total roots US #1 carrot yield Total yield
>1½" ¾ to 1½ total >1½" ¾ to 1½ total
----------- 1000s of roots/acre ----------- ----------------- tons/acre -----------------

BOLERO AND PRIME CUT
Hybrid
Bolero 86 237 344 415 13.7 17.4 31.8 38.7
Prime Cut 40 82 129 220 8.6 8.6 17.4 29.8
Probability1 0.0004 0.005 0.002 0.007 0.02 0.014 0.009 0.008
Seeding rate
1.0 million 71 125 204 273 13.2 10.8 24.4 34.6
1.5 million 55 195 269 362 9.1 15.3 24.7 34.0
Probability1 0.15 0.02 0.03 0.009 0.08 0.02 0.89 0.76
Tillage
Chisel plow 65 171 251 328 12.0 13.9 26.1 35.0
Soil Spader 61 149 222 307 10.3 12.2 23.1 33.6
Probability1 0.54 0.55 0.52 0.70 0.27 0.48 0.29 0.60
C. V. (%) 44 43 30 24 53 36 24 15

BOLERO ONLY
Seeding rate
0.5 million 54 b2 16 c 70 c 134 c 13.3 a 1.5 c 14.8 b 32.2 b
1.0 million 91 a 191 b 298 b 363 b 14.9 a 15.0 b 30.8 a 37.7 a
1.5 million 81 ab 284 b 390 b 467 b 12.5 ab 19.9 ab 32.8 a 39.8 a
2.0 million 57 b 405 a 518 a 621 a 7.8 b 22.6 a 31.4 a 37.7 a
Probability 0.03 <.0001 <.0001 <.0001 0.07 <.0001 <.0001 0.03
C. V. (%) 38 50 35 29 43 42 21 13

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the Bolero seeding rate section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

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Table 63. Quality of carrots in a flat planted carrot study at the Oakes Irrigation Research Site - late September harvest.
Treatment US #1 > ¾" Total US #1 Multiple root Root size Root length Root diameter
-------- % of total yield --------- oz/root ----- inches ------

BOLERO AND PRIME CUT
Hybrid
Bolero 80 82 11 3.2 9.3 1.21
Prime Cut 57 57 32 4.6 10.2 1.12
Probability1 0.08 0.07 0.06 0.009 0.11 0.11
Seeding rate
1.0 million 68 69 21 4.5 10.1 1.19
1.5 million 70 71 22 3.3 9.4 1.15
Probability1 0.51 0.53 0.66 0.002 0.09 0.40
Tillage
Chisel plow 72 73 17 3.9 9.4 1.18
Soil Spader 65 66 26 3.9 10.1 1.15
Probability1 0.14 0.16 0.02 0.94 0.21 0.42
C. V. (%) 9 10 27 22 10 10

BOLERO ONLY
Seeding rate
0.5 million 46 b2 46 b 48 b 7.0 a 9.2 ab 1.37 a
1.0 million 80 a 82 a 10 a 3.5 b 9.7 a 1.25 b
1.5 million 81 a 83 a 11 a 2.8 bc 8.9 ab 1.18 b
2.0 million 80 a 82 a 10 a 2.1 c 8.7 b 1.20 b
Probability <.0001 <.0001 <.0001 <.0001 0.17 0.0008
C. V. (%) 14 14 44 19 11 6

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the Bolero seeding rate section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

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Table 64. Quantities of carrots in a tillage by seeding rate study at the Oakes Irrigation Research Site - late July harvest.
Treatment Number of US #1 carrots Total roots US #1 carrot yield Total yield
> ¾" 3/8 to ¾" total > ¾" 3/8 to ¾" total
--------- 1000s of roots/acre --------- --------------- tons/acre ---------------
Hybrid
Bolero 231 214 445 502 12.5 4.8 17.3 19.2
Prime Cut 62 165 227 340 3.7 4.3 8.0 11.5
Probability1 0.0004 0.01 <.0001 <.0001 0.002 0.07 0.002 0.003
Seeding rate
1.0 million 139 121 260 330 8.4 3.3 11.8 14.7
1.5 million 153 258 412 511 7.7 5.8 13.5 16.0
Probability1 0.046 <.0001 <.0001 <.0001 0.02 <.0001 0.0004 0.0016
Tillage/rows
Disked + Bed, 2 rows 142 268 a2 409 a 540 a 7.5 5.9 a 13.4 a 16.8 ab
Disked + Bed, 3 rows 166 221 ab 386 a 477 ab 8.9 5.3 a 14.2 a 17.2 a
Chisel + Bed, 2 rows 132 234 ab 366 a 446 b 7.6 5.7 a 13.3 a 15.7 b
Chisel + Bed, 3 rows 151 207 b 358 a 427 b 8.3 5.2 a 13.5 a 15.4 b
Chisel, No Bed 153 110 c 263 b 319 c 8.5 2.7 b 11.2 b 13.7 c
Soil Spader 134 98 c 233 b 315 c 7.7 2.4 b 10.2 b 13.5 c
Probability 0.07 <.0001 <.0001 <.0001 0.08 <.0001 <.0001 <.0001
C. V. (%) 24 42 29 24 19 37 18 13

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the tillage/rows section, values in the same column followed by the same letter are not significantly different at the 0.05 level. No letters in column means there were no differences between values in that column.

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Table 65. Quality of carrots in a tillage by seeding rate study at the Oakes Irrigation Research Site - late July harvest.
Treatment US #1
> ¾"		 Total
US #1		 Multiple root Root size Root length Root diameter Straight score1
-------- % of total yield --------- oz/root ----- inches ------ 1 to 10
Hybrid
Bolero 65 90 6 1.3 8.5 1.03 4.7
Prime Cut 33 69 22 1.3 10.0 0.88 4.4
Probability2 0.0002‡ 0.0002 0.004† 0.29 0.008 0.005 0.10
Seeding rate
1.0 million 54 77 16 1.5 9.3 0.96 4.4
1.5 million 45 81 12 1.1 9.2 0.95 4.6
Probability2 <.0001 0.02 0.013†,¶ <.0001 0.74 0.55 0.14
Tillage/rows
Disked + Bed, 2 rows 40 d3 77 cd 15 b 1.1 b 8.8 b 0.92 b 4.4 a
Disked + Bed, 3 rows 48 bc 79 bc 14 b 1.2 b 8.6 b 0.90 b 4.7 a
Chisel + Bed, 2 rows 44 cd 83 ab 11 ab 1.2 b 9.9 a 0.94 b 4.8 a
Chisel + Bed, 3 rows 51 b 86 a 8 a 1.3 b 9.6 a 0.94 b 4.8 a
Chisel, No Bed 60 a 79 bc 15 b 1.5 a 8.9 b 1.00 a 4.3 a
Soil Spader 53 ab 71 d 23 c 1.6 a 9.6 a 1.01 a 4.1 a
Probability <.0001‡ <.0001 <.0001 <.0001 0.002 0.001 0.2
C. V. (%) 19 11 53 19 11 9 18

1The higher the score the straighter the carrot.

2If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

3In the tillage/rows section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

†Hybrid by seeding rate interaction (higher percentage multiply roots with lower seeding rate only for Prime Cut, no difference with Bolero).

‡Hybrid by tillage/rows interaction (difference between hybrids greater with beds).

Seeding rate by tillage/rows interaction (seeding rate response only for disked treatments).

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Table 66. Quantities of carrots in a tillage by seeding rate study at the Oakes Irrigation Research Site - late August harvest.
Treatment Number of US #1 carrots Total roots US #1 carrot yield Total yield
> ¾" 3/8 to ¾" total > ¾" 3/8 to ¾" total
--------- 1000s of roots/acre --------- --------------- tons/acre ---------------
Hybrid
Bolero 304 98 402 473 23.7 2.6 26.3 31.1
Prime Cut 143 115 258 364 12.3 3.3 15.6 23.2
Probability1 0.002 0.12 0.006 0.014 0.002 0.012†,‡ 0.002 0.003
Seeding rate
1.0 million 203 66 268 347 18.0 1.9 19.9 26.6
1.5 million 244 147 391 490 18.1 3.9 22.0 27.6
Probability1 0.0002 <.0001 <.0001 <.0001 0.90 <.0001† 0.006 0.12
Tillage/rows
Disked + Bed, 2 rows 245 ab2 190 a 435 a 546 a 17.8 a 4.9 a 22.7 a 28.8 a
Disked + Bed, 3 rows 256 a 120 b 376 b 456 b 19.7 a 3.3 b 23.1 a 28.3 a
Chisel + Bed, 2 rows 220 ab 132 b 352 b 444 b 18.1 a 3.9 b 22.0 ab 27.9 a
Chisel + Bed, 3 rows 245 ab 114 b 359 b 430 b 19.2 a 3.2 b 22.4 a 26.5 ab
Chisel, No Bed 210 b 42 c 252 c 338 c 18.6 a 1.1 c 19.8 b 26.8 ab
Soil Spader 165 c 39 c 204 c 298 c 14.6 b 1.1 c 15.6 c 24.4 b
Probability <.0001 <.0001 <.0001 <.0001 0.002 <.0001‡ <.0001 0.007
C. V. (%) 23 46 25 22 20 42 17 12

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the tillage/rows section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

†Hybrid by seeding rate interaction (No difference in hybrids at 1 million, but Prime Cut higher than Bolero at 1.5 million)

‡Hybrid by tillage/rows interaction (Bolero less than Prime Cut on beds, but reversed when planted flat).

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Table 67. Quality of carrots in a tillage by seeding rate study at the Oakes Irrigation Research Site - late August harvest.
Treatment US #1
> ¾"		 Total
US #1		 Multiple root Root size Root length Root diameter Straight score1
-------- % of total yield --------- oz/root ----- inches ------ 1 to 10
Hybrid
Bolero 76 84 9 2.2 9.2 1.19 5.3
Prime Cut 52 66 25 2.4 10.4 1.10 5.4
Probability2 0.002 0.003 0.006 0.31 0.04 0.14 0.40
Seeding rate
1.0 million 65 72 20 2.7 10.0 1.17 5.4
1.5 million 63 78 14 1.9 9.7 1.12 5.4
Probability2 0.27 0.003 0.0005 <.0001 0.11 0.047 1.00
Tillage/rows
Disked + Bed, 2 rows 61 cd3 78 a 14 ab 1.8 c 9.3 b 1.12 5.6 a
Disked + Bed, 3 rows 67 ab 80 a 15 ab 2.1 b 9.1 b 1.15 5.6 a
Chisel + Bed, 2 rows 63 bc 78 a 12 a 2.1 b 10.3 a 1.12 5.4 a
Chisel + Bed, 3 rows 71 a 84 a 10 a 2.1 b 10.5 a 1.12 5.7 a
Chisel, No Bed 67 ab 72 b 19 b 2.8 a 9.2 b 1.17 5.0 b
Soil Spader 55 d 59 c 33 c 2.9 a 10.6 a 1.17 4.9 b
Probability <.0001 <.0001 <.0001 <.0001 <.0001 0.73 <.0001
C. V. (%) 14 12 46 18 9 11 10

1The higher the score the straighter the carrot.

2If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

3In the tillage/rows section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

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Table 68. Quantities and yields of carrots in a flat planted carrot study at the Oakes Irrigation Research Site. Comparison of hybrid, seeding rate, and tillage treatments - Late September harvest.
Treatment Number of US #1 carrots Total roots US #1 carrot yield Total yield
>1½" ¾ to 1½" total >1½" ¾ to 1½" total
--------- 1000s of roots/acre --------- --------------- tons/acre ---------------
Hybrid
Bolero 53 331 423 504 8.7 24.1 33.6 40.1
Prime Cut 21 211 283 383 4.5 16.4 21.9 31.9
Probability1 0.002 0.0005 0.003 0.02 0.011 0.0006 0.0003 0.0004
Seeding rate
1.0 million 42 217 280 356 7.9 17.9 26.4 34.8
1.5 million 32 325 426 530 5.3 22.6 29.2 37.2
Probability1 0.005 <.0001 <.0001 <.0001 0.0003 <.0001 0.006 0.011
Tillage/rows
Disked + Bed, 2 rows 24 b2 355 a 459 a 571 a 4.2 b 23.9 ab 29.6 a 38.2 a
Disked + Bed, 3 rows 23 b 328 ab 399 a 486 b 3.9 b 26.0 a 30.8 a 38.6 a
Chisel + Bed, 2 rows 29 b 298 b 391 a 489 b 5.6 b 22.2 b 29.1 ab 36.5 ab
Chisel + Bed, 3 rows 22 b 330 ab 406 a 488 b 4.0 b 23.9 ab 29.0 ab 34.9 bc
Chisel, No Bed 65 a 171 c 251 b 328 c 12.0 a 13.9 c 26.1 b 35.0 bc
Soil Spader 58 a 143 c 212 b 299 c 9.9 a 11.6 c 22.0 c 32.8 c
Probability <.000 1 <.0001 <.0001 <.0001 <.0001 <.0001 <.0001 0.004
C. V. (%) 46 29 29 24 52 22 17 12

1If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

2In the tillage/rows section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

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Table 69. Quality of carrots in a tillage by seeding rate study at the Oakes Irrigation Research Site - late September harvest.
Treatment US #1
> ¾"		 Total
US #1		 Multiple root Root size Root length Root diameter Straight score1
-------- % of total yield --------- oz/root ----- inches ------ 1 to 10
Hybrid
Bolero 82 84 8 2.8 9.5 1.19 5.0
Prime Cut 65 68 23 3.2 10.2 1.07 5.1
Probability2 0.008† 0.006† 0.006†,‡ 0.09 0.08 0.04 0.37
Seeding rate
1.0 million 73 75 17 3.4 10.0 1.14 5.0
1.5 million 74 77 14 2.5 9.7 1.12 5.1
Probability2 0.59 0.13 0.03† <.0001 0.13 0.32 0.27
Tillage/rows
Disked + Bed, 2 rows 73 b3 77 ab 14 abc 2.2 c 9.3 b 1.07 a 5.1 ab
Disked + Bed, 3 rows 77 ab 79 ab 15 bc 2.6 b 9.3 b 1.13 a 5.4 a
Chisel + Bed, 2 rows 76 ab 80 a 10 a 2.5 bc 10.6 a 1.13 a 5.3 a
Chisel + Bed, 3 rows 79 a 82 a 11 ab 2.6 bc 10.5 a 1.11 a 5.0 abc
Chisel, No Bed 72 b 73 b 17 c 3.9 a 9.4 b 1.18 a 4.8 bc
Soil Spader 63 c 65 c 27 d 3.9 a 10.1 a 1.16 a 4.7 c
Probability <.0001† <.0001† <.0001‡ <.0001 <.0001 0.08 0.009
C. V. (%) 12 12 44 20 9 10 12

1The higher the score the straighter the carrot.

2If probability is less than 0.05 then the difference between the two values immediately above that probability is considered significant.

3In the tillage/rows section, values in the same column followed by the same letter are not significantly different at the 0.05 level.

†Hybrid by seeding rate interaction (no difference in seeding rate for Bolero, but only for Prime Cut).

‡Hybrid by tillage/rows interaction (no difference in tillage/row for Bolero, but only for Prime Cut).

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