Container plants in well spaced racks on a metal bench

Plant Testing: Calibrations and Standards

Watering Wand Calibration

Instructions

  1. Start your metronome. You may use the provided charts as reference or start at 60bpm and adjust accordingly (Table 3).
  2. Turn on the water. On the first beat, begin filling the graduated cylinder.
  3. Note how many beats have passed once your cylinder has filled with the desired volume of water.
  4. Adjust the bpm of the metronome and/or the flow rate of your watering wand until your desired volume has been standardized to the metronome.
    • Ex: 45mL of water in 3 beats at 60bpm.

Calibrations and Standards

Common Bleach Dilutions

Table 1: Dilutions of commonly available bleach products needed to obtain approximately 0.525% sodium hypochlorite concentrations (5000ppm available chlorine).
Percent sodium hypochlorite in bleachParts bleach

Parts water

Diluted bleach percent sodium hypochlorite
5.25%

1

9

0.525%
6.0%

1

10.4

0.526%
8.25%

1

14.6

0.529%
8.3%

1

14.8

0.525%

Standard Irrigation Volumes 

Table 2: Standardized volumes of water for bench testing of leachate from container plants. The irrigation volume listed should be applied to each container for each of the six irrigations used in the standard protocol. The total amount of water applied for a test (all 6 irrigations) is approximately equal to the nominal volume of the container. Note that the container volumes are based on data from suppliers and may not be exact. 
Container typeContainer volume, mlIrrigation volume per irrigation, mlPercentage of container volume per irrigation
LT6 / RCL4

65.5

12

18.30%

RP (Rose pot 2.25x3.25 inch)

100

18

18.00%

SC7 Supercell Stubby

107

20

18.70%

SC10 Supercell / LT8

164

30

18.30%

DP16 (Deepot 16)

262

45

17.20%

"TB2" / AB35 (Treeband 2x5 inch)

397

70

17.80%

DP40 (Deepot 40)

655

110

16.80%

DP60 (Deepot 60)

983

165

16.80%

"TB46" / AB46 (Treeband 3.6x6 inch)

1,098

200

18.30%

"TB410" / AB410 (Treeband 4x10 inch)

2,340

400

17.10%

"TP413" / CP413CH (Treepot 4x13.5 inch)

2,650

450

17.00%

"TP414" / TP4 (Treepot 4x14 inch)

2,830

500

17.70%

#1 ("1 gal")

2,839

500

17.60%

#5 ("5 gal")

14,385

2500

17.40%

#15 ("15 gal")

49,210

8000

16.30%

Watering Wand Calibrations

Table 3: Metronome timings for single irrigation events for various nursery container sizes and irrigation wand flow rates. Maximum flow rates are limited by container size and the amount of head space in the container. If it is necessary to run tests on containers of different sizes concurrently, it is most convenient to select a flow rate and metronome speed that generates an even number of beats for each container size.
Container typeIrrigation volume, mlMetronome setting, beats/minIrrigation duration, beatsIrrigation duration, secFlow rate, ml/sec
SC7

20

60

2

2

10

SC10

30

60

3

3

10

SC10

30

60

2

2

15

DP16

45

60

3

3

15

DP16

45

80

3

2.3

20

TB2

70

60

3

3

23.3

TB2

70

69*

4

3.5

20

TB2

70

88*

3

2

34.375

DP40

110

75

4

3.2

34.375

DP60

165

75

6

4.8

34.375

DP60

165

68*

3

2.6

62.5

TB46

200

75

4

3.2

62.5

TP414, #1

500

75

10

8

62.5

TP414, #1

500

75

5

4

125

#5

2500

75

15

12

250

#15

8000

75

48

38.4

250

#5

2500

90

10

6.7

375

#15

8000

90

32

21.3

375

Reference

Phytosphere.com, http://phytosphere.com/BMPsnursery/test3_4bench.htm

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