CENTRAL VALLEY POSTHARVEST NEWSLETTER

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1 CENTRAL VALLEY POSTHARVEST NEWSLETTER COOPERATIVE EXTENSION UNIVERSITY OF CALIFORNIA Kerney Agriculturl Center 9240 S. Riverbend Avenue, Prlier, CA USA (559) April 2005 Vol. 14, No. 1 Crlos H. Crisosto Editor Contents: Evlution of Ozone Gs Penetrtion Through Citrus Commercil Pckges nd Control of Green nd Blue Molds Sporultion During Cold Storge Evlution of the Effect of Ozone Exposure on Decy Development nd Fruit Physiologicl Behvior Abstrcts Dr. Crisosto s Ozone Publictions Future Dtes This newsletter is posted on our website t You must subscribe to receive miled copy. Visit our websites EVALUATION OF OZONE GAS PENETRATION THROUGH CITRUS COMMERCIAL PACKAGES AND CONTROL OF GREEN AND BLUE MOLDS SPORULATION DURING COLD STORAGE Introduction Lluís Plou, Joseph L. Smilnick, Monir Mnsour, Crlos H. Crisosto, nd Thoms J. Clrk In recent work we reported the bility of gseous ozone continuously relesed t low doses (0.3 or 1 ppm, v/v) to inhibit the sporultion of severl importnt posthrvest pthogens of tble grpes, stone fruit, nd citrus fruit (Plou et l., 2001, 2001b, 2002). Sporultion of Penicillium digittum nd P. itlicum on cold-stored ornges or lemons ws suppressed without injuring the fruit. In those trils, however, exposure of the fruit to the gs ws unimpeded nd we did not evlute the effectiveness of ozone pplied to commercilly-pcked citrus fruit. The objectives of this work were to test the bility of ozone gs to penetrte into different commercil citrus fruit pckges nd to The University of Cliforni prohibits discrimintion ginst or hrssment of ny person employed by or seeking employment with the University on the bsis of rce, color, ntionl origin, religion, sex, physicl or mentl disbility, medicl condition (cncer-relted or genetic chrcteristics), ncestry, mritl sttus, ge, sexul orienttion, citizenship, or sttus s covered vetern (specil disbled vetern, Vietnm-er vetern or ny other vetern who served on ctive duty during wr or in cmpign or expedition for which cmpign bdge hs been uthorized). Inquiries regrding the University s nondiscrimintion policies my be directed to the Affirmtive Action/Stff Personnel Services Director, University of Cliforni, Agriculture nd Nturl Resources, 1111 Frnklin, 6th Floor, Oklnd, CA Telephone (510)

2 Pge 2 Centrl Vlley Posthrvest Newsletter evlute the effectiveness of the gs in controlling sporultion on commercillypcked citrus fruit. Mterils nd methods Fruit inocultion. Lne lte nvel ornges (Citrus sinensis (L.) Osbeck) from commercil orchrds in the Sn Joquin Vlley (Cliforni), were used in the experiments before ny commercil posthrvest tretments were pplied. P. digittum nd P. itlicum were grown on PDA in petri dishes t 25ºC for 7 to 10 dys. Spores were rubbed from the gr surfce nd high-density spore suspension (pproximtely 10 6 spores ml -1 ) ws prepred. Ornges were inoculted 1-cm deep into the flesh in the equtor of two opposite fces with plstic syringe with 20-mm needle. Approximtely 0.25 ml of the spore suspension ws pplied t ech inocultion point. Fruit pckging. The following types of pckges were prepred seprtely with fruit inoculted with ech pthogen. See Tble 1 for chrcteristics of ech pckge. Tble 1. Chrcteristics of the different pckges used in the experiments. Pckge Dimensions (inches) (long x wide x tll) Volume (in 3 ) Lid Box vented re (%) Crton 17.3 x 11.9 x ,408.7 Yes 2.6 RPC 23.5 x 15.5 x ,678.9 No 35.9 Mster crton Plstic bg 19.5 x 13 x ,675.7 Yes x ) Crton (nked): stndrd corrugted fiberbord citrus crtons with vents were filled with ornges. Inoculted fruit were plced in the four corners nd t the center of the crton t both the bottom nd top levels of the crton. Ten inoculted ornges per crton were used. Crtons were stored with the lids on. 2) RPC (nked): returnble plstic boxes were filled with pproximtely 50 ornges. Inoculted fruit were plced in the four corners nd t the center of the box t both the bottom nd top levels of the box. Ten inoculted ornges per box were used. 3) RPC (bgged): 5 lb polyethylene bgs with smll vents were filled with ornges, 4 were inoculted nd 10 were not inoculted. Eight bgs were plced in ech RPC. 4) Mster crton (bgged): polyethylene bgs were filled with inoculted nd non-inoculted ornges s previously described nd plced in Mster crtons. Ten bgs were plced in ech crton. Crtons were stored with the lids on. Six pckges of ech type were prepred with fruit inoculted with P. digittum nd six with fruit inoculted with P. itlicum. Mster crtons were only prepred with fruit inoculted with P. itlicum. For ech pthogen, three of these six pckges (replictes) were rndomly stcked on one pllet nd the other three on nother pllet. Pcked fruit ws held t 55 ± 2ºF for 24 h before ozone exposure. Continuous exposure to gseous ozone. A wter-cooled coron dischrge ozone genertor (Model Genesis CD-25G, Del Industries, Sn Luis Obispo, CA) ws instlled in n djcent non-ozonted room nd set to produce 2.5 g h -1 ozone. The gs ws continuously relesed to 23,940 ft 3 cold storge room with constnt temperture of 55 ± 2ºF (12.8 ± 1ºC) through 0.2-inch dimeter Teflon tube nchored to the wll of the room. The room ws erted through 105 ceiling cones (with 6 inch outlet) spced 5 ft from ech other. About 24 h fter inocultion nd pckging, the pllet

3 Centrl Vlley Posthrvest News Pge 3 contining one hlf of the pcked fruit ws stored in this room for 13 dys. The pllet contining the other hlf of the pcked fruit ws stored t the sme temperture nd for the sme time in n identicl non-ozonted room (ir tmosphere, control room). The ozone concentrtion in the room nd inside some of the pckges on the pllet ws continuously monitored by 6-chnnel UV bsorption ozone nlyzer (Model 450 Nem, API Inc., Sn Diego, CA) with minimum detection limit of ppm. Air from the smpling points in the ozonted room ws pumped through 0.15 inch internl dimeter tubes to the nlyzer, which ws locted in the djcent room ner the genertor. The smpling points re specified in Tble 2. Sporultion ssessment. Green nd blue mold sporultion on Lne lte nvel ornges pcked nd stored in both ozonted nd control rooms were recorded for ech inoculted fruit fter 13 dys of storge t 55ºF. A sporultion index ws used where numbers 0, 0.5, 1, 2, 3, 4, nd 5, respectively, indicted soft lesion but no spores or mycelium present, mycelium but no spores present, < 5%, 6 to 30%, 31 to 60%, 61 to 90%, nd > 91% of the fruit surfce covered with spores. Sttisticl nlysis. Scores in the sporultion index were considered s quntittive vrible. Ech vlue in the dt set ws trnsformed to the squre root of the vlue plus 0.5. An nlysis of vrince ws pplied to the trnsformed dt nd mens were seprted by Fisher s Protected Lest Significnt Difference test (LSD, P = 0.05). Results nd discussion Averge levels of the ozone concentrtion for the entire storge period re given for ech smple point (Tble 2) nd type of pckge (Tble 3). Ozone penetrtion in ech type of pckge, clculted s percentge of the ozone concentrtion in the room mbient, is lso presented (Tble 3). Tble 2. Averge ozone levels for the entire storge period t the different smpling points. Anlyzer chnnel Chnnel 1 Chnnel 2 Chnnel 3 Chnnel 4 Chnnel 5 Chnnel 6 Smpling point Inside plstic bg in RPC box Inside RPC box (nked fruit) Inside crton (nked fruit) Inside plstic bg in Mster crton Inside crton (nked fruit) In the room mbient Position in the pllet Ozone levels (ppm, v/v) Middle 0.12 Middle 0.59 Middle 0.03 Middle 0.07 Top A comprison between ozone concentrtions inside the different pckges indicted tht the gs penetrted more esily into RPC boxes thn into crtons or Mster crtons. Nevertheless, ozone concentrtion in RPC boxes ws significntly higher in the spces surrounding the nked fruit thn inside plstic bgs (Tble 3). Tble 3. Averge ozone levels nd percentge of ozone penetrtion (bsed on the verge level in the room) for the entire storge period inside the different types of pckges. Pckging system Ozone levels (ppm, v/v) Ozone penetrtion (%) Crton (nked) RPC (nked) RPC (bgged) Mster (bgged) Ozone penetrtion ws relted to the vented re of ech pckge (Tble 1), indicting tht the gs ws not ble to go through corrugted fiberbord crton or polyethylene bgs. Ozone penetrtion ws cceptble only in RPC boxes with nked fruit (82%, Tble 3). On the other hnd, the position of the box on the pllet lso influenced the ozone concentrtion; ozone

4 Pge 4 Centrl Vlley Posthrvest Newsletter levels inside mid-plced crton were in generl lower thn inside top-plced crton (chnnel 3 vs. chnnel 5, Tble 2). Sporultion of both P. digittum nd P. itlicum ws significntly inhibited by ozone exposure on ornges pcked nked in RPC boxes, but it ws not on ornges pcked following the other pckging methods (Fig. 1). According to the percentges of ozone penetrtion inside the pckges (Tble 3), this result confirmed the need for good penetrtion nd full contct to the decyed re on the fruit for ozone gs to be effective in controlling sporultion. Conclusions Gseous ozone continuously generted in cold storge room t rtes rnging 0.5 to 1 ppm (v/v) effectively penetrted nd controlled sporultion of both P. digittum nd P. itlicum on ornges pcked nked in RPC boxes. The gs ws not ble to penetrte properly through corrugted fiberbord crton or polyethylene bgs. Therefore, it ws not ble to control sporultion on ornges pcked in stndrd crtons, Mster crtons, or plstic bgs. Effective control of sporultion relied on ctul physicl contct between the gs nd the decyed re of the fruit. References Plou, L., Crisosto, C. H., Smilnick, J. L., Adskveg, J. E., nd Zoffoli, J. P Evlution of the effect of ozone exposure on decy development nd fruit physiologicl behvior. Act Hort. 553: Sporultion index (score) Plou, L., Smilnick, J. L., Crisosto, C. H., nd Mnsour, M. 2001b. Effect of gseous ozone exposure on the development of green nd blue molds on cold stored citrus fruit. Plnt Dis. 85: Plou, L., Crisosto, C. H., Smilnick, J. L., Adskveg, J. E., nd Zoffoli, J. P Effects of continuous 0.3 ppm ozone exposure on decy development nd physiologicl responses of peches nd tble grpes in cold storge. Posthrvest Biol. Technol. 24: Control Ozone b b Crton (nked) RPC (nked) RPC (bgged) Mster (bgged) Pckging system Green mold No dt Blue mold Fig. 1. Sporultion index on Lne lte ornges rtificilly inoculted with Penicillium digittum or P. itlicum, pcked following different pckging systems, nd stored t 55ºF for 13 dys in n ir tmosphere (control) or in n ozonted tmosphere (0.5-1 ppm O 3 v/v). Within pckging systems, columns with the sme letter re not significntly different ccording to Fisher s Protected LSD test (P < 0.05) pplied fter n nlysis of vrince to the squre root trnsformed dt. Non-trnsformed mens re shown.

5 Centrl Vlley Posthrvest News Pge 5 EVALUATION OF THE EFFECT OF OZONE EXPOSURE ON DECAY DEVELOPMENT AND FRUIT PHYSIOLOGICAL BEHAVIOR L. Plou 1, C. H. Crisosto 1, J. L. Smilnick 2, J. E. Adskveg 3 nd J. P. Zoffoli 4 1 Dept. of Pomology, University of Cliforni, Dvis, CA 95616, USA; 2 Horticulturl Crops Reserch Lbortory USDA-ARS, Fresno, CA 93727, USA; 3 Dept. of Plnt Pthology, University of Cliforni, Riverside, CA 92521, USA; 4 Dept. de Fruticultur, Universidd Ctólic de Chile, Csill , Sntigo, Chile Proc. 4th Int. Conf. on Posthrvest Eds. R. Ben-Arie & S. Philosoph-Hds Act Hort. 553, ISHS Keywords: ornge, pech, grpe, ethylene, respirtion Introduction Since the declrtion of GRAS sttus (Generlly Recognized As Sfe) for ozone in the United Sttes in 1997, interest in developing ozone pplictions in the food industry hs incresed. Mterils nd methods Artificilly inoculted ornges, peches, nd tble grpes were stored t 5ºC nd 90% RH under 0 (control room) or 0.3 ppm ozone (OSHA short-term exposure limit). Decy incidence nd severity, nd externl disese ppernce, s well s the number of infected berries round the inoculted berry were checked weekly. Respirtion nd ethylene production of O Henry peches, previously stored for 1, 2, nd 3 weeks t 5ºC nd 90% RH under ozone free or 0.3 ppm ozone, were mesured dily during 5-dy softening period t 20ºC nd 90% RH. Individully weighed Zee Ldy peches were stored for 6 weeks t 5ºC nd 90% RH under 0 or 0.3 ppm ozone. Weight loss ws recorded weekly. Results nd discussion Ozone t 0.3 ppm did not ffect decy incidence or severity on rtificilly inoculted Elegnt Ldy peches during 4 weeks storge t 5ºC, except for brown rot, cused by Monilini fructicol (Tble 1). Ozone exposure t 5ºC ltered norml mycelium growth nd inhibited sporultion. Norml mycelium growth resumed fter ozone exposure. The incidence of citrus green nd blue molds, cused by Penicillium digittum nd P. itlicum, respectively, on inoculted Vlenci ornges ws significntly delyed by 1 week under 0.3 ppm ozone t 5ºC (Fig. 1). Ozone exposure prevented the sporultion of both pthogens. Ozone t 0.3 ppm eliminted gry mold (Botrytis cinere) nest formtion on Thompson Seedless tble grpes stored for 7 weeks t 5ºC (Fig. 2). Pech respirtion nd ethylene production were not ffected by 3 weeks ozone exposure (0.3 ppm). After 4 weeks exposure to 0.3 ppm ozone, peches becme more susceptible to wter loss (dt not shown). Conclusions The lck of nesting nd soilge could hve n economic impct on bin stored fruit. Ozone tretment could reduce the prolifertion of fungicide-resistnt strins. Ozone t 0.3 ppm did not prevent decy of rtificilly inoculted fruits. Diseses developing on fruit infected by wound pthogens in the field would be difficult to control using ozone in ir during storge.

6 Pge 6 Centrl Vlley Posthrvest Newsletter Tble 1. Influence of ozone exposure (0.3 ppm) on disese incidence nd severity on rtificilly inoculted Elegnt Ldy peches stored t 5ºC nd 90% RH. Storge period (dys) Pthogen Tretment x Incidence y Severity z Incidence Severity Incidence Severity (%) (mm 2 ) (%) (mm 2 ) (%) (mm 2 ) Monilini fructicol Control Ozone 28.7 b 14.9 b b b Botrytis cinere Control Ozone Mucor piriformis Control Ozone b Penicillium expnsum Control Ozone x For ech pthogen, vlues within columns followed by unlike letters re different ccording to Fisher s protected LSD test (P = 0.05). y Incidence dt were trnsformed to the rcsine of the squre root of the proportion of infected fruits before the nlysis of vrince. Actul dt re shown. z Lesion re. Fig. 1. Citrus green nd blue mold incidence (brs) nd severity (lines) on rtificilly inoculted Vlenci ornges stored for 4 weeks t 5ºC nd 90% RH under 0 (ir) or 0.3 ppm ozone. Fig. 2. Proportion of infected berries surrounding one berry inoculted with B. cinere in clusters of Thompson Seedless tble grpes stored t 5ºC nd 90% RH under 0 (ir) or 0.3 ppm ozone.

7 Centrl Vlley Posthrvest News Pge 7 Abstrcts From Posthrvest Biology nd Technology Vol. 24: EFFECTS OF CONTINUOUS 0.3 PPM OZONE EXPOSURE ON DECAY DEVELOPMENT AND PHYSIOLOGICAL RESPONSES OF PEACHES AND TABLE GRAPES IN COLD STORAGE Lluís Plou, Crlos H. Crisosto, Joseph L. Smilnick b, Jmes E. Adskveg c nd Jun P. Zoffoli d Deprtment of Pomology, University of Cliforni, Dvis, Kerney Agriculturl Center, 9240 South Riverbend Ave., Prlier, CA 93648, USA b Horticulturl Crops Reserch Lbortory, USDA-ARS, 2021 South Pech Ave., Fresno, CA 93727, USA c Deprtment of Plnt Pthology, University of Cliforni, Riverside, CA 92521, USA d Fcultd de Agronomí, Pontifici Universidd Ctólic de Chile, Csill , Sntigo, Chile Continuous ozone exposure t 0.3 ppm (v/v) (US-OSHA Threshold Limit Vlue for short term exposure) inhibited eril mycelil growth nd sporultion on Elegnt Ldy peches wound inoculted with Monilini fructicol, Botrytis cinere, Mucor piriformis, or Penicillium expnsum nd stored for 4 weeks t 5 C nd 90% reltive humidity (RH). Aeril growth nd sporultion, however, resumed fterwrd in mbient tmospheres. Ozone exposure did not significntly reduce the incidence nd severity of decy cused by these fungi with the exception of brown rot. Gry mold nesting mong Thompson Seedless tble grpes ws completely inhibited under 0.3 ppm ozone when fruit were stored for 7 weeks t 5 C. Gry mold incidence, however, ws not significntly reduced in spry inoculted fruit. Continuous ozone exposure t 0.3 ppm incresed wter loss fter 5 weeks of storge t 5 C nd 90% RH in Zee Ldy peches but not fter 4 weeks of storge in Flme Seedless grpes. Respirtion nd ethylene production rtes of O'Henry peches were not ffected by previous exposure to 0.3 ppm ozone. In every test, no phytotoxic injuries of fruit tissues were observed in ozonted or mbient tmosphere tretments. From Plnt Disese Vol. 85(6): EFFECT OF GASEOUS OZONE EXPOSURE ON THE DEVELOPMENT OF GREEN AND BLUE MOLDS ON COLD STORED CITRUS FRUIT L. Plou, J. L. Smilnick, C. H. Crisosto, nd M. Mnsour The effects of gseous ozone exposure on in vitro growth of Penicillium digittum nd Penicillium itlicum nd development of posthrvest green nd blue molds on rtificilly inoculted citrus fruit were evluted. Vlenci ornges were continuously exposed to 0.3 ± 0.05 ppm (vol/vol) ozone t 5 C for 4 weeks. Eurek lemons were exposed to n intermittent dynight ozone cycle (0.3 ± 0.01 ppm ozone only t night) in commercil cold storge room t 4.5 C for 9 weeks. Both ornges nd lemons were continuously exposed to 1.0 ± 0.05 ppm ozone t 10 C in n export continer for 2 weeks. Exposure to ozone did not reduce finl incidence of green or blue mold, lthough incidence of both diseses ws delyed bout 1 week nd infections developed more slowly under ozone. Sporultion ws prevented or reduced by gseous ozone without noticeble ozone phytotoxicity to the fruit. A synergistic effect between ozone exposure nd low temperture ws observed for prevention of sporultion. The prolifertion of spores of fungicide-resistnt strins of these pthogens, which often develop during storge, my be delyed, presumbly prolonging the useful life of

8 Pge 8 Centrl Vlley Posthrvest Newsletter posthrvest fungicides. In vitro rdil growth of P. itlicum, but not of P. digittum, during 5- dy incubtion period t 20 C ws significntly reduced by previous 0.3 ± 0.05 ppm ozone exposure t 5 C for 4 dys. Inoculum density did not influence the effect of gseous ozone on decy incidence or severity on ornges exposed to 0.3 ± 0.05 ppm ozone t 20 C for 1 week. Susceptibility of ornges to decy ws not ffected by previous continuous exposure to 0.3 ± 0.05 ppm ozone t 20 C for 1 week. A coron dischrge ozone genertor ws effective in bting ethylene in n empty export continer. From Levnt Agricol, Especil Postcosech COLD STORAGE OF CITRUS UNDER OZONE ENVIRONMENT: EFFECT ON POSTHARVEST DISEASES Lluis Plou 1, Joseph L. Smilnick 2, nd Crlos H. Crisosto 3 1 Deprtmento de Postcosech, Instituto Vlencino de Investigciones Agrris (IVIA), Aprtdo Oficil, Mondd, Vlenci. Emil: lluis.plou@ivi.es 2 USDA-ARS, Sn Joquin Vlley Agriculturl Sciences Center 3 Deprtment of Pomology, University of Cliforni, Dvis. Kerney Agriculturl Center Before the growing interest of the Spnish citrus industry in the exposure of cold-stored fruit to ozone gs, results of recent reserch conducted in Cliforni re presented in this pper. Reserch focused on the effect of gseous ozone exposure on the incidence nd development of the most importnt citrus posthrvest diseses in our conditions, nmely green nd blue molds, cused respectively by Penicillium digittum nd P. itlicum. Ozone in ir ws not ble to control infections estblished within the rind of the fruit. Therefore, it cnnot substitute the tretments with synthetic fungicides tht re currently pplied in drenchers or pckinglines. Continuous or intermittent exposure to ozone t 0.3 ppm (current Threshold Limit Vlue-Short Term Exposure Limit (TLV-STEL) estblished by the US Occuptionl Sfety nd Helth Administrtion) ws not phytotoxic to the fruit nd gretly inhibited eril mycelil growth nd sporultion on rticicilly inoculted ornges nd lemons stored t low temperture (4-5 C). As consequence of this prevention of sporultion, pthogenicl inoculum lod in the pckinghouses nd prolifertion of spores of fungicide-resistnt strins of the pthogens could be reduced. However, since ozone gs ws not ble to penetrte through fiberbord crtons or plstic bgs, its prcticl use during fruit storge is limited to highly vented pckges such s field bins, open-top continers, or returnble plstic continers. Becuse of its extremely high oxidizing power, ozone my be hrmful to humns, phytotoxic to fruit, nd corrosive to numerous common mterils. Therefore, when generting system is implemented, doption of sfety mens nd monitoring nd control of ctul ozone concentrtions inside the cold storge rooms re very importnt issues to consider. From Ozone Science nd Engineering Vol. 24: IMPACT OF OZONATED WATER ON THE QUALITY AND SHELF-LIFE OF FRESH CITRUS FRUIT, STONE FRUIT AND TABLE GRAPES J. L. Smilnick, D. M. Mrgosn, nd F. Mlikot-Gbler Interpretive Summry: Fungi tht rot the fruit re problem nd must be controlled in order to effectively store nd mrket the fruit. Ozone tretment did not control the most troublesome rot fungi on citrus fruit, peches nd nectrines, or tble grpes. At very high doses, ozone did prtilly control rot on peches nd tble grpes, but these doses cused injury to the

9 Centrl Vlley Posthrvest News Pge 9 fruit. The brief immersion of these fruit in ozonted wter does not pper to be promising pproch to mnge rot problems. Technicl Abstrct: Spores of fungi tht cuse posthrvest decy of fresh fruit die rpidly in ozonted wter. We determined the impct of sporocidl or higher O 3 doses on fruit shelf-life & qulity. Fruit were plced in stinless steel bskets immersed in 1.5 to 10 ppm O 3, dried in ir, nd exmined fter storge. O 3 concentrtion did not chnge during tests. Green mold nd sour rot on citrus fruit, cused by Penicillium digittum nd Geotrichum citri urntii, respectively, were not reduced by 20 min immersion in 10 ppm O 3. These fungi infect through wounds; their spores were plced in shllow wounds (1 mm wide x 2 mm deep) 24 hr before tretment. On five pech vrieties, the verge nturl incidence of brown rot, cused by Monilini fructicol, ws reduced from 10.9 to 5.4% by 1 min immersion in 1.5 ppm O 3. A tretment of 15 min with 5 ppm O 3 further reduced decy to 1.7%, but consistent control of brown rot ws ssocited only with this severe tretment nd it cused shllow pits on the fruit. Brown rot cused by spores plced in wounds before tretment ws rot controlled. Immersion for 1 or 5 min in 5 ppm O 3 reduced nturl erobic bcteri popultions by 1.1 nd 1.6 log 10 units, respectively, nd yest nd filmentous fungl popultions by 0.7 nd 1.3 log 10 units, respectively. Spores of Botrytis cinere, cuse of gry mold, were spryed on tble grpe clusters, the clusters were dried, then immersed for 1 to 6 min in 10 ppm O 3. In two tests, immersion for 1 min in O 3 reduced gry mold from 35% mong untreted grpes to bout 10%, while in two other tests, the incidence ws only reduced from 35 to 26%. Minor injury to the rchis of Crimson Seedless grpes occurred t high O 3 rtes. In conclusion, immersion in ozonted wter did not control posthrvest decy of citrus fruit, injured peches nd nectrines t doses tht relibly controlled decy. DR. CRISOSTO S OZONE PUBLICATIONS Plou, Lluis, Crlos H. Crisosto, Dvid Grner, nd Lis M. Bsinl Effect of continuous exposure to exogenous ethylene during cold storge on posthrvest decy development nd qulity ttributes of stone fruits nd tble grpes. Posthrvest Biology nd Technology 27: Plou, L., J.L. Smilnick, C.H. Crisosto, M. Mnsour, nd P. Plz Ozone gs penetrtion nd control of the sporultion of Penicillium digittum nd Penicillium itlicum within commercil pckges of ornges during storge. Crop Protection 22: Plou, Lluis, Crlos H. Crisosto, Joseph L. Smilnick, Jmes E. Adskveg, nd Jun P. Zoffoli Effects of continuous 0.3 ppm ozone exposure on decy development nd physiologicl responses of peches nd tble grpes in cold storge. Posthrvest Biology nd Technology 24: Plou, Lluis, Joseph L. Smilnick, Crlos H. Crisosto, nd Monir Mnsour Effect of gseous ozone exposure on the development of green nd blue molds on cold stored citrus fruit. Plnt Disese 85(6): Plou, Lluis, Joseph L. Smilnick, Crlos H. Crisosto, nd Monir Mnsour Effect of gseous ozone exposure on the development of green nd blue molds on cold storge citrus fruit. Centrl Vlley Posthrvest Newsletter 10(2):2-3. Plou, Lluis, Crlos H. Crisosto, Joseph L. Smilnick, Jmes A. Adskveg, nd Jun P. Zoffoli Effects of continuous 0.3 ppm ozone exposure on decy development nd physiologicl responses of peches nd tble grpes in cold storge. Centrl Vlley Posthrvest Newsletter 10(2):2. Plou, Lluis, Joseph L. Smilnick, Crlos H. Crisosto, nd Monir Mnsour Effect of gseous ozone exposure on the development of green nd blue molds on cold storge citrus fruit. Centrl Vlley Posthrvest Newsletter 10(2):2-3. Plou Lluis, C.H. Crisosto, J.L. Smilnick, J.E. Adskveg, nd J.P. Zoffoli Evlution of the effect of ozone exposure on decy development nd fruit physiologicl behvior. Proceedings 4 th Interntionl Conference on Posthrvest. Act Horticulture 553:

10 Pge 10 Centrl Vlley Posthrvest Newsletter Crisosto, Crlos H., Dvid Grner, Joe Smilnick, nd Jun Pblo Zoffoli Ability of the oxtomcv ozone genertor to reduce ethylene levels. Perishbles Hndling Qurterly 103: Crisosto, Crlos H., Dvid Grner, Joe Smilnick, nd Jun Pblo Zoffoli Ability of the oxtomcv ozone genertor to reduce ethylene levels in n export continer. Centrl Vlley Posthrvest Newsletter 9(2):7-8. FUTURE DATES 2005 Vriety Disply nd Reserch Updte Seminrs t the Kerney Agriculturl Center. Mrk your clendrs for these dtes: Fridy, June 3 Fridy, July 1 Fridy, August 12 8:00 9:00.m.: Vriety disply by stone fruit nurseries, breeders nd the USDA; 9:00 10:00.m.: Reserch Updte Topics (For exmple: Nutrient deficiencies, Dwrfing & semidwrfing rootstocks, Keeping trees short, IPM updtes, Irrigtion mngement nd wter stress). For more informtion cll: Scott Johnson (559) ; Kevin Dy (559) , Ext. 211; Hrry Andris (559) ; Brent Holtz (559) , Ext. 209; or Bob Beede (559) , Ext