Evaluating Suitability of Open-Pollinated Melon Varieties for Intensive Organic Production

Evaluating Suitability of Open-Pollinated Melon Varieties for Intensive Organic Production

Summary

In 2010 Treble Ridge Farm performed a SARE-funded test of eighteen varieties of open-pollinated, mostly heirloom melons, as well as two varieties of hybrid melons that have performed well in the duplicated trials at the University of Maine and the University of New Hampshire. Eric Sideman, the Crop Specialist at the Maine Organic Farmers and Gardners Association, and Mark Hutton, from the University of Maine Extension, served as advisors on the project. Our goal was to identify open-pollinated melons that perform well in our climate under organic management.

Objectives/Performance Targets

The melons were seeded on May 1 in an unheated greenhouse into OMRI-approved biodegradable peat pots (DOT pots) full of a MOFGA-approved organic potting soil mix (Living Acres Komplete NP Germination Mix) combined with 10% OMRI-approved worm castings (Wiggle Worm Soil Builder Earthworm Castings 1-0-0). Eighteen pots were sown with three seeds each for each variety. Germination for many varieties was very strong, but others showed poor results. In most cases of poor germination I observed symptoms of damping-off. Germination performance for each variety is reported under the variety results: varieties with “excellent” germination produced viable seedlings in 15-18 pots, varieties with “good” germination produced viable seedlings in 12-15 pots, varieties with “fair” germination produced viable seedlings in 9-12 pots, and varieties with “poor” germination produced viable seedlings in fewer than 9 pots. An attempt to transplant a seedling from a pot with multiple seedlings to an empty pot failed, as the disturbed seedling promptly died.

While the seedlings grew in the greenhouse, a MOFGA-approved commercial compost (Living Acres Kompost-1 1.5-6-2)was spread in the field at 150# per 1000 sq ft and covered with 3’ black plastic mulch in rows 6’ on center.

Seedlings were thinned to one plant per pot and transplanted through the plastic mulch in their pots on May 21. Transplants were watered in with 8 oz of a 1:64 dilution of OMRI-approved fish/kelp emulsion. As many varieties did not produce viable seedlings in fifteen or more pots, I was unable to plant full five-plant blocks of each variety to improve the statistical significance of the production data. Because we had a different number of plants for each variety, results are expressed as the average per plant instead of per block. To help avoid a repeat of this problem, I plan to plant fewer seeds in more pots next year. A few weeks after tranpslanting the plants were foliar fed with a 1:128 dilution of fish/kelp emulsion. However, for most of the summer the daytime temperatures were too high for effective foliar feeding.

Accomplishments/Milestones

2010 was hardly a “test year” for melons in Maine. We experienced plenty of sunshine and heat, and the melons responded with early production and high yields. The melon harvest began on the last day of July, and from about 500 row feet of melons planted, we harvested nearly 1500# of marketable fruits – 50% higher than the expected average yield listed in Knott’s Vegetable Handbook. Many of the heirloom varieties showed great potential for commercial production, although a cooler season will be necessary to test their potential in less optimum conditions. Other varieties appeared less suitable for market growers due to poor production, poor flavor, or a strong tendency toward imperfections. A common defect among the heirlooms was a readiness to soften, which limits their usefulness in a commercial setting due to poor shelf life and losses during transportation.

For each variety, we recorded total yield by weight and number of melons and total marketable yield (total weight minus the weight of any melons that were bruised, softened, mouse-eaten, moldy, ridiculously undersized, or horrendously ugly). Three melons of each variety were cut up and served to a panel of eight people for a blind taste testing; panelists were asked to rate each variety on a scale from 1 (“I wish I hadn’t put that in my mouth”) to 5 (“I just died and went to melon heaven”). Three different melons from each variety were tested for sugar content (a few varieties did not get Brix ratings because they stopped producing unusually early and we didn’t have any specimens on hand by the time we performed these tests). A storage trial was originally intended to be part of the experiment, but this year an equipment glitch caused all the melons in the storage trial to freeze in the cooler. The results of all these measurements, plus other comments, are reported alphabetically by variety below, followed by a ranking of the varieties on each parameter.

Ashkahabad

Germination: Poor
Start of Harvest: 9/10
End of Harvest: 9/10
Fruits/Plant: 1.0
Average Weight: 3.82#
% Marketable: 79%
Brix: 5.5°
Flavor Rating:3.3
MY/Plant: 3.00#

Comments: Roundish, lopsided fruit are smooth and lime-green. Harvest when axillary leaf had died back, as fruit will not slip from vine. Tasters commented that fruit was more reminiscent of cucumber than melon, but found the taste complex and pleasant and the texture good. Market loss due to splitting.

Burrell’s Jumbo

Germination: Exc.
Start of Harvest: 8/13
End of Harvest: 9/3
Fruits/Plant: 3.2
Average Weight: 2.79#
% Marketable: 68%
Brix: 9.6°
Flavor Rating: 3.4
MY/Plant: 6.1#

Comments: Apparently “Jumbo” was a misnomer for this variety, at least under our conditions. Formed ordinary-sized oblong attractive fruit with full coverage of light netting. Obtained good flavor ratings despite mediocre sugar content. Market loss most commonly due to mold on the rind.

Early Hanover

Germination: Exc.
Start of Harvest: 8/10
End of Harvest: 8/26
Fruits/Plant: 5.2
Average Weight: 2.11#
% Marketable: 51%
Brix: 10.5°
Flavor Rating: 3.4
MY/Plant: 5.6#

Comments: Greatly resembled the larger, more heavily ribbed and netted specimens of Minnesota Midget. Extremely susceptible to softening. High marketable yields could possibly be obtained through daily picking. The fruit should be picked at forced slip rather than full slip to ensure better flavor and the ability to travel from field to market without dissolving into a pile of mush.

Early Silver Line

Germination: Good
Start of Harvest: 7/31
End of Harvest: 8/29
Fruits/Plant: 7.5
Average Weight: 1.53#
% Marketable: 68%
Brix: 8.1°
Flavor Rating: 2.1
MY/Plant: 7.9#

Comments: Attractive fruit are oblong, smooth yellow rind striped with white. Crisp white flesh. Popular with customers due to unusual appearance. Market loss commonly due to splitting or mouse damage.

Greely’s Wonder

Germination: Poor
Start of Harvest: 8/17
End of Harvest: 8/26
Fruits/Plant: 2.4
Average Weight: 6.60#
% Marketable: 54%
Brix: 9.3°
Flavor Rating: 2.8
MY/Plant: 8.5#

Comments: Roundish, lopsided fruit have a thin, smooth rind and very soft, juicy orange flesh. Would be very difficult to transport – like handling a 6# ripe peach. Also received poor flavor ratings due to its extreme juiciness, described by many as “watery”. Market loss most commonly due to softening.

Green Nutmeg

Germination: Fair
Start of Harvest: 8/23
End of Harvest: 9/3
Fruits/Plant: 3.5
Average Weight: 1.83#
% Marketable: 52%
Brix: 11.1°
Flavor Rating: 4.4
MY/Plant: 3.3#

Comments: Small, oblong fruit with full coverage of delicate netting and green flesh. By far the highest-rated of the green-fleshed melons, although some tasters complained of a “mushy” texture. Market loss most commonly due to softening.

Halona (HYBRID)

Germination: Fair
Start of Harvest: 8/10
End of Harvest: 8/29
Fruits/Plant: 2
Average Weight: 3.87#
% Marketable: 62%
Brix: no data
Flavor Rating: 2.5
MY/Plant: 4.8#

Comments: This top performer in University of Maine trials was bested by most of the open-pollinated varieties in this trial. Market loss most commonly due to splitting.

Honey Rock

Germination: Fair
Start of Harvest: 8/17
End of Harvest: 8/29
Fruits/Plant: 2.9
Average Weight: 2.43#
% Marketable: 89%
Brix: 13.1°
Flavor Rating: 4.0
MY/Plant: 6.3#

Comments: Aptly named variety is very sweet and has a practically impenetrable rind. Round fruit with netting that is very coarse and heavy, providing a distinctive look. Very few market losses, primarily due to softening around the stem scar.

Iroquois

Germination: Exc.
Start of Harvest: 8/17
End of Harvest: 9/3
Fruits/Plant: 3.1
Average Weight: 3.33#
% Marketable: 56%
Brix: 11.7°
Flavor Rating: 4.7
MY/Plant: 5.8#

Comments: Oblong, netted fruit resemble Burrell’s Jumbo but are somewhat larger. Top-rated for flavor. Market loss most commonly due to small mold spots on the rind.

Jenny Lind

Germination: Exc
Start of Harvest: 8/17
End of Harvest: 8/26
Fruits/Plant: 4.0
Average Weight: 3.18#
% Marketable: 47%
Brix: 12.1°
Flavor Rating: 3.1
MY/Plant: 5.9#

Comments: Fruit are heavily netted and shaped like a butternut squash, with green flesh. Did not obtain particularly good flavor ratings despite high sugar content. Tasters complained of an “earthy” or “musky” flavor. Market loss due to a strong tendency to soften on the button end.

Maverick (HYBRID)

Germination: Exc.
Start of Harvest: 8/13
End of Harvest: 8/17
Fruits/Plant: 3.1
Average Weight: 3.32#
% Marketable: 70%
Brix: 11.3°
Flavor Rating: 3.1
MY/Plant: 7.3#

Comments: Fared much better than Halona in this trial. Market loss most commonly due to splitting.

Minnesota Midget

Germination: Exc.
Start of Harvest: 8/6
End of Harvest: 8/26
Fruits/Plant: 6.6
Average Weight: 1.41#
% Marketable: 76%
Brix: 9.1°
Flavor Rating: 3.3
MY/Plant: 7.1#

Comments: Appearance highly variable, with fruit ranging from ½ lb to 2 lbs, varying degrees of netting and varying degrees of ribbing, shape ranging from round to oblong to somewhat flattened in the more heavily ribbed specimens. Would benefit from breeding for improved stability. Market loss commonly due to softening.

Noir des Carmes

Germination: Exc.
Start of Harvest: 8/10
End of Harvest: 8/26
Fruits/Plant: 3.5
Average Weight: 4.21#
% Marketable: 0%
Brix: 6.6°
Flavor Rating: 2.1
MY/Plant: 0#

Comments: This melon, highly praised in catalog descriptions, proved to be uncommonly ugly and of poor quality in this trial. While it matured early and produced well here, it probably needs more heat to live up to its potential. The smooth rind was invariably marred by a rough, unattractive fungal infection that rendered the fruit unmarketable.

Oka

Germination: Exc.
Start of Harvest: 8/17
End of Harvest: 8/29
Fruits/Plant: 2.7
Average Weight: 3.27#
% Marketable: 70%
Brix: 8.4°
Flavor Rating: 3.1
MY/Plant: 6.3#

Comments: Turban-shaped fruit, occasionally with a button on the blossom end, unusual slate-colored smooth rind with varying amounts of light netting. Market losses most commonly due to defects in the rind.

Pear

Germination: Exc.
Start of Harvest: 8/23
End of Harvest: 9/3
Fruits/Plant: 1.7
Average Weight: 4.88#
% Marketable: 69%
Brix: 8.5°
Flavor Rating: 3.3
MY/Plant: 5.7#

Comments: Long, tan, sutured fruits resemble giant Delicata squash. Thin-walled flesh and large seed cavity makes the fruit light for their size (often as long as 18”). Market loss most commonly due to sun-scald.

Prescott Fond Blanc

Germination: Good
Start of Harvest: 8/17
End of Harvest: 9/3
Fruits/Plant: 1.5
Average Weight: 4.06#
% Marketable: 59%
Brix: 9.9°
Flavor Rating: 2.1
MY/Plant: 3.7#

Comments: Flattened, lumpy salmon-pink fruits are certainly set apart from “normal” melons but unfortunately not in the departments of yield or quality. While it was sometimes difficult to discern the difference between rind defects and the normal degree of rind ugliness, rind defects were the most common cause of market loss.

Susan Healy

Germination: Poor
Start of Harvest: 8/17
End of Harvest: 8/26
Fruits/Plant: 2.3
Average Weight: 4.28#
% Marketable: 45%
Brix: 10.5°
Flavor Rating: 3.1
MY/Plant: 4.4#

Comments: Oblong pinkish fruits with a light but coarse-textured netting. Market loss most commonly due to splitting.

Sweet Granite

Germination: Fair
Start of Harvest: 8/6
End of Harvest: 8/26
Fruits/Plant: 4
Average Weight: 2.41#
% Marketable: 40%
Brix: no data
Flavor Rating: 2.4
MY/Plant: 3.8#

Comments: Smooth orange rind and soft orange flesh, football-shaped. Irregular, somewhat unattractive appearance. Market loss commonly due to softening or mouse damage.

Tigger

Germination: Good
Start of Harvest: 8/13
End of Harvest: 9/3
Fruits/Plant: 3.8
Average Weight: 1.30#
% Marketable: 64%
Brix: 6.4°
Flavor Rating: 1.5
MY/Plant: 3.1#

Comments: Showstoppingly beautiful fruit are a round and smooth, glowing orange with lighter orange zigzag stripes. Crisp white flesh is not highly flavorful despite being plesantly aromatic, although some specimens are respectably sweet. It’s really all about the looks here anyway. Market loss most commonly due to splitting or to an abnormality (genetic or environmental?) causing some fruit to be all yellow.

Valencia Winter Melon

Germination: Poor
Start of Harvest: 9/10
End of Harvest: 9/10
Fruits/Plant: 0.80
Average Weight: 5.98#
% Marketable: 86%
Brix: 13.5°
Flavor Rating: 4.2
MY/Plant: 4.1#

Comments: Teardrop-shaped fruit are heavily wrinkled with a smooth dark-green rind. White flesh fades to pale salmon at the seed cavity. Harvest when axillary leaf has died back and ground spot attains a creamy color, as fruit will not slip from vine.

Impacts and Contributions/Outcomes

Marketable Yield per Plant, from Lowest to Highest:

Noir des Carmes (0#)
Tigger (3.1#)
Green Nutmeg (3.3#)
Prescott Fond Blanc (3.7#)
Sweet Granite (3.8#)
Susan Healy (4.4#)
Halona* (4.8#)
Early Hanover (5.6#)
Pear (5.7#)
Iroquois (5.8#)
Jenny Lind (5.9#)
Burrell’s Jumbo (6.1#)
Honey Rock, Oka (6.3#)
Minnesota Midget (7.1#)
Maverick* (7.3#)
Early Silver Line (7.9#)
Greely’s Wonder (8.5#)

Average Brix, from Lowest to Highest:

Ashkahabad (5.5°)
Tigger (6.4°)
Noir des Carmes (6.6°)
Early Silver Line (8.1°)
Oka (8.4°)
Pear (8.5°)
Minnesota Midget (9.1°)
Greely’s Wonder (9.3°)
Burrell’s Jumbo (9.6°)
Prescott Fond Blanc (9.9°)
Early Hanover (10.5°)
Susan Healy (10.5°)
Green Nutmeg (11.1°)
Maverick* (11.3°)
Iroquois (11.7°)
Jenny Lind (12.1°)
Honey Rock (13.1°)
Valencia Winter Melon (13.5°)
Halona* and Sweet Granite – no data

Average Flavor Rating, from Lowest to Highest:

Tigger (1.5)
Noir des Carmes, Early Silver Line, Prescott Fond Blanc (2.1)
Sweet Granite (2.4)
Halona* (2.5)
Greely’s Wonder (2.8)
Oka, Susan Healy, Maverick*, Jenny Lind (3.1)
Ashkahabad, Pear, Minnesota Midget (3.3)
Burrell’s Jumbo, Early Hanover (3.4)
Honey Rock (4)
Valencia Winter Melon (4.2)
Iroquois (4.7)

Average Fruit Size, from Lowest to Highest:

Tigger (1.30#)
Minnesota Midget (1.41#)
Early Silver Line (1.53#)
Green Nutmeg (1.83#)
Early Hanover (2.11#)
Sweet Granite (2.41#)
Honey Rock (2.43#)
Burrell’s Jumbo (2.79#)
Jenny Lind (3.18#)
Oka (3.27#)
Maverick (3.32#)
Iroquois (3.33#)
Ashkahabad (3.82#)
Prescott Fond Blanc (4.06#)
Noir des Carmes (4.21#)
Susan Healy (4.28#)
Pear (4.88#)
Valencia Winter Melon (5.98#)
Greely’s Wonder (6.60#)

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