Reducing Postharvest Losses by using SO2 Applications on

Fresh Fig Cultivars

Crisosto et al., 2005

http://groups.ucanr.org/freshfig/

•Initial Fumigation•Use of SO2 Pad

Cultivars

Brown Turkey

Kadota

(720 fruit)

(884 fruit)

Measurements

• Fruit Quality (%) • Sound fruit (commercial fruit)• Fruit with decay• Fruit with off-color• Fruit with bleaching (‘Brown Turkey’)

Use of SO2 to Control Decay

Luvisi, D.A. H.H. Shorey J.L. Smilanick, J.F. Thompson, B.H. Gump and J. Knutson. 1992. Sulfur dioxide fumigation of table grapes. University of California, Division of Agriculture and Natural Resources Bulletin 1932, 21 pp.

Concentration x Time

At least 100 CT- 100 ppm per hour

- 200 ppm per 30 min

- 400 ppm per 15 min

Smilanick, J.L.and D.J. Henson. 1992. Minimum Gaseous Sulphur Dioxide Concentrations and Exposure Periods To Control Botrytis-Cinerea. Crop Protection. 11(6):535-540.

Palou, L., C.H. Crisosto, D. Garner, L.M. Basinal, J.L. Smilanick and J.P. Zoffoli. 2002. Minimum constant sulfur dioxide emission rates to control Gray Mold of cold-stored table grapes. Am. J. Enol. Vitic. 53(2):110-115.

Treatments

• 0 CT = 0 ppm-hr SO2 CONTROL

• 25 CT = 25 ppm-hr SO2

• 50 CT = 50 ppm-hr SO2

• 100 CT = 100 ppm-hr SO2

Timer

Dosimeter

Meter

Effect of SO2 CT on‘Brown Turkey’ Bleaching

Measured after 6 days at 32Measured after 6 days at 32ooFF

0

5

10

15

20

0 CT 25 CT 50 CT 100 CT

% Bleaching

Measured after 6 days at 32F +3 days at 68F (shelf life)

Effect of SO2 CT onSound Fruit (%)

Treatment ‘Brown Turkey’ ‘Kadota’

(CT)

0 CT 8.6 50.0

25 CT 42.9 74.1

50 CT 28.6 37.0

100 CT 11.4 53.7

Effect of SO2 on% Sound Fruit

‘Kadota’ after 6 days at 32oF + Shelf Life (68oF)

0

25

50

75

100

0 1 3 4

Days at 68oF

% Sound Fruit

0 CT

25 CT

50 CT

100 CT

Effect of SO2 on% Off-color

0

25

50

75

100

1 2 4

Days at 68oF

% Fruit with OFF-COLOR

0 CT

25 CT

‘Kadota’ after 13 days at 32oF + Shelf Life (68oF)

Off-Color

“Off-color” blemish in ‘Kadota’ fig

SO2 Generating

Pads One and two phases

Table Grape Export Packaging

• Box• Liner• Absorbent pad• Fruit• Diaper

• SO2 pad

Investigating using SO2 Pads with Fresh Fig Cultivars

• SO2 Pad = w/ SO2 generating pad during cold storage; removed during shelf life evaluation

• CONTROL = w/o SO2 pad

SO2 pad

‘Kadota’

SOSO22 pad pad no SOno SO22 pad pad

Picture taken after 21 days at 32Picture taken after 21 days at 32ooFF

Conclusions

• SO2 treatments look very promising (especially <50CT (ppm-hr).

• After cold storage and during first 2 days of shelf life, 25 CT displayed the highest % sound fruit.

• After a simulated postharvest handling, the SO2 pad treatment displayed higher % sound fruit for both cultivars.

Acknowledgments

• Louise Ferguson, Plant Sciences, UC Davis • Ed Stover, Plant Scienes, UC Davis • Maxwell Norton, UCCE Merced• Dan Rivers, UCCE Merced• Richard Matoian, CA Fig Advisory Board• Andrew Waterhouse, Enology, UC Davis

IndustryCooperators

• Ron Radoicich, Terrestre Nursery Inc.• Kevin Herman, Madera Co. Farm Advisor/Specialty Crop• Javier Gil, Specialty Crop• Doug Mueller, Specialty Crop• Brent Holtz, Madera Co. Farm Advisor

KAC Crisosto PH Research Staff

• Gayle Crisosto• David Garner• Vanessa Bremer• Stephanie Dollahite• Michael Pitchford

Cooperators