POSTHARVEST PHYSIOLOGY OF FRUITS

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
503	1119	1020	80%
503	1122	1040	20%

Progress 10/01/98 to 09/30/03

Outputs
Effects of pre- and post-harvest factors on fruit quality are carried out under this regional project. 1. Evaluation of responses of new apple selections to air and controlled atmosphere (CA) storage regimens. A multi-state project has been completed in which new selections from an associated regional project have been evaluated, with the aim of determining commercial viability. The results of the current project, headed by Dr. Randy Beaudry, MI, are being prepared for publication. 2. Research has continued on the new apple cultivar, Honeycrisp, which has susceptibility to a number of physiological disorders, bitter pit, soft scald and soggy breakdown. Factors associated with occurrence of these disorders have been identified and information on calcium spray, storage temperatures and postharvest handling treatments has been provided to the industry. Volatiles changes in fruit that might lead to identification of fruit that are susceptible to disorder development have been studied. One peer-reviewed paper has been published and four are in review or press. 3. Research has continued on the efficacy of 1-methylcyclopropane (MCP), an inhibitor or ethylene binding, for controlling apple fruit ripening. Results to date indicate that the chemical is having a huge impact on commercial apple handling, storage and marketing, and over 100 storage rooms were treated with the chemical in 2003. Our research has defined a number of risk factors for the industry. Commercial experience, however, is revealing a number of concerns that are being addressed on behalf of industry. 4. The possible role of antioxidant enzymes in the development of superficial scald has been studied. Total activity of single enzymes are not useful markers for scald susceptibility, but isozyme patterns may indicate relationships

Impacts
Knowledge about the control of soft scald in Honeycrisp will reduce losses and boost grower and market confidence in the cultivar. Research on 1-MCP should allow the full potential of this treatment to be realized by the New York and US apple industries.

Publications

Tong, C.B.S., Bedford, D.S., Luby, J.J., Beaudry, R.M., Mattheis, J.P., Propsom, F.M., Watkins, C.B., and Weis, S.A. 2003. Location and temperature effects on soft scald in 'Honeycrisp' apples. HortScience 38: 1153-1155.
Wargo, J.M., Merwin, I.M., and Watkins, C.B. 2003. Fruit size, yield and market value of 'GoldRush' apple are affected by amount, timing and method of nitrogen fertilization. HortTechnology 13: 5-13. Watkins, C.B. 2003. Principles and practices of postharvest handling and stress. In: Apples: Crop Physiology, Production and Uses, Chapter 23, p 585-614. D. Feree and I.J. Warrington (eds.). CAB Publishing.
Watkins, C.B., and Rao, M.V. 2003. Genetic Variation and Prospects for Genetic Engineering of Horticultural Crops for Resistance to Oxidative Stress Induced by Postharvest Conditions. In: Postharvest Oxidative Stress in Horticultural Crops, Chapter 10, p199-224. Hodges, M. (ed.). The Hawthorn Press, Binghamton, New York.
Watkins, C.B., and Miller, W. B. 2003. Implications of 1-methylcyclopropene registration for use on horticultural products. In: Biology and Technology of the Plant Hormone Ethylene III, p385-390. Vendrell, M., Klee, H., Pech, J.C., Romojaro, F. (eds.) IOS Press, Amsterdam, Netherlands.
Wargo, J., and Watkins, C. 2003. Honeycrisp maturity guidelines for western NY. New York Fruit Quarterly 11 (3): 27-30.
Watkins, C.B., and Nock, J.F.. 2003. 1-Methylcyclopropene (1-MCP) - New York update and recommendations . p18-55. In: Apple handling and Storage, Proceedings Storage Workshop 2003, Dept Hort. Publ. 22.
Watkins, C.B., and Nock, J.F. 2003. Honeycrisp maturity and storage recommendations . p81-87. In: Apple handling and Storage, Proceedings Storage Workshop 2003, Dept Hort. Publ. 22.
Watkins, C.B., and Nock, J.F. 2003. Postharvest treatments to decrease soggy breakdown and soft scald disorders of Honeycrisp apples. New York Fruit Quarterly 11 (3): 33-35.
Watkins, C.B., Nock, J.F., and Iungerman, K.A. 2003. Harvest date effects on maturity, quality and storage disorders of Honeycrisp from the Champlain Valley. New York Fruit Quarterly 11 (3): 23-26.
Watkins, C.B., and Rosenberger, D.A. 2003. Diphenylamine. p1-8. In: Apple handling and Storage, Proceedings Storage Workshop 2003, Dept Hort. Publ. 22.
Kochhar, S., Conklin, P.L., Brown, S.K., and Watkins, C.B. 2003. A quantitative and qualitative analysis of antioxidant enzymes in relation to susceptibility of apple fruit to superficial scald. J. Amer. Soc. Hort. Sci. 129: 910-916.
Meyers, K.J., Watkins, C.B., Pritts, M.P., and Liu R.H. 2003. Antioxidant and antiproliferative activities of strawberries. J. Agric. Food Chem. 51: 6887-6892.
Robinson, T.L., and Watkins, C.B. 2003. Cropload of Honeycrisp affects not only fruit size but many quality attributes. New York Fruit Quarterly 11 (3):7-10.
Rosenberger, D., Schupp, J., Hoying, S., Cheng, L., and Watkins C. 2003 Managing bitter pit in Honeycrisp. New York Fruit Quarterly 11 (3):17-21.
Stover, E.W., Fargione, M.J., and Watkins, C.B., Iungerman, K.A. 2003. Harvest management of Marshall 'McIntosh' apples: Effects of AVG, NAA, ethephon, and summer pruning on preharvest drop and fruit quality. HortScience 38:1093-1099.
Beaudry, R., and Watkins, C. 2003. Use of 1-MCP on apples. New York Fruit Quarterly 11(1): 11-13.
Capdeville, G. de, Beer, S.V., Watkins, C.B., Wilson, C.L., Tedeski, L.O., and Aist, J.R. 2003. Pre- and post-harvest harpin treatments of apples induce resistance to blue mold. Plant Disease 87:39-44.
Fernandez-Trujillo, J. P., Nock, J.F., Kupferman, E.M., Brown, S.K., and Watkins, C.B. 2003. Peroxidase activity and superficial scald development in apple fruit. J. Agric. Food Chem. 51: 7182-7186.

Progress 01/01/02 to 12/31/02

Outputs
Our research has continued to focus on two important issues for North East fruit growers. 1.Understanding of the efficacy and limitations of the new inhibitor of ethylene action, 1-methylcyclopropene (1-MCP; commercial name SmartFresh), approved for commercial use by the EPA in 2002. The industry has been enthusiastic about adopting this chemical as it has the potential to dramatically improve maintenance of fruit quality, both for storage operators and for consumers. Successful implementation of 1-MCP into handling systems, however, requires a multi-year program to identify the effects of cultivar, harvest maturity, and the delays between harvest and application of 1-MCP before air and controlled atmosphere storage. Also, we are investigating problems that are arising from commercial testing, e.g. enhanced susceptibility of fruit to carbon dioxide injury, and devising strategies to overcome these problems. Two manuscripts are in preparation, and information has already been made available to the fruit industry. A web site with a summary of existing information about 1-MCP has been established and is being updated regularly. 2.Understanding of the physiology of a new apple cultivar, Honeycrisp, as part of a regional program for evaluation of postharvest characteristics of new apple cultivars. This cultivar is being widely planted, but has extreme susceptibility to the calcium deficiency-related disorder bitter pit and low temperature-related disorder, soft scald. A trial involving five-states that indicates the potential variation in fruit susceptibility to soft scald has been accepted for publication. Manuscripts about the effects of maturity, and pre and post harvest treatments to alleviate the disorders are being prepared for publication. The effect of factors that aggravate or alleviate soft scald on fermentation and other volatile compounds are being studied.

Impacts
Two major impacts have resulted from the current research. First, while much knowledge is still required, the commercial adoption of 1-MCP for the first time in the 2002 apple harvest season could not have occurred safely without initial understanding of its efficacy and limitations. Second, knowledge about the control of soft scald and bitter pit in Honeycrisp will reduce losses and boost grower and market confidence in the cultivar.

Publications

Gunes, G., Liu, R.H., Watkins, C.B. 2002. Controlled atmosphere effects on postharvest quality and antioxidant activity of cranberry fruits. J. Agric. Food Chem. 50: 5932-5938.
Wargo, J., Watkins, C. 2002. Is 1-MCP a missing piece to the Jonagold puzzle? Fruit Notes 02 (8):6-7.
Watkins, C.B. and Miller, W.B. 2002. A summary of physiological processes or disorders in fruits, vegetables and ornamental products that are delayed or decreased, increased, or unaffected by application of 1-methylcyclopropene (1-MCP). http://www.hort.cornell.edu/department/faculty/watkins/ethylene/index .htm
Watkins, C.B., Rosenberger, D.A. 2002. Cornell Fruit Handling and Storage Newsletter. 14pp.

Progress 01/01/01 to 12/31/01

Outputs
Effects of pre- and post-harvest factors on fruit quality are carried out under this regional project. Our focus in the current year is on the understanding of the physiology of a new apple cultivar, Honeycrisp, and adoption of a new inhibitor of ethylene action, 1-methylcyclopropene (1-MCP), that has the potential to dramatically affect fruit storage. 1. A regional program for evaluation of postharvest characteristics of new apple cultivars, which involves several states, has been initiated. Most emphasis has been on Honeycrisp because it has excellent quality characteristics, is being widely planted, but has extreme susceptibility to the calcium deficiency-related disorder bitter pit and low temperature-related disorder, soft scald. We have identified harvest date relationships with soft scald susceptibility, and identified control methods to minimize bitter pit and soft scald occurrence. A trial involving five-states that indicates the potential variation in fruit susceptibility to soft scald has been completed and prepared for publication. 2. The efficacy of 1-methylcyclopropane (MCP), an inhibitor or ethylene binding, for controlling apple fruit ripening has been initiated. Results to date indicate that the chemical will have a huge impact on commercial apple handling, storage and marketing, if it receives FDA approval as expected. Differences in cultivar responses and associated storage procedures must be defined however, before the chemical can be used safely by the industry. We have defined effects of cultivar, harvest maturity, delays between harvest and application of 1-MCP before air and controlled atmosphere storage. 3. Projects on the effects of carbon dioxide on storage quality of apples and apple slices have been completed and published.

Impacts
Knowledge about the control of soft scald in Honeycrisp will reduce losses and boost grower and market confidence in the cultivar. Research 1-MCP should allow the full potential of this treatment to be realized in the near future as registration is expected in 2002. Carbon dioxide treatment may have uses for modified atmosphere of apples slices, and is being evaluated further. Longer-term research is aimed at expanding fundamental knowledge and improving and creating new technologies to assure the continued supply of quality fruit.

Publications

Watkins, C.B., Nock, J.F., Iungerman, K.A. 2001. What do New York results tell us about the future of MCP. p79-96. In: Storage Workshop 2001: Apple handling and Storage. NRAES-153.
Watkins, C.B., Wargo, J.M., Hoying, S.A., Nock, J.F.2001. The Grow New York project: MCP effects on apples. p112-122. In: Storage Workshop 2001: Apple handling and Storage. NRAES-153.
Amissah, J.G.N., Hotchkiss, J.H., Watkins, C.B., 2001. Influence of diphenylamine and carbon dioxide concentration on the color and texture of cut apples. IFT Annual Meeting Abstract 88E-8, New Orleans, LA.
Capdeville, G., de, Beer, S.V., Watkins, C.B., Wilson, C.L., Aist, J.R. 2001. Harpin-induced resistance for the control of blue mold of apples. Phytopathology 91:S166.
Fernandez-Trujllo, J. P., Nock, J.F., Watkins, C.B. 2001. Superficial scald, carbon dioxide injury, and changes of fermentation products and organic acids in 'Cortland' and 'Law Rome' apple fruit after high carbon dioxide stress treatment. J. Amer. Soc. Hort. Sci. 126:235-241.
Gunes, G., Watkins, C.B. 2001. Postharvest quality of cranberries as affected by controlled atmospheres. HortScience 36:571.
Gunes, G., Hotchkiss, J.H., Watkins, C.B. 2001. Effects of gamma irradiation on the texture of minimally processed apple slices. J. Food Sci. 66:63-67.
Watkins, C.B., Nock, J.F., Iungerman, K.A. 2001. Understanding the soft scald problem in Honeycrisp. p9-20. In: Storage Workshop 2001: Apple handling and Storage. NRAES-153.
Rosenberger, D., Schupp, J., Watkins, C, Iungerman, K., Hoying, S., Straub, D., Cheng, L. 2001. Honeycrisp: Promising profit maker or just a problem child? New York Fruit Quarterly 9(3):9-13.
Gunes, G., Watkins, C.B., Hotchkiss, J.H. 2001. Physiological responses of fresh-cut apple slices under high CO2 and low O2 partial pressures. Postharvest Biol. Technol. 22:197-204.
Schupp, J.R., Rosenberger, D.A., Watkins, C.B., Cheng, L., Hoying, S.A. 2001. Understanding the bitter pit problem in Honeycrisp. p1-8. In: Storage Workshop 2001: Apple handling and Storage. NRAES-153.
Schupp, J., Straub, R., Rosenberger, D., Watkins, C. 2001. Managing Honeycrisp for production and quality. Compact Fruit Tree 34:107-109.
Watkins, C.B. 2001. Ethylene synthesis, mode of action, consequences and control. In Fruit Quality and its Biological Basis. Knee, M. (ed). Sheffield Academic Press. p180-224.
Watkins, C.B., Pritts, M.P. 2001. The influence of cultivar on postharvest performance of fruits and vegetables. Acta Horticulturae 553:59-63.
Watkins, C.B., Fernandez-Trujillo, J.P, Nock, J.F. 2001. Fermentation products and succinate in two apple cultivars with different tolerances to carbon dioxide. Acta Horticulturae 553:273-274.

Progress 01/01/00 to 12/31/00

Outputs
Most focus of this project is on the development of MCP technology, and the new cultivar Honeycrisp, for the NY and other US apple industries. 1. The effect of MCP on the storability of several apple cultivars is being investigated. Initial results have been published in refereed scientific journals and in industry publications. Factors that may impact its commercial success, such as the treatment temperatures and delays between harvest and treatment, are being evaluated using a combination of laboratory and industry based trials. 2. Honeycrisp is an important new cultivar for the northeast, but is susceptible to the physiological disorders, bitter pit and soft scald. Calcium trials for control of bitter pit have been initiated, and the physiology of soft scald development studied. Results show that a delay treatment before cold storage will control the soft scald, and that the benefits of higher storage temperatures diminish as harvest date is delayed. Initial recommendations have been made to the industry. Research on the physiology of superficial scald has been published. Investigations into the potential involvement of enzymes that degrade active oxygen species such as catalase and peroxidase and thereby affect scald development are continuing, with emphasis on investigation of a unique genetic population of seedlings with varying susceptibility to the disorder. Studies on the metabolic effects of high carbon dioxide during injury development in whole fruit has been completed and written up for publication. This work has cast doubt on a long-standing hypothesis that carbon dioxide injury is due to succinate accumulation in the fruit. Research on the physiology of apple slices to irradiation has been published, and is now centered on responses to elevated carbon dioxide in the storage atmosphere.

Impacts
Research on MCP should allow the full potential of these treatments to be realized by US apple industries in the near future. Initial recommendations for storage of Honeycrisp will allow confidence in the cultivar to grow. Longer-term research is aimed at expanding fundamental knowledge and improving and creating new technologies to assure the continued supply of quality fruit.

Publications

Whitaker, B.D., Nock, J.F., Watkins, C.B. 2000. Peel tissue a-farnesene and conjugated trienol concentrations during storage of 'White Angel' x 'Rome Beauty' hybrid apple selections susceptible and resistant to superficial scald. Postharvest Biol. Technol. 20: 231- 241.
Watkins, C.B., Bramlage, W.J., Brookfield, P.L., Reid, S.J., Weiss, S.A., Alwan, T.F. 2000. Cultivar and growing region influence efficacy of warming treatments for amelioration of superficial scald development on apples after storage. Postharvest Biol. Technol. 19:33-45.
Watkins, C.B., Fernandez-Trujillo, J. P., Nock, J.F. 2000. Carbon dioxide effects on metabolism of two apple fruit cultivars. HortScience 35:828.
Watkins, C.B., Nock, J.F. 2000. MCP: Facts, speculation, and how could it affect the NY apple industry? New York Fruit Quarterly 8(3): 5-9.
Watkins, C.B., Nock, J.F. 2000. Cultivar variation in response to 1-methylcyclopropene application to apple fruit in air and controlled-atmosphere storage. HortScience 35: 469 (439).
Watkins, C.B., Nock, J.F., Whitaker, B.D. 2000. Responses of early, mid and late season apple cultivars to postharvest application of 1-methylcyclopropene (1-MCP) under air and controlled atmosphere storage conditions. Postharvest Biol. Technol. 19:17-32.
Watkins, C.B., Rosenberger, D.A. 2000. Cornell Fruit Handling and Storage Newsletter. 13pp.
Harker, F.R., Elgar, H.J., Watkins, C.B., Jackson, P.J., Hallett, I.C. 2000.Physical and mechanical changes in strawberry fruit after high carbon dioxide treatments. Postharvest Biol. Technol. 19:139-146.
Gunes, G., Hotchkiss, J.H., Watkins, C.B. 2000. Influence of Gamma Irradiation on Texture of Fresh-cut Apples. IFT Annual Meeting, Abstract #65A-34,Dallas, TX.
Gunes, G., Watkins, C.B., Hotchkiss, J.H. 2000. Effects of irradiation on respiration and ethylene production of apple slices. J. Sci. Food Agric. 80:1169-1175.
Kader, A.A., Watkins, C.B. 2000. Modified atmosphere packaging - towards 2000 and beyond. HortTechnol. 10: 483-486.
Wargo, J.M., Merwin, I.A., Watkins, C.B. 2000. Effects of ReTain, nitrogen fertilization, and mid-summer trunk scoring on fruit color and quality of 'Jonagold' apples. New York Fruit Quarterly 8(4):24-26.
Merwin, I., Watkins, C., Wargo, J. 2000. Practical methods for improving fruit quality on Jonagold. Northeast Tree-Fruit 4(1): 3-4, and Tree Fruit News of Central New York, Jan:5-6.
Wargo, J., Watkins, C.B. 2000. Predicted CA cutoff dates for 'McIntosh' and comments on possible effects of a cool summer. Fruit Notes 00(15): 7-8.
Wargo, J., Watkins, C.B. 2000. 1-MCP trials come to Western NY. Fruit Notes 00(117): 1-2.
Wargo, J.M., Merwin, I., Watkins, C. 2000. Nitrogen, trunk scoring and AVG treatments influence fruit color and quality of 'Jonagold' apple. HortScience 35: 495 (574).
Watkins, C.B. 2000. Responses of horticultural commodities to high carbon dioxide as related to modified atmosphere packaging. HortTechnol. 10:501-506.

Progress 01/01/99 to 12/31/99

Outputs
Several experiments investigating the effects of pre- and post-harvest factors on fruit quality have been carried out under this project. 1. A project on the effects of ReTain, a chemical that inhibits ethylene production on Jonagold fruit quality at harvest and during storage, in relation to nitrogen status of trees has been completed. Results, which have been presented to industry and are being prepared for publication, provide a management technique for use by the growers. 2. Non-chemical techniques for control of superficial scald. Intermittent warming procedures to alleviate scald have been used to increase understanding of disorder development and results published. An additional paper is in press. Investigations into the potential involvement of enzymes that degrade active oxygen species such as catalase and peroxidase and thereby affect scald development are continuing. Our focus has been on investigation of a genetic population of seedlings with varying susceptibility to the disorder. A collaborative project with USDA-MD has been completed and prepared for publication. Evaluation of high carbon dioxide treatments for control of scald has been completed and is being prepared for publication. This treatment is not suitable for New York-grown apples because of differential susceptibility to injury and because the treatment only delays rather than prevents the disorder. 3. Initial studies on the responses of strawberry fruit to high carbon dioxide atmospheres have been completed and published. This research indicates that strawberry fruit differ widely in responses to carbon dioxide, indicating differential effects for use of modified atmosphere-based technology. These cultivars are being used as material to investigate metabolism of fruit under carbon dioxide to provide information about positive and negative responses to the gas. 4. The efficacy of 1-methylcyclopropane(MCP), an inhibitor or ethylene binding, for controlling apple fruit ripening has been initiated. Results to date indicate that the chemical will have a huge impact on commercial apple handling, storage and marketing, if it receives FDA approval as expected. Differences in cultivar responses and associated storage procedures must be defined however, before the chemical can be used safely by the industry. 5. A regional program for evaluation of postharvest characteristics of new cultivars, which involves several states, has been initiated. Most emphasis has been on Honeycrisp because it has excellent quality characteristics, is being widely planted, but has extreme susceptibility to low temperature-related disorders.

Impacts
Recent findings on scald can potentially save the apple industry millions of dollars in unnecessary chemical use and the reduction of fruit loss in storage. Research on ReTain and MCP should allow the full potential of these treatments to be realized in the near future. Longer-term research is aimed at expanding fundamental knowledge and improving and creating new technologies to assure the continued supply of quality fruit.

Publications

Alwan, T.F., Watkins, C.B. 1999. Intermittent warming effects on superficial scald of 'Cortland', Delicious' and 'Law Rome' apples. Postharvest Biol. Technol. 16:203-212.
Fernandez-Trujillo, J.P., Nock, J.F., Watkins, C.B. 1999. Fermentative metabolism and organic acid concentrations in fruit of selected strawberry cultivars with different tolerances to carbon dioxide. J. Amer. Soc. Hort. Sci. 124:696-701.
Watkins, C.B., Rosenberger, D.A. 1999. Cornell Fruit Handling and Storage Newsletter. 12pp.
Watkins, C.B., Manzano-Mendez, J.E., Nock, J.F., Zhang, J.J., Maloney, K.E. 1999. Cultivar variation in response of strawberry fruit to high carbon dioxide treatments. J.Sci. Food Agric. 79:886-890.

Progress 01/01/98 to 12/31/98

Outputs
Several experiments investigating the effects of pre- and post-harvest factors on fruit quality have been carried out: 1. The influence of ReTain, a chemical that inhibits ethylene production, on fruit quality at harvest and during storage. Treated and untreated fruit from the Champlain region are being stored separately and in combination with each other so that recommendations for correct management practices can be made to the industry. 2. Non-chemical techniques for control of superficial scald. Experiments are continuing on the effects of high CO2 and low O2 treatments, and use of food additives, as we seek alternatives methods to replace diphenylamine (DPA). Our emphasis is currently on use of low O2 levels. Research on the involvement of enzymes which degrade active oxygen species such as catalase and peroxidase in scald resistance have been extended to Delicious and other cultivars. 3. Potential use of DPA for maintaining firmness under high CO2 treatment conditions. Our research is showing that loss of DPA for use by the industry may have a number of unexpected side effectsincluding lower flesh firmness and susceptibility to CO2 injury. 4. Research on the responses of strawberry fruit to high # CO2 atmospheres has been extended to include effects of the gas on fermentation enzymes and organic acids.

Impacts
(N/A)

Publications

Elgar, H.J., Burmeister, D.M., Watkins, C.B. 1998. Storage and handling effects on a CO2-related internal browning disorder of 'Braeburn' apples. HortScience 33:719-722.
Ferguson, I.B., Snelgar, W., Lay-Yee, M., Watkins, C.B., Bowen, J.H. 1998. Expression of heat shock protein genes in apple fruit in the field. Aust. J. Plant Physiol. 25:155-163.
Lau, O.L., Barden, C.L., Blankenship, S.M., Chen, P.M., Curry, E.A. , DeEll, J.R., Lehman-Salada, L., Mitcham, E.J., Prange, R.K., Watkins, C.B. 1998. A North American cooperative survey of 'Starkrimson Delicious' apple responses to O2 storage on superficial scald and other disorders. Postharvest Biol. Technol. 13:19-26.
Pritts M., Watkins, C. 1998. Harvesting, handling, and transportation of fresh fruit. Chapter 12, p 104-108, In: Strawberry Production Guide, NRAES-88.
Rao, M.V., Watkins, C.B., Brown, S.K., Weeden, N.F. 1998. Active oxygen species metabolism in 'White Angel' x 'Rome Beauty' apple selections resistant and susceptible to superficial scald. J. Amer. Soc. Hort. Sci. 123:299-304.
Stover, E.W., Watkins, C.B., Fargione, M.J., Iungerman, K.A. 1998. Effects of AVG, NAA, ethephon, and summer pruning on preharvest dop and fruit quality of 'McIntosh'. HortScience 33:513 (390). (abstract)
Watkins, C.B., Beaudry, R.M., Robinson, T.L., Lakso, A.N. 1998. ReTain effects on fruit size, maturity, and storage quality of 'Jonagold' apples. HortScience 33:208. (abstract)
Watkins, C.B., Bartsch, J.A. 1998. Temperature management of apple fruit for maintenance of quality for local and export markets. New York Fruit Quarterly 6(3):2-5.
Watkins, C.B., Zhang, J. 1998. Metabolic responses of fruit to carbon dioxide. Acta Horticulturae 464:345-350.
Watkins, C.B., Brookfield, P.L., Elgar, H.J., McLeod, S.P. 1998. Development of a modified atmosphere package for export of apple fruit. p. 586-592. In: Proc. Intl. Congress for Plastic in Agric., Tel Aviv, Israel, March 1997.
Zhang, J.J., Watkins, C. 1998. Molecular responses of strawberry fruit to high carbon dioxide. HortScience 33: 516 (410). (abstract)
Elgar, H.J., Watkins, C.B., Lallu, N. 1999. Harvest date and crop load effects on a carbon dioxide-related storage injury of 'Braeburn' apple. HortScience. In press.
Harker, F.R., Watkins, C.B., Brookfield, P.L., Miller, M.J., Reid, S.J., Jackson, P.J., Bieleski R.L. Bartley T. 1999. Maturity and regional influences on watercore development and its postharvest disappearance in 'Fuji' apples. J. Amer. Soc. Hort. Sci. 124: in press.
Watkins, C.B., Manzano-Mendez, J.E., Nock, J.F., Zhang, J.J., Maloney, K.E. 1999. Cultivar variation in response of strawberry fruit to high carbon dioxide treatments. J.Sci. Food Agric. in press.

Progress 01/01/97 to 12/31/97

Outputs
Several experiments investigating the effects of pre- and post-harvest factors on fruit quality have been carried out. 1. Preharvest effects: Our focus has been on the influence of ReTain, a chemical which inhibits ethylene production, on fruit quality at harvest and during storage. 2. Non-chemical techniques for control of superficial scald: Experiments are continuing on the effects of high CO2 and low O2 treatments as we seek alternatives methods to replace diphenylamine (DPA). Results from a regional project investigating the effects of 0.7% O2 on 'Delicious' fruit from several sites in Nth America, as well as research on intermittent warming effects, have been submitted or are in press. Our emphasis is currently on use of slightly higher O2 levels with modification of CO2 to control scald without off-flavor development. 3. Initial experiments have been carried out to investigate the potential involvement of enzymes which degrade active oxygen species such as catalase and peroxidase, and one manuscript is in press. 4. Benefits of DPA for maintaining firmness and ameliorating CO2 injury are being investigated in 'McIntosh' and 'Empire' apples as loss of the chemical to the industry may have a number of implications for modern storage practices. 5. The responses of strawberry fruit to high CO2 atmospheres has been assessed further by comparing alcohol dehydrogenase activities in 'Cavendish', which is tolerant to high CO2 and 'Honeoye' which accumulates alcohols in response to high CO2.

Impacts
(N/A)

Publications

Lau, O.L., et al. 1998. A North American cooperative survey study of 'Starkrimson Delicious' apple responses to 0.7% O2 storage on superficial scald and disorders. Postharvest Biol. Technol. In press.
Rao, M.V., Watkins, C.B., Brown, S.K., Weeden, N.F. 1998. Active oxygen species metabolism in 'White Angel' x 'Rome Beauty' apple selections resistant and susceptible to superficial scald. J. Amer.
Watkins, C. 1997. Update on calcium and DPA research. p. 65-73. In: Apple harvesting, handling, and storage, NRAES 112
Watkins, C.B., Burmeister, D.M., Elgar, H.J., F.W. Liu. 1997. A comparison of two carbon dioxide-related injuries of apple fruit. p. 119-124. In: vol. 2, CA '97 Proc. (A.A. Kader, ed.), Postharvest
Watkins, C.B., Manzano-Mendez, J.E., Nock, J.F., Zhang, J., Maloney, K.E. 1997. Cultivar variation in responses of strawberry fruit to high carbon dioxide treatments. HortScience 32:505 (459).
Watkins, C.B., Silsby, K.J., Goffinet, M.C. 1997. Controlled atmosphere and antioxidant effects on external CO2 injury of 'Empire' apples. HortScience 32:1242-1246.
Watkins, C.B., et al. 1997. ReTainTM - experiences with McIntosh and Jonagold in NY. p. 19-25. In: Apple harvesting, handling, & storage,
Lakso, A.N., Robinson, T.L., Stover, E.W., Stiles, W.C., Hoying, S., Iungerman, K., Telgheder, C., Watkins, C.B., Silsby, K. 1997. Multi-site thinning comparisons with 'Empire' and 'McIntosh' apples.

Progress 01/01/96 to 12/30/96

Outputs
Effects of pre- and post-harvest factors on fruit quality have been investigated. 1. The effect of minerals, especially calcium, contents in apple fruit is being studied and will be completed during 1997. A study on the effects of mite infestation on maturity and quality of 'Delicious' apples has been completed and published. 2. Experiments are continuing on the effects of intermittent warming, high carbon dioxide and low oxygen treatments as we seek alternatives methods to replace diphenylamine for scald control. A regional project investigating the effects of 0.7% oxygen on 'Delicious' fruit from several sites in Nth America, as well as research on intermittent warming effects, are being written for publication. 3. We have identified several key factors associated with susceptibility of 'Empire' fruit to CO2 injury, including effects of atmosphere, delays in air before exposure to high carbon dioxide, and use of antioxidants e.g. diphenylamine. 4. Responses of seven strawberry cultivars to high CO2 atmospheres has been assessed. Volatile accumulation varied among cultivars. 'Annapolis', for example, appears very tolerant of high CO2 treatment levels as indicated by low accumulations of ethanol, acetaldehyde and ethyl acetate in the fruit. In contrast, 'Kent' and 'Governor Simcoe' accumulated large amounts of these compounds. Differences in cultivar responses to CO2 should be considered by growers planning to store fruit under these conditions to extend marketing options.

Impacts
(N/A)

Publications

Alwan, T., Watkins, C.B. 1996. Intermittent warming effects on superficial scald of apple fruit. HortScience 31:605 (232). (Abs)
Francesconi, A.H.D., Watkins, C.B., Lakso, A.N.,Nyrop, J.P. Barnard, J., Denning, S.S.. 1996. Interactions of European Red Mite and crop load on maturity and quality, ... of 'Starkrimson Delicious' apples. J. Amer. Soc. Hortic. Sci. 121:96
Lakso, A.N., Francesconi, A.H.D., Nyrop, J.P., Watkins, C.B. 1996. Influence of foliar pests on apple fruit size and quality. New York Fruit Quarterly 4(2&3): 12-13
Paull, R., Watkins, C.B. 1996. Are the effects of heat treatments on physiology due to heat shock proteins HortScience 31:691 (741).(Abs)
Watkins, C. 1996. Harvest date predictions for 1996. New York State Extension Fruit News 1 (7): 1-2.
Watkins, C., Stiles, W. 1996. Calcium sprays for the 1996 season. New York State Extension Fruit News 1 (5): 6-7.
Watkins, C.B., Silsby, K.J., Goffinet, M.C. 1997. Atmosphere and antioxidant effects on external CO2 injury of 'Empire' apples. HortScience 32: in press.
Watkins, C.B., Silsby, K.J. 1996. Carbon dioxide injury of 'Empire' apples. HortScience 31:639(430).(Abs).

Progress 01/01/95 to 12/30/95

Outputs
The following investigations are being carried out within this project: 1. Non-chemical techniques for control of superficial scald - intermittent warming, high carbon dioxide and low oxygen treatments - to replace diphenylamine. 2. Calcium effects on fruit quality. 3. Cultivar, maturity and carbon dioxide effects on strawberry fruit quality. 4. Effects of high carbon dioxide on gene expression of strawberry. Preliminary research in this project was submitted as part of a successful application to the USDA for funding (see 143303). 5. Modelling of UV destruction of ethylene in controlled atmosphere storage conditions. This project is in its second year, and fruit evaluation of experiments in the present season is still incomplete. It is anticipated that 3 manuscripts will be submitted for publication during 1996.

Impacts
(N/A)

Publications

Progress 01/01/94 to 12/30/94

Outputs
Within and between orchard variation in the response of 'Empire' apples to carbon dioxide concentration (2% or 5% in 2% oxygen) under controlled atmosphere conditions at either 1 or 3C is being investigated. Fruit were harvested from three individual trees in each of six orchards. Maturity and quality factors, and mineral analyses of fruit at harvest were measured and will be related to susceptibility of fruit to carbon dioxide and/or chilling injury (fruit will be removed from storage in February and June, 1995). A series of collaborative experiments have been initiated with faculty at Ithaca and Geneva: effects of preharvest potassium sprays, spacing and ground cover treatments,rootstocks and mite infection on fruit maturity, and quality at harvest and after storage are being assessed. A collaborative study within the NE103 working group has been initiated to study the use of low oxygen (0.7%) for control of superficial scald in 'Delicious' apples. Maturity and quality characteristics of 'McIntosh' apples from the Champlain region and Western New York are being studied.

Impacts
(N/A)

Publications

Progress 01/01/93 to 12/30/93

Outputs
The ethylene climacteric in attached apples was influenced by the potassium status of trees, by weather in August and September, and by repeated annual root pruning, and was not influenced by reduced soil temperature associated with artificial shading of the orchard floor. Chilling injury of stored apples was aggravated by cool temperatures in August followed by rain in September. CA apples were more firm than air-stored apples 60 days after CA was established. Carbon dioxide injury of 'Cortland' apples was aggravated by high carbon dioxide and also by low oxygen in storage. Carbon dioxide and oxygen influenced concentrations of farnesene and conjugated trienes in 'Cortland' apple skins. BHT, corn oil, and repeated monthly water washing of 'Cortland' reduced storage scald. RQ and the oxygen threshold for alcohol accumulation (OTAA) were influenced by apple variety and strain. OTAA was also influenced by senescence in air storage, but not in CA.

Impacts
(N/A)

Publications

Progress 01/01/92 to 12/30/92

Outputs
Studies with Jerseymac showed the 'tree factor' that inhibits the ripening of attached apples operates on the gene level: it is not an ethylene inhibitor as previously thought. Rapid controlled atmosphere storage followed by 1.5% oxygen + 2.0% carbon dioxide at 0.0C resulted in superior condition of Jonamac, Sparton, Jonagold, Empire, Delicious, Goldens, Mutsu, Idared and Law Rome apples. Elevating temp. from 0.0 to 1.1 to 2.2C resulted in progressively poorer fruit condition. Increasing the controlled atmosphere delay from 4-7 days to 14-17 days at 0.0C was more detrimental to fruit condition than raising the temp. from 0.0 to 1.1C. Preliminary studies indicated butylated hydroxytoluene may be a promising substitute for diphenylamine in controlling superficial scald of apples.

Impacts
(N/A)

Publications

Progress 01/01/91 to 12/30/91

Outputs
As in the 1989 'Empire' apple crop, simulation of reduced orchard light intensity in the 1990 crop influenced leaf N, P, Ca and B and delayed the fruit ethylene climacteric. However, contrary to the finding in 1989, reduced light intensity decreased flesh browning during storage of the 1990 'Empire' crop. The "tree-factor" that delays the ethylene climacteric in attached 'Idared' apples is not a fruit growth hormone, as previous studies suggested. In comparison with 2-3% CO2, CA storage of 'Empire' apples at 1% CO2 reduced senescent breakdown at 3C and flesh chilling injury at OC. The 'Marshall' strain of 'McIntosh' was found to be more susceptible to low-oxygen injury in CA than other 'McIntosh' strains because (a) internal oxygen concentrations were lower and (b) anaerobic compensation points occurred at higher fruit internal oxygen concentrations. Contrary to an Italian report, analysis of skin trienes could not be used to predict scald in 'Delicious' and 'Law Rome' apples. Contrary to a Michigan report, atmosphere flushing to control CO2 did not control scald on 'Cortland', 'Delicious' and 'Law Rome' apples. In comparison with C2H4 concentrations of 30-90 ppm, 2-6 ppm C2H4 had no significant effects on the condition of several apple cultivars stored in 1.5% oxygen. BHT (5000 ppm) applied at monthly intervals until late January significantly reduced scald of 'Law Rome' apples air-stored in poly bags at 3C.

Impacts
(N/A)

Publications

Progress 01/01/90 to 12/30/90

Outputs
Biology: Effects of 'McIntosh' strain and rootstock on apple ripening dates wereverified and also shown to be additive. This information helps growers select strains and rootstocks to spread the harvest period of 'McIntosh'. 'Marshall' strain of 'McIntosh' developed high alcohol concentrations in CA because the apple skin was highly resistant to gas diffusion. This strain required higher O2 in CA. Survey and research indicated the CA industry shift to rapid CA for 'McIntosh' could justify changing the legal CA qualifying period from 90 to 60 days. Observations in 3 seasons showed the storage period for 'McIntosh' should be limited to 1-2 mos. in 32 F air, 3-4 mos. in regular CA, and rapid CA or low ethylene CA should be used if storage exceeds 4 mos. In comparison with regular CA, low-ethylene CA (<1 ppm) significantly reduced incidences of storage scald on 'Delicious' apples, indicating low ethylene CA may be substituted for chemical control of scald. Research and survey data collected in 4 seasons showed CA conditions for 'Empire' should be 35-38 F, 1.5% O2, 2.0% CO2 to reduce flesh softening, CO2 injury, chilling injury, and flesh browning. Technology: Survey data showed carbon CO2 scrubbers need fine tuning to reduce O2 added to CA during CO2 scrubbing. Tests in a commercial CA room showed heated catalyst was more effective and less costly than "Purafil" or UV scrubbing of ethylene from the storage atmosphere.

Impacts
(N/A)

Publications

Progress 01/01/89 to 12/30/89

Outputs
Analyses of Empire apples from an orchard fertilizer test showed the ethylene climacteric was significantly correlated with leaf Mg, K, or B in two of three seasons. CA survey data confirmed research findings that fruit condition is significantly influenced by storage O2, OF, C2H4 and storage removal data. Lab studies showed that atmosphere flushing and carbon CO2 scrubbing remove large quantities of C2H4 when C2H4 is in high concentration, but these two methods of CO2 control do not supplement the ethylene scrubbing when C2H4 is low (1 ppm). UV radiation was effective in destroying atmospheric C2H4 at 1.3-1.4%, 2.7-3.0 % and 21% O2. McIntosh apples were stored in air (0 degrees C) and in CA (2.8 degrees C) using four regimes: regular CA, rapid CA, high CO2CA, and low ethylene CA. At one-month intervals samples were firmness tested upon removal from storage and after 7 days at 20 degrees C. The positive effects of the 3 CA modification were evident as early as 1 month after harvest and persisted for the duration of the study (4 months).

Impacts
(N/A)

Publications

Progress 01/01/88 to 12/30/88

Outputs
Five different storage methods for 'McIntosh' apples were compared. Apples softened most rapidly in refrigerated air storage at 0 d.C followed by regular CA storage in which a CA condition of 2% O2 + 3% CO2 at 3 d.C was established in 10 days. Rapid CA and high CO2 slow cooling CA were equally good and were better than regular CA. In the high CO2 slow cooling procedure, apples were cooled from 18 d.to 3 d.C in 15 days while being kept in CA with CO2 concentrations decreasing from 12% to 3%. Low ethylene CA was most effective among the 5 methods for maintaining the firmness of 'McIntosh' apples. 'Empire' apples stored for 6 months in CA at 3 d.C were almost as firm as those stored at 0 d.C, but the former softened more rapidly when kept in air at 20 d.C for 7 days immediately following the test storage. Hastened C2H4 climacteric in 'Empire' apple associated with high leaf B in two seasons. 'Empire' senescent breakdown associated with low leaf P and storage chilling injury with degree of tree shading. 'Delicious' C2H4 climacteric not associated with accumulated hours of light during growing season. Changes in five harvest maturity indices were independent of changes in IEC. Studies in 3 seasons indicated IEC is not a reliable index of potential storage life of 'Empire' apples. O2 below 2.0% injured some 'McIntosh.' CA storage at 38 d.F was preferred to 32 d. for 'Idared' and 'Empire.'.

Impacts
(N/A)

Publications

Progress 01/01/87 to 12/30/87

Outputs
Controlled atmospheres containing 1.5% O2 + 3% CO2 were the best for long term storage of non-daminozide treated 'McIntosh,' 'Delicious' and 'Idared' apples. Storage atmosphere of 1.0% O2 + 1.5% CO2 was not better than 1.5% O2 + 3% CO2 for 'McIntosh.' O2 concentrations of 1.5% and 2% were equally good for 'Idared.' Ethylene removal had some benefit for 'McIntosh' and 'Idared' but not for 'Delicious.' 'McIntosh' stored at 0 degrees C developed core and cortex browning but that stored at 3 degrees C was normal. Adding CO2 up to 12% in the storage atmoshpere significantly suppressed flesh softening of 'McIntosh' during a 15-day slow cooling from 18 degrees C to 3 degrees C and of 'Delicious' during a 20-day delayed cooling at 10 degrees C. Firm flesh browning and vascular strand browning of 'McIntosh' apples was associated with low K and low B. CA keeping quality of 'Empire' was associated with high leaf K and low leaf B. Internal C2H4 concentration at harvest was not a reliable indictor of potential CA storage life for 'Empire' from 36 farms. In commercial CA storage of 'Empire' keeping quality was significantly related to rapid CA, but not related to mineral content, harvest date, and CA opening date. 'Idared' as well as 'McIntosh' developed various forms of chilling injury at 0 degrees C. Economic and efficacy data were obtained for ME-300 ethylene scrubbers. Relationship between fruit volatile content and storage disorder development was cultivar specific. .

Impacts
(N/A)

Publications

Progress 01/01/86 to 12/30/86

Outputs
Four apple cultivars were studied with five methods for estimating the initiation of the ethylene climacteric dates in an orchard. There was no consistently good substitute for periodic measurement of internal ethylene concn. in freshly picked fruit. There were signficant within-cultivar variation in starch index when apples initiated the ethylene climacteric in the orchard. Low ethylene CA with 1.5% O2 and 3% O2 effectively preserved the firmness of non-daminozide treated McIntosh apples for more than 7 months. Some lots of McIntosh developed low O2 injury at 1.5% O2 at 3 degrees C. The effectiveness of CA storage atmospheres in delaying ripening in storage was directly related to delaying the onset of autocatalytic ethylene production (MI,NY-I). Low ethylene CA with 1.5% O2 and 3% CO2 gave only marginal beneficial effect with Idared apples. Costs for ethylene scrubbing in commercial CA rooms varied from 22 to 29 cents/bu.

Impacts
(N/A)

Publications

Progress 01/01/85 to 12/30/85

Outputs
Orchard sampling scheme was developed for determinations of 'Empire' ethylene climacteric. Calendar date was shown to be reliable indirect harvest maturity index for 'Empire' apples and for 'Concord' grapes. Tissue browning in CA was shown to be closely associated with low K 'Empire' apples. Ethylene scrubbing for low ethylene CA was made commercially feasible in four New York CA rooms. Some factors contributing to low oxygen injury in CA were elucidated. The rates of ethylene production of daminozide-sprayed 'McIntosh' apples were <0.1 ul kg-1hr-1 for the first 4 months & <0.5 ul kg-1 hr-1 for the subsequent 3 months in low ethylene CA. Rapid cooling (within 3 days) and rapid CA (within 7 days) were necessary for a successful low ethylene CA storage. The only benefit of low ethylene CA for 'Delicious' apples was the reduction of storage scald. Low ethylene CA 'idared' apples, which were sprayed with daminozide, had better shelf life than normal ethylene CA apples. 'Empire' apples with or without daminozide spray all responded to low ethylene CA. Daminozide spray extended the optimum harvest date of 'Empire' apples for at least one week.

Impacts
(N/A)

Publications

Progress 01/01/84 to 12/30/84

Outputs
Our research on low-ethylene CA storage and ultra-low-oxygen storage of apples progressed continuously and rapidly. Daminozide-sprayed (1000 ppm orchard spray in mid-July) 'McIntosh' apples which were cooled and stored in low-ethylene CA within 5 days after harvest maintained their firmness and freshness nearly perfectly for 7.5 months. However, delayed storage for more than 5 days diminished the low-ethylene Ca effect. Daminozide-sprayed 'Empire', 'Delicious' and 'Idared' apples were also successfully stored in simulated low-ethylene CA for 7 months. These apples were firm and fresh and had a long shelf life after the storage. 'Empire' apples without being sprayed with daminozide also kept well in low-ethylene CA, but 'Delicious' and 'Idared' apples without being sprayed with daminozide softened significantly in low-ethylene CA. Of the 6 types of ethylene scrubbers tested under commercial conditions, only one, a Cornell design for potassium permanganate-alumina beads, was worthy of recommendation. An imported heated-catalyst ethylene scrubber looked promising, but needs modification to reduce its electrical usage. Seed counts of McIntosh apples from a commercial CA room with low oxygen injury and of McIntosh held at 1.0% O(2) in an experiment suggested that low seed count may increase the susceptability of McIntosh to low O(2) injury.

Impacts
(N/A)

Publications

Progress 01/01/83 to 12/30/83

Outputs
Significant progress was made in low-ethylene CA storage of apples. 'McIntosh' apples sprayed with daminozide were successfully stored from Setpember 1982 to May 1983 without a loss of firmness or freshness in a 1400-bushel semi-commercial size low-ethylene CA room. Increasing daminozide concentrations from 1000 to 2000 ppm made little difference. Ethylene climacteric of control applies can be used as a maturity index of daminozide-treated apples. Up to 4 days of delayed cooling or delayed CA did not upset the low-ethylene CA. Low O(2)at 1% level did not improve firmness retention in low-ethylene CA as it did in regular CA. A method was developed to quickly determine alcohol concentration in commercial lots of apples stored under low O(2) conditions. Ethylene absorption by KMnO(4)/alumina beads was reduced by: low temp, low O(2), low cfm thru absorbant bed, and absorption of moisture from storage atmosphere. Rapid CA added 1.7 lbf to firmness of Empire apples at 3% O(2). Rapid CA required to minimize low-O(2) injury in low-O(2) CA. Slow cooling in Rapid CA dramatically reduced benefit of this new storage practice.

Impacts
(N/A)

Publications

Progress 01/01/82 to 12/30/82

Outputs
Initiation of ethylene production and ripening responses to internal ethylene byattached apples delayed by low orchard temperatures late in the growing season. Firmness, starch, and internal ethylene useful in predicting keeping quality of apples. Internal ethylene of daminozide-sprayed McIntosh apple is a poor maturity index, but the internal ethylene of unsprayed apple is a good maturity index for the sprayed apples to be stored in low-ethylene CA. Keeping qaulity of apples related to high CO(2), low O(2), and low ethylene in CA storage. Off flavor of low O(2) injured apples caused by ethylacetate. Low-ethylene CA effectively preserved the condition and quality of daminozide-sprayed McIntosh apples in long-term storage. The earlier the fruit was harvested the firmer the fruit was at harvest and after storage. Low-ethylene CA was of little use for McIntosh without daminozide-spray, however. Reducing O(2) concentration in the range from 3 to 1% reduced firmness loss due to storage in high ethylene CA but had little effect in low-ethylene CA. Firm post-storage apples lost their firmness rapidly at 70 degrees F. Delayed harvest increased ethylene production and reduced O(2) concentration decreased ethylene production in low ethylene CA.

Impacts
(N/A)

Publications

Progress 01/01/81 to 12/30/81

Outputs
A positive correlation was found between the rate of ethylene evolution and the concentration of ethylene in the cores of 'McIntosh' apples. Maximum retention of flesh firmness was associated with low internal ethylene concentration. Repeated experiments confirmed that the low ethylene CA storage is an effective method to control excessive softening and breakdown of 'McIntosh' apples in long term storage. The procedure involves a combination of daminozide application, optimum harvesting date and low ethylene CA environment. More basic information related to this procedure has to be collected before the procedure becomes commercially practical, however. Substantial progress has been made in the investigation of following items: Ethylene production rate changes of the fruit during low ethylene CA storage period. Effects of minute 0(2) and CO(2) concentration changes in the storage atmosphere on the ethylene production rates. Critical time intervals at which the fruit must be harvested for this method of storage. A practical method to predict such time intervals.

Impacts
(N/A)

Publications

Progress 01/01/80 to 12/30/80

Outputs
Senescent Breakdown of McIntosh Apples in Storage: Fruit firmness and breakdownin December (0 degrees C air storage) was good indicator of breakdown development in CA. Delayed storage (1 week) did not increase McIntosh breakdown, but some NAA fruit thinning sprays did. Repeated CaCl(2) tree sprays were ineffective, but postharvest CaCl(2) dips and pressure infiltration reduced breakdown. The infiltration caused some visible injury. Breakdown was significantly reduced and/or controlled by: heating apples above 80 degrees F for 2 days before storage, low storage temperature, low storage humidity, lower than normal O(2) in CA, and high CO(2) in CA. A combination of daminozide orchard spray in July, early harvest, and low-ethylene CA was the most promising control measure for McIntosh breakdown. Low Ethylene CA: Daminozide-treated McIntosh in low-ethylene CA were firmer than those stored in normal-ethylene CA until February. However, differences were small in March. A Purafil ethylene scrubber kept ethylene in 1400-bushel CA below 1 ppm until January, but not later into storage season. Reduction of O(2) from 3% to 1.5% decreased ethylene production and reduction of CO(2) from 3% to zero increased ethylene production in CA. Daminozide tree spray in July reduced ethylene production in and after CA. Ethylene inhibitor AVG applied preharvest completely inhibited ethylene synthesis of Red and Golden Delicious in storage.

Impacts
(N/A)

Publications

Progress 01/01/79 to 12/30/79

Outputs
Senescent breakdown of McIntosh apples in storage. Significant reductions or control of breakdown were associated with low humidity in 0 degrees C air storage, very low ethylene concentrations in CA storage, as well as early harvest or postharvest calcium dip treatment for apples in both storage environments. The following tested variables did not significantly affect breakdown: air pollutants, pesticides, herbicides, delayed storage. Responses to daminozide, ethephon, NAA thinning sprays, and calcium tree sprays were variable. Reliable predictions of breakdown in late spring were made from observations of breakdown which developed after 2 weeks at 18 degrees C in December. Low ethylene CA. Daminozide sprays delayed the onset of the respiratory climacteric and reduced the ethylene production rate of McIntosh apples. Daminozide-treated apples had a long storage life, excellent post-storage condition and quality when harvested shortly before the onset of the climacteric and promptly stored in CA with ethylene scrubbing. Under development is a method to predict the time of the onset of the climacteric by examining the changes in fruit sensitivity to exogenous ethylene during the maturation period. Practical methods to remove ethylene from CA are under investigation. Misc. Severe storage scald of early picked Starkrimson Delicious was controlled by 2000 ppm DPA post-harvest dip treatments.

Impacts
(N/A)

Publications

Progress 01/01/78 to 12/30/78

Outputs
McIntosh apples, which were sprayed with SADH and were harvested before the onset of climacteric, were free from breakdown and had firm texture, good condition, and good eating quality after 7 1/2 months of storage in CA with minimal ethylene. Similar apples softened excessively and had severe breakdown after CA storage with high ethylene. The effect of ethylene removal in CA was more pronounced on SADH-treated apples than on untreated apples. When McIntosh were held under siumulated commercial CA conditions the following factors influenced storage breakdown of the apple flesh: summer sprays of SADH; harvest date; calcium chloride tree sprays and postharvest dips; storage in polyethylene bags. Relative humidity levels ranging from 73% to 96% did not influence flesh breakdown. CA storage of 0 degrees C retarded ripening (firmness and panel evaluations) and controlled flesh breakdown of Empire apples. Empire breakdown was significantly worse in apples (4 orchards) picked after predicted best harvest date. A method of modification of apple quality by short-term heat treatment has been explored. Two to 4 days of heating to 40 degrees C significantly reduced fruit acidity without changing its soluble solids. Heat-treated apples had a firmer texture than controls during subsequent 1 to 4 weeks holding at 20 degrees C.

Impacts
(N/A)

Publications

Progress 01/01/77 to 12/30/77

Outputs
Harvest and postharvest qualtiy of Golden Delicious apples was more closely related to degree of yellow at harvest than to harvest date (135, 142, 149, 156 days past FB). Firmness and panel scores showed Empire apples have long satisfactory harvest period. A correlation between the length of preclimacteric life span and the minimum treatment time required for ethylene ripening response may be used to predict the time of onset of natural climacteric of McIntosh apples. Based on a study of 1,034 consumers, there was a strong preference for firmer McIntosh apples within the range of 8 to 13 lbs. While 76% of 13-lb apples were rated as "crisp" only 32% of the 8-lb fruits were rated similarly. Three-year study showed 1% and 2% CO(2) with 3% O(2) resulted in comparable firmness levels and taste panel scores for several apple cutlivars. Greener Golden Delicious at harvest gave greater response to high CO(2) before CA storage. After 180 days storage normal Ca Delicious were firmer than high CO(2) treated Delicious which were delayed in 0 degree air for 90 days before CA. After 5 to 8 months of CA storage McIntosh apples which were harvested before the onset of climacteric were less ripe than those harvested after the onset of climacteric. The former had an equal or better eating quality, less breakdown, and poorer red color compared to the latter. High ethylene concn in CA hastened ripening of apples which were harvested at preclimacteric stage.

Impacts
(N/A)

Publications

Progress 01/01/76 to 12/30/76

Outputs
Freshly harvested McIntosh were held in hypobaric storage, high CO(2), and in low, medium and high relative humdity CA for 2, 4, 6 and 8 weeks before storage under normal CA conditions. In comparison with normally handled CA controls, these fruits had higher incidences of breakdown and higher percentages of fruitswith less than 7 pounds firmness after 1 week at 70F. CA storage at 32 (0-)% CO(2) + 4-5% O(2)) increased firmness, had no influence on breakdown and increased brown core. In comparison with 38 CA, Macoun in 32 CA were more firm, preferred by taste panel, but were more severly affected by breakdown. McIntosh apples harvested preclimacteric were firmer, more acid and less ripe after storage in CA without ethlyene than that with 10- or 500-ppm ethylene. Ethylene in CA had no effect on McIntosh harvested after the onset of climacteric or on Cortland regardless of harvesting date. Delicious apples treated with high CO(2) for 2 weeks before CA were significantly firmer than normal CA Delicious. In April normal CA Delicious were more firm and judged to be less ripe than CO(2) treated Delicious which were held in air for 90 days andthen placed into CA for 90 additional days. When apples were slowly cooled during CO(2) pretreatment, CO(2) effect was negated, apples were more ripe and had significanlty more scald and breakdown.

Impacts
(N/A)

Publications