Lef Removl s Influence on Pinot Noir Bsl lef removl chnges chemicl nd voltile compositions By Hui Feng, Fng Yun, Ptrici A. Skinkis nd Michel C. Qin Cluster-zone lef removl refers to delierte removl of selected leves round grpe clusters. It hs een widely used in the vineyrds of cool-climte viticulturl regions to improve ir circultion nd sunlight exposure s well s decrese disese pressure. 1,44,56 Cnopy microclimte is importnt in determining fruit nd wine qulity. 18,55 A dense cnopy with indequte sunlight exposure cn result in poor-qulity grpes. 34 On the contrry, sunlight-exposed grpes re generlly higher in totl solule solids, nthocynins nd phenolics nd lower in titrtle cidity nd mlte compred to shded fruit lthough climte conditions my hve n importnt impct. 7,21,22 Overexposure to sunlight lso leds to greter thn optiml erry temperture, resulting in fruit sunurn nd inhiition of color development. 52 Therefore, determining pproprite levels of lef removl for optimum sunlight exposure is importnt for producers to consider when mnging vines to yield high-qulity grpes. Grpe-derived voltile secondry metolites ply importnt roles in fruit nd wine rom qulity, since they reflect the prticulr vriety, vineyrd, regionl climte nd soil type. 41 Only smll portion of grpe voltile compounds re present in their free forms, nd the mjority exist in non-voltile, glycosidiclly ound forms or other precursor forms. 16,59 However, these non-voltile precursors cn e converted to the voltile form through enzymtic or chemicl hydrolysis during vinifiction nd ging, thus contriuting to wine rom. 16,28,29 Little reserch hs een done on voltile composition with lef removl in red grpe cultivrs. Mny studies investigted the influence of lef removl on grpe-derived terpenoids of white grpe vrieties; however, results re still inconclusive. For exmple, in reserch conducted in British Columi (Cnd), sl lef removl incresed oth free- nd oundform terpenoids in Gewürztrminer grpes. 44 However, reserch on Riesling hs shown only increses in ound-form terpenoids with lef removl. 45,64 Conversely, in centrl Europe, wine mde from Riesling grpes grown with lef removl showed no differences in free nd ound forms of terpenoids compred to those with no lef removl, while increses in freend ound-form terpenoids were oserved in Suvignon Blnc wine y lef removl. 24 Conflicting results my e due to vineyrd loction, sesonl climte, cultivr, rootstock, timing nd severity of lef removl. The effects of lef removl on grpe-derived C 13 -norisoprenoids hve not een sufficiently studied. C 13 -norisoprenoids constitute n importnt prt of the voltile compounds of neutrl type grpes such s Cernet Suvignon, 3 Syrh, 39 Suvignon Blnc 3 nd Pinot Noir. 12 These compounds cn e formed y direct degrdtion of crotenoids, or they cn e stored s glycoconjugtes tht relese their voltile glycone during fermenttion vi enzymtic nd cid hydrolysis processes. 2,5,59 Sunlight exposure hs een speculted to influence levels of C 13 -norisoprenoid in grpes. R. Ristic et l. reported tht fter cid hydrolysis, Shirz wine mde from shded fruit hd decresed levels of β-dmscenone nd 1,1,6-trimethyl-1,2-dihydronphthlene (TDN) compred to those mde from typiclly exposed fruit. 46 Other reserch hs reported either n increse or no chnge of β-dmscenone in shded grpes. 25,27 Fruit-zone shding is concern in the Pinot Noir vineyrds of Oregon s Willmette Vlley due to the high vegettive growth common in the region. Excessive vine growth results from the region s mple winter nd spring rinfll comined with the high wter-holding cpcity of soils. Therefore, sl lef removl is commonly pplied post-fruit set in vineyrds throughout the region. However, it is uncler wht level of lef removl is required to chieve optiml qulity. A three-yer study ws designed 5 WINES&VINES June 216
PRACTICAL WINERY & VINEYARD GRAPEGROWING to investigte vrying intensities of sl lef removl on Pinot Noir grpe qulity with focus on voltile compounds nd their precursors. Mterils nd methods Vineyrd experimentl design A lef-removl tril ws conducted from 21 to 212 in two vineyrds locted in Oregon s Willmette Vlley. In 21, the tril ws conducted t commercil vineyrd in Dyton, Ore. The vineyrd ws plnted in 1995 to vine density of 2,489 vines per cre with Pinot Noir clone 115 grfted to 339C rootstock. The vine rows re oriented north-south with trctor row y vine spcing of 1 meter y 1.5 meters. In 211 nd 212, the tril ws conducted t Oregon Stte University s Woodhll Reserch Vineyrd in Alpine, Ore. This vineyrd ws plnted in 26 to vine density of 1,383 vines per cre with Pinot Noir clone Pommrd grfted to 11-14 rootstock. The vine rows re oriented north-south with trctor row y vine spcing of 1.4 meters y 2.1 meters. Both vineyrds were cne-pruned to ilterl Guyot system nd verticlly shoot-positioned. Stndrd vineyrd-mngement prctices including pest nd cnopy mngement were performed ech yer with the exception of lef removl. Bsl leves were removed from vines with four different intensities. Tretments included: 1) % lef removl; 2) 5% lef removl, where every other lef long the shoot ws removed strting t the sl node nd working up to the node ove the top-most cluster; 3) industry stndrd (IS) lef removl, where only leves tht covered the clusters on the estern (morning sun) side of the vine cnopy were removed, nd 4) 1% of leves removed from oth the est nd west side of the cluster zone, strting from the se of the shoot up to the node ove the top-most cluster. The IS tretment ws evluted in 211 nd 212 to compre tretments with commercil prctices in vineyrds. Lef removl ws imposed t one point in the growing process, the pe-sized stge of erry development, on six-vine plots in rndomized complete lock design with five field replictes. At the time of lef removl in the 1%, 5% nd IS tretments, ll lterl shoots in the cluster zone were removed. Wether dt Wether dt were collected onsite for ech growing seson. Dt for dily temperture were logged nd used to clculte growing degree-dys nd the men dily temperture. Growing degree-dy (GDD 5 ) units were clculted using the dily men of T mx nd T min with minimum threshold of 5 F nd no mximum threshold pplied. Dily precipittion ws recorded for ech growing seson. Vine growth nd cluster exposure Cnopy size nd density, photosyntheticlly ctive rdition, yield nd dormnt pruning weights were mesured nnully. In 21, the mount of leves removed were determined y collecting ll primry nd lterl leves removed during tretment ppliction, ringing them to the l nd scnning them on lef-re meter. In 211 nd 212, more detiled lef-re quntifiction ws conducted. Lef res were mesured fter tretment ppliction nd t vérison. After pplying lef-removl tretments, oth totl lef re removed nd remining on the vine were mesured using non-destructive quntifiction method descried in Schreiner et l. 48 The percentge of lef re removed ws clculted nd compred etween lef removl tretments. Vine lef re ws quntified t vérison ech yer (21, 211, 212) using the nondestructive templte method descried ove. The templte ws used to mesure ll leves on one rndomly selected shoot from ech of the six experimentl vines per plot. The shoot lef re ws multiplied y shoot count to clculte whole vine lef re. Incident light in the cluster zone ws quntified shortly fter vérison, in the erly ripening stges, ech yer on cler, cloudless dy y using LP-8 ceptometer. This device mesures photosyntheticlly ctive rdition (PAR), nd it ws quntified t 1.m., solr noon nd 2:3 p.m. y plcing the sensor rod prllel to the vine row t the height of the cluster zone on the est nd west side of north-south-oriented vine rows. Three mesures were tken with the ceptometer long the plot length on ech side of the cnopy. Lef re index (LAI), mesure of cnopy density, ws quntified using the ceptometer. At vérison, the ceptometer ws plced ove the cluster zone nd prllel with the vine row to mesure the density of the cnopy ove the clusters. A totl of three mesures were tken long the length of ech six-vine plot. At hrvest, whole-vine yield ws quntified on three rndomly selected vines per plot. In the dormnt period tht followed ech growing seson, one-yer-old dormnt cnes were pruned off nd weighed. The pruning weight nd yield dt were used to clculte vine lnce (yield per vine divided y pruning weight per vine). Determintion of grpe chemicl composition Anlysis of grpe mturity prmeters t hrvest A seven-cluster smple ws rndomly selected from grpes hrvested from ech plot, trnsported to the l nd kept cool (42.8 F) until nlysis. All clusters were mesured for cluster size metrics (cluster weight, erry weight nd erries per cluster). The erries from the sevencluster smple were pressed to juice to mesure totl solule solids (TSS), ph nd titrtle cidity y titrtion. 63 A suset of hrvested clusters were trnsported to the l nd immeditely frozen t -176 BASIC FRUIT MATURITY AT HARVEST RELATIVE TO LEAF REMOVAL Yer Tretment TSS (Brix) ph TA (g/l) 21 (Dyton, Ore.) 212 (Alpine, Ore.) None 2.9 3.14 1.1 5% 2.4 3.8 1. 1% 2.3 3.9 1.2 p n.s..362 n.s. None 19.8 3.5 9.9 5% 19.9 3.6 9.6 1% 19.4 3. 1.1 p n.s. n.s. n.s. IS 25. 3.21 8. None 25.3 3.27 7.8 5% 25.1 3.24 7.7 1% 25.1 3.19 7.7 p n.s. n.s. n.s. Mens re presented (n=5); different letters indicte difference in mens etween tretments using Tukey HSD men seprtion t α=.5.; n.s.: indictes no sttisticl differences. : TA refers to titrtle cidity shown in g/l of trtric cid equivlents. Lef removl tretments include the following: None (no lef removl), 1% (ll leves in the cluster zone removed), 5% (hlf of the leves in the cluster zone removed) nd IS (industry stndrd where leves re only removed in the cluster zone on the est side of the cnopy). June 216 WINES&VINES 51
% Amient PAR CLUSTER ZONE SUNLIGHT EXPOSURE 7 6 5 4 3 2 1 7 6 5 4 3 2 1 7 6 5 4 3 2 1 1.m. Solr noon 2:3 p.m. 21 211 c 212 c c 1% 5% IS None 1% 5% IS None 1% 5% IS None Percent of mient photosyntheticlly ctive rdition received in the cluster zone t 1.m., solr noon nd 2:3 p.m. in 21, 211 nd 212. Tretments include ll cluster zone leves removed (1%), hlf of ll cluster zone leves removed (5%), industry stndrd with est-side only leves removed (IS), nd no leves removed from the cluster zone (None). Different letters ove error rs indictes difference in mens etween tretments using Tukey HSD men seprtion t =.5. 52 WINES&VINES June 216 F. After two dys, the grpes were mnully destemmed while frozen. Berries from different clusters were pooled nd seled in storge gs for ech field-replicte respectively nd stored t -8 C until nlysis of secondry metolites. Results nd discussion Wether nd vine performnce Wether conditions: Wether dt vried etween yers nd the two tril sites. Focus ws plced on sesonl wether comprisons of the Alpine vineyrd, s the tril ws replicted t tht site for two yers. The 211 seson ws cooler thn 212, with men dily tempertures eing.36 F cooler in 211 nd het unit ccumultion 63 GDD 5 lower thn in 212. Precipittion in the 211 growing seson ws more thn doule tht of 212. Consistent with the different wether conditions, vine phenologicl development exhiited temporl vrition etween yers nd sites. The numer of dys etween ud rek nd hrvest ws nerly two weeks longer t the Dyton site (21) thn t the Alpine site in 211 nd 212. At the Alpine site, wrmer tempertures nd less precipittion in 212 led to dvnced fruit ripening nd n erlier hrvest compred to 211. In 212, fruit reched out 25 Brix t 39 dys post-vérison, while fruit reched out 2 Brix t 45 dys post-vérison in 211. (See tle Bsic Fruit Mturity t Hrvest Reltive to Lef Removl on pge 51.) Vines were delyed in development in 211 due to cool spring nd summer, nd fruit ws not llowed to remin on the vine s long to chieve higher TSS. Vine growth: No differences were found in the numer of shoots nd clusters per vine, yield or cluster weight reltive to lef-removl tretments within ech yer. This is to e expected, s vines were mnged to typicl commercil stndrds with stndrdized numer of uds per vine t pruning, nd shoot nd cluster thinning prctices resulted in uniform shoot nd cluster counts in the vineyrd. Lef-removl tretments effectively resulted in different mounts of leves removed from the cluster zone. In 21, the 1% lef removl hd 641 cm 2 more lef re per vine removed thn the 5% lef removl tretment (p =.181), for totl of seven more leves removed per vine. More sl leves were removed in the 1% tretment thn the 5% nd IS tretments in 211 (p<.1) nd 212 (p=.4). The 1% lef-removl tretment removed 25% to 27% of leves per vine when tretments were pplied in 211 nd 212, respectively. The 5% nd IS tretments hd similr lef re removed (15% to 16%) in 211 nd 212. Despite differences in the mount of leves removed, wholevine lef re did not differ y tretment when mesured t vérison in 21 or 211. This is likely ecuse the mount of leves removed t the pe-size stge is only smll frction of the totl lef re present on the vine t vérison, since grpevine cnopies continue to grow in shoot length nd lterl shoot development until vérison. 58 Similrly, S. Poni et l. found no differences in totl lef re lter in the seson, with lef removl conducted pre-loom ecuse of incresed lterl lef shoot growth. 37 There ws minor difference in vine lef re t vérison in 212, with 1% nd IS tretments hving 23% nd 9% less lef re, respectively, thn the control (None). C. Intrieri et l. found differences in totl shoot lef re with lef removl in Sngiovese, ut results were due to differences in lterl lef re, not min shoot lef re. 17 The 212 lterl shoot numer differed y tretment (p =.129), with the 1% tretment hving fewer lterl shoots nd the smllest totl lef re. It is possile tht the differences in lef re etween 211 nd 212 were due to the differences in precipittion from loom to vérison, with.3 inches in 212 compred to 5.7 inches in 211. Bsl lef removl tretments in this study did not remove enough leves to compromise vine function, s yield, pruning weights
PRACTICAL WINERY & VINEYARD GRAPEGROWING nd crop lod (yield weight:pruning weight) were not different in ny yer tht they were mesured. When similr timing nd severity of lef removl tretments were pplied y S. Stff et l., yield nd pruning weights were reduced in 5% nd 1% lef-removl tretments compred to no lef removl due to lck of shoot growth t the time of lef removl. 53 In studies where lef removl hs ltered vine growth, the tretments were pplied in erlier growth stges such s pre-loom nd/ or hd more significnt lef re removed, therey ffecting vine crohydrte ssimiltion nd physiologicl development. 1,37,57 As long s lef removl is pplied post-fruit set with only sl leves removed, studies hve shown no effect on vine yield, pruning weights or crop lod. 26 Cluster exposure: Lef removl effectively ltered the percent of mient PAR mesured in the cluster zone t 1.m. (21 nd 211) nd 2:3 p.m. (ll three yers), ut there ws no effect t solr noon. The percent of PAR ws highest in vines with 1% lef removl (p<.1), nd the vines with 5% nd IS lef removl hd similr levels of PAR (see Cluster Zone Sunlight Exposure on pge 52). The lck of difference in incident light mesured in the cluster zone t solr noon ws One-hundred percent of leves re removed from the cluster zone (ove), strting from the se of the shoot up to the node ove the top-most cluster. expected nd is in greement with other reserch conducted on verticlly shoot-positioned cnopies, since the sun is positioned directly overhed, cusing lockge of light to the fruit zone y the wll of cnopy. 38 Grpe chemicl composition Fruit mturity prmeters: When compring A R C H I T E C T U R E D E S I G N P L A N N I N G M A N A G E M E N T TTB LABEL APPROVALS Low per-lel costs Gov t. Liison Negotitions or Footwork Resonle Hourly Rtes TRADEMARK SEARCHES As Low s $185 Your trde nmes or designs re serched t the U.S. Ptent Office to help estlish vlule ownership or void costly legl liility. Over 1 yers totl stff experience hndling every government liison need for industry. Phone or write for detils. PATTY SKINKIS www.strtp.com 7 7. 9 3 5. 7 9 4 4 2 N. Glee Rd., Suite 321 Arlington, Virgini 2223 Phone: (73) 524-82 Fx: 525-8451 TOLL-FREE 1-8-642-6564 Mjor Credit Crds Accepted www.trdemrkinfo.com Since 1957 June 216 WINES&VINES 53
fruit mturity prmeters t hrvest, lef removl did not ffect TSS or TA in ny yer, nd ph ws decresed in only one yer (21) (see tle on pge 51). The lck of difference in fruit mturity ws nticipted, s there were no differences in vine yield in ny yer, nd there ws no difference in cnopy lef re in two out of three yers. There ws likely sufficient lef re to support fruit development nd ripening in ll three yers. Our findings re in greement with recent studies from oth cool-climte regions 2,21,26 nd wrm-climte regions 5,33,57 where sl lef removl hd little impct on sic mturity. Studies tht hve resulted in erry ripening differences involved more drstic vine defolition, leving too few leves for sufficient crohydrte ssimiltion nd fruit development. 1 Results of cluster nd cnopy exposure studies suggest tht TSS, ph nd TA re influenced more y vine environmentl interction nd crohydrte ssimiltion thn cluster light exposure, while secondry metolite composition is more influenced y cluster, not cnopy exposure. 4,6,19,33,35 Grpe phenolic composition: Five nthocynin glycosides were nlyzed, including delphindin-3-monoglucoside (Dp), cynidin- 3-monoglucoside (Cy), petunidin-3-monoglucoside (Pt), peonidin-3-monoglucoside (Pn) nd mlvidin-3-monoglucoside (Mv). Mv ws the most undnt nthocynin, which is in greement with previous Pinot Noir reserch. 26,34,41 The 1% lef-removl tretment hd consistently higher concentrtions of Pt nd Mv thn the control (%) in 21 nd 212 y n verge of 62% nd 53%, respectively (p<.5). 54 WINES&VINES June 216 LEAF REMOVAL AT STOLLER VINEYARD Stoller Fmily Estte s 194-cre vineyrd includes 12 cres of Pinot Noir nd 54 cres of Chrdonny. According to Stoller vineyrd mnger Ro Schultz, hnd lef removl egins on the estern side of the cnopy s soon s loom hs completed. We will remove leves on the western side postvérison on cloudy dys to void sunurn nd to open the cnopy to llow more ir circultion, Schultz explins. We open the cnopy quite lot, removing ll leves nd lterls in the fruit zone on the estern side of the cnopy. We re le to complete lef removl on ll 194 cres within 2.5 weeks with lrge group of workers. We retin one cluster per shoot. Tht is pretty typicl, though we do lot of work on estimting cluster weights to mke sure we rech our trget yields. Tht, in yers with smller clusters, cn sometimes men more clusters. Leves re pulled on the est-fcing side of the cnopy. Other reserch suggests tht chnges in vine microclimte such s incresed sunlight exposure nd temperture increses nthocynin compounds. 5,23,33,53 Despite difference in cluster exposure nd PAR in 211, there were no differences in ny nthocynins mesured. Other studies hve shown yerly vriility in nthocynin with cluster exposure, nd the difference my e due to temperture nd/or light conditions tht yer. 5,8 Lef removl ffected the level of quercetin glycosides ech yer of the study. The 1% lefremovl tretment consistently hd the highest quercetin glycoside concentrtion in erries compred to % lef removl in ll yers. The IS nd 5% lef-removl tretments hd similr concentrtion of quercetin glycosides s the 1% tretment in 211 nd 212. The concentrtion of quercetin glycosides incresed with incresing cluster exposure nd incresing PAR in ll three yers. Others hve shown incresed quercetin glycosides with cluster exposure. 41,55,53 Quercetin glycosides hve een ssocited with nthocynin polymeriztion in wine nd cn enhnce wine color stility nd qulity. 41 The comined effect of sl lef removl on incresing nthocynins nd quercetin glycosides my llow for oth greter color intensity nd stility in wine ging, potentilly leding to overll enhnced wine qulity. No differences were oserved for the flvn-3-ols, including ctechin nd epictechin, mong lef-removl tretments. These findings re in greement with other reserch on flvn-3-ol monomers of Pinot Noir, 55 Syrh 8 nd Cernet Suvignon grpes. 14 Grpe voltiles nd their precursors C6 compounds: The C 6 lcohols nmely 1-hexnol, trns-2-hexenol, trns-3-hexenol, nd cis-3-hexenol were present in oth free nd ound form. However, the C 6 ldehydes hexnl nd trns-2-hexenl were found in free form only. Lef-removl tretments hd no influence on concentrtion of the C 6 compounds (free nd ound forms) in ny of the three yers. Other reserchers hve linked C 6 compounds with erry mturity, demonstrting decreses in C 6 compounds with incresing fruit mturity. 52,35,37 Since the fruit did not vry in sic ripeness or crop lod, it is understndle why there were no differences in the C 6 compounds t hrvest. Terpenoids: Both free-form nd oundform terpenes were influenced y lef-removl tretments, ut results were vrile y yer nd vineyrd. In 21, 1% lef removl hd 13% nd 1% higher free-form linlool nd gerniol nd 58% to 15% greter ound-form terpenoids, respectively (p<.5), compred to no lef removl. In 211, 1% lef removl resulted in 48% nd 33% greter concentrtions of trns-linlool oxide nd linlool, respectively (p<.5). When three yers of dt were comined, there ws positive correltion etween totl ound-form terpenoid concentrtions nd PAR in the cluster zone (r 2 =.7178, p<.1). Light exposure hs een shown to increse terpenoid concentrtions in grpes, especilly ound-form terpenoids, while free-form terpenoids tend to e less responsive to sunlight exposure. 46,5 Given the incresed incident light exposure y lef removl in this study (see Cluster Zone Sunlight Exposure on pge 52), it cn e hypothesized tht cluster exposure to light medited the ccumultion or iosynthesis of ound-form terpenoids. In 212, lef removl did not influence ound-form terpenoid concentrtions despite differences in cluster zone PAR. The lck of differences my e result of greter fruit ripeness tht yer nd higher sesonl tempertures, potentilly leding to losses to voltility. Other studies hve shown terpenoid concentrtions to vry y differences in temperture cross yers or sites. 45,5 The men dily temperture from vérison to hrvest in 212 ws 1.98 F greter thn 211, nd erries were hrvested t pproximtely 5 Brix higher in 212. Other studies suggest tht more moderte exposure my enhnce voltile rom compound concentrtion. 66 C 13 -norisoprenoids: One of the most importnt C 13 -norisoprenoids for Pinot Noir, β-dmscenone, ws found in oth free nd ound form; ound-form β-dmscenone ws pproximtely1 times higher in concentrtion thn the free form in ll three PATTY SKINKIS
PRACTICAL WINERY & VINEYARD GRAPEGROWING yers (see β-dmscenone Concentrtion in Grpes ). Previous studies proposed tht β-dmscenone in grpes were formed from crotenoid degrdtion, nd insted of forming free-form β-dmscenone, most of the degrdtion products were trnsformed to β-dmscenone glycoside conjugtes which would e relesed chemiclly or enzymticlly during vinifiction nd wine ging. 48,61 The concentrtions of β-dmscenone vried etween yers. Since 21 smples were collected from different vineyrd thn in 211 nd 212, it is not possile to compre s clone, vine ge nd vine growth differences existed etween the sites. However, higher concentrtions of β-dmscenone were oserved in 212 compred to 211 t the Alpine site. This my e due to the difference in erry ripeness nd the wether in those yers, prticulrly tempertures in the ripening phse (see tle on pge 51). The 1% lef-removl tretment hd higher ound-form β-dmscenone thn the no-lef removl tretment in ll three yers β-damascenone CONCENTRATION IN GRAPES A Concentrtion (µg/kg erry) 1..8.6.4.2 n IS n None n 5% n 1% B Concentrtion (µg/kg erry) 1 8 6 4 2 n IS n None n 5% n 1% 21 211 212 21 211 212 Yer Yer Concentrtions of free-form (A) nd ound-form β-dmscenone (B) in Pinot Noir grpes with different vineyrd lef-removl tretments from 21 to 212, nd Men±SD re presented (n=5). Different letters indictes difference in mens etween tretments using Tukey HSD men seprtion t =.5. Lef removl tretments include the following: None (no lef removl), 1% (ll leves in cluster zone removed), 5% (hlf of the leves in cluster zone removed) nd IS (industry stndrd where leves re only removed from the cluster zone on the est side of the cnopy). Gomerg, Fredrikson & Assocites Mrket Reserch For The Wine Industry We perform extensive mrket reserch nd dt collection to crete the wine industry s leding dtses nd reports Products include: The Gomerg-Fredrikson Report: The Executive Mrketing Report of the Wine Industry WineDt Wine Pricing Report: Competitive supplier pricing for more thn 13,4 products Distriutor Mrket Service: Gin competitive dvntge y nlyzing your position in the wholesle mrket www.gfwine.com 77.94.3922 inquiry@gfwine.com The wine industry hs trusted Kennedy/Jenks Consultnts for professionl environmentl engineering services since the 195s. We specilize in providing cost-sving, sustinle solutions to meet winery needs. OUR SERviCES include: Wstewter Wter Supply Storm Wter Solid Wste Fcility Plnning Design Construction Mngement Hzrdous Mterils Wter/Energy Audits Air Emissions nd Odors Regultory Complince Lnd-Use Permitting/CEQA e: BoChrok@KennedyJenks.com t: 415.243.215 www.kennedyjenks.com/wine June 216 WINES&VINES 55
CORRELATION BETWEEN β-damascenone AND CLUSTER ZONE SUNLIGHT EXPOSURE A Concentrtion (µg/kg erry) 1..8.6.4.2 21 212 211 2 4 6 % Amient PAR B Concentrtion (µg/kg erry) 1 8 6 4 2 21 212 211 2 4 6 % Amient PAR Concentrtions of free-form β-dmscenone (A) nd ound-form β-dmscenone (B) in Pinot Noir grpes s function of % mient PAR of cluster zone from 21 to 212. In (A), regression nlysis indicted liner reltionships demonstrted y the equtions s following, in 21 y =.93x +.4339 (r2 =.6384, p<.1), in 211 y =.14x +.816 (r2 =.6712, p<.1), nd in 212 y =.7x +.377 (r2=.647, p<.1). In (B), regression nlysis indicted liner reltionships demonstrted y the equtions s following, in 21 y =.136x + 3.4753 (r2 =.8428, p<.1), in 211 y =.218x +.887 (r2 =.8949, p<.1), nd in 212 y =.269x + 1.1175 (r2 =.735, p<.1). nd free-form β-dmscenone in two of the three yers (p<.5). (See β-dmscenone Concentrtion in Grpes on pge 55.) No other lef-removl tretments hd consistent influence on free- nd ound-form β-dmscenone. When compring light nd fruit composition dt ech yer, positive correltion ws found etween levels of free- nd ound-form β-dmscenone nd PAR in the cluster zone (see Correltion Between β-dmscenone nd Cluster Zone Sunlight Exposure ove) in ll three yers. This provides good evidence for the reltionship of incresed sunlight exposure When compring light nd fruit composition dt ech yer, positive correltion ws found etween levels of freend ound-form ß-dmscenone nd PAR in the cluster zone. on β-dmscenone in this cool climte. Other reserch hs shown n increse in erry norisoprenoid concentrtion with incresing sun exposure of oth red nd white grpe cultivrs, 4,66 lthough other reserchers hve reported no chnge or decrese of β-dmscenone level in sun-exposed grpes. 27,32 The impct is highly dependent on grpe cultivrs or wrmer climte regions. F. Yun nd M.C. Qin studied the crotenoid composition nd the evolution of β-dmscenone in Pinot Noir grpes during 56 WINES&VINES June 216 erry development nd found tht β-dmscenone concentrtion incresed from the erly stge of erry development until hrvest. 13,62 Results of this study suggest tht sl lef removl my e ltering the ccumultion or iosynthesis of primry metolites tht ffect metolite iosynthesis lter in the ripening process. It is generlly ccepted tht crotenoid synthesis strts in the first stge of erry development nd continues until vérison, fter which the compounds degrde to C 13 -norisoprenoid compounds. 2,63 As group of photosynthetic pigments, crotenoids re ffected y environmentl fctors such s sunlight. It hs een reported tht sunlight exposure increses the levels of crotenoids in unripe grpes compred to shded grpes. But in the ripening process, grpes exposed to sunlight show significnt decrese in crotenoids compred to grpes under shde conditions. 4,32,44 The increse of β-dmscenone with lef removl in our study my e relted to either incresed crotenoids vilility, resulting from more ctive photosynthesis in pre-vérison erries or due to post-vérison cluster sunlight exposure tht ccelertes crotenoid degrdtion. 43 This re of study is currently under reserch t the genomic level. 63 Studies tht pir gene function with environmentl fctors will ssist in understnding erry rom enhncement through vineyrd-mngement prctices. Conclusion Cluster-zone lef removl conducted t the pe-size erry stge effectively modified cnopy microclimte (sunlight) nd influenced erry composition. The level of lef removl implemented in this study is fesile for ppliction in commercil vineyrds. The incresed intensity of lef removl (1%) did not reduce vine productivity (cnopy growth or yield) or lter cnopy:yield rtios, oth of which cn influence ripening directly. The gretest lef removl tretment (1%) effectively improved Pinot Noir grpe qulity through the increse of phenolics (nthocynins nd quercetin glycosides) nd grpe-derived voltile compounds nd their precursors (terpenoids nd C 13 -norisoprenoids) without cusing fruit sunurn. Results of this work could help grpegrowers mnge their vine cnopies more effectively to optimize Pinot Noir fruit nd wine qulity in Oregon s cool climte. Dr. Hui Feng is recent grdute of Oregon Stte University in Corvllis, Ore., nd is currently working for E. & J. Gllo Winery. Fng Yn is Ph.D. cndidte studying in the Qin L t OSU. Dr. Michel C. Qin is professor in the Deprtment of Food Science & Technology t OSU. Qin erned chelor s degree in chemistry from Wuhn University of Chin nd mster s degree from the University of Illinois t Urn-Chmpign. He holds Ph.D. from the University of Minnesot nd hs pulished more thn 7 peer-reviewed reserch ppers relted to flvor chemistry. Dr. Ptty Skinkis is viticulture extension specilist nd ssocite professor in the Deprtment of Horticulture t OSU. She holds chelor s degree in horticulture from the University of Wisconsin- River Flls nd Ph.D. in horticulture (viticulture) from Purdue University. She hs worked with the winegrpe industry in Oregon for nine yers, providing pplied reserch nd eduction to meet production needs. This text ws edited from first puliction in Food Chemistry 173 (215) 414-423. The uthors grtefully cknowledge the Northwest Center for Smll Fruits Reserch (NCSFR) for finncil support nd Stoller Fmily Estte Vineyrd for the use of their vineyrd for reserch in 21. The references for this rticle re ville online t winesndvines.com