Field Performance of Six Chardonnay Clones in the Napa Valley

Transcription

1 Field Perfrmance f Six Chardnnay Clnes in the Napa Valley J. A. WOLPERT ~*, A. N. KASIMATIS 2, and E. WEBER 3 Viticultural perfrmance f six certified, virus-tested clnes f Chardnnay frm Fundatin Plant Materials Service (), University f Califrnia, Davis, was determined at tw sites in the Napa Valley. Vine grwth (as weight f ne-year-drmant cane prunings), yield, cluster number, cluster weight, berry weight, and fruit maturity indices ( Brix, titratable acidity, and ph) were measured ver a fur-year perid, 1988 thrugh Perfrmance f clnes was very similar at the tw sites. clnes 6 and 15 had the greatest grwth, abut 3 kg/vine, while 14 had the least grwth, 1.0 kg/vine. Highest yields were seen in 5, 4, and 6 (abut 10.5 t 13 kg/vine), fllwed by 14 and 15 (9 t 10 kg/vine), and last in 16 (abut 4.5 kg/vine). 4 and 5 had the heaviest clusters (mre than 200 g) and 16 the lightest (less than 100 g). 4, 5, and 14 had the greatest numbers f berries/cluster (abut 160) fllwed by 6 with 120, 15 at 110, and 16 at abut had the greatest average berry weight, and 14 had the least. The clnal influence n fruit maturity was nt great, except that the ph f 16 fruit was typically 0.1 t 0.2 units higher than ther clnes. KEY WORDS: Chardnnay, selectin, clne, clnal selectin Chardnnay is recgnized as ne f the finest white winegrape varieties in the wrld. It is the primary variety used in the highly prized French white wines f Burgundy, Chablis, and Champagne. Chardnnay is als grwn in ther Eurpean cuntries and is widely used in Australia, New Zealand, Chile, and U.S. fr prductin f high quality table wines. In Califrnia, Chardnnay was present befre the turn f the century, but was nt widely prduced as a varietal wine. Olm (15) cites Wiley's reprt (20) that n Chardnnay wines frm Califrnia were amng thse entered in the 1900 Paris Expsitin. In a ppular article, Asher (3) traced the histry f the variety, and reprted that nly tw cmmercial Chardnnay vineyards survived Prhibitin. One f these, the Wente Brthers Vineyard in Livermre, was respnsible fr much f the budwd used fr later vineyard expansin in the state. In 1960, Califrnia plantings f Chardnnay were estimated at nly 150 acres (1). Lack f interest in the variety can be attributed in part t the fact that available selectins were ften extrardinarily lw in yield (1 t 2 tns/acre). Gheen (persnal cmmunicatin) determined by field indexing that ne particularly lwyielding selectin was nevertheless free f detectable viruses. Between 1970 and 1980, the Chardnnay acreage in Califrnia quadrupled, increasing frm 2700 t 1Viticulture Extensin Spcialist and 2Specialist Emeritus in the Department f Viticulture & Enlgy, University f Califrnia, Davis, CA 95616; and 3Farm Advisr, University f Califrnia Cperative Extensin, Napa Cunty. *Crrespnding authr. Acknwledgements: Authrs thank E. P. Vilas, Jr. and S. Gallagher fr valuable technical supprt, and acknwledge the assistance f K. Bwers in the establishment f research trials. The superb cperatin f vineyards managers Dug Hill, Jaeger Vineyards, and Jim Frisinger, Drew Jhnsn and Bb Steinhauer, Beringer Vineyards is gratefully acknwledged. The authrs als thank the American Vineyard Fundatin fr financial supprt. Manuscript submitted fr publicatin 2 December Cpyright 1994 by the American Sciety fr Enlgy and Viticulture. All rights reserved. mre than (19). By 1988, it had quadrupled again, reaching acres. By 1992, Califrnia had mre than acres f Chardnnay, placing it first amng all wine cultivars, white r red. The increase is prjected t cntinue and may reach by the year 1997 (16). The dramatic increase in recent years can be attributed in large measure t imprved yields resulting frm successful clnal selectin. H. P. Olm, prfessr in the Department f Viticulture and Enlgy, University f Califrnia, Davis, began clnal selectin f Chardnnay in the late 1950s. Previusly, Luis P. Martini f the Luis M. Martini Winery, St. Helena, Califrnia, had selected clnes frm F. McCrea's Stny Hill vineyard in Napa Cunty, which had riginated as a mass selectin frm Wente Brs. After preliminary experiments in the Martini vineyard, Olm tk advanced selectins t the Oakville Experimental Vineyard f UC Davis. There, he cmpared the Martini selectins t imprted nes: ne clne chsen by Olm in Mersault, France, in 1951, and tw selectins prvided by Prf. M. Sick frm Clmar, France. Olm (unpublished data) reprted that the advanced Martini selectins included in these trials yielded as much as 5 tns per acre, 2 t 3 tns per acre mre than the imprted selectins. Recently, Chardnnay clnal research trials in Australia have shwn (Fundatin Plant Materials Service, University f Califrnia) selectins t be amng the higher yielding clnes tested (8,10,14). The value f clnal selectin had been challenged in Califrnia since the wrk f F. T. Biletti (6) n the variety Muscat f Alexandria. He fund that selectins displaying high-yielding r lw-yielding characteristics in situ did nt maintain thse characteristics when prpagated int a carefully cntrlled experiment. Other anecdtal experience, bth freign and dmestic, implied that "clnal" differences were lst when selectins were freed frm deleterius viruses. Hwever, the Olm 393

2 394- WOLPERT et al. experiments shwed that significant differences culd be identified amng clnes testing free f virus, implying that these differences were genetically based and stable. A number f investigatrs have since identified clnal differences including yield, cluster weight, berry weight, and fruit maturity in Semilln (17); yield, berry weight, and wine characteristics in Pint nir (9,13); yield and terpene cncentratin in Muscat blanc ~ petite grains (12); general perfrmance f Chardnnay and Pint nir in Burgundy (5); fruitfulness and rt ptential f Pint nir (4); and yield cmpnents f Cabernet Sauvignn (7). The purpse f the research reprted here was t viticulturally evaluate six Chardnnay clnes and t dcument any differences in clnal perfrmance between tw sites in the Napa Valley. Materials and Methds Experiments were established at the time f planting in tw cmmercial vineyards. The Jaeger Vineyards trial was planted in 1984 in a site abut 5 km nrth f the city f Napa. Vines were spaced 2.44 m X 3.04 m apart (8 ft X 10 ft, vine x rw), with 1346 vines/ha (544 vines/ ac). Vines were trained t a tw-wire trellis system, with the first wire at abut 105 cm (42 in) abve the sil and the secnd in a vertical plane at abut 150 cm (60 in). Vines were head-trained and pruned t a cmbinatin f canes and spurs. Canes riginating at the lwer wire were arched ver the upper wire and tied t the lwer wire. Sht psitining was nt practiced. Winter pruning was dne by the cperatr's vineyard staff; the number f buds retained was set in accrdance with cmmn practice fr the bserved vine grwth. Nrmally, this crrespnded t tw 12-bud canes and abut fur tw-bud spurs per vine. The vineyard was cleancultivated in rw middles and weeds were cntrlled in a tw-ft strip under the vine rw by means f herbicides. The secnd trial was established in 1985 at Beringer Vineyards, 1 km east f Yuntville. Vines were planted 2.44 m X 3.66 m apart (8 ft X 12 ft, vine by rw), with 1121 vines/ha (454 vines/ac). Vines were trained t a "T" trellis, with the lwer wire at 105 cm (42 in) and tw upper wires at abut 150 cm (60 in) separated by abut 45 cm (18 in). Vines were trained t a bilateral crdn and spur-pruned t abut 18 tw-bud spurs per vine. Shts typically grew up between the tw upper wires and then arched ver them, depending n the extent f sht elngatin. The vineyard was clean-cultivated by means f discing the rw middles, while spring rwplwing was used t clean weeds frm under vine rws. The tw vineyards were separated by abut 9 km. Weather recrds frm the nearest statin indicate that Jaeger Vineyards was the cler f the tw sites. Fr the years f the three years f the experiment, , Jaeger averaged 1646 degree days (base 10 C) while Beringer averaged Rainfall was typically abut 800 mm per year, the majrity f which falls in the winter mnths f Nvember thrugh March. Overhead sprinkler systems were used in bth trials and ttal irrigatin water applied averaged abut 80 mm in the Jaeger trial and abut 180 mm in the Beringer. The sil type at bth sites was characterized as a Yl lam (2). The trials were established with spring plantings f certified AXR#1 (Vitis vinifera Aramn x V. rupestris Ganzin #1) rtings which were field-budded in the late summer f that same year. Bth trials were designed as randmized cmplete blcks with 10-vine experimental units and fur replicates. At least tw guard rws and tw end-f-rw guard vines were emplyed. Each trial was lcated within a Chardnnay vineyard blck and cultural practices were thse f a typical Napa Valley cmmercial Chardnnay vineyard. Crp adjustment by pst-blm cluster thinning was nt practiced in either trial. Budwd fr the clnes chsen fr study was taken frm certified, virus-tested vines grwn at Fundatin Plant Materials Service (), University f Califrnia, Davis (Table 1). Only clnes testing free f virus were used, in rder t ensure that bserved differences were genetic and nt due t virus. When multiple selectins were available differing nly in the duratin f heat treatment, the selectin with the greatest days f heat treatment was chsen. Fur f the six clnes ( 4, 5, 6, and 14) were riginally selected frm McCrea's Stny Hill Vineyard and planted at Martini's Stanly Lane ranch in the Carners regin f Napa Cunty. Of the remaining tw clnes, ne was frm Washingtn state and the ther frm Rutherglen, Australia. Beginning in 1988 and cntinuing thrugh 1991, data were taken frm bth sites (1988 data nt shwn). Trials were hand-harvested n a vine-by-vine basis, clusters were cunted and vine yields measured. The yield cmpnent berries/cluster was arrived at by calculatin (ave cluster weight ave berry weight). Prir t harvest a single 100-berry sample was taken per tenvine plt. The sample was returned t the labratry where it was weighed t determine average berry weight. Berries were then crushed and juice was filtered thrugh cheeseclth. Sugar cntent was measured as Brix by means f a hand-held, temperature-cmpensating refractmeter. Juice ph was measured by ph meter, and t determine titratable acidity, a 5-mL aliqut was titrated with 0.1 N NaOH t ph 8.2 endpint. During the drmant seasn, vines were pruned n a vine-by-vine basis. One-year-ld cane prunings were Table 1. Fundatin Plant Materials Service () clne numbers and surces f Chardnnay tested. Surce Heat treatment Clne# (days) 4 Martini 5V21, Olm # Martini 6V11, Olm # Martini 3V4, Olm # Martini 1V20, Olm # Prsser, WA; LR2V P , Rutherglen, Australia 60

3 CHARDONNAY CLONES m 395 Table 2. Grwth and yield f Chardnnay clnes, Jaeger Vineyards, Napa, Califrnia, Pruning wt (kg. vine -1) Yield (kg. vine -1) Yield:pruning wt rati N yr ave yr ave yr ave (89-91) 4 1.3b 1.3bc 1.7bc 1.4d 11.2a 10.3 ab 9.2a 10.2b 9.1 b 9.6a 6.0b 8.2b 5 1.6b 1.5b 1.9b 1.7c 12.3a 12.8a 9.9a 11.7a 8.3b 8.8a 5.6b 7.6b 6 2.8a 2.5a 3.2a 2.8a 10.8a 10.4 ab 6.5b 9.3b 4.1 c 4.7b 2.2c 3.7c b 0.9c 1.2c 1.0e 10.8a 8.6b 9.0a 9.5b 11.0a 10.9a 7.8a 9.9a a 2.5 a 3.1 a 2.7 a 10.7 a 11.7 a 5.8 b 9.4 b 4.4 c 5.0 b 2.2 c 3.9 c b 1.7 b 2.1 b 1.8 b 4.8 b 4.8 c 3.0 c 4.2 c 3.0 c 4.6 b 1.5 c 3.1 c separated frm ld wd and were weighed. Pruning weights are reprted with the data frm the previus grwing seasn; e.g., pruning weights frm the drmant seasn are reprted as 1990 data. Data analysis was by ANOVA with mean separatin by Duncan's multiple range (p < 0.05). Multiple year analysis was als dne by ANOVA, utilizing a splitblck design with clne as the main-plt and year as subplt. The test f year effects was dne using the year X blck effect while the year X clne interactin effects were tested with residual errr. Average values were calculated using data frm the years 1989, 1990, and 1991 nly. Results and Discussin Cane pruning weights, yield cmpnents, and fruit maturity indices fr the three-year perid 1989 thrugh 1991 are presented fr the Jaeger trial (Tables 2-5) and Beringer trial (Tables 6-9), and as three-year averages fr bth lcatins (Tables 10 and 11). The year 1988 was nt presented because pruning weights indicated that vine grwth had nt reached a stable level. In bth trials, 6 and 15 prduced the mst cane grwth (abut 3 kg/vine) and 14 the least (1.0 kg/vine) (Tables 1 and 5). The relative grwth f the clnes was cnsistent in bth sites thrughut the three-year study. Based n the average at Jaeger (Table 2), 5 was the highest yielding clne (11.7 kg/vine), fllwed by a grup f clnes including 4, 6, 14, and 15 (9.4 t 10.2 kg); 16 (4.2 kg) was by far the lwest yielding clne. A similar pattern was seen at Beringer (Table 6) where clnes 4, 5, and 6 were equally high yielding (12.0 t 13.0 kg/vine), fllwed by 14 and 15 (9.6 t 10.2 kg); 16 was again the lwest-yielding clne by a wide margin (4.9 kg). A strng clne X year interactin fr yield in bth trials (Table 10) was prbably due in part t erratic yield f 15 in 1991 at Jaeger and in 1990 at Beringer. Yields in bth trials were high, averaging as much as 15.7 MT/ha (7.0 tn/ac) at the Jaeger site and 14.6 MT/ha (6.5 tn/ac) at the Beringer site. Yields f clnes 4, 5, 6, and 14 were higher than that reprted by Olm (unpublished data). This is nt surprising cnsidering that the Olm trial was nn-irrigated and that it emplyed St. Gerge rtstck, which is reprted t reduce yield in small-clustered varieties (11,21). Cirami (8) reprted that the clnes yielded 8.5 t 10 kg/vine (11 t 13 MT/ha), abut 24% t 43% mre than a clne frm Australia. Hwever, he fund in a secnd trial that Table 3. Yield cmpnents f Chardnnay clnes, Jaeger Vineyards, Napa, Califrnia, Cluster number (vine -1) Cluster wt (g) N yr ave yr ave 4 74 b 52 b 35 a 54 cd 151 a 194 a 262 a 203 a 5 81 b 65a 39a 62ab 151 a 196a 258a 202a 6 91 a 65 a 38 a 65 a 118 b 159 a 173 b 150 c b 50 b 38 a 55 bc 141 a 172 a 234 a 182 b a 74 a 38 a 67 a 119 b 159 a 153 b 144 c c 48 b 28 b 47 d 75 c 100 b 107 c 94 d

4 396 R WOLPERT et al. Table 4. Yield cmpnents f Chardnnay clnes, Jaeger Vineyards, Napa, Califrnia, Berries/cluster Berry wt (g) N ab ab 6 98 bc a abc c yr ave yr ave 166 a 180 a 160 a 1.12 a 1.17 b 1.46 b 1.25 b 169 a 175 a 157 a 1.24 a 1.16 b 1.47 b 1.29 b 130 b 120 b 116 b 1.21 a 1.22 b 1.45 b 1.29 b 168 a 175 a 164 a 0.95 a 1.03 c 1.34 c 1.11 c 132b 117b 118b 1.13a 1.20b 1.31 c 1.21 bc 63 c 64 c 68 c 1.22 a 1.58 a 1.67a 1.49 a Table 5. Fruit maturity indices f Chardnnay clnes, Jaeger Vineyards, Napa, Califrnia, Brix Titratable acidity (g/l) ph N b 22.7ab b 22.2b a 22.8ab c 23.3a a 23.2a a 23.5a yr ave yr ave a 22.4 b 6.9 ab 7.6 a 6.5 a 7.0 a 3.20 c 3.28 d 23.2 a 22.2 b 7.2 a 7.6 a 6.5 a 7.1 a 3.20 c 3.28 d 23.5 a 22.9 a 6.3 bc 6.4 b 6.4 a 6.4 b 3.30 b 3.38 b 23.7 a 22.3 b 6.6 abc 6.8 b 5.8 b 6.4 b 3.20 c 3.32 c 23.3 a 23.0 a 6.6 abc 6.8 b 5.9 b 6.4 b 3.32 b 3.39 b 23.2 a 23.3 a 6.2 c 6.4 b 5.6 b 6.1 c 3.44 a 3.51 a yr ave (89-91) 3.30 c 3.26 e 3.31 c 3.26 e 3.32 c 3.34 c 3.32 c 3.28 d 3.41 b 3.37 b 3.50 a 3.48 a Mean separatin by Duncan's multiple range, p < (a selectin f 6 with fewer days f heat treatment) had rughly equivalent yields t a French selectin ANTAV (nw ENTAV) 84 and 18% greater yield than ANTAV 13. Yield:pruning weight rati (YPR) varied greatly amng clnes. In bth trials, 14 had the greatest YPR f all clnes, 9.9 at Jaeger and 11.7 at Beringer, due t a cmbinatin f very lw pruning weights and relatively large yields. Mderate YPRs were seen fr 4 and 5 primarily due t mderate pruning weights. Lw YPRs were seen in 6 and 15 because their pruning weights were relatively high. 16, which als had a lw YPR, was unusual in that it cmbined very lw yield with mderate pruning weights. The high YPR fr 14 might raise cncern that this clne was ver-crpped. Hwever, pruning weights remained cnstant ver three years in bth trials, at 1.0 kg/vine, indicating that high crp levels were nt being achieved at the cst f declining grwth. Fruit maturity Table 6. Grwth and yield f Chardnnay clnes, Beringer Vineyards, Yuntville, Califrnia, Pruning wt (kg. vine -1) Yield (kg. vine -1) Yield:pruning wt rati N d 1.4 cd 1.5 e d 1.9 c 1.9 d b 2.9 b 3.4 b e 1.1 d 1.0 f a 3.6a 3.8a c 2.5 b 2.6 c 3-yr ave (89-91) 1.4 e 13.2 ab 10.5 a 1.8 d 14.1 a 8.9 a 3.0b 12.8ab 9.3a 1.0 f 11.5 b 8.4 a 3.5 a 11.6 b 4.7 b 2.5 c 4.8 c 3.1 b yr ave yr ave 15.5 a 13.0 a 11.3 ab 9.0 a 11.4 b 10.6 a 15.6 a 12.9 a 9.4 b 5.5 b 9.2 c 8.0 b 13.9 b 12.0 a 5.1 c 3.3 bc 4.5 d 4.3 c 11.9 c 10.6 b 12.6 a 9.3 a 13.3 a 11.7 a 11.2 c 9.2 c 3.7 c 1.3 c 3.1 d 2.7 d 6.8 d 4.9 d 2.3 c 1.4 c 2.8 d 2.2 d Mean separatin by Duncan's multiple range, p < 0.05.

5 CHARDONNAY CLONES- 397 Table 7. Yield cmpnents f Chardnnay clnes, Beringer Vineyards, Yuntville, Califrnia, Cluster number (vine -1) Cluster wt (g) N c 5 71 bc 6 82 ab c a c yr ave yr ave 56 ab 60 c 60 b 209 a 189 a 261 a 219 a 51 bc 64 b 62 b 201 a 172 b 246 b 206 b 64 a 73 a 73 a 158 c 142 c 192 d 164 d 52 abc 54 d 56 b 187 b 160 b 221 c 189 c 50 bc 71 a 71 a 126 d 93 d 157 e 125 e 40 c 48 e 49 c 81 e 76 e 144 e 100 f Table 8. Yield cmpnents f Chardnnay clnes, Beringer Vineyards, Yuntville, Califrnia, Berries/cluster Berry wt (g) N a 144 a a 124 b b 108 c a 141 a c 71 d d 54 e yr ave yr ave 186 a 164 a 1.28 b 1.32 b 1.41 bc 1.34 bc 171 b 152 b 1.26 b 1.39 a 1.45 b 1.36 b 131 d 121 c 1.28b 1.31 b 1.47b 1.35 bc 172 ab 162 a 1.10 c 1.13 c 1.28 c 1.17 d 113 d 96 d 1.23 b 1.30 b 1.39 bc 1.31 c 74 e 60 e 1.52 a 1.40 a 1.96 a 1.63 a indices (Tables 5, 9, and 11) supprt a cnclusin f nrmal ripening. On the ther hand, the lw YPRs f 6 and 15 were due in large part t the large pruning weights which well exceeded a recmmended level f 0.6 kg/m f rw fr undivided canpies (18). Fr bth clnes, stable yield and pruning weight values did nt indicate an under-crpped vine r excessive shading. Yield differences at bth lcatins were due in sme degree t all f the yield cmpnents, including cluster number, cluster weight, berries/cluster and berry weight. Typically, 4 and 5 had the heaviest clusters, averaging mre than 200 g (Tables 3 and 7). The very lw yield f 16 was due t its having the fewest and lightest clusters. The yield cmpnent berries/cluster was greatest in 4, 5 and 14, mderate in 6 and 15, and lwest in 16. Berry weight did nt vary greatly amng the Table 9. Fruit maturity indices f Chardnnay clnes, Beringer Vineyards, Yuntville, Califrnia, Brix Titratable acidity (g/l) ph N yr ave (89-91) b 22.7ab 23.6a 22.4b b 21.7 d 23.8 a 22.5 c b 22.1bcd 23.8a 22.6c a 22.6 ab 24.1 a 23.4ab b 22.5abc 24.2a 23.1b a 22.0 cd 23.8 a 23.1 b a 23.0a 23.9 a 23.6a ab 7.8a 7.7 ab 7.3 bc 7.6 ab 7.2 bc 7.0c yr ave yr ave 7.6 a 6.5 a 7.0 a 3.20 c 3.28 d 3.30 c 3.26 e 8.4 a 6.1 ab 7.4 a 3.28 e 3.30 c 3.37 c 3.32 d 8.6 a 6.2 a 7.5 a 3.28 e 3.34 c 3.40 cd 3.34 cd 7.4 b 5.8 ab 6.8 cd 3.38 c 3.45 b 3.43 bc 3.42 b 7.7 b 5.7 b 7.0 c 3.31 d 3.33 c 3.44 b 3.36 c 8.2 a 6.2 a 7.2 b 3.41 b 3.43 b 3.46 b 3.43 b 7.3 b 5.8 ab 6.7 d 3.50 a 3.56 a 3.58 a 3.55 a

6 398- WOLPERT et al. Table 10. A cmparisn f average pruning weights and yield cmpnents f Chardnnay clnes at tw sites, Beringer Vineyards, Yuntville, and Jaeger Vineyards, Napa, Califrnia, ( ). Pruning wt Yield Yield: pruning Cluster n. Cluster wt (g) Berries Berry wt N. (kg. vine -1) (kg. vine -1) wt rati per vine (g) per cluster (g) Beringer Jaeger Beringer Jaeger Beringer Jaeger Beringer Jaeger Beringer Jaeger Beringer Jaeger Beringer Jaeger 4 1.4e 1.4e 13.0a 10.2b 10.6a 8.2b 60b 54cd 219a 203a 164a 160a 1.34 bc 1.25b d 1.7 d 12.9 a 11.7a 8.0 b 7.6 b 62 b 62 ab 206 b 202 a 152 b 157 a 1.36 b 1.29 b b 2.8 a 12.0 a 9.3 b 4.3 c 3.7 c 73 a 65 a 164 d 150 c 121 c 116 b 1.35 bc 1.29 b f 1.0f 10.6b 9.4b 11.7a 9.9a 56b 55bc 189c 182b 162a 164a 1.17d 1.11 c a 2.7 a 9.2 c 9.4 b 2.7 d 3.9 c 71 a 67 a 125 e 144 c 96 d 118 b 1.31 c 1.21 bc c 1.8c 4.9d 4.2c 2.2d 3.1 c 49c 47d 100f 94d 60e 68c 1.63a 1.49a Fprbability, main effects r interactins C Y ns C X Y ns ns ns ns ns ns ns C = clne; Y = year. Mean separatin by Duncan's multiple range, p < 0.05; ns = prbability f F> clnes except that 16 had berries substantially heavier than average and 14 lighter than average. The relatinship f yield t pruning weight, cluster number, and cluster weight was examined (Fig. 1). Yield was mre clsely crrelated with cluster weight (r 2 = 0.79) than cluster number (r 2 = 0.34), prbably because cluster weight incrprates bth berries/cluster and berry weight. Yield was nt crrelated with pruning weight (Fig. 1A), indicating that grwth was nt significantly affected by crp lad in these clnes, i.e., ver- r under-crpping was nt ccurring, and suggesting that the yield differences were genetic and nt cultural, i.e., Table 11. A cmparisn f average fruit maturity indices f Chardnnay clnes at tw sites Beringer Vineyards, Yuntville and Jaeger Vineyards, Napa, Califrnia, ( ). Brix Tritratable acidity ph (g/l) Beringer Jaeger Beringer Jaeger Beringer Jaeger N c 22.4 b 7.4 a 7.0 a 3.32 d 3.26 e c 22.2 b 7.5 a 7.1 a 3.34 cd 3.26 e ab 22.9 a 6.8 cd 6.4 b 3.42 b 3.34 c b 22.3 b 7.0 c 6.4 b 3.36 c 3.28 d b 23.0 a 7.2 b 6.4 b 3.43 b 3.37 b a 23.3 a 6.7 d 6.1 c 3.55 a 3.48 a Fprbability, main effects r interactins Clne (C) Year (Y) C X Y "2, e,, > ') 4 3 ~ 2 c 1 e- l.._ a e- ~ 60!_. ~- 50 :: ~ 150. = ~ " m 0 r 2 = 0.04 I v i l i J16 B16 B15 J~5 J4 J14B14 B6 t.i I t I dl~ 16 B15 J15 B6 ~" r 2 = 0.34 I t t t I t r 2 = 0.79 J B '0 1'2 14 Yield (kg vine 1) Fig. 1. Crrelatin f yield with pruning weight, cluster number, and cluster weight fr six Chardnnay clnes at tw sites. J = Jaeger Vineyards; B = Beringer Vineyards, and numbers refer t Fundatin Plant Materials Service clnes (see Table 1 fr mre details). B4

7 CHARDONNAY CLONES m 399 bud number retained. Further study f bud numbers retained versus pruning weight at different vine spacings wuld be needed in rder t clearly establish the relatinship f grwth and yield cmpnents. Despite the great difference in crp lad and YPR, fruit maturity indices did nt differ greatly. Typically, fruit f 16 was amng the mst mature (n average 23.5 Brix) and 4 and 5 amng the least mature (n average 22.5 Brix). This difference in maturity was likely the result f the significantly lwer prductin f 16 when cmpared t 4 and 5, amng the highest prducers. Titratable acidity fllwed the same trend in that it was lwest (mst mature) fr 16 and highest (least mature) in 4 and 5. The values fr ph were nt greatly different except that 16 was cnsistently higher in ph, even when cmpared t clnes f cmparable maturity; cmpare 15 and 16 in 1991 at the Jaeger lcatin (Table 5) r cmpare 6 and 16 in 1991 at the Beringer lcatin (Table 7). Wines were made frm bth trials fr three years. Cmpsitin and characterizatin f wines will be discussed in a later manuscript. Cnclusins clnes tested in these trials differed in their viticultural characteristics; a detailed cmparisn fllws. 4 and 5 are the mst similar. Bth were high-yielding clnes with large numbers f heavy clusters, high numbers f berries per cluster, and mderately heavy berries. Bth exhibited mderate grwth, with 5 prducing abut 0.3 kg/vine mre drmant prunings than 4. Bth clnes culd be recmmended fr grwers desiring high yield and fr cnditins where site and rtstck cmbinatins are expected t result in high vigr. 6 is a high-yielding clne. It has as many, r mre, clusters than 4 and 5 but its clusters are abut 45 g lighter, primarily due t abut 30 t 40 fewer berries per cluster. 6 is a vigrus clne; while maintaining high yields, it had high pruning weights. This clne culd be recmmended fr grwers desiring high yields and using a divided canpy where the higher pruning weights wuld be an advantage. 14, like 4 and 5, is a high-yielding clne with mderately high numbers f clusters per vine. Its clusters are smewhat lighter than 4 and 5, primarily because f smaller berries. 14 differs frm the ther clnes in that it had lw pruning weight (1.0 kg/vine.) This clne culd be recmmended t grwers wh desire high yields but wh als plan a clsespaced vineyard where high vigr wuld be undesirable. 15 is als a mderately high-yielding clne, due t a large number f clusters per vine. Hwever, its cluster weight is nly mderate because f significantly fewer berries per cluster and mre "sht berries," characteristics which were visually apparent. It is impr- tant t nte that yield in 15 was mre erratic than ther clnes (see Table 2, 1991, and Table 6, 1990). 16 had a visually distinct cluster which was small, withut a wing r well-develped shulder and with significant numbers f "sht berries" and large berries. The small clusters cntributed t the lw yield alng with fewer clusters per vine. The presence f sht berries cntrasts with the large berry weights (Table 4 and 8). Bias in the sampling prcess, twards the larger berries, is a likely explanatin. Leaves f 16 als appeared t be darker green, thicker, and had mre deeply dentate teeth at the margin. Althugh this clne has been verified as being true t type (J. M. Bursiqut, unpublished reprt), it is clearly different frm the thers. It shuld be nted that clnes with large numbers f berries per cluster must be cautiusly chsen when a vineyard site has a high rt ptential. A psitive relatinship amng high numbers f berries/cluster, tight cluster architecture and rt ptential has been fund (Vail, Wlpert and Gubler, unpublished data). Literature Cited 1. Amerine, M. A., and A. J. Winkler. Califrnia Wine Grapes: Cmpsitin and quality f their musts and wines. Calif. Agric. Expt. Sta. Bull pp. (1963). 2. Ann. Sil survey f Napa Cunty, U.S. Dept. f Agric., Sil Cnservatin Serv. (1978). 3. Asher, G. Chardnnay: buds, twigs and clnes. Gurmet, pp 62, 66, , May (1990). 4. Bernard, R., and M. Leguay. Clnal variability f Pint Nirin Burgundy and its ptential adaptatin under ther cler climates. In:Prceedings f the Internatinal Sympsium n Cl Climate Viticulture and Enlgy. D. A. Heatherbell, P. B. Lmbard, F. W. Bdyfelt, and S. F. Price (Eds). pp OSU Agricultural Experiment Statin Tech. Publ. #7628 (1984). 5. Bernard, R., M. Leguay, and R. Bidrn. La selectin clnale en Burggne, un ~l~ment de prgr~s pur la viticulture de CSte d'or. Prg. Agric. Vitic. 100: (1982). 6. Biletti, F. T. Selectin f planting stck fr vineyards. Hilgardia 2:1-23 (1926). 7. Bwen, P. A., and W. M. Kliewer. Influence f clnal variatin, pruning severity, and cane structure n yield cmpnent develpment in 'Cabernet Sauvignn' grapevines. J. Am. Sc. Hrtic. Sci. 115: (1990). 8. Cirami, R. M. Clnal selectin f Chardnnay grapevines. Austral. Grapegrwer Winemaker, Tech Issue, pp (1993). 9. Cirami, R. M., M. G. McCarthy, and D. G. Furkaliev. Pint nir- clnes suitable fr champagne r red wine styles. Austral. Grapegrwer Winemaker pp (1984). 10. Ewart, A. J., and J. H. Sitters. Wine assessment f Pint nir, Chardnnay and Riesling clnes. In: Prceedings f the Internatinal Sympsium n Cl Climate Viticulture and Enlgy. D. A. Heatherbell, P. B. Lmbard, F. W. Bdyfelt, and S.F. Price (Eds). pp OSU Agricultural Experiment Statin Tech. Publ. #7628 (1984). 11. Lider, L. A., A. N. Kasimatis, and W. M. Kliewer. Effect f pruning severity and rtstck n grwth and yield f tw grafted, cane-pruned wine grape cultivars. J. Am. Sc. Hrtic. Sci. 98:8-12 (1973). 12. McCarthy, M. G. Clnal and pruning effects n muscat a petite grains blanc yield and terpene cncentratin. Am. J. Enl. Vitic. 43: (1992). 13. Nn, D., J. Whiting, and K. Orr. Wine quality assessments f Pint nir selectins. Austral. Grapegrwer Winemaker. April pp (1989). 14. Oag, D. Chardnnay clnal evaluatin in a summer rainfall climate. Austral. Grapegrwer Winemaker, April pp (1991 ).

8 400 m WOLPERT et al 15. Olm, H. P. Chardnnay. (fli editin). Wine Advisry Bard, 3 pp. (1971). 16. Schfield, G. M. Chardnnay: an assessment f supply and demand. Grape Intelligence. Gerge M. Schfield C., St. Helena, CA (1993). 17. Scudamre-Smith, P., D. Oag, C. Ann, and A. Zeppa. Semilln: clnal evaluatin and tasting. Austral. N.Z. Wine Ind. J. pp (1992). 18. Smart, R., and M. Rbinsn. Sunlight int wine: a handbk fr winegrape canpy management. 83 pp. Australian Industrial Publishers Pty. Ltd, Underdale (1991 ). 19. Tippet, J. Califrnia Grape Acreage. Califrnia Agricultural Statistics Service, Sacrament, CA. 33 pp (1992). 20. Wiley, H. W. American wines at the Paris Expsitin f 1900, their cmpsitin and character. U.S. Dept Agric. Bur. Chem., Bull. 72. U.S. Gvt. Printing Office, Washingtn, D.C. (1903). 21. Wlpert, J. A., and M. A. Walker. Field evaluatin f winegrape rtstcks. Final reprt t the American Vineyard Fundatin, 21 pp (1993).