PrePre--Harvest Factors that Harvest Factors that Affect Quality of Melons:Affect Quality of Melons:

Calcium

UV Reflective Mulch

Jorge M. FonsecaDecember 3, 2003

Western Vegetable QualityWestern Vegetable Quality

SUMMARY

Overview General Information

Fall 2003 Experience: YumaCalcium

UV Reflective Mulch

MUSKMELON QUALITYFirms, well netted, well formed

USDA grade 1: 8% Sugar (10 Brix best)

~15 days shelf life at 36-41 oF.

4.4-2.6 lbs

Strong orange for most muskmelon cv.

High levels of Vit. C and B carotene

QUALITY AT HARVEST

QUALITY AT HARVEST

Last two weeks are critical

Good leaf condition (no disease)

Good supply of Mg

No excessive irrigation or rainfall

Harvested at one-half to full slip

CALCIUM: BACKGROUNDWork of Gene Lester

Four applications AA-Ca chelate or Mannitol-Ca complex

Honeydew: Fruit firmness increased, same Brix

Cantaloupes: Same firmness and Brix. Firmness was higher during storage

CALCIUM FACTOR

Essential in cell division and elongation

Fruit Growth!

Primary building block for cell wall

Exchange balance of other nutrients

Decrease permeability to Sodium

1st Study: Yuma-Fall 03

Four applications after flowering

Quality: At harvest, fresh cuts

Gold Express

Impac

Effect of Calcium on Quality

Treatments

CaCl2: 0, 30, 60 mM

(CaNo3)2: 0, 30,60 mM

NaCl: 0, 50, 100 mM (solution)

Nutri-Cal

CAN-17

Effect of Calcium Application on Effect of Calcium Application on Soluble Solids Soluble Solids ------Gold ExpressGold Express

9

10

11

12

13

14

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

oB

rix

Effect of Calcium Application on Effect of Calcium Application on Diameter and Resistance to Diameter and Resistance to Penetration Penetration ------cvcv. Gold Express. Gold Express

No differences*

8090

100110120

130140

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Yie

ld (

lbs)

Effect of Calcium Application on Effect of Calcium Application on YieldYield------Gold ExpressGold Express

Effect of Calcium Application on Effect of Calcium Application on Juice Leakage of Fresh Cuts, 5 d Juice Leakage of Fresh Cuts, 5 d after processingafter processing------Gold ExpressGold Express

0

5

10

15

20

25

30

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Juic

e le

akag

e (m

l/kg

) 0% NaCl

Nutrical

CAN 17

CaCl 30 CaCl 60 CaNO3 30 CaNO3 60

FUTURE WORK

Environment Effect

Other Interactions:Titanium

Humic Acid

More on Fresh Cuts and other melons

UV REFLECTIVE MULCHUV REFLECTIVE MULCH

UV REFLECTIVE MULCH:

Effect on No. of Fruits

Reflective Control

No. Fruits / 10 plants

1 6

1 8

2 0

2 2

2 4

LSD = 0.998

Effect of UV Reflective Mulch on Number of Fruits

in Muskmelon Plants

OTHER WORKS

Hymenopteran insects were found more in reflective mulch (Pereira et al., 2000).

Higher CO2 fixation (Ito et al., 1996)

100% increase in cantaloupe yield (Stapleton and Summer, 2000).

UV REFLECTIVE MULCHUV REFLECTIVE MULCHThe effect of Reflective Mulching on yieldThe effect of Reflective Mulching on yield

0

10

20

30

40

50

60

Weight (Lbs/10 plants)

Mulch Control

LSD= 3.32

UV REFLECTIVE MULCHUV REFLECTIVE MULCHThe effect of Reflective Mulching on fruit The effect of Reflective Mulching on fruit weightweight

2.1

2.2

2.3

2.4

2.5

2.6

2.7

2.8

Weight (Lbs/fruit)

Mulch Control

LSD= 0.15

UV REFLECTIVE MULCHUV REFLECTIVE MULCHThe effect of The effect of JasmonicJasmonic acid applied before acid applied before transplanting on early floweringtransplanting on early flowering

0

0.5

1

1.5

2

2.5

Mulch No-Mulch

No. Flowers after 9 d transpl. (in 10

plants)

JasmonicNo-Jasmonic

FUTURE WORK

Confirm 1st year results

Evaluate effect on shelf life

Evaluate water usage

Western Vegetable QualityWestern Vegetable Qualityhttp://cals.arizona.edu/crops/vegetables/

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jfonsecajfonseca@ @ ag.arizona.eduag.arizona.edu