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CHAPTER 51
1962 Guide And Data Book
face. Control: Control in field. Market the affected spinach promptly.
White Rust 1Albugo)
Slight yellowing of areas in leaf abore white blister-like pustules filled with white masses of spores. Control: Control in
SQUASH
Blade Rot (Mycosphaeref/a)
Hard, dry black decay dotted with minute black pimple-like fruiting bodies. Occurs at stem ends or sides of fruits. Control; Avoid skin breaks oo fruit; handle promptly.
Dry Rots {Altemaria; Cfadosporn/jn/ Fiaanum)
Small, deep dry decayed areas. The decayed portion is easily lifted out of surrounding healthy tissue. Surface mold low-grow ing, either greenish black or pinkish white. Control: Prevent skin breaks. Avoid temperature below 50 F in storage.
Rhizopus Soft Rot (See Table 1, Note 3.)
SWEET POTATOES
Black Rot (Cerafosfome//a)
Greenish-black decay frequently fairly shallow and sometimes circular in outline at surface. Control: Follow recommended control measures. Heat treatment at 105 to 110 F, for 24 hr will prevent development of black rot.
Chilling Injury
Brown tinged with black discolored areas scattered or associ ated with vasculare. Interior becomes pithy. Often produced by exposure to lower temperature for only a few days. Uncured root* more sensitive than cured ones. Control: Store at 55 to GO F.
Freezing Injury
Soft leaky condition of flesh. Outer layer of potato dark brown. Control: Do not subject to low temperature. Sweet potatoes freeze at 29 F.
Rhizopus Soft Rot
(See Table 1, Note 3). Cure 4 to 7 days at 85 F before storage.
Altemaria Rot
TOMATOES
Decayed area brown to black, with or without a definite margin. Lesions firm, rot extends into flesh of fruit Dense velvety, olivegreen or black spore masses frequently grow over affected sur
faces. Control: Avoid mechanical injuries at packing time. Avoid temperatures below SO F in green fruit
Bacterial Soft Rot (See Table 1, Note 1.)
Gadosporium Rot
Thin, brownish blemishes or black shiny spots of shallow decay later cowed by green, velvety mold. Control: Use care in har vesting and packing. Do not hold for longer than 8 days below 50 F. Temperatures below 50 retard coloring but haaten decay.
Late Blight Rot (Phytophthora)
Greenish brown to brown, roughened areas with rusty-tan margin. Control; Apply field control measures. Cull carefully before packing.
Phoma Rot
Slightly sunken, moderately penetrating, black areae at edge of stem scar and elsewhere on fruit. Black pimple-likefruiting bodies
develop later. Decayed tissues firm, brown to black. Found in
Eastern-grown tomatoes. Control: Apply field control measures. Use care in harvesting and packing. Avoid temperatures below
Rhizopus Rot (See Table 1, Note 3.) Soil Rot (Rh/zocfonta)
Small, circular, brown spots frequently with conccntric-ring markings; later large, brown, fairly firm lesions. In advanced
stages under warm conditions may develop cream-colored brown mycelium and irregular scleorita. Control: Before packin/ sort out tomatoes with early lesions if disease b prevalent.
WATERMELONS
Anihrocnose (Coi/etofrichum)
Numerous greenish, elevated spots with yellow centers. Later
sunken and covered with moist pink spore mmtapa Control AddIv
field control measures.
' vv y
Phytophthora Rot {Phytophthora sp.)
Small, irregular, watereoaked spots varying from grayish-green to brown. Under humid conditions a white, cottony mold coven surface of larger lesions. larger lesions may extend 2 to 4 in into fleshy pulp of the interior. Control: Careful inspection to eliminate infected melons at loading time should reduce the amount of decay during transit and marketing.
orem-Dia kot yuipioota;
Brown, fairly firm decay usually starting at stem-end and affecting large part of the melon. Black fruiting bodies develop later. Control: At time of loading in cars recut the steins aod treat them with Bordeaux paste or other recommended fungicide.
BIBLIOGRAPHY
Gerhardt Fisk: Use of Film Boz Linen to Extend Storage Life OfPeon and Applet (U8DA Circular 964,1955).
R. E. Hardenburg, H. A. Schomer, and M. Uota: Polyethylene film for fruit (Modem Packaging VoL 31,1958, p. 137).
J. M. Harvey and W. T. Pentzer: Market Diseases of Fruits and Vegetables, Grapes and Other Small Fruits (UBDA Handbook 189, 1960).
Instruction* for Forecasting Decay in Table Grapes (USDA, AMS 392, i960).
C. F. Pierson, A. M. Neubert, M. A. Smith, E. R. Wolford and Morris Thompson: Studies of Rhizopus rot of cannery peaches in the State of Washington (Washington Stats Horticul tural Proceedings, 54,1958, p. 179).
Forecasting bull's eye rota in Northwest-grown apples in storage (Plant Disease Reporter, 42, 1958, p. 1394).
G. B. Ramsey, J. S. Wiant, and L. P. McColloch: Market Diseases of Fruits and Vegetables: Tomatoes, Peppers, and Egoplants (USDA Handbook 28, 1952).
G. B. Ramsey and J. S. Wiant: Market Diseases of Fruits and Vegetables: Asparagus, Onions, Beans, Peas, Carrots, Celery, and Related Vegetables (USDA Miscellaneous Publication 440, 1941).
G. B. Ramsey, B. A. Friedman, and M. A. Smith: Market Diseases of Beets, Chicory, Endise, Escarale, Globs Artichoke, Lettuce, Rhubarb, Spinach and Sweetpotatoes (USDA Handbook 155,1959).
G. B. Ramsey and M. A. Smith: Market Diseases of Cabbage, Cauliflower, Turnips, Cucumbers, Melons, and Related Crons (USDA Handbook 184, 1961).
G. B. Ramsey, J. 8. Wiant, and M. A. Smith: Market Diseases of Fruits and Vegetables: Potatoes (USDA Miscellaneous Publica tion 98, 1949).
D. H. Rose, Charles Brooks, C. 0. Bratley, and J. R. Winston: Market Diseases of Fruits and Vegetables: Citrus and Other Subtropical Prude (USDA Miscellaneous Publication 498, 1943).
D. H. Rose, L. P. McColloch, and D. F. Fisher: Market Dis eases of Fruits and Vegetables: Apples, Pears, and Quinces (USDA Miscellaneous Publication 168, 1951).
D. H. Rose, D. F. Fisher, C. Brooks, and C. O. Bratley: Market Diseases of Fruits and Vegetables: Peaches, Plums, Cherries, and Other Stone Fruits (USDA Miscellaneous Publication 228, 1950).
D. H. Rose, R. C. Wright, and C. O. Bratley: Freezing Injury of Fruits and Vegetables (USDA Circular 713, 1944).
H. A. Schomer, and G. F. Sainsbury: Controlled Atmosphere Storage of Storking Delicious Apple m the Pacific Northwest (USDA, AMS 178,1957).
R- C. Wright, D. H. Rose, and T. M. Whiteman: The Com mercial Storage of Fruits, Vegetables, and Nursery Stocks (USDA Handbook 66, 1954).
T. M. Whiteman: Freezing Points cf Fruits, Vegetables, and Florist Stocks (Marketing Research Report 196, USDA, 1967).
CHAPTER 52
SUPPLEMENTS TO REFRIGERATION
judioxidants. Sprout Inhibitors and Other Growth Regulators, Modified Atmospheres, Ultraviolet Light, Fumigation, Antiseptic Washes, TVeofecf Fruit Wrappers, Box Liners, Paper Bags and Cartons, Sulfur Dust, Irradiation, Miscellaneous Treatments
LTHOUGH refrigeration is about the most effective Rancidity in frozen creamed turkey was counteracted by add
A method for retarding spoilage of fresh food, supple- ing antioxidants while the meat was being cooked. ,mental treatments are beneficial in some cases and are espe Development of rancidity in shelled walnut meats has been
cially valuable where only moderately cool temperatures are retarded by treating them with a coating containing butyiated
.jovi during a part or all of the storage period. Among the sup hydroxyanisole, or butyiated hydroxy toluene and packaging
plemental treatments are controlled storage atmospheres, air them under nitrogen in a plastic film that is impermeable to
purification, use of sterilizing lamps, fumigants, antiseptic moisture and oxygen.1"4
washes and treated fruit wrappers. Spoilage.of fresh food is usually the result of decay caused
SPROUT INHIBITORS AND OTHER
by bacteria or fungi, changes in composition brought about
GROWTH REGULATORS
by respiration aod enzymatic action and the development or absorption of undesirable odors- All raw food is contami nated to some extent with bacteria and fungi that are capable of causing rapid decay if the food is kept at room tempera ture or higher.
The activity of tile decay organisms is retarded by lower temperatures but some of them continue to develop slowly, even at temperatures near freezing. Enzymes cause desirable ffhzngwH such as ripening but when the enzymatic changes continue too long, over-ripeness and undesirable breakdown result Enzymatic activity is reduced about half with each 18 F deg reduction in temperature, but temperatures below 0 F are necessary to hold it to a minimum. Fresh fruits and vegetables are still alive after harvest and continue to respire in storage. During the respiration process oxygen of the air combines with the carbon of the plant tissues, which occurs chiefly as sugars and starch, and forms various decomposition products and finally carbon dioxide and water. The respira tion rate of fruits and vegetables may be reduced by lower ing the temperature, reducing the amount of available oxygen, increasing the concentration of carbon dioxide and removing gases that stimulate respiration.
Stored foods may absorb undesirable odors from other foods, decaying food products and building materials. Unde sirable odors may be avoided by using building materials that do not have a distinctive odor, by sanitation, by segre gated storage for certain foods and by air purification with ozone and activated carbon air filters.
Sprout inhibitors are used to some extent to retard develop ment of sprouts in storage. They are particularly valuable for vegetables that cannot be stored at temperatures low enough to prevent sprouting because of lack of such storage facilities or because such low temperatures injure the vegetable or affect its processing quality.
Methyl ester of naphthalene acetic acid may be sprayed or dusted on potatoes as they are put into storage or shredded tissue paper impregnated with it may be mixed with the pota toes. Potatoes receiving these treatments have remained dor mant four or five months at storage temperatures of 50 to 55 F. Investigations have demonstrated that sprouting of
onions, potatoes and carrots in storage can be inhibited by spraying the plants a few weeks before harvest with a solution of maleic hydrazide.
Other research has shown that spraying or dipping potatoes in a 0.5 percent suspension of chloro-lPC will inhibit sprout ing. This treatment is effective when applied either as the potatoes are put in or removed from storage.
Nonanol alcohol is used to suppress potato sprouting in commercial storages in Great Britain. The alcohol is vapor ized at a regulated rate in a special fumigator and circulated through the ventilator ducts of the storage space. It is not necessary to start treatment until the buds start to enlarge. Treatment is repeated as required to suppress sprouting.
Gamma irradiation has been shown to suppress sprouting of onions, sweetpotatoes and white potatoes. Dosages of 8000 r or higher were necessary for onions and sweetpotatoes and
ANTIOXIDANTS
1000 r or higher for white potatoes. Dosages above 20,000 r caused breakdown and increased decay in white potatoes.*-10
Antioxidants have been shown to increase the storage life of frozen poultry, nut meats, fats, oils and fat-containing foods by retarding development of rancidity. Fats and fatty foods were protected by treating the parchment, glassine
paper, paraffin wax, wax-coated paper and paper board in which they were packed with butyiated hydroxyanisole. The Addition of propyl gallate, nordihydro-guaiaretic acid and ntric acid increased the effectiveness of butyiated hydroxyanisole in some
California lemons are treated sometimes with a growth regulating substance, 2;4-D or 2,4,5-T to retard altemaria rot which does not develop until late in the storage period after the button has become weak or dead. The treatment keeps the button green longer and thus delays altemaria rot. The growth regulating substance is applied before storage in the water-wax emulsion or sprayed on the fruit after washing.11
Butyiated hydroxyanisole, propyl gallate and combinations
MODIFIED ATMOSPHERES
of them reduced deterioration of the fat of frozen eviscerated Aod cut-up poultry. These antioxidants were most effective
Carbon Dioxide
^hen tiie meat was coated with a 3 percent aqueous gelatine
Carbon dioxide gas is used commercially as a supplement to
solution containing 0.15 percent suspended antioxidants. refrigeration in the storage and transportation of meat, fish,
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