Melon Growing Methods

Nine Palms Ranch Research Report, 2006

Lead: Dan Johnston
Team Members: Mary Collins, Suna Herder, Joan Kendig, Karen Schaffer

Overview

We compared four techniques for growing melons in order to determine the best yield in terms of numbers, quantity and quality of the fruit. As an adjunct, one of the methods included a trellis configuration in order to determine the feasibility of vertical growth for Santa Clara residents who do not have access to space required to grow melons in the traditional manner. The four methods were:

  • Heat sink - The idea behind this method was to surround the plant with a medium that would absorb heat in the day and release heat to the soil during the night. In this case the medium were ordinary fireplace bricks.
  • Black plastic - consisted of a strip of black plastic covering the row of melons. The strip was approximately 24 feet long and 3 feet wide. Purpose was to trap solar energy to heat the soil.
  • Control plot - Melon plants were planted directly into the oil.
  • Trellis plot - Trellis was constructed out of 5-foot high concrete reinforced mesh wire and secured with rebar or stakes.


Melon plot. From left to right: trellis, control, black plastic, heat sink

 


Close-up of heat sink brick arrangement

Soil preparation

On May 12th a 24-foot square plot at Nine Palms was spread with approximately 6 inches of Garrod's horse compost and rototilled. Four rows, 4 feet wide were raised and separated by 3-foot paths. Each row was 24 feet long and 3 feet wide. The rows were oriented approximately northwest to southeast.

Seeding/planting

Seeding was started approximately May 1 in four-inch pots and consisted of two melon varieties: Ambrosia cantaloupe and French Orange, a Charentais hybrid. Seeds for both were from Park Seeds.

Four seeds of each variety were planted in 40 pots (20 Ambrosia, 20 French Orange Charentais) and thinned to strongest three at planting. Each row was started with a French Orange and alternated with an Ambrosia. Each row had four French Orange and four Ambrosia consisting of three plants per hill. 48 Ambrosia and 48 French Orange were planted in the four rows. Planting was conducted on June 4th with each three plants receiving a handful of alfalfa pellets in the bottom of each hole.

Watering

Watering was conducted Mondays, Thursdays and Sundays on an automatic drip system for 45 minutes each day.

Fertilization and pesticides

Other than mentioned above, no other fertilizers were applied after planting. No pesticides were applied.

Harvesting

Harvesting was started Tuesday the 8th of August and continued every Tuesday and Thursday until the 29th of September. Harvesting was discontinued when plant growth declined and melon quantity and quality also declined significantly. Harvesting totaled 16 days during the 8-week growing period.

On the left is an Ambrosia melon, on the right is a French Orange Charentais melon. The Ambrosia is a particularly large example, but the Charentais is average.

Observations

Table 1 shows the total production for each method and variety. The black plastic method yielded the most melons. The heat sink and control had similar results. The trellis method produced the least, yet still quite respectably, and the melons were the largest on average.

 

Heat sink

Black Plastic

Control

Trellis

 

Ambr.

French Orange

Ambr.

French Orange

Ambr.

French Orange

Ambr.

French Orange

Total weight

74.54

53.9

113.3

53.17

79.4

45.23

70.01

46.1

Total melons harvested

30

41

41

35

31

34

23

26

Average melon weight

2.48

1.31

2.76

1.51

2.56

1.33

3.04

1.77

Table 1: Grand Totals, from 8/8/06 to 9/29/06

Chart A shows the weekly production for Ambrosias and chart B the weekly production for French Orange Charentais. Notice that the black plastic method produced most of its melons in the first three weeks. The trellis method produced more modestly, but at a more even rate throughout the season.


Chart A

 


Chart B

 

Black plastic achieved 50% (84 lbs) of total productivity approximately August 18th or two weeks into the growing period. The heat sink plot achieved 50% (66 lbs.) of total of total productivity approximately August 25th or 3 weeks into the growing period. Control plot reached 52% (62 lbs.) of total productivity in the same time as the heat sink. Trellis reached 50% (57 lbs.) of total productivity approximately September 1st or 4 weeks into the growing period.

Comments

It is surmised that soil temperature is the single-most factor responsible for total yield, growth, and maturity rates. Soil temperatures were taken through the month of July, 5 measurements each bed. Temperatures were measured between 9 and 10 a.m. Average July soil temperatures were as follows:

  • Heat sink: 79 degrees
  • Black plastic: 81 (85-90) degrees*
  • Control: 79 degrees
  • Trellis: 79 degrees

*Black plastic temperatures were measured several inches from the plants in uncovered soil. However, temperatures under the plastic were consistently four to nine degrees higher.

A small percentage of melons were lost due to rats or gophers. No diseases were observed that affected the growth or maturity of any melon plants.

Summary

The most productive technique in this project was the black plastic method. Clearly, the black plastic provided the necessary medium to raise soil temperatures, trap and retain heat during night-time cooling. Additionally, although it cannot be independently confirmed, black plastic may have contributed significantly to moisture retention affecting overall yield. On a slightly negative the black plastic matured at a rapid rate (2 weeks) and did not provide a consistent flow of fruit throughout the 8-week growing period. This is indicated in the attached charts.

The second best method as far as production was the control plot. In all aspects it was equal to the heat-sink method in terms of average total yield and maturity rates.It is recommended for those gardeners who have the space and prefer a no-fuss melon patch.

The third recommended method is the trellis. Although it was not the most productive in terms of gross yield, it was the most consistent in providing fruits on a regular basis without a drop in production unlike the black plastic method. It is highly recommended for gardeners with limited gardening space who desire a consistent supply of fruit during the growing period.

The fourth method (the heat sink) is not recommended due to the work involved, brick expense, labor and preparation of the plot. In retrospect and in consultation with a mason expert, it was recommended that a better medium would have been concrete cinder blocks as they heat faster and release heat faster due to the fact that they are less dense. Bricks on the other hand are denser requiring a higher temperature heat and are slower to release heat into the soil. This method may warrant a second trial but then again the black plastic for now is "king."


Dan with melons