EFFECT OF HARVEST TIMING ON ONION YIELD AND STORABILITY, 2009

 

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

John Taberna
Western Laboratories,
Parma, ID

 

Introduction

Onion harvest for long-day varieties in the Treasure Valley generally extends from mid-August into early October.  Optimal dates for onion harvest are not known.  Harvest timing guidelines (calendar date or percentage of tops that are down) need to be determined.  The effect of harvest timing on yield at harvest and storage losses due to decomposition is unknown.  This trial evaluated the effect of harvest timing on bulb yield and storability.

Materials and Methods

Trials were conducted in furrow- and drip-irrigated fields at the Malheur Experiment Station in 2008 with storage prolonged into 2009.  The furrow-irrigated field was managed to maintain soil water tension below 25 cb.  The last irrigation was on August 27.  Varieties ‘Calibra’ (Bejo), ‘Montero’ (Nunhems), and ‘Joaquin’ (Nunhems) were replicated five times.  The drip-irrigated field was managed with three irrigation criteria: 10, 20, and 30 cb.  Varieties ‘Vaquero’ (Nunhems) and Joaquin were sampled from each irrigation treatment (10, 20, and 30 cb) and were replicated four times at each irrigation criterion.  The last irrigation was on September 5.  Optimal soil water tension for onions on silt loam is in the range of 20-25 cb for furrow irrigation and 15-20 cb for drip irrigation (Shock et al. 2005).

Each sample consisted of all bulbs from 6.8 ft of one double row in each 23-ft long, four double-row plot.  The samples were taken weekly starting on August 15 and ending on September 12.  The bulbs from each sample were topped, put in burlap bags, and placed on bare dry soil adjacent to the field to cure for 7 days.  After curing the bulbs were graded.  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 (<2.25 inches), medium (2.25-3 inches), jumbo (3-4 inches), colossal (4-4.25 inches), and supercolossal (>4.25 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.  At each sampling date, the onions in each plot were visually rated for the percentage of tops that were down.

After grading, one slice from each of ten bulbs from each sample was placed in a pre-weighed can for each plot.  The wet onion tissue plus can was weighed, dried in a forced-air oven at 140°F, and weighed again.  The remaining bulb sample was weighed again and put in a cooler at 34°F.  Starting on October 21, all samples were taken out of storage monthly and the rotten bulbs from each sample were removed and weighed.  The remaining sample was weighed and put back in storage.  The final weighing and removal of rotten bulbs was on February 25, 2009.  The actual total storage durations were 6.25, 6, 5.75, 5.5, and 5.25 months for the August 15, August 22, August 29, September 5, and September 12 harvests, respectively.

Results and Discussion

Yield
Furrow-irrigated Field
For Calibra and Montero, most of the tops were down by September 5 (Table 1).  For Joaquin, the highest percentage of tops down occurred at the last harvest date of September 12.  Marketable yield at harvest increased up to September 5 for Joaquin and Montero.  The percentage of tops down on September 5 was 22 percent for Joaquin and 84 percent for Montero.  Marketable yield of Calibra at harvest did not significantly increase after the first harvest date of August 15.  From the first harvest on August 15 to the last harvest on September 12, the percentage of tops down for Calibra ranged from 20 to 90 percent and marketable yield at harvest ranged from 523 to 576 cwt/acre.

For Calibra and Montero, total yield after storage increased as the percentage of tops down at harvest increased (Fig. 1).  For Joaquin, yield after storage was highest when onions were harvested with 27 percent tops down.

Averaged over the three varieties, the percentage of tops down increased up to the last harvest date of September 12 (70 percent tops down).  Surprisingly, averaged over the three varieties, total yield after 5 months of storage increased up to the last harvest date of September 12.  Averaged over the three varieties, the percent total losses during storage decreased with successive harvest date and were lowest at the last harvest date, September 12. 

Drip-irrigated Field
Averaged over irrigation treatments, the percentage of tops down continued to increase up to the last harvest date of September 12 for Vaquero and Joaquin (Table 2).  Averaged over irrigation treatments and varieties, the percentage of tops down increased up to the last harvest on September 12.  Averaged over irrigation treatments and varieties, marketable yield at harvest did not significantly increase after September 5.  Averaged over irrigation treatments and varieties, total yield and losses after storage were similar for the first three harvest dates (Aug. 15, 22, and 29).  Total yield after storage was significantly higher for the September 5 and September 12 harvests.  Storage losses were lowest with the last harvest on September 12. 

For Vaquero and Joaquin, averaged over irrigation treatments, total yield after storage increased as the percentage of tops down at harvest increased (Fig. 2). 

Bulb Nutrient Content
Furrow-irrigated Field
Averaged over varieties, there were significant differences in bulb nutrient content between harvest dates for P, K, S, Ca, Mg, Zn, and Mn (Table 3).  However, only Ca content showed a clear trend in response to harvest date.  Calcium content decreased with successive harvest date.

Drip-irrigated Field
Averaged over varieties and irrigation regimes, there were significant differences in bulb nutrient content between harvest dates for P, K, S, Ca, Mg, Zn, and Mn (Table 4).  However, only P, S, Ca, Mg, and Mn content showed a clear trend of decreasing nutrient content with successive harvest date.

Conclusions

For furrow-irrigated onions, yields at harvest did not increase after the August 29 harvest, about 2 days after the last irrigation on August 27.  For long term storage of furrow irrigated onion, harvest needed to be delayed until September 12, about two weeks after the last irrigation.  For the drip-irrigated onions, yields increased until September 5, the same date as the last irrigation.  For the drip-irrigated onions, storage losses were lowest at the last harvest on September 12, about 1 week after the last irrigation.

References

Shock, C.C., R. Flock, E. Feibert, C.A. Shock, A. Pereira, and L. Jensen. 2005. Irrigation monitoring using soil water tension. Oregon State University Extension Service EM 8900.

Acknowledgements
This project was partially funded by the Western Sustainable Agricultural Research and Education Program, the Idaho-Eastern Oregon Onion Committee, cooperating onion seed companies, and Oregon State University.

 

Table 1.  Yield and grade for three furrow-irrigated onion varieties harvested on five dates in 2008, and marketable yield after storage ending on February 25, 2009.  Malheur Experiment Station, Oregon State University, Ontario, OR.

 

At harvest

 

After storage to February 25

Harvest date

Tops down

Marketable yield by grade

Total yield

 

Marketable yield out of storage

Storage loss

 

>4¼ in

4-4¼ in

3-4 in

2¼-3 in

Total

 

 

%

   ----------------------------------------- cwt/acre -------------------------------------

%

 

                                                                     Calibra

 

Aug. 15

20.0

0.0

0.0

364.5

158.9

523.4

548.5

 

285.3

48.3

Aug. 22

54.0

16.1

37.9

395.5

108.6

558.1

573.5

 

316.6

45.7

Aug. 29

68.0

0.0

0.0

540.1

50.1

590.2

601.0

 

384.6

36.0

Sept. 5

86.0

0.0

6.2

524.7

45.5

576.3

576.8

 

484.6

16.0

Sept. 12

90.0

0.0

7.7

503.1

64.7

575.5

594.8

 

546.0

8.4

average

63.6

3.2

10.4

465.6

85.6

564.7

578.9

 

403.4

30.9

 

                                                                    Joaquin

Aug. 15

5.0

0.0

63.7

472.5

74.2

610.3

616.2

 

350.9

42.1

Aug. 22

10.0

36.2

62.4

512.4

81.2

692.2

703.9

 

397.0

43.5

Aug. 29

16.0

10.8

184.1

656.4

18.5

869.8

879.9

 

550.4

26.8

Sept. 5

22.0

85.5

259.6

439.2

8.6

792.9

808.7

 

500.1

28.4

Sept. 12

32.0

28.5

263.5

453.8

2.5

748.3

763.7

 

610.5

16.6

average

17.0

32.2

166.7

506.8

37.0

742.7

754.5

 

481.8

31.5

 

                                                                    Montero

Aug. 15

16.0

0.0

4.1

491.9

62.3

558.3

569.7

 

343.8

40.2

Aug. 22

48.0

0.0

14.0

568.7

37.2

620.0

632.7

 

371.7

34.7

Aug. 29

66.0

0.0

26.2

577.1

24.7

627.9

636.1

 

442.5

30.7

Sept. 5

84.0

0.0

58.6

627.9

27.1

713.6

713.9

 

500.5

29.9

Sept. 12

90.0

0.0

67.8

592.5

34.7

694.9

704.2

 

645.6

8.3

average

60.8

0.0

34.1

571.6

37.2

642.9

651.3

 

460.8

28.7

 

                                                                    Average

Aug. 15

13.7

0.0

22.6

443.0

98.5

564.0

578.1

 

326.7

43.5

Aug. 22

37.3

17.4

38.1

492.2

75.6

623.4

636.7

 

361.7

41.8

Aug. 29

50.0

3.6

70.1

591.2

31.1

696.0

705.6

 

459.2

31.5

Sept. 5

64.0

28.5

108.1

530.6

27.1

694.3

699.8

 

495.1

23.8

Sept. 12

70.7

9.5

113.0

516.5

34.0

672.9

687.6

 

600.7

10.7

LSD (0.05)

 

 

 

 

 

 

 

 

 

 

Variety

5.4

NS

66.1

76.2

29.3

80.1

73.6

 

50.6

NS

Harvest date

3.6

NS

47.3

60.0

30.8

47.6

48.0

 

66.7

9.9

Variety X harv. date

6.3

NS

81.9

104.0

NS

82.5

83.2

 

NS

NS

 

 

Table 2.  Yield and grade for two onion varieties submitted to three drip-irrigation regimes and harvested on five dates in 2008, and marketable yield after storage ending on February 25, 2009. Oregon State University, Ontario, OR.

 

 

At harvest

 

After storage to February 25

Harvest date

Tops down

Marketable yield by grade

Total yield

 

Marketable yield out of storage

Storage loss

>4¼ in

4-4¼ in

3-4 in

2¼-3 in

Total

 

 

%

-------------------------------------------- cwt/acre ---------------------------------------------

%

 

Vaquero 10 cb

 

Aug. 15

10

60.2

146.4

580.1

44.9

831.6

831.6

 

473.3

39.8

Aug. 22

35

180.8

258.3

484.5

5.8

929.4

932.2

 

598.5

30.8

Aug. 29

42.5

166.4

322.2

339

19.7

847.2

851.4

 

523.6

46.7

Sept. 5

60

64.5

470.9

352.5

2.9

890.8

928.6

 

794.5

14.5

Sept. 12

77.5

120.4

287

494.1

9.6

1023.4

1042.7

 

971.9

6.7

average

45

118.5

297

450

16.6

904.5

917.3

 

672.3

27.7

 

Vaquero 20 cb

 

Aug. 15

8.8

86

136.6

517

30.4

770.1

785.3

 

549

33.3

Aug. 22

22.5

128.4

116.1

460.1

21.9

726.5

731.9

 

492.8

42

Aug. 29

32.5

61.1

215.5

424.7

18.2

719.5

725.1

 

501.4

43.4

Sept. 5

52.5

188.8

203.2

471.9

0

863.9

914.1

 

821.7

20.3

Sept. 12

62.5

236.9

399.7

302.4

8.7

947.7

972.7

 

886.3

9.1

average

35.8

140.2

214.2

435.2

15.8

805.5

825.8

 

650.2

29.6

 

Vaquero 30 cb

 

Aug. 15

17.5

58.8

120.5

446.2

42.1

667.6

671.4

 

488.3

29.9

Aug. 22

37.5

36.9

87.1

352.6

166

642.6

657.8

 

491.3

33.1

Aug. 29

52.5

19.7

122.8

440.1

50.5

633.1

640.8

 

505.1

40.6

Sept. 5

65

42.4

100.2

486.3

25.4

654.3

688.6

 

577.9

10.3

Sept. 12

77.5

30.8

225.4

395.8

67.4

719.4

734.8

 

670.6

8.8

average

50

37.7

131.2

424.2

70.3

663.4

678.7

 

546.6

24.5

 

Vaquero  average

 

Aug. 15

12.1

68.3

134.5

514.4

39.2

756.4

762.8

 

506.3

30.6

Aug. 22

31.7

115.4

153.8

432.4

64.5

766.1

774

 

521.1

28.9

Aug. 29

42.5

82.4

220.2

401.3

29.5

733.3

857.8

 

510

39.8

Sept. 5

59.2

98.6

258.1

436.9

9.4

803

843.8

 

731.3

13.6

Sept. 12

72.5

129.4

304

397.4

28.6

885.3

878.3

 

831.2

8.4

average

43.6

98.8

214.1

436.5

34.2

788.8

823.3

 

620

24.3

 

Joaquin 10 cb

 

Aug. 15

7.5

129.8

103.5

428.8

27.5

689.7

697.7

 

450.3

35.1

Aug. 22

12.5

94.3

175.4

444.9

20.5

735.1

738.4

 

420.7

34.6

Aug. 29

17.5

195.8

134.1

315.2

2.9

648

650.4

 

462.2

45.3

Sept. 5

27.5

236

357.3

236

6.7

835.9

853.9

 

687.5

15.9

Sept. 12

40

192.6

300.5

264.8

9.6

767.6

792.8

 

721.7

5.3

average

21

169.7

214.2

337.9

13.5

735.3

746.6

 

548.5

27.2

 

Joaquin 20 cb

 

Aug. 15

6.3

100.2

122.2

420.8

34.1

677.3

687.1

 

445.9

24.5

Aug. 22

15

165.1

91.3

422.4

26.1

704.8

707.1

 

454.5

23.3

Aug. 29

20

141.1

133.4

306.7

33

614.2

791.3

 

431.4

32.1

Sept. 5

32.5

163.7

291.8

447.8

15.4

918.8

918.8

 

758.6

16

Sept. 12

32.5

140.6

287

367.9

5.8

801.3

823.6

 

779.8

9.4

average

21.3

142.1

185.1

393.1

22.9

743.3

785.6

 

574.1

21.1

 

Joaquin 30 cb

 

Aug. 15

10

62.8

108.4

318.5

69.1

558.8

583.8

 

315.6

48.8

Aug. 22

22.5

99.3

184.5

247.5

33.2

564.6

570.5

 

385.6

30.8

Aug. 29

22.5

51.9

136.9

320.8

28.1

537.7

547.5

 

398.3

36.7

Sept. 5

32.5

98.2

292.8

319.7

4.8

715.6

716.5

 

620.3

14.3

Sept. 12

45

88.6

252.3

301.4

29.9

672.2

695.5

 

635.3

7.7

average

26.5

80.2

195

301.6

33

609.8

622.8

 

471

27.6

 

Joaquin average

 

Aug. 15

7.9

97.6

111.4

389.4

43.6

641.9

656.2

 

404

39

Aug. 22

16.7

119.6

150.4

371.6

26.6

668.1

672

 

420.3

35.8

Aug. 29

20

129.6

134.8

314.2

21.3

599.9

749.4

 

430.7

41.8

Sept. 5

30.8

166

314

334.5

9

823.4

829.7

 

688.8

16.8

Sept. 12

39.2

140.6

279.9

311.4

15.1

747

770.6

 

712.3

7.4

average

22.9

130.7

198.1

344.2

23.1

696.1

735.6

 

531.2

28.2

 

Average

 

Aug. 15

10

83

122.9

451.9

41.4

699.2

709.5

 

452.9

35

Aug. 22

24.2

117.5

152.1

402

45.6

717.1

723

 

468.5

32.5

Aug. 29

31.3

106

177.5

357.7

25.4

666.6

803.6

 

470.3

40.8

Sept. 5

45

132.3

286

385.7

9.2

813.2

836.7

 

710.1

15.2

Sept. 12

55.8

135

292

354.4

21.8

813.2

824.5

 

769.1

7.9

LSD (0.05)

 

 

 

 

 

 

 

 

 

 

Variety

9.2

NS

NS

NS

NS

61.1

50.2

 

60.7

6.3

Harvest date

4.2

NS

57.8

NS

NS

65.7

66.7

 

81.6

6.9

Variety X harv. date

5.9

NS

NS

NS

NS

NS

NS

 

NS

NS

 

 

Table 3. Nutrient content of onion bulbs from three varieties harvested on five dates and grown under furrow irrigation in 2008. Malheur Experiment Station, Oregon State University, Ontario, OR.

Harvest date

Tops down

N

P

K

S

Ca

Mg

Zn

Mn

Cu

Fe

B

Na

 

%

------------------ % fresh weight -------------------

----------------- ppm fresh weight ------------------

 

Calibra

Aug. 15

20.0

0.144

0.030

0.136

0.045

0.050

0.015

2.35

2.73

0.352

17.06

1.58

0.0072

Aug. 22

54.0

0.153

0.031

0.142

0.047

0.042

0.014

1.68

2.22

0.252

11.65

1.33

0.0057

Aug. 29

68.0

0.151

0.029

0.135

0.043

0.043

0.014

1.88

2.95

0.312

46.42

1.22

0.0072

Sept. 5

86.0

0.186

0.031

0.143

0.047

0.039

0.013

1.84

1.84

0.268

8.27

1.15

0.0057

Sept. 12

90.0

0.194

0.033

0.145

0.052

0.039

0.014

1.40

1.31

0.308

6.93

1.80

0.0059

average

63.6

0.166

0.031

0.140

0.047

0.043

0.014

1.83

2.21

0.298

18.07

1.42

0.0064

 

Joaquin

Aug. 15

5.0

0.179

0.041

0.160

0.055

0.070

0.020

3.42

3.56

0.481

37.60

2.17

0.0091

Aug. 22

10.0

0.179

0.043

0.180

0.059

0.066

0.019

2.08

3.17

0.466

13.93

2.22

0.0087

Aug. 29

16.0

0.167

0.032

0.142

0.047

0.063

0.019

2.12

4.79

0.408

45.81

1.74

0.0092

Sept. 5

22.0

0.211

0.040

0.176

0.059

0.057

0.017

2.05

2.22

0.397

10.66

1.74

0.0086

Sept. 12

32.0

0.221

0.037

0.167

0.057

0.048

0.016

1.85

1.75

0.314

8.07

1.76

0.0074

average

17.0

0.191

0.039

0.165

0.055

0.061

0.018

2.30

3.10

0.413

23.21

1.93

0.0086

 

Montero

Aug. 15

16.0

0.182

0.041

0.166

0.062

0.058

0.019

4.36

4.37

0.536

34.59

2.17

0.0084

Aug. 22

48.0

0.196

0.033

0.163

0.059

0.055

0.018

2.13

3.76

0.664

23.61

2.05

0.0084

Aug. 29

66.0

0.187

0.035

0.153

0.055

0.053

0.019

2.35

5.53

0.524

47.27

1.82

0.0085

Sept. 5

84.0

0.204

0.034

0.165

0.060

0.045

0.016

1.91

2.83

0.473

15.20

2.00

0.0078

Sept. 12

90.0

0.245

0.039

0.188

0.061

0.054

0.018

1.98

2.04

0.379

34.59

2.27

0.0090

average

60.8

0.203

0.037

0.167

0.059

0.053

0.018

2.55

3.71

0.515

31.05

2.06

0.0084

 

By harvest date averaged over varieties

Aug. 15

13.7

0.168

0.038

0.154

0.054

0.059

0.018

3.38

3.55

0.456

29.41

1.97

0.0082

Aug. 22

37.3

0.178

0.036

0.163

0.056

0.055

0.017

1.98

3.11

0.475

16.21

1.91

0.0077

Aug. 29

50.0

0.171

0.033

0.145

0.049

0.054

0.018

2.15

4.65

0.43

46.50

1.65

0.0085

Sept. 5

64.0

0.200

0.035

0.161

0.055

0.047

0.015

1.93

2.30

0.379

11.37

1.63

0.0074

Sept. 12

70.7

0.220

0.036

0.167

0.057

0.047

0.016

1.74

1.70

0.334

16.53

1.95

0.0074

LSD (0.05)

 

 

 

 

 

 

 

 

 

 

 

 

 

Variety

5.4

0.005

0.004

0.002

0.004

0.003

0.001

0.406

0.687

0.054

NS

0.320

0.0009

Harvest date

3.6

NS

0.003

0.009

0.003

0.005

0.001

0.408

1.267

NS

NS

NS

NS

Var. X harv. date

6.3

NS

0.006

0.015

NS

NS

NS

0.707

NS

NS

NS

NS

NS

 

 

Table 4.  Nutrient content of onion bulbs from for two onion varieties grown under three drip irrigation regimes and harvested on five dates in 2008. Malheur Experiment Station, Oregon State University, Ontario, OR. 

Harvest date

Tops down

N

P

K

S

Ca

Mg

Zn

Mn

Cu

Fe

B

Na

 

%

--------------- % fresh weight -------------------

---------------- ppm fresh weight------------------

 

Vaquero 10 cb

Aug. 15

10.0

0.155

0.040

0.153

0.057

0.067

0.018

2.67

2.71

0.529

29.36

2.10

0.0129

Aug. 22

35.0

0.174

0.038

0.144

0.053

0.064

0.018

7.03

3.62

0.55

69.46

1.81

0.011

Aug. 29

42.5

0.162

0.036

0.144

0.055

0.054

0.016

3.06

2.29

0.442

35.52

1.82

0.0083

Sept. 5

60.0

0.187

0.036

0.147

0.052

0.055

0.016

2.05

2.23

0.483

30.28

1.97

0.0116

Sept. 12

77.5

0.160

0.034

0.148

0.052

0.053

0.014

1.73

1.14

0.438

21.81

1.78

0.01

average

45.0

0.167

0.037

0.147

0.054

0.059

0.016

3.31

2.40

0.489

37.29

1.90

0.0108

 

Vaquero 20 cb

Aug. 15

8.8

0.196

0.053

0.199

0.077

0.079

0.022

2.92

2.81

0.586

17.31

2.58

0.0129

Aug. 22

22.5

0.184

0.045

0.155

0.058

0.070

0.018

4.86

2.29

0.601

28.64

2.13

0.0111

Aug. 29

32.5

0.177

0.037

0.141

0.054

0.056

0.015

2.69

2.05

0.438

20.30

1.76

0.0081

Sept. 5

52.5

0.192

0.036

0.166

0.057

0.064

0.016

2.63

1.83

0.579

15.57

2.18

0.0124

Sept. 12

62.5

0.182

0.037

0.151

0.055

0.057

0.014

1.84

1.25

0.453

8.94

1.86

0.0096

average

35.8

0.186

0.041

0.162

0.060

0.065

0.017

2.99

2.05

0.532

18.15

2.10

0.0108

 

Vaquero 30 cb

Aug. 15

17.5

0.186

0.048

0.181

0.066

0.069

0.018

2.68

2.44

0.563

14.96

2.07

0.0098

Aug. 22

37.5

0.178

0.044

0.158

0.060

0.071

0.017

5.29

2.04

0.601

15.18

2.12

0.0094

Aug. 29

52.5

0.170

0.043

0.168

0.059

0.061

0.017

3.92

3.19

0.556

41.31

2.15

0.0075

Sept. 5

65.0

0.176

0.042

0.166

0.059

0.058

0.015

2.22

2.06

0.542

14.98

1.95

0.0106

Sept. 12

77.5

0.178

0.037

0.150

0.056

0.063

0.015

2.08

2.11

0.546

10.76

2.25

0.0099

average

50.0

0.178

0.043

0.165

0.060

0.065

0.016

3.24

2.37

0.562

19.44

2.11

0.0094

 

Vaquero  average

Aug. 15

12.1

0.179

0.047

0.178

0.067

0.072

0.019

2.76

2.65

0.56

20.55

2.25

0.0118

Aug. 22

31.7

0.179

0.042

0.153

0.057

0.068

0.018

5.73

2.65

0.584

37.76

2.02

0.0105

Aug. 29

42.5

0.170

0.039

0.151

0.056

0.057

0.016

3.22

2.51

0.479

31.56

1.91

0.008

Sept. 5

59.2

0.185

0.038

0.160

0.056

0.059

0.016

2.30

2.04

0.535

20.28

2.03

0.0115

Sept. 12

72.5

0.173

0.036

0.150

0.054

0.058

0.014

1.88

1.50

0.479

13.84

1.96

0.0098

average

43.6

0.177

0.040

0.158

0.058

0.063

0.017

3.18

2.27

0.527

24.80

2.04

0.0103

 

Joaquin 10 cb

Aug. 15

7.5

0.164

0.034

0.138

0.055

0.069

0.018

2.56

3.41

0.601

39.59

2.29

0.01

Aug. 22

12.5

0.151

0.036

0.138

0.051

0.073

0.018

3.56

2.82

0.509

38.88

1.89

0.0121

Aug. 29

17.5

0.158

0.032

0.129

0.050

0.055

0.014

3.37

1.86

0.402

19.98

1.83

0.0078

Sept. 5

27.5

0.161

0.034

0.139

0.049

0.050

0.013

1.86

1.84

0.42

14.45

1.72

0.0083

Sept. 12

40.0

0.153

0.036

0.145

0.053

0.053

0.013

1.97

1.59

0.473

8.72

1.60

0.0089

average

21.0

0.157

0.035

0.138

0.052

0.060

0.015

2.66

2.30

0.481

24.32

1.87

0.0094

 

Joaquin 20 cb

Aug. 15

6.3

0.186

0.044

0.160

0.064

0.070

0.019

2.58

2.77

0.487

29.61

2.26

0.0117

Aug. 22

15.0

0.193

0.043

0.147

0.055

0.073

0.019

4.73

3.20

0.575

31.35

2.36

0.0128

Aug. 29

20.0

0.174

0.035

0.136

0.052

0.060

0.015

2.29

2.19

0.412

32.90

1.88

0.0087

Sept. 5

32.5

0.163

0.034

0.150

0.052

0.053

0.014

2.26

2.74

0.932

52.51

2.02

0.0094

Sept. 12

32.5

0.173

0.035

0.144

0.052

0.052

0.013

1.92

1.63

0.434

11.65

1.63

0.0098

average

21.3

0.178

0.038

0.147

0.055

0.062

0.016

2.76

2.51

0.568

31.60

2.03

0.0105

 

Joaquin 30 cb

Aug. 15

10.0

0.198

0.044

0.181

0.069

0.083

0.020

2.65

3.22

0.584

21.92

2.26

0.0114

Aug. 22

22.5

0.181

0.047

0.167

0.062

0.074

0.018

4.97

2.57

0.621

13.52

2.20

0.0108

Aug. 29

22.5

0.182

0.042

0.156

0.058

0.055

0.015

5.38

1.99

0.484

12.85

1.96

0.0073

Sept. 5

32.5

0.158

0.035

0.144

0.052

0.053

0.012

1.77

1.34

0.48

34.02

1.90

0.0076

Sept. 12

45.0

0.157

0.036

0.152

0.054

0.055

0.013

1.87

1.29

0.473

31.06

2.02

0.0085

average

26.5

0.175

0.041

0.160

0.059

0.064

0.016

3.33

2.08

0.529

22.67

2.07

0.0091

 

Joaquin average

Aug. 15

7.9

0.183

0.041

0.160

0.063

0.074

0.019

2.60

3.13

0.558

30.37

2.27

0.011

Aug. 22

16.7

0.175

0.042

0.151

0.056

0.073

0.018

4.42

2.86

0.569

27.92

2.15

0.0119

Aug. 29

20.0

0.171

0.036

0.140

0.054

0.057

0.015

3.68

2.02

0.432

21.91

1.89

0.0079

Sept. 5

30.8

0.161

0.034

0.144

0.051

0.052

0.013

1.97

1.97

0.611

33.66

1.88

0.0085

Sept. 12

39.2

0.161

0.036

0.147

0.053

0.053

0.013

1.92

1.50

0.46

17.14

1.75

0.0091

average

22.9

0.170

0.038

0.148

0.055

0.062

0.016

2.92

2.30

0.526

26.20

1.99

0.0097

 

By harvest date averaged over varieties

Aug. 15

10.0

0.181

0.044

0.169

0.065

0.073

0.019

2.68

2.89

0.559

25.46

2.26

0.0114

Aug. 22

24.2

0.177

0.042

0.152

0.056

0.071

0.018

5.08

2.76

0.576

32.84

2.08

0.0112

Aug. 29

31.3

0.170

0.038

0.146

0.055

0.057

0.015

3.45

2.26

0.456

26.52

1.90

0.0079

Sept. 5

45.0

0.173

0.036

0.152

0.054

0.056

0.014

2.13

2.01

0.573

26.97

1.96

0.01

Sept. 12

55.8

0.167

0.036

0.148

0.054

0.056

0.014

1.90

1.50

0.469

15.49

1.86

0.0094

 

Irrigation average

10 cb

33.0

0.162

0.036

0.143

0.053

0.059

0.016

2.99

2.35

0.485

30.80

1.88

0.0101

20 cb

28.5

0.182

0.040

0.155

0.058

0.063

0.017

2.87

2.28

0.55

24.88

2.07

0.0106

30 cb

38.3

0.176

0.042

0.162

0.059

0.064

0.016

3.28

2.23

0.545

20.54

2.09

0.0093

LSD (0.05)

 

 

 

 

 

 

 

 

 

 

 

 

 

Irrigation

NS

0.013

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

Variety

9.2

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

Harvest date

4.2

NS

0.003

0.008

0.004

0.005

0.001

0.750

0.373

NS

NS

0.140

0.0011

Var. X harv. date

5.9

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

0.0016

Figure1a
Figure1b
Figure1c
Figure 1.  Relationship between percent tops down at harvest and total yield at harvest in 2008 and marketable yield after storage up to 25 February 2009 for three varieties grown under furrow irrigation.

Figure2a

Figure2b
Figure 2.  Relationship between percent tops down at harvest and total yield at harvest in 2008 and marketable yield after storage up to 25 February 2009 for two varieties grown under drip irrigation grown under three irrigation criteria.