Resource Information

     
Vegetable Cultivar Trials on Molokai  
     

By: Alton Arakaki and Hector Valenzuela

University of Hawaii, College of Tropical Agriculture and Human Resources, Department of Horticulture, 3190 Maile Way, Honolulu, HI 96822

Results from cultivar and cultural trials with vegetable crops conducted at the Molokai Applied Research and Demonstration Farm.



Overview
Cucumber Variety Trials
Broccoli Cultivar Trials
Carrot Cultivar Trials
Head Cabbage Cultivar Trial
Chinese Cabbage Cultivar Trial
Daikon Cultivar Trials
Zucchini Cultivar Trials
Seed Companies
Acknowledgements and Disclaimer



OVERVIEW
Cultivar and cultural trials with horticultural crops are conducted on an ongoing basis at the Molokai Applied Research and Demonstration Farm by University of Hawaii Cooperative Extension Agents. Results are reported through field days and extension leaflets distributed to local producers. However, the results of some of these trials are applicable to producers state-wide, especially for those growing vegetables in areas with environmental conditions similar to those found in Molokai. For more information on any of these trials please contact Alton Arakaki, CES Molokai at 808-567-6833, or H. Valenzuela, UH Manoa at 808-956-7903.

CUCUMBER VARIETY TRIALS
By: Alton Arakaki and Hector Valenzuela

Spring 1987 Trial
Trials were conducted to evaluate slicing cucumber production during the Spring growing season in Molokai. All trials were conducted at the Molokai Applied Research and Demonstration Farm. For the first trial cucumber was seeded on Feb. 17, transplanted on March 9 and harvested from April 4 to May 12, 1987. Plant spacing was 1 ft between plants in the row and 5 ft between rows for a final 8,680 plants/Acre density. The crop received 1000 lbs/Acre 10-30-10 at pre-plant and was post-plant fertigated with 10-18 lbs/Acre of 12-26-26 every other week up to the 4th week of harvest. The trial consisted of three replications under trellis- and one replication under ground-culture. Varieties used are listed in Table Cu-1, and trial results in Tables Cu-2 (trellis) and Cu-3 (ground culture).

Results
The top three yielding cultivars during the month long harvest for the trellised trials were ‘AC #1810’, the UH variety ‘Ohia’, and ‘Slicenice’. All yielded over 75,000 lbs/Acre at populations of 8,680 plants/Acre. Percent Grade A Fruits were over 55% for these three varieties while percentage of OGs or culls was below 30% while this value for the lower yielders (Table Cu-2) was above 40%, with the exception of ‘NVH-829’. The top three yielding cultivars in the ground-culture trial were ‘Slicenice’, ‘Ohia’, and ‘NVH 829’. Therefore ‘Slicenice’ and the UH variety ‘Ohia’ performed well under both trellis- and ground-cultures. Overall for the lower-yielding varieties yield was reduced by 45% and for the high yielding ones by 33% when grown in the ground compared to trellis-culture (Table Cu-3). Fruit quality was also higher for cucumbers grown under trellis with an average 52% of Grade A fruit compared to 36% for plants in ground culture. For commercial production growers thus have to evaluate the benefits of trellising including improved fruit quality, harvest efficiency, and easier pest management (by improving better aeration and possibly lower disease pressure, and by achieving better foliage coverage with pesticide applications), compared to the costs of placing the trellises.

Table Cu-1. Cucumber varieties evaluated for production in Molokai, Spring, 1987.

Variety

Disease tolerance

Seed source

AC #1810

1, 3, 4, 5, 6

Abbott

Spring 442/Pollinator

3, 4

Asgrow

XPH1187

 

Asgrow

Slice Nice

1,2,3,4,5,6

Arco

Castlehy 2512

 

Arco

Castlemaster

 

Arco

NVH 2100 (Monarch)

1,2,3,4,5,6

Northrup King

NVH 829

3,4

Northrup King

Ohia

7

U.H.

Milo

7

U.H.

     

1. Angular leaf spot

4. Cucumber Mosaic Virus

2. Anthracnose

5. Cucumber Scab

 

3. Powdery mildew

6. Downy mildew

 
 

7. WMV II

 



Table Cu-2.Trellised cucumber cultivar yields in Molokai, Spring, 1987.

Cultivar Total yields (lbs/Acre) Marketable yields
(lbs/Acre)
Percent Grade A Fruits Percent Grade B Fruits Percent Off-grade Percent Culls

Higher Yielders

         

AC #1810

106,722

84,361

68

11

20

1

Ohia

106,286

78,408

59

15

26

0

Slicenice

110,207

78,335

57

14

29

0

NVH 2100

102,511

72,454

54

16

29

0.4

Spring 442/Pollinator

103,891

71,583

49

20

31

0.5

XPH11 87

108,392

71,075

52

13

34

0

Lower Yielders

         

Castlemaster

90,968

52,635

45

13

42

0

Milo

94,598

51,909

43

11

45

0.5

NVH 829

78,858

51,197

50

15

35

0

Castlehy 2512

82,546

47,988

45

13

42

0.2



Table Cu-3. Ground culture cucumber cultivar yields in Molokai, Spring, 1987.

Percent Percent
Total yields Marketable yields Grade A Grade B Percent Percent Cultivar (lbs/Acre) (lbs/Acre) Fruits Fruits Off-grade Culls

Cultivar Total yields (lbs/Acre) Marketable yields (lbs/Acre) Percent Grade A Fruits Percent Grade B Fruits Percent Off-grade Percent Culls Ground/
Trellis (%)
Higher Yielders              

SliCenice

101,495

55,756

40

14

45

0

71

Ohia

107,152

50,529

39

8

52

1

64

NVH 829

89,734

44,866

32

18

49

1

88

NVH 2100

78,190

44,431

44

13

42

0.8

61

AC #1810

67,736

43,995

56

9

34

1

52

Lower Yielders

             

XPH1187

89,734

41,599

36

10

52

1

58

Sprint 442

97,574

38,896

25

14

59

0.9

54

Castlemaster

70,132

34,630

36

14

49

1

66

Milo

82,546

26,136

24

8

66

2

50

CastlHy 2512

46,174

25,700

32

23

44

0

53



Spring 1990 Trial
Plants were seeded on Jan. 18, transplanted on Feb. 5, and harvested for about 3 weeks from March 13 to April 9, 1990. Plant spacing was 1 ft between plants in the row and 5 ft between rows for a final 8,680 plants/Acre density. Total plants per cultivar in the trial were 210 with 15 plants per plot. The crop received 800 lbs/Acre 10-20-20 at pre-plant and was fertigated beginning 2 weeks after planting with 20 lbs/Acre of 20-20-20 every other week up to the 4th week of harvest. Vydate at 1 gal/Acre was applied 1 week prior to transplanting for nematode control. Poast was applied for weedy grass control. Bayleton was applied for powdery mildew, and benlate for anthracnose control. The pickling varieties tested mature at about 55 days after planting.

Results
Results are shown in Table Cu-4. The top yielding varieties for this trial were ‘Sweet Slice’, ‘Blitz’, ‘Burpeeana II’, ‘VGD-6054’, and ‘Raider’. Of the top varieties, the slicing type ‘Sweet Slice’ and the pickling-types ‘Blitz’, and ‘Triplemech’ had the higher percentage of high quality Grade A fruit at >50% of total yields (Table Cu-4). ‘Slicenice’ which was also tested in 1987, also was among the higher yielders in this trial which indicates its possible adaptability to Molokai with potentials for commercial production and stable yields. In your farm first grow new cultivars on a small scale at least for a couple of seasons to evaluate local adaptability, and to get acquainted with its particular cultural requirements, prior to increasing planting acreage significantly.

Table Cu-4.Ground culture cucumber cultivar yields in Molokai, Spring, 1990.

Cultivar

Source

Total yields
(lbs/Acre)

Percent Grade A Fruits

Percent Grade B Fruits

Percent Off-grade

Percent Culls

Higher Yielders

           

Sweet Slice

Peto

2,078

1

7

33

8

Blitz

Peto (pickling)

2,001

2

0

26

11

Burpeeana II

Burpee

1,970

9

6

53

3

VGD-6054

Asgrow

1,846

3

7

39

11

Raider

Harris

1,825

5

3

48

14

Slicenice

ARCO

1,773

7

7

47

8

Triplemech

Peto (pickling)

1,763

6

4

23

6

Maximore 102

Abbott

1,721

8

0

57

5

Lower Yielders

           

Gemini 7

Peto

1,597

5

3

27

5

Lani

UH

1,587

5

0

47

8

Milo

UH

1,587

7

3

47

3

VGD-6165

Asgrow

1,555

6

3

51

0

Amira II

Peto

1,504

7

5

59

8

Supersett

Peto

1,441

9

6

52

4

Dasher II

Peto

1,358

9

11

46

14

Calypso

Abbott

1,286

2

10

28

10

Armada

Peto

1,255

7

0

33

0

Maximore 100

Abbott

1,244

6

9

35

0

Exp. Hybrid 474b

Harris

1,213

3

0

53

4

Cherokee

Sun

1,172

5

0

33

0

Dynasty

Peto

1,151

8

0

31

11



Standard cucumber varieties grown in Hawaii include 'Burpee Hybrid II', 'New Market #2', 'Sweet Slice Hybrid', 'Lani' and 'Hilo' UH hybrids, 'Dasher II', 'Sakata #69', and 'Slicemaster'. Other for-trial varieties which look promising include 'Genuine', 'Spring Swallow', 'Soarer', 'Southern Delight', 'Pegasus', Green Knight', 'Tokyo Slicer', 'Conquistador', and 'Brocade.'

Recommended Cultural Practices for Cucumber Production in Molokai.
1. Seeding. Seed in trays, transplant just before the seedling roots fill the tray cell, approximately 14-16 days after seeding. Seeds can also be direct seeded, 2 seeds per hill. All seed should be treated with a fungicide but most commercial seed is pre-treated.
2. Mulch. Mulch rows with 3-4 feet plastic mulch.
3. Irrigation. Drip tube beneath the plastic mulch.
4. Trellis and netting. Use 6'6" metal tee, placed 10 ' apart in rows, and through mulch 11 gauge wire with nylon mesh net, 2 strands of wire are used to stretch the netting.
5. Plant spacing. 12-18 inches between plants, 5-6 feet between rows.
6. Fertilization. Preplant 800-1000 lbs/Acre 10-30-10 placed under
mulch. Liquid feed through the irrigation system, 10-15 lbs/Acre 20-20-20 every other week.
7. Training vines on trellis. Vines should be placed or trained on trellis netting at least 3 times per week and daily during periods of vigorous growth.
8. Pest Control. Insecticide treatments may be required for leafminers, whiteflies, thrips and aphids. Inspect plants for presence of insects before spraying. Even if insects are present it does not mean they will cause economic damage. Try as much as possible to gauge their density, and spray accordingly, to maintain an insect population density below economic damage levels.
Remember: there is a population of beneficial insects in the field most of the time, helping to control harmful insects. It has been documented that insects DO develop resistance to persistently applied chemicals. Some scholars believe that it is only a matter of time before insects build resistance to particular insecticides.Fungicide treatments may be required for powdery mildew management.
9. Irrigation. When the first fruit has formed, water moisture in the soil must be maintained close to field capacity at all times. Cucumbers have high water demand during fruit production. Approximately 93-97 percent of the fruit is water plus transpiration rates are high during this active growing state.
10. Harvest. During peak periods pick daily. At other times harvest is conducted at no less than every other day. It is important to remove all mature and damaged fruits from the plants all the time, in order to maintain plant vigor.


BROCCOLI CULTIVAR TRIALS
By: Alton Arakaki and Hector Valenzuela

Introduction
Most of the broccoli consumed in Hawaii is imported from the continental U.S. Five trials were conducted in Molokai to evaluate the yield of several commercial cultivars during the Spring, Summer, Fall, and Winter.

Spring Experiment, 1986
Nine varieties were evaluated. The trial had 3 replications and 9 plants per replication. The crop was seeded in March 25 and transplanted on April 22, 1986. The planting arrangement was a double row-staggered planting with 2 ft between plants in the row, 2.5 feet between rows, and 3 ft between plots for a density of 5,787 plants/Acre. The plots received pre-plant 1000 lbs/Acre 10-30-10 and at post-planting side-dressed 640 lbs/Ac of calcium nitrate. Results are shown in Table B-1. In this trial all varieties were affected by hollow stem except ‘Top Star’, which showed the highest yield. ‘Aux. 7901’ heads were non uniform in size and shape. ‘Cape Queen’ heads varied in size and tended to be lumpy. ‘DeCicco’ had a long stem and small flat heads that were fluffy and uneven. ‘Futura’ had a dome-shaped head.

Table B.1. Broccoli cultivar yields in Molokai, Spring 1986.
Head
Stem Head Yield Weight per Side- Tight- 1st harvest Last harvest
Cultivar size (in) size (in) (lb/Ac) plant (lbs) shoots ness1 (date) (date)

Cultivar

Stem size (in)

Head size (in)

Yield (lb/Ac)

Weight per plant (lbs)

Side- shoots

Head Tight- ness1

1st harvest (date)

Last harvest (date)

Higher Yielders

             

Top Star

1.6

7.9

7,744

1.3

No

1

Jun. 20

Jul. 11

Green Comet

2

8

5,929

1

Yes

2.7

Jun. 10

Jun. 20

Cape Queen

2

8.7

5,808

1

Yes

3

Jun. 13

Jun. 20

Citation

1.8

7.2

5,505

0.9

Yes

3

Jun. 3

Jun. 23

Lower Yielders

               

Bonanza

1.8

8

4,840

0.8

Yes

3

Jun. 3

Jun. 13

Aux. 7901

1.5

7.2

4,598

0.8

No

2.7

Jun. 20

Jul. 2

Futura

2

6

2,783

0.5

No

3

Jun. 20

Jul. 11

De Cicco

1.7

6

2,420

0.4

No

4

Jun. 23

Jul. 11

Apollo -- -- -- -- -- -- -- --



1 Yield at 5,787 plants/Acre.

Spring Experiment, 1991
Broccoli was seeded on Feb. 6 and transplanted on March 4, 1991. The trial consisted of three replications with 15 plants per replication. Planting distance was 0.75 ft between plants in the row and 3.5 ft between rows for a population of 16,596 plants/Acre. 1000 lbs/Acre of 10-30-30 were applied at preplant, and calcium nitrate at 640 lbs/Acre was side-dressed two weeks after planting. Herbicide treatment was with Dacthal, and the plots were also hand weeded as needed. Bravo and benlate were used as fungicides, and pydrin and sevin for insect control. Results are shown in Table B-2.

Table B.2. Broccoli cultivar yields in Molokai, Spring 1991

Cultivar

Source

Yield1 (lbs/Acre)

Weight per plant (lbs/plant)

Higher Yielders

     

Southern Crop

Takii

26,830

1.62

Premium Crop

Takii/Peto

23,787

1.43

Galaxy

Asgrow

23,511

1.41

Lower Yielders

     

Cruiser

Takii

19,915

1.2

Green Duke

Takii

14,936

0.9

Green Comet

Abbott/Takii

10,787

0.65

Cape Queen

Takii

10,510

0.63


1 Yield at 16,596 plants/Acre.

Summer Experiment
Plants were seeded on April 5 and transplanted on May 2, 1989. Spacing was 0.75 ft between plants and 3.5 ft between rows for a density of 16,596 plants/Acre. Total number of plants per variety in the trial was 45. Land preparation included plow, disc, pre-plant fertilizer application, and drip line laying. Pre-plant fertilizer rates were 1000 lbs/Acre of 10-30-10, and calcium nitrate at 640 lb/Acre was side-dressed after planting. Insect control was with Pydrin and Sevin.
Results are shown in Table B-3.

Table B.3. Broccoli cultivar yields in Molokai, Summer 1989

Cultivar

Percent Grade A

Percent Grade B

Percent Off-Grade

Yield1 (lbs/Acre)

Weight per plant (lbs)

Higher Yielders

         

Prominence

5

75

20

7,283

0.44

Zeus

100

0

0

7,283

0.44

Green Comet

100

0

0

7,283

0.44

Green Top

100

0

0

7,099

0.43

Lower Yielders

         

Southern Commet

100

0

0

6,085

0.36

Premium Crop

100

0

0

5,716

0.34

Cape Queen

0

100

0

5,808

0.35

Pinnacle

0

77

22

5,347

0.32

1 Yield at 16,596 plants/Acre.

Fall and Winter Trials
For the Fall trial ‘Premium Crop’ was seeded on Oct. 22, 1993 and was harvested from Dec. 27 to Jan. 5, 1994. Spacing was 1 by 2.5 ft for a density of 17,425 plants/Acre. Yields at this density were 1.4 lbs per head or 19,864 lbs/Acre. For the winter trials broccoli was seeded on Oct. 27, 1986 and harvested from Jan. 9 to Feb. 5, 1987. Plant spacing was 1.5 feet between plants in the row and 5 ft between rows. Plants were fertilized with 1000 lbs/Acre of 10-30-10 and were fertigated with 80 lbs/Acre of 12-26-26 applied once a week for 4 weeks. Results are shown in Table B-4.

Table B.4. Broccoli cultivar yields in Molokai, Winter 1993.

Cultivar

Date first harvest

Date last harvest

Yield1 (lbs/Acre)

Weight per plant (lbs)

Higher Yielders

       

XPH-852

Jan. 23

Feb. 5

8,334

1.44

Apollo

Jan. 23

Feb. 3

6,969

1.2

Citation

Jan. 23

Feb. 3

6,766

1.17

Gem

Jan. 20

Feb. 5

6,504

1.12

Lower Yielders

       

Green Valiant

Jan. 20

Feb. 5

6,417

1.1

Galaxy

Jan. 9

Jan. 23

5,299

0.91

Packman

Jan. 9

Jan. 28

4,936

0.85

Baccus

Jan. 9

Jan. 23

3,107

0.54

So. Commet

Jan. 15

Jan. 26

6,185

1.07


1 Yield at 16,596 plants/Acre.

Results
The top yielding varieties in the Spring were ‘Southern Crop’, ‘Premium Crop’, and ‘Galaxy’. In the Summer the higher yields were obtained by ‘Prominence’, ‘Zeus’, ‘Green Comet’, and ‘Green Top’. In the Winter the higher yields were obtained by ‘XPH-852’, ‘Apollo’, ‘Citation’, and ‘Gem’. Average overall yields were 4,953 in the Spring 1986 (low yields due to hollow-heart), 18,611 in the Spring 1991, 6,488 lbs/Acre in the Summer, 19,864 lbs/Acre in the Fall, and 6,057 lbs/Acre in the Winter. Yields for Premium were 23,787 in the Spring, 5,716 in the Summer, and 19,864 lbs/Acre in the Fall. Yields for Cape Queen were 10,510 in the Spring and 5,808 lbs/Acre in the Summer. Yields for Southern Comet were 6,080 in the Summer and 6,185 lbs/Acre in the Winter. These data indicate that yields are in general lower in the summer due to the higher temperatures, low during winter, perhaps due to more diseases, and that some varieties are adapted in Molokai for the specific growing seasons. The data also indicates the maturity date for some of the varieties tested, which is important to know for cultivar selection, and to schedule annual marketing and farming operations.


CARROT CULTIVAR TRIALS
By: Alton Arakaki and Hector Valenzuela

Introduction and Methods
Most of the carrot consumed in Hawaii is imported from the continental U.S. However as new ag land becomes more available the opportunity may exist for local production during specific market windows, or for the local production of specialty carrots. Cultivar trials with carrot were thus conducted in August and again in October 1986 to evaluate yields and adaptability to local Fall and Winter climatic conditions in Molokai. In the first trial carrot was direct-seeded on Sep. 15, and harvested on Dec. 6, 1986. The soil was treated with Vydate for nematode management. The trial had 3 replications. The plants received preplant 500 lb/Acre 10-30-10 and 500 lbs/Acre 10-30-10 side-dressed 4 weeks after seeding. Results shown in Table C-1 include yields obtained for both thinned and unthinned plots.

Table C-1.Carrot cultivar yields in Molokai, seeded Sept. 15, 1986.

Thinned Plots

       

Thinned Plots

Cultivar

Thinned yields (lbs/Acre)

Un-thinned yield (lbs/Acre)

Percent Grade A Fruits

Percent Grade B Roots

Percent culls

Higher Yielders

         

Charger

6,978

6,978

58

0

52

Fanci Pak

6,385

27,299

65

0

34

Orlando Gold PS

9,874

16,844

69

0

31

Short in Sweet

28,338

28,918

8

50

40

Lower Yielders

         

Toudo

18,455

0

67

0

33

Orlando Gold

12,197

15,682

35

0

65

Red Cored Chatney

18,455

0

0

100

0

PSX 6283

3,928

19,167

0

0

100

Nantes Half Long

871

0

0

0

100


1 Yield at 69,440 plants/Acre.

For the second trial the crop was seeded on Oct. 23 and harvested in 3 Feb., 1987. Spacing was 3 inches between plants in the row and 30 in between rows for a density of 69,440 plants/Acre. Plots received 500 lb/Acre of 10-30-10 pre-plant, and were post-plant side-dressed with 500 lbs/Ac 10-30-10.

Results
Results are shown in Table C-2. A major problem was experienced due to overseeding. The best varieties on terms of yields and marketability were ‘Charger’, ‘Fanci Pak’, and ‘Orlando Gold’ in the first trial and ‘Apache’ and ‘Crunchy’ in the follow-up trial. Cultivar differences were observed in their response to high density (un-thinned) plantings. The lower performance of ‘Orlando Gold’ in the first trial may indicate its lower adaptability to the warmer conditions experienced during the late Summer/early Fall in Molokai than in the cooler late Fall conditions.

Table C-2. Carrot variety yields in Molokai, seeded Oct. 23, 1987

Cultivar

Yield (lbs/Acre)

Weight per plant (lbs)

Apache

82,473

1.19

Crunchy

80,150

1.15

Dess Dan

45,305

0.65

Nantes Mexican Strain

31,365

0.45

Gold keeper

24,395

0.35

Orlando Gold

24,395

0.35

Golden State

22,652

0.33

Olympiad

20,910

0.3

Goldmine

17,425

0.25

Dominator

16,263

0.23



HEAD CABBAGE SUMMER CULTIVAR TRIAL
By: Alton Arakaki and Hector Valenzuela

Methods
A trial was conducted to evaluate the growth of 20 head cabbage varieties in Molokai during the Summer months. The crop was seeded on May 2, transplanted on June 2, and harvested 70 days later. The experiment had 3 replications per variety with 6 plants used per plot. Spacing was 1 ft between plants in the row and 5 feet between rows for a plant population of 8,713 plants per acre.

Results
Results are shown in Table Cab-1, including the projected yields at standard commercial plant populations of 14,460 used when plants are spaced 1.5 by 2 feet.

Table Cab-1. Yield of Head Cabbage in Molokai

Cultivar

Weight per head (lb)

Yield at low density,1 x 5 ft (lb/Acre)

Yield at high density, 1.5 x 2 ft (lb/Acre)

Higher Yielders

     

Green Cup

2.5

22,145

36,752

Scarlet O'Hara2

1.5

13,069

21,690

Southern Treasure

1.48

12,948

21,489

Globe King

1.02

8,955

14,861

KK Cross

0.94

8,228

13,656

Resist Crown

0.91

7,986

13.255

KY Cross

0.9

7,856

13,054

Globe Master

0.83

7,260

12,050

Resist Top

0.8

7,018

11,648

Mighty Globe

0.8

7,018

11,648

       

Lower Yielders

     

CG Cross

0.77

6,776

11,246

NS Cross

0.77

6,776

11,246

Green Commet1

0.69

6,050

10,041

Rapid Ball

0.67

5,808

9640

YR Summer

0.67

5,808

9,640

Tight Globe

0.55

4,840

8,033

Heads Up3

0.3

2,420

4,016

Fortune

0.19

1,694

2,811

Green Stone

0.33

2,904

4,820

Sun Up3

0.37

3,267

5,422

1 Takii
2 Shephards
3 Harris Moran



CHINESE CABBAGE TRIAL
By: Alton Arakaki and Hector Valenzuela

Methods
A trial was conducted to evaluate the growth of two Chinese cabbage varieties during the Winter in Molokai. The crop was seeded in Oct. 22, 1993 and harvested from Dec. 27 to Jan. 15, 1994. Spacing was 2.5 ft between rows and 1 ft between plants in the row, for a density of 17,426 plants/Acre.

Results
The yields obtained were:

Cultivar Yield (lbs/Acre) Weight per plant (lbs)
AS Veg #1 58,150 3.3
189 Miniture 43,565 2.5



DAIKON CULTIVAR TRIALS IN POAMOHO
By: Hector Valenzuela

Methods
A trial was conducted in the Summer 1994 to evaluate the growth of 18 daikon varieties at the University of Hawaii Poamoho Experiment Station in Oahu. The station is located at 870 ft elevation and has 45 inches median annual rainfall. The red Wahiawa silt clay soil is derived from basalt that is kaolinitic with oxides of iron and manganese with pH of 5-6.5 and organic matter content of 2%. The crop was direct seeded on July 15, 1994. Standard protocols were followed for commercial daikon production. 'Chinese Improved Earliest', the earliest cultivar and the standard variety grown in Oahu was harvested on August 29 and on Sept. 11. The other varieties were harvested on Sept. 12 and 19th. The trial consisted of two replications, with 30 feet per replication. Plant spacing was 3-4 inches between plants, and two rows per bed. Distance between rows in the bed was 1 feet and distance between beds was 2 feet, for an estimated final population density of 115,733 plants per Acre.

Daikon Cultivar Descriptions
Summer Mino Early (Marutane). Japanese long white, heat resistant, root about 18 in long, and 2 in diameter, neck color is white, medium slow bolting, tolerant against virus, black rot and soft rot, grows well in subtropical areas, excellent uniformity and easy to grow.
Kyoto flash (Marutane). Japanese long white. About 13 in long and 3 in diameter, 2 lb each.. Neck color is green, good mild taste.
Spring Joy (Marutane). Japanese long white, Very slow bolting, about 12 in long, and 4 in diameter, neck color is green, Suitable for greenhouse production, easy growing and excellent taste.
All Season or Tokinashi (Marutane). Open pollinated. Japanese long white. Extra slow bolting. Root about 16 in long and 2 in diameter, white neck color.
Omny (Sakata). F-1 hybrid. More vigorous than All Season. Tolerant to premature bolting. Slightly green on neck end. Suitable for close planting. Root about 16 in long. Virus, black rot and soft rot tolerant.
SOA 0102 and 0103 (Sakata)
Narumi (Mikado)
April Cross (Takii).
Extra low bolting, vary late pithiness. White neck, 16 in long, 1.5-2 lb, excellent quality for cooking, pickling, salad.
Minowase Summer Cross No. 3 (Takii). Resistant to virus, fusarium, and heat. Excellent quality, white neck, 16 in long, 1.5-2 lb, excellent quality for cooking, pickling,salad.
Relish Cross (Takii). Excellent quality, very late pithiness, green neck, 15 in long, 1.5-2 lb, good quality for cooking, pickling, salad. High tolerance to virus.
Shariki (Kyowa). Hybrid. Compact and erected leaves with green shoulder. Weighs about 3 lb and is 14 in long and 2.5 in diameter.
Red Coat (Know You). Plants are small, erect, vigorous, tolerant to TuMV, good for close planting. Straight roots are about 8 in long and 2 in diameter. Purple-red skin and flesh, suitable for salad.
Kyoto Ball (Marutane). Japanese ball type, Excellent uniformity. Root about 6 in length and 6 in diameter, and 4 lb each. Neck color light green. Flesh is white and texture is crisp and mild, good for boiling.
Nova Shogoin (Marutane). Japanese ball type, about 6 in long and 6 in diameter, weight per root is about 2 lbs, light green neck color.
High Snow (Know You). Hybrid. Plants are large, vigorous and early. Roots are 10 in long and 3 in diameter, about 2 lbs. Straight, white skin, and flesh, fine texture and high yielding. Good for warm season planting.

Results
Results are shown in Table D-1. Yields of about 40 MT/Acre or greater were obtained by 'Chinese Improved Earliest', 'Kyoto Flash', 'April Cross', and 'SDA-0103'. 'High Snow' roots had similar desirable characteristics as the standard 'Chinese Improved Earliest', but yields were about 40% lower. This variety may thus be useful as a second choice if seed for 'Chinese Improved' is unavailable. Root dimensions were obtained from 3-4 roots per variety and were in general smaller than those values reported by the seed catalogs. 'Red Coat' had uniform roots and should be promising for salads and for pickled dishes. Follow-up trials are being conducted for winter production in Poamoho and Volcano and results will be reported as they become available.

Table D-1. Yields and yield parameters of daikon cultivars grown in Poamoho, Summer 1994.

Cultivar

Total Marketable yields (lb/Ac)

Percent Grade A

Percent Grades A & B

Marketable Weight per 30 ft row (lbs)

Root diameter (in)

Root length (in)

Mean root weight (lb)

               

Long Type, Higher Yields

           

SDA-0103

44,768

85

87

46

2.1

12.9

0.99

April Cross

41,798

87

89

43

2.1

15

0.98

Kyoto Flash

39,676

84

86

41

2.1

12.7

1.2

Chinese Improved

39,464

82

93

41

     

Relish Cross

36,918

93

88

38

2.2

12.6

1.03

SDA-0102

35,221

92

98

36

2.5

12.7

1.24

               

Long Type, Lower Yields

           

Marumi

32,675

87

87

34

2.1

10.6

0.78

Shariki

30,128

94

96

31

2.2

12.4

0.93

Minowase Summer

28,219

87

86

29

2.1

15

1.16

High Snow

24,612

94

94

25

2.9

10.9

1.4

Spring Joy

24,440

86

71

25

1.9

12.9

1.07

Red Coat

22,278

90

90

15

2.4

7.8

0.68

Summer Mino

22,066

87

76

23

2.2

16.3

1.1

Omny

21,005

92

91

22

2.2

14.7

1.35

All Season

11,457

60

79

12

1.6

10.5

0.42

Ball Type

             

Nova Shogoin

23,339

51

82

24

3.3

5.8

0.85

Kyoto Ball

15,700

69

80

16

4

5

1.1



ZUCCHINI CULTIVAR TRIALS
By: Hector Valenzuela and Stacy Riede

Methods
A trial was conducted in the Summer 1994 to evaluate the growth of 7 zucchini varieties at the University of Hawaii Poamoho Experiment Station in Oahu. The station is located at 870 ft elevation and has 45 inches median annual rainfall. The red Wahiawa silt clay soil is derived from basalt that is kaolinitic with oxides of iron and manganese with pH of 5-6.5 and organic matter content of 2%. The crop was direct seeded on July 13, 1994. Standard protocols were followed for commercial zucchini production. The fruit was first picked on August 15th, and was thereon picked 10 times for four weeks. The plants were spaced 5 feet between hills and 6 feet between rows. The field was thinned to two plants per hill. The crop was bordered by several sweet corn rows and several malathion baited lures were placed in the plots for melon fly control. The varieties were monitored and rated based on their susceptibility (as determined by apparent visual "silver leaf" symptoms) to the silver leaf whitefly. Some viral symptoms developed late in the crop growth cycle and had no apparent effect on final yields.

Zucchini Cultivar Descriptions
Elite (Harris Moran). Hybrid. Earlier than other varieties. Fruits are long and slim and when picked young, cylindrical in shape.. A lustrous sheen to fruit color adds attractiveness to the fruit. Fruit color is medium green, shape is long, nearly cylindrical. High yields.
Midnight (Harris Moran). Hybrid. Very dark green fruit, fruit is cylindrical with blunt ends, uniform fruit shape, and holds green color well under light sunlight.
Elira (Nunhems). F1 hybrid. Medium vigorous plant growth, open plant habit. Medium long, cylindrical fruits. Dark green, glossy color, high yielding, suitable for field and greenhouse production.
Botna (Nunhems). F1 hybrid. Vigorous growth. Single stem without laterals, long, slender, cylindrical fruits, medium green, glossy fruit color, flecked with light green. Fruit easy to pick, suitable for field or greenhouse production.
Giada (Nunhems). F1 hybrid, vigorous plant growth, open plant habit. Medium early harvests, medium long, global/cylindrical fruit shape, light green to white colored fruits, very productive
Commander (PetoSeed). Dark green fruit with fine speckles, refined blossom end, open plant type, early maturity approx. 48 days. Cylindrical fruit, vigorous bush, fruit 8-9 in long, good for processing and fresh market.
Ambassador (PetoSeed). High yields over a long season and earliness. Fruit has a medium green, waxy exterior. Open plant habit. Fruit is 7-8 in long, cylindrical and smooth, plant type is compact bush, open habit with easy picking.

Results
Trial results are shown in Table Zu-1. 'Giada', a white fruited variety had the greatest yields producing over 34 tons per acre. Other top yielders were 'Ambassador' which is the standard green zucchini variety in Hawaii, 'Botna', and 'Elite'. The top yielders had greater fruit quality with approximately 50% of fruit produced graded as marketable, and with 30-37% of all fruit produced classified as Grade A. About 50% of the fruit produced for all varieties was graded as jumbos (graded here as unmarketable). Due to labor limitations we only harvested 2-3 times per week, instead of daily pickings as is done commercially, which resulted in the large incidence of jumbos. 'Commander' showed the least incidence of silverleaf whitefly with below moderate damage levels. The other varieties showed intermediate damage levels, while 'Botna' had the highest damage ratings, among all varieties tested. The whitefly was not a significant problem in this trial, but information on tolerance to whitefly feeding may be important for cultivar selection in locations where high whitefly numbers are expected. Similar observations were made in trials conducted in Waianae in which 'Classic' showed the least symptoms, 'Ambassador' was intermediate and 'Spineless' zucchini showed the most damage from whitefly feeding (unpublished data).

Table Zu-1. Zucchini cultivar yields in Poamoho Station, Summer 1994.

Cultivar & (seed source)

Yield per 100 ft row (lbs)

Yield per Acre (lbs)(z)

Fruit No. per Acre

Marketable/ Total Fruit Weight (%)

Percent Grade A by weight(y)

Percent Grade B by weight(y)

Whitefly damage index
(1 low: 5 high)

Giada (Harris)

216a(x)

31,262a

34,262a

50

37a

12a

3.4bc

Ambassador (Peto)

173ab

25,144ab

28,384ab

48

31ab

17a

3.3b

Botna (Nuhmems)

173ab

25,134ab

28,766ab

46

30ab

16a

4.9d

Elite (Harris)

166ab

24,044ab

27,046ab

45

26abc

19a

3.7bc

Midnight (Harris)

115bc

16,657bc

20,452bc

38

23bc

15a

4.1c

Commander (Peto)

113bc

16,422bc

18,628c

36

17c

19a

2.2a

Elira (Nunhems)

102c

14,760c

17,456c

39

22bc

17a

3.4bc


(z) Yields based on density of about 3,000 hills per acre (spacing of 3 by 3 ft).

(y) Percent Grade A and B fruit is based on percent out of total fruit weight produced per plant including culls and jumbos. Jumbo fruit yields were similar to marketable yields and were not included as marketable fruit. The large number of jumbos was due to the infrequent harvesting (2-3 times per week instead of weekly as is done in commercial operations).

(x) Numbers followed by the same letter within each column are not significantly different according to Duncans New multiple range test (P<0.05).


SEED COMPANIES
Champion Seed
529 Mercury Lane
Brea, CA 92621

Known-you seed Co., Ltd.
26, Chung Cheng 2nd Road
Kaohsiung
Taiwan

Kyowa Seed Co., Ltd
15-13 Nanpeidai
Shibuya-ku
Tokyo, Japan

Murutane Co. Ltd.
C.P.O. Box 65
Kyoto 600 Japan

Sakata Seed America Inc. (also see Champion Seed)
POB 880
18905 Serene Dr.
Morgan Hill, CA 95037-0880

American Takii, Inc. (also see Champion)
301 Natividad Rd
Salinas, CA 93906

ACKNOWLEDGMENTS
Thank-you to: the listed seed companies for supplying seed samples; to Stacy Riede for help in experiment design and preparation; to Richard Nakano and the staff at Poamoho Experiment station for excellent field maintenance, data collection, and for helping to host the field day in September 1994.

DISCLAIMER
Reference to a company or product name does not imply approval or recommendation of the product by the College of Tropical Agriculture and Human Resources, Cooperative Extension Service, University of Hawaii, or the United State Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable. All materials should be used in accordance with label instructions or manufacturer's directions.