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2000 CORNELL FRUIT HANDLING AND STORAGENEWSLETTERItems of Interest for Storage OperatorsinNew York and BeyondChris B. WatkinsDepartment of HorticultureCornell UniversityIthaca, NY 14853Voice: 607-255-1784; Fax: 607-255-0599E-mail: cbw3@cornell.eduandDavid A. RosenbergerCornell's Hudson Valley LaboratoryPO Box 727, Highland, NY 12528Voice: 845-691-7231; Fax: 845-691-2719E-mail: dar22@cornell.eduItemPageHoneycrisp – some preliminary observations . . . . 2MCP – an update . . . . . . . . 3Postharvest pathogens create new problems for apple storage . . 3Postharvest pathogens may be contributing to lost sales and low prices . 4Determining inoculum sources for postharvest decays . . . 6Getting started with packing house sanitation . . . . 8What about fungicide alternatives? . . . . . . 10ReTain effects during storage of Empire apples . . . . 11Ethrel effects on storage quality of McIntosh . . . . 12Mention of specific trade names or omission of other trade namesdoes not imply endorsement of products mentioned ordiscrimination against products not mentioned.You may now locate the CA Newsletter in electronic format at:http://www.hort.cornell.edu/extension/commercial/fruit/index.html

2Honeycrisp – some preliminary observationsHoneycrisp is a new apple variety forNew York that has created lots of marketenthusiasm. However, problems with this varietycould destroy market confidence for the apple.The most important postharvest problems arebitter pit and soft scald.Bitter pit generally is thought to berelated to calcium concentrations in the fruit. Itsincidence is often worse in younger, vigorouslygrowing trees than in mature, evenly croppingtrees. Therefore, a combination of preharvestcalcium sprays together with good orchardmanagement will likely result in satisfactorycontrol of pit. We are currently investigating theeffectiveness of calcium sprays for pit controland initial results should be available by spring.Soft scald, however, has been of greaterconcern because its appearance in the marketplace has been sporadic. Also, the problem issometimes expressed as an internal browningthat is not apparent on the outside of the fruit. Inthe 1999 harvest season, we carried out our firsttrials with Honeycrisp. We focussed on theeffects of:1. Temperature, because soft scald may be achilling-injury, and therefore controlled byraising the storage temperature;2. Diphenylamine (DPA) application, becausethis antioxidant compound, when used forcontrol of superficial scald, has beeneffective for control of soft scald in othervarieties;3. Delays before storing fruit at low storagetemperatures, as sometimes this can controlthe disorder.Fruit were harvested in a Western New Yorkorchard on September 17, 1999, and treated asdescribed in Table 1.Soft scald was reduced by storing fruit at36 o F compared with 33 o F, and by treatment offruit with DPA at harvest, but these reductions inincidence, while significant, did not eliminate thedisorder. In contrast, a delay of a week at 50 o Fprior to either 33 or 36 o F storage markedlyreduced soft scald incidence, overall averaging0.6% compared with 19% in the non-delaytreatments. Factors such as firmness and solublesolids were not affected by treatment, but theaverage bitter pit incidence of fruit subjected to adelayed cooling treatment was 25% comparedwith 14% in the non-delay treatment. Therefore,use of delayed cooling treatments should be usedonly on fruit with a low bitter pit risk.Table 1: Soft scald incidence in Honeycrisp fruituntreated or treated at harvest with 1000ppmDPA, and then stored at 33 o or 37 o F, or kept at50 o F for one week before being stored at 33 o or36 o F.TreatmentSoft Scald(%)Stored at 33 o F28aStored at 36 o F19bDPA-treated, stored at 33 o F 19bDPA-treated, stored at 36 o F 8cOne week at 50 o F, then stored at 2cd33 o FOne week at 50 o F, then stored at 0d36 o FDPA-treated, one week at 50 o F, 0dthen stored at 33 o FDPA-treated, one week at 50 o F, 0dthen stored at 36 o FValues with different letters indicatedifferences between means at the 5% level.We were reluctant to make recommendationsfor use of delay treatments for control ofsoft scald based on one year of data. However,trials performed in 2000 have confirmed theseresults, and informal tasting of the fruit does notsuggest that Honeycrisp quality is affected bydelayed cooling treatments. Also, at least twogrowers have tried this or similar methods withgood results. Therefore, a tentativerecommendation is made that a short delay,either at 50 o F or in a barn at similartemperatures, before cold storage might be worthtrying. In the longer term, however, storagetemperature control, perhaps 38-40 o F, may be abetter solution, at least for early to mid-harvestedfruit. This year’s research, which is still inprogress, suggests that a higher storagetemperature is less effective for late harvestedfruit than early harvested fruit. Furtherrecommendations will be made available to theindustry before the 2001 harvest.

3MCP – an update1-Methylcyclopropene or MCP is a newcompound that will likely become available tofruit and vegetable industries. It is an organiccompound, which blocks ethylene receptors andprevents ethylene effects in plant tissues forextended periods. MCP can have major effectson ripening of apple fruit, and undoubtedly willhave an enormous impact on our apple industryas well as those elsewhere.Firmness (lb)181614121020201816141210201816141210DeliciousMCP treated warmMCP treated coldcontrol treated warmcontrol treated cold0 2 4 6Gala0 2 4 6Jonagold0 2 4 6Months in storageFigure 1 Flesh firmness of Delicious, Gala orJonagold apples treated with 1ppm MCP either warmon the day of harvest or after cooling overnight andstored in air for up to 6 months. Evaluations weremade after removal to 68oF for 7 days.A summary of MCP research carried out atCornell University can be found in the New YorkFruit Quarterly 8(3): 5-9 (2000), and will not berepeated here. However, one issue of focusduring the 1999 harvest season was acomparison of effects of treating fruit warm andtreatment of cold fruit on the day followingharvest using Cortland, Delicious, Empire, Gala,Jonagold, McIntosh, and Redcort varieties. It isunclear at this stage what the optimum treatmentconditions for our apple varieties will be undercommercial conditions. We observed three typesof response, and these are illustrated in Figure 1.Delicious responded less well to MCP whentreated cold than warm. Effects of MCP on Galawere independent of treatment temperature.Jonagold responses were better for cold fruit thanwarm fruit. Cortland, Empire, and McIntoshresponses were similar to that of Delicious.Redcort was similar to Jonagold. These datasuggest the possibility that treatment with MCPmight be optimal when fruit are treated warm onthe day of harvest, at least for some varieties.During the 2000 harvest season westudied the effects of application temperature andthe types of delay between harvest and treatmentthat might occur under commercial conditions. Inaddition we have been able to carry out extensivesemi-commercial trials with MCP with thesupport of the New York Apple Association.Results will be reported to the industry at the2001 Storage Workshop at Ithaca.AgroFresh, Inc. (Rohm and Haas Co.) isactively pursuing Federal registration of MCP.Acute toxicity, mutagenicity and productchemistry studies indicate a favorable toxicologyprofile. In addition, 1-MCP is structurally relatedto plant-containing materials, is applied atextremely low dose levels, and there is noexpectation of measurable residues in foodcommodities. EPA registration was granted forflowers in April, 1999 and is expected forpostharvest use on fruits and vegetables in 2001.Postharvest pathogens create new problems for apple storageThe two common postharvest pathogens onapples are Penicillium expansum , the cause ofblue mold, and Botrytis cinerea, the cause ofgray mold. These fungi have traditionally beenconsidered “wound pathogens”, meaning thatthey invade fruit primarily through wounds

4created during harvesting, packing, or transport.During the past 10 years, however, storageoperators have noted increasing levels of decayin unwounded fruit, especially Empire fruit, thatare held in long-term CA storage.Some of the results of our postharvestresearch were recently presented in New YorkFruit Quarterly 8(3): 24-28 (2000). Conclusionsfrom the studies reported there and fromprevious work can be summarized as follows:1. The combination of DPA and benzimidazolefungicides (Benlate, Topsin-M, Mertect340F) provided excellent control of P.expansum and B. cinerea from the early1970’s through the early 1990’s.2. Many storages now contain strains of P.expansum that are completely resistant to theDPA/benzimidazole treatment. Except forcaptan, no other fungicide is registered forpostharvest use.3. P. expansum can invade non-woundedEmpire apples through the fruit stem duringCA storage. Initial tests suggested that fruitwith high boron content are moresusceptible to stem invasion than are fruitwith low to moderate levels of boron.Empire fruit are apparently more susceptibleto stem invasion than are most othercultivars because most of the serious losseshave occurred with Empire.4. Huge numbers of spores of P. expansumcan persist on empty bins that containeddecayed fruit. Contaminated bins provide avenue for cycling inoculum from one seasonto the next. As the proportion of the P.expansum population that is resistant tofungicides increases, the level of decayincreases and the inoculum load on binsincreases correspondingly.5. In the absence of new postharvestfungicides, improved decay control can onlybe achieved by improving packinghousesanitation.Postharvest pathogens may be contributing to lost sales and low pricesDecay Problems Evident in Retail Stores: Asurvey was conducted during winter of 2000 todetermine if and how often rotten applesappeared in consumer packages presented forsale in chain stores. Data collectors for thissurvey visited 22 to 25 grocery stores in the mid-Hudson Valley (Newburgh, New Paltz,Kingston, Poughkeepsie) on each of four dates.Stores were not notified of the visits. The datacollectors were instructed to peruse the displaysof bagged apples as if they intended to make apurchase. They recorded the varieties of baggedapples on display and noted whether or not thebags contained any visibly decayed fruit. Ifdecayed fruit were evident in one or more bags,the data collectors counted the number of bagson display and recorded how many of those bagscontained decayed fruit. To avoid beingconspicuous, data collectors did not examineevery bag in a multi-layered display. Insteadthey attempted to record what consumers wouldsee if they looked at the display with theintention of making a purchase. This method ofchecking for decays probably under estimatedthe actual levels of decay in bagged fruit becausesome decayed fruit may have been hidden withinthe bags.Bagged Empire and McIntosh wereavailable in at least 16 and sometimes in as manyStores or bags with decay (%)6050403020100Stores with decayed EmpireStores with decayed MacsBags with decayed EmpireBags with decayed Macs27 Jan 00 3 Feb 00 11 Feb 00 11 Apr 00Figure 2. Percentage bagged apple displays inretail stores that contained decayed fruit, andestimated proportions of bags in those displaysthat contained decays. Results are based onsurveys of 17-20 stores on each of four dates.as 21 stores on the various survey dates. Theproportion of Empire displays that containeddecayed fruit varied from a low of 20% onFebruary 3 to a high of 47% on April 11 (Fig. 2).Among those displays that contained decayedEmpire fruit, the proportion of individual bagsthat contained decays ranged from 18% to 27%.For McIntosh, the proportion of stores withdecayed fruit on display ranged from 10-28%,

5and 12-27% of the individual bags in thosedisplays contained decays. In some cases, juicefrom decayed fruit had leaked through the bags,leaving the surface of the plastic bags sticky withresidue.The survey reported here was conductedin the Hudson Valley, but the decay problem isnot limited to any single region. Labels on bagsthat contained decayed fruit showed that fruitoriginated from all of the various productionareas within New York as well as fromMassachusetts, Vermont, Pennsylvania,Washington State, and Ontario.Editorial Opinion & Discussion Relatedto the Retail Store Survey: Many factors arecontributing to the sorry condition of apples inretail stores. As noted earlier, we no longer haveeffective fungicides for controlling postharvestdecays, and Empire has turned out to be a verydecay-susceptible variety. Inoculum levels onbins and in packinghouses presumably have beenincreasing each year as the populations offungicide-resistant strains of P. expansum havebecome predominant. As a result, apples goinginto bags are exposed to increasingconcentrations of spores and are more likely todevelop decays at wounds or stem punctures.Fruit to fruit contact in bags ensures that therewill always be some freshly-wounded fruit.Changes in chain store requirements forbagged apples are also contributing to decayproblems. Instead of 3-lb bags, chains are nowdemanding 5-lb and 10-lb bags. With more fruitper bag, the probability increases that at least onefruit in the bag will develop decay even if thepercentage of decay per 100 fruit remains thesame. When fruit are packed in cells or on trays,decays can be individually removed anddiscarded at the retail level, but decayed fruitcannot be easily removed from bags. The movetoward selling larger fruit in bags rather than inloose displays therefore increases the probabilitythat the consumers will find decayed fruit ondisplay.Another significant factor contributingto decays in bagged fruit is the increasinglycommon demand by chain stores that baggedapples be packed in store-brand poly bags. Theuse of store-brand bags has created inventorynightmares for packing house operators. Moreimportantly, store-brand bags are contributing todecay problems at the retail level becausepackinghouse operators can no longer move outpacked inventory in a timely manner.Most packing houses pack tray and/orcell packs of large-sized fruit at the same timethat they are packing poly bags of smaller sizedfruit. In many cases, orders for the larger (andoften more profitable) cell-packs drive decisionsconcerning what varieties and what lots of fruitwill be packed on any given day. The smallerfruit coming off of the line at the same time gointo bags on the assumption that the broker will“find a home” for the bagged fruit within a fewdays. But what brand of bags should the storageoperator use when a buyer has not yet beenidentified? When bagged apples were sold withthe producer’s or packer’s name on the bag, theinventory of packed, poly-bagged fruit could berotated fairly quickly because the packedinventory could be sold to a number of differentretail chains. With the advent of store-brandpoly bags, the bagged fruit can go to only onechain store. If that chain buys from a differentbroker or decides to feature Washington Stateapples for the next several weeks, the packedbags languish in cold storage while the fruit losesfirmness and decay fungi begin to take their toll.How can the industry address themarketing problem that exists when decayedfruit appear in poly bags? Solutions mightinclude one or more of the following:1. Improved sanitation in packinghousesmight reduce the probability that fruitgoing into bags will develop decay. (Noinoculum means no decay). Steps can betaken immediately, as outlined later inthis report, to improve sanitation inpackinghouses. However, considerabletime, research, and facility modificationsmay be required before the industry cansolve the current decay problem viasanitation alone.2. Packing house operators could refuse toput fruit into bags until they know whenand where the bagged fruit will be sold.However, it seems unlikely that anyonewill pass up a potential sale of trays orcell packs just because they have not yetgenerated a sale for the bagged fruit thatwill come off of the packing line at thesame time.3. Larger, consolidated packinghouses andsales desks might allow more efficienthandling of orders from the relativelyfew chain store buyers, thereby reducingsituations where inventories of baggedfruit must be held for extended periodsbefore they are sold. However,consolidation alone does not ensure that abetter quality product will reachconsumers.

64. The apple industry in New York, NewEngland, and Michigan could bandtogether and refuse to pack fruit in storebrandpoly bags. Eliminating store-brandbags would cut packing costs at the sametime that it would allow more orderlymarketing of bagged fruit. However,historical precedent suggests that almosteveryone in the apple industry wouldrather die than cooperate. The industryunity that would be needed to eliminatestore-brand bags is not likely to be foundin the near future.Given the current status of the appleindustry, none of the proposed solutions seemvery practical. Without some action, however,decays in packed fruit will continue contributingto reduced consumption of apples and furtherdeclines in apple movement and prices.Determining inoculum sources for postharvest decaysRelatively little is known about the sourcesof inoculum that contribute to postharvest decayscaused by P. expansum. Inoculum canaccumulate in recirculating postharvest drenchesand in water flotation tanks, but where do thesespores originate? For many years, pathologistsbelieved that the primary source of Penicilliuminoculum was soil carried on the bottoms of fieldbins. More recently, however, we began tosuspect that inoculum recycles from year to yearon the field bins themselves.Inoculum carried on bins: To determine howmany spores can be carried on bins, empty binswere “washed” using a portable postharvestdrencher. Water samples were collected aftereach set of five bins had been washed, andinoculum levels in the water samples weredetermined by dilution plating. The number ofspores recovered per bin was calculated bytaking into account the number of bins washed,the total volume of the wash water in thedrencher, and the number of colonies thatdeveloped per milliliter of water placed ondilution plates.The bin-washing experiment showedthat a single contaminated bin can carry morethan two billion spores (Table 2). Althoughplastic bins carried only about one-fourth asmany spores as the wooden bins from the sameCA room, the plastic bins still harbored morespores than their relatively “clean” appearancewould have suggested. Running 100 bins thateach release 2 billion spores through apostharvest drencher that contains 1000 gallonsof solution would raise inoculum concentrationsin the drencher solution to more than 50,000spores/ml. For many postharvest experimentswith Empire fruit, spore concentrations of 20,000spores/ml are enough to cause 100% decay inwounded fruit. Thus, inoculum carried onwooden bins in clearly sufficient to account forcarry-over of inoculum from year to year.A bin sanitation experiment was conductedduring July 1999 to determine effectiveness ofsanitizing bins with a quaternary ammoniasolution (Deccosan 315). All decayed fruit wereremoved from empty wooden bins and the binswere then washed with Deccosan 315. Thisprocess resulted in a 99% reduction in thenumber of spores that could be retrieved fromthe bins, but some of the sanitized bins stillcarried nearly 8 million spores. The economicbenefits of sanitizing bins remains unproven, buta 99% reduction in carry-over inoculum wouldseem to be a step in the right direction.Will chlorinated water in the water dumpson packing lines sanitize bins? Apparently not:The bins from which we recovered 2 billionspores came from a packing line that fastidiouslymaintains chlorine levels in their water flumes.Thus, it appears that effective sanitizing of binscan only be completed by applying quaternaryammonium santiziers (or perhaps steam) in aseparate operation after bins are emptied.Inoculum transported in air: Airborne sporesin packinghouses are probably the major source

9Table 3. Effects of postharvest treatment on fruit firmness and on the incidence of decays caused by Penicillium expansum andBotrytis cinerea a in Empire fruit held in CA storages from 29 September 1999 through 14 July 2000.Storage ANumber of decayed fruit per bin Fruit firmness 1P. expansum B. cinerea 14 Jul 21 JulNo postharvest treatment .............................................................. 1.4 0.7* 15.5 13.9With postharvest treatment 2 ....................................................... 10.7* 3 0.0 15.7 13.9Storage BNo postharvest treatment .................................................................6.9 1.8* 13.5 12.9With postharvest treatment........................................................... 16.8* 0.4 14.0 12.61 Fruit firmness was measured by testing both sides of 10 fruit per replicate when fruit were removed from cold storage on 14 Jul andagain after a 7-day shelf life test at 70 o F.2 Postharvest treatments of DPA plus Mertect 340F applied by the packinghouse.3 Asterisks indicate that means are significantly different in the paired comparisons (P

10rots, packinghouses are designed with wallsseparating the input and output ends of thepacking lines. The fruit packing operation isphysically separated from the part of the linewhere bins are emptied and decayed fruit areremoved. The physical separation keeps sporesfrom the “dirty” part of the packing line fromblowing into the area where fruit are beingpacked.Putting a wall through the middle of theapple packing line will be impractical in mostsituations. However, air flow patterns andlocations of exhaust fans might be adjusted tominimize the movement of air from the waterdump area toward the area where fruit arepacked.What About Fungicide Alternatives?Captan used in postharvest treatments mightprevent P. expansum from invading stems inEmpire fruit. Captan has never been veryeffective for protecting against postharvestdecays in wounds, but there is some evidencethat it may be adequate for protecting stems.More tests are currently in progress. Wherecaptan-treated fruit are acceptable to buyers,using captan in postharvest drenches might helpto reduce decay in Empire fruit as compared tousing only DPA plus Mertect 340F. However,avoiding all postharvest treatments on Empirefruit is still likely to be the best option.Several biocontrol fungicides have beenregistered for postharvest use on apples, but theyare either ineffective or unavailable due todistribution and marketing problems. In somecases, these products are only registered for useas line sprays and they therefore cannot be usedin drenches prior to CA storage.Novartis has a new fungicide with the tradename of “Scholar” that could prove useful as apostharvest treatment for apples. The genericname for Scholar is fludioxonil. It is aphenylpyrrole fungicide with a different mode ofaction than any of the other fungicides currentlyregistered for field or postharvest use on apples.Scholar has been very effective against P.expansum in several trials conducted at theHudson Valley Lab, but it probably will requireat least two more years of testing before it can beregistered.Even if Scholar or some other new fungicideis eventually registered for apples, resistance tothe new fungicide will develop quickly unlessinoculum levels are kept to a minimum. Thecombination of DPA and benzimidazolefungicides remained effective for nearly 20 yearsonly because of a fortuitous interaction betweenDPA and the fungicides that sloweddevelopment of resistance. In the absence ofDPA, the benzimidazoles would have controlledpostharvest decays for only about five years, anda similar fate can be anticipated for any othernew fungicides that might be introduced unlessthe new product is managed carefully to forestallresistance.ConclusionsImproved sanitation will be essential forminimizing losses during CA storage, forreducing the incidence of decayed fruit inconsumer packages, and for preventing rapiddevelopment of fungicide resistant strains thatwould compromise any new fungicide that mightbe introduced. Basic sanitation measures thatshould be implemented immediately include thefollowing:1. Chlorinate water flumes in packing houses.2. Do not apply postharvest fungicide/DPAtreatments unless absolutely necessary.3. Look for improved ways to sanitize floorsand surfaces in packinghouses and toeliminate inoculum from contaminated bins.

11ReTain effects during storage of Empire applesLast year we reported on CA storage ofMcIntosh fruit which had been untreated ortreated with ReTain before harvest. In general,our results indicated that while effects of ReTainon fruit maturity, especially internal ethyleneconcentration, could be significant, nodifferences in storage quality were detected. Inthe1999 harvest season we carried out a similarexperiment using Empire, a variety that producesless ethylene than McIntosh. Fruit wereharvested from four Western New York orchardson two occasions. Fruit maturity was assessed onfruit from each orchard and then fruit from eachorchard were stored under CA conditions (2%O 2 /2% CO 2 ) at 36 o F. Untreated and ReTaintreatedfruit were stored separately, but for thefirst harvest date, separate CA chambers withmixed-treatments were also established. ReTaintreatedand untreated fruit were mixed in thesame chamber to determine if ethyleneproductionfrom the non-treated fruit wouldcompromise the potential storage-enhancementthat might be provided if Retain-treated fruitwere never exposed to untreated fruit that weregenerating ethylene.At the first harvest date, fruit fromuntreated trees in two orchards had high internalethylene, but ReTain treatment prevented thisincrease (Table 4). By the second harvest onOctober 7, however, ReTain only controlledethylene in orchard 4.Fruit were removed from storage after 5months and quality evaluated after 1 and 7 daysat 68 o F. ReTain-treated fruit were firmer thancontrol fruit overall, but averaged only 0.3 lbgreater firmness over both harvest dates. Becausetreatment effects for 1 and 7 days shelf life werethe same, only data for 1 day of shelf life areshown (Table 5). These show that the responseto ReTain during storage was greatly affected byorchard. There was no significant effect oftreatment for orchards 1 to 3, but ReTain-treatedfruit from orchard 4 was 0.9 lb firmer than theuntreated fruit. The firmness benefit for fruitfrom this orchard was found at both harvests.Interestingly, orchard 4 had the most soft fruit atharvest (Table 4).Untreated fruit had similar firmness oneither day 1 or day 7, regardless of whether fruitwere stored separately or with ReTain-treatedfruit (Table 6). ReTain-treated fruit, however,were slightly firmer when stored with othertreated fruit than with untreated fruit on day 1,but not on day 7.Our conclusions are that ReTaintreatment may result in significant maintenanceof firmness, especially in fruit from an earlymaturing block. However, these effects areorchard-specific and inconsistent. In general,ReTain should be used as a harvest managementtool rather than a means of maintaining qualityduring storage.Table 4 Internal ethylene concentrations (ppm) and flesh firmness (lb) of untreated or ReTain-treatedEmpire fruit from four Western New York orchards harvested on two occasions.Harvest date Orchard Internal ethylene concentration Flesh firmness (lb)number(ppm)Untreated ReTain-treated Control ReTain-treated9/28/99 1 3.77 0.22 17.7 17.82 0.17 0.15 18.1 17.83 17.04 0.26 18.0 18.34 0.14 0.13 17.2 17.510/7/99 1 4.55 15.27 14.0 14.22 0.72 2.61 14.2 14.53 6.91 6.73 14.2 13.84 5.70 0.19 13.5 14.3

12Table 5: Flesh firmness (lb) of untreated or ReTain-treated Empire fruit from four Western New Yorkorchards after 5 months of CA storage, evaluated after 1 day at 68 o F.Harvest date Orchard # Flesh firmness (lb)Control ReTain-treated9/28/99 1 15.2 15.82 15.4 16.03 15.5 15.54 14.8 15.710/7/99 1 14.0 14.22 14.2 14.53 14.2 13.84 13.5 14.3Table 6: Flesh firmness (lb) of Empire apples from four orchards in Western New York that were eitheruntreated or sprayed preharvest with ReTain. Fruit were stored under CA conditions for 5 months, eitherseparated or mixed, and tested after 1 or 7 days at 68 o F.Storage type Untreated ReTain-treated1 day 7 days 1 day 7 daysSeparate 15.2b 14.2de 15.8a 14.4cdMixed 15.5b 14.0e 15.4b 14.7cEthrel effects on storage quality of McIntoshIn the Hudson Valley, spraying Ethrelon McIntosh trees to enhance fruit color andallow harvest before fruit drop occurs hasbecome a standard management procedure forthe industry. We are often asked about the effectsof treatment on fruit quality, especially as somegrowers then store treated fruit under CAconditions. Ed Stover and I ran trials in 1996involving storage of Ethrel -treated fruit.Standard procedures used by theHudson Valley growers were followed. Theseinvolved harvest of fruit within a 6-day windowafter Ethrel treatment (August 30). Fruit weretransported to Ithaca, cooled overnight, and CAatmospheres applied. Fruit were assessed after 3and 6 months, plus 1 or 7 days at 68 o F.Firmness of Ethrel -treated fruitharvested on September 4 was 14.3 lb comparedwith 15.0 lb in the untreated control fruit. Bothuntreated and treated fruit softened duringstorage for either 3 or 6 months, but Ethrel -treated fruit were always softer 1 day afterremoval (Table 7). Effects of treatment weresmall after a 7-day shelf life period. No effects oftreatment on incidence of disorders weredetected.What does one conclude from thesedata? Ethrel-treatment permits harvest of fruitwith marketable color before excessive fruit dropoccurs. The present market puts a premium oncolor, rather than firmness, and in the absence offirmness standards this situation is likely tocontinue. However, our results suggest thatEthrel -treated McIntosh should not be held inCA more than 3 months. These data wereobtained using fruit harvested at the latter part ofthe window for Ethrel use, i.e., 4-6 days after

13harvest. but depending on temperatures eachseason there will be considerable variation.Although the results are likely to generallyapplicable, slower responses might be expectedfrom fruit treated with lower rates of Ethrel orharvested sooner after harvest. As a finalcomment, trials this year show that Ethrel-treatedMcIntosh will not respond to MCP.Table 7 Flesh firmness (lb) of Hudson Valley-grown McIntosh apples either untreated or treated beforeharvest with Ethrel, and stored in CA for 3 and 6 months, pus 1 or 7 days at 68 o F.Fruit stored 3 monthsFruit stored 6 monthsDay 1 Day 7 Day 1 Day 7Control 13.6a 11.8c 12.3b 12.0bcEthrel-treated 11.2d 10.8de 10.5ef 10.1fValues with different letters indicate differences between means at the 5% level.Acknowledgments:The New York Apple Research and Development Program, the New York Apple ResearchAssociation, and Novartis funded the research reported here. Paul Woolley of Hilltop Nurseriesprovided the Honeycrisp fruit used for the ‘delay’ experiment. The ReTain experiments could not havebeen carried out without the help of Ken Silsby of Sun Orchard Fruit Company and their growers, andRegina Rickenburg of Valent BioSciences. We thank Fritz Meyer, Jackie Nock, Catherine Ahlers, andAlbert Woelfersheim for excellent research assistance. Robert and Doug Minard provided the portabledrencher used for washing bins to determine spores loads carried on bins. Thanks to Deborah Breth,Pete Russell, Rod Farrow, Sun Orchards, and Lake Ontario Fruit for cooperating on the trial comparingEmpire stored with and without postharvest treatment. Thanks to Dressel Farms for providing CAstorage for fruit involved in some of the experiments reported here.