Field Evaluation of Cold Hardy Citrus in Coastal Georgia
VARIETY TRIALS
tion in most years, except that ichang region and has an automated weather Field Evaluation of papeda was substantially damaged in station that records air temperature, Cold Hardy Citrus in the last year of the study. Seven culti- precipitation, and other weather vars produced fruit at least once dur- variables. The soil type is an Albany ing their fi rst 4 years: nansho daidai, Fine Sand. Coastal Georgia ichang papeda, ‘Nippon’ orangequat, ‘Mr John’s Longevity’ citrangequat, PLOT AND CULTURAL CONDITIONS. ‘Owari’ satsuma, ‘Changsha’ man- Trees were spaced 8 to 12 ft (2.4 to Mark Rieger,1 Gerard Krewer,2 darin, and procimequat. Based on 3.7 m) apart in east-west oriented rows that were about 20 ft (6.1 m) 3 3 cold hardiness, fruiting, and growth Pam Lewis, Mindy Linton, characteristics, ‘Owari’ satsuma, apart, on raised beds 12 to16 inches and Tom McClendon4 ‘Changsha’ mandarin, ‘Mr John’s (30.5 to 40.6 cm) in height and 5 ft Longevity’ citrangequat, and ‘Nippon’ (1.5 m) wide to improve drainage. orangequat provided the hardiest, Beds were mulched with wood chips most precocious and desirable fruiting ADDITIONAL INDEX WORDS. kumquat, to control weeds and conserve mois- citrangequat, mandarin, satsuma, landscape trees in this study. ture. The planting was fertilized twice freezing stress, frost annually with 14N–6P–11.6K slow-re- SUMMARY. Sixteen cultivars of citrus omeowners in areas colder lease fertilizer (Osmocote; The Scotts (Citrus spp.) and close citrus relatives than the nation’s traditional Co., Marysville, Ohio) or a granular were planted in Savannah, Georgia Hcitrus producing regions 10N–4.4P–8.3K source, and irrigated to evaluate their potential as fruiting desire to grow many non-commer- as needed. An overhead irrigation sys- landscape trees in an area that rou- cial citrus cultivars and close relatives tem was used for routine irrigation and tinely experiences minimum tempera- [trifoliate orange (Poncirus trifoliata), once for freeze protection during an tures of 15 to 20 °F (–9.4 to –6.7 °C) kumquats, and hybrids thereof) that unusually early and severe freeze on 21 during winter. Three to six trees of make attractive landscape trees and Nov. 2000, [minimum temperature of each cultivar were planted in 1998, and stem dieback and defoliation data produce edible fruit. Although esti- 18.9°F (–7°C)]. Other than this date, were collected in 1999, 2001, and mates of hardiness vary depending on trees were not irrigated for freeze pro- 2002. During the 4 years of the study, source, some are touted as being cold tection. Shoots originating from the air temperatures fell below 32 °F (0.0 hardy to single digit or teens Fahrenheit rootstock or on the lower 12 to 18 °C) 27 to 62 times per season, with (–7 to –15 °C), and would therefore inches (45.7 cm) of the main trunk absolute minima ranging from 13 to be suitable for warm-temperate and were removed each year. Dead wood 18 °F (–10.6 to –7.8 °C), depending coastal areas of the southeastern U.S. was removed in the spring of each year on year. In general, kumquats (For- However, claims of hardiness are often after measurements of stem dieback tunella spp.), represented by ‘Meiwa’, poorly documented, and fl uctuating were made. New growth fl ushes were ‘Nagami’, and ‘Longevity’, were com- winter temperatures characteristic of sprayed with insecticide in the second, pletely killed (or nearly so) in their fi rst year in the fi eld after air tempera- this region may result in poor cold third, and fourth years to control citrus ture minima of 13.5 °F (–10.28 °C). acclimation (Davies and Albrigo, leaf miner (Phyllocnistis citrella) dam- Others experiencing 100% dieback 1994), which prevents attainment of age, and weeds within the beds were were ‘Meyer’ lemon (Citrus limon x C. maximum hardiness. controlled with glyphosate herbicide. reticulata) and ‘Eustis’ limequat (C. Scant documentation exists for suc- CULTIVARS. Sixteen cultivars were aurantifolia x Fortunella japonica), cessful dooryard cultivation of hardy obtained from commercial nurseries, which were tested twice during the citrus cultivars in the southeastern U.S. and three to six trees of each cultivar study. Kumquat hybrids, including (Krewer and Powell, 1983; McCLen- were planted in Spring 1998, with procimequat [(C. aurantifolia x F. ja- don, 2001a, 2001b). Trees are often the exception of ‘Changsha’ manda- ponica) x F. hindsii), ‘Sinton’ citrange- observed in the landscape, particularly in rin, where 30 trees were planted to quat [(C. sinensis x Poncirus trifoliata) x unknown kumquat], ‘Mr John’s coastal areas with warm microclimates. provide plant material for an additional Longevity’ citrangequat [(C. sinensis Anecdotal reports of trees surviving study. Unless otherwise noted, trees x P. trifoliata) x F. obovat], razzlequat and fruiting are valuable collectively, were grown on their own roots. (Eremocitrus glauca x unknown kum- but multi-year tests of these cultivars Kumquats. ‘Meiwa’, ‘Nagami’, quat), and ‘Nippon’ orangequat (C. with documented temperature data are and ‘Longevity’ were chosen to rep- unshiu x F. crassifolia) survived freez- unavailable. This study was undertaken resent pure kumquat cultivars. ‘Meiwa’ ing, but all experienced at least some to evaluate the hardiness and growth and ‘Nagami’ were grafted on sour or- defoliation and stem dieback. ‘Owari’ characteristics of several candidate cul- ange (C. aurantium) rootstock, and satsuma (C. unshiu), ‘Changsha’ man- tivars at a site that routinely experiences ‘Longevity’ was own-rooted. C. reticulata darin ( ), nansho daidai minimum temperatures of 15 to 20 °F Kumquat hybrids. Six cultivars (C. taiwanica) and ichang papeda (C. ichangensis) experienced only minor during winter. with kumquat parentage included stem dieback but substantial defolia- ‘Nippon’ orangequat, ‘Eustis’ Materials and methods limequat, procimequat, ‘Sinton’ 1 Department of Horticulture, University of Georgia, SITE. The Coastal Gardens Re- citrangequat, ‘Mr John’s Longevity’ Athens, GA 30602. search Farm (lat. 32°N, long. 81°W), 2Department of Horticulture, Rural Development citrangequat, and razzlequat. All kum- Center, P.O. Box 1209, Tifton, GA 31793. in Savannah, Ga., about 20 miles (32.2 quat hybrids were own-rooted except km) from the coast was used for the 3Coastal Gardens Research Farm, #2 Canebrake Rd, ‘Eustis’, which was grafted on sour Savannah, GA 31419. study. This site has a rather cold mi- orange rootstock. ‘Eustis’ limequat 4205 East North St., Greensboro, GA 30642. croclimate relative to the surrounding was replanted in Spring 2000 after all
540 ● July–September 2003 13(3) original trees were killed by freezing in stem length) × 100, and percent defo- climation was tree age; young trees the fi rst year. One of three original ‘Mr liation was calculated as (#remaining are generally less cold tolerant than John’s Longevity’ trees killed by freez- leaves/total node number) × 100. Tree older trees (Yelenosky, 1996). Thus, ing was replaced with a tree budded height, to the nearest 0.5 ft (15 cm) the study conditions presented a strong on ‘Carrizo’ citrange (Citrus sinensis above the soil line were measured in challenge in terms of freezing stress. x Poncirus trifoliata) rootstock Spring November 2001, after four seasons COLD HARDINESS RANKINGS. 1999. 2000; four additional trees, similarly in the fi eld. At the same time, fruit Five cultivars were either completely propagated, were also planted at this number and weight per fruit were also killed or injured beyond the point time, bringing the total to seven for measured, counting all fruit per tree, of recovery after the fi rst year in the this cultivar. and weighing a representative fruit fi eld (Table 2). This included all three Mandarins. ‘Changsha’, ‘Owari’ sample on a portable electronic bal- kumquats, ‘Meyer’ lemon, and ‘Eustis’ satsuma, and ‘Snow Picked’ (unknown ance. A thorniness rating was made limequat. Of the three trees planted, Citrus reticulata; Oregon Exotics on mature stems according to the fol- one yuzu and two ‘Snow Picked’ man- Nursery, Grants Pass, Ore.) were lowing scale based on thorn length: 0 darin trees were killed and not replant- chosen based on reports of superior = no thorns, 1 = ≤¼ inch (6.4 mm), ed, precluding further data collection. cold hardiness. ‘Owari’ was grafted on 2 = ¼ to ½ inch (12.7 mm), 3 = ½ to One of the ‘Mr John’s Longevity’ trees sour orange rootstock, and the others 1 inch (25.4 mm), 4 = 1 to 2 inches was also killed, but trees were later re- were own-rooted. (50.8 mm), 5 = >2 inches. placed so this cultivar could continue Other citrus species. Yuzu (Citrus Data were analyzed by analysis of to be evaluated. Considerable stem junos), nasho daidai, ichang papeda, variance (ANOVA) and Tukey’s mean dieback and defoliation occurred for and ‘Meyer’ lemon were also chosen separation, or ANOVA on ranks with most of the kumquat hybrids, includ- based on reports and observations of Dunn’s test to separate means when ing procimequat, ‘Nippon’, ‘Sinton’, superior cold hardiness in southern data were not normally distributed. and ‘Mr John’s Longevity’, but razzle- Georgia. Only ‘Meyer’ was grafted Data on fruit weight and thorniness quat was among the least damaged of (sour orange rootstock). ‘Meyer’ were not analyzed statistically due to the 16 cultivars studied. Two of the lemon was replanted in Spring 2000, high variation and low replication; they mandarins, ‘Owari’ and ‘Changsha’, after all original trees were killed by are provided for descriptive purposes also showed little or no stem dieback, freezing. Replanted ‘Meyer’ lemons only. similar to ichang papeda and nansho were grown from rooted cuttings to daidai. allow for the possibility of resprouting Results 2001. All of the replanted ‘Eustis’ from roots if trees were killed. TEMPERATURE DATA. Winter and ‘Meyer’ trees were killed complete- DATA COLLECTION AND ANALYSIS. weather was typical for the site, with ly, as in 1999, during the unusually cold Winter temperature data covering the the exception of the 2000-01 winter, 2000–01 winter. Although ‘Meyer’ 4- year period were recorded continu- which had an unusually high number of were own-rooted with the intention ously at the Coastal Gardens Research freezes and record early and late freezes of reestablishing trees from surviving Farm by an automated weather station; (Table 1). Temperature minima ranged roots, no resprouting occurred from data were retrieved from archives at from 13 to 18 °F, and all winters had the roots the following spring. Nine of
Table 1. Winter weather data from Coastal Gardens Research Farm, Savannah, Ga. over the 4-year study; °C = 5/9(°F – 32). Min Nights Nights temp <32 °F <20 °F winter Year (no.) (no.) (°F) Comments 1998–1999 27 2 13.5 Unusually warm November and December preceded freezing on 11 of 14 nights in January; 1 week of >70 °F preceded 4 freeze nights in late February down to 22.1 °F 1999–2000 44 7 16.2 10 d >70 °F preceded 4 freeze nights in early December down to 19.9 °F 2000–2001 62 12 13.1 Unusually early and record late freezes (10 Oct. and 19 Apr., respectively); highs in the 70s and 80s °F in October and November, only 1 week of normal temps preceding 4 nights down to 18.9 °F on 21 Nov. (irrigated this date for protection); below freezing every night from 17 Dec. to 11 Jan., then 21 Jan. to 29 Jan. 2001–2002 30 2 18.5 Early frost (late October) then warm (60 to 80 °F) through 20 Dec., then 13 of next 20 nights below freezing down to 18.5 °F
● July–September 2003 13(3) 541 VARIETY TRIALS
Table 2. Cold hardiness rankings for citrus and related cultivars after fi rst year in stature, and were not expected to be fi eld (1999), Coastal Gardens Research Farm, Savannah, Ga. strong growers. ‘Owari’ satsuma did Stem not grow to 6 ft also, but fruited heavily dieback Defoliation in 2000 and 2001, often bending limbs Taxon (%) (%) downward and causing some trees to lean. Furthermore, ‘Owari’ did not z ‘Eustis’ limequat 100 a 100 a posses the largely upright growth ‘Nagami’ kumquat 100 a 100 a habit of the other cultivars. ‘Meyer’ lemon 100 a 100 a Seven of nine cultivars produced ‘Meiwa’ kumquat 83 ab 100 a at least some fruit by Fall 2001; only ‘Longevity’ kumquat 78 ab 100 a razzlequat and ‘Sinton’ citrangequat Yuzu 64 ab 100 a did not produce fruit during the study Procimequat 59 ab 89 ab (Table 5). Of the seven which fruited in ‘Nippon’ orangequat 55 ab 58 ab 2001, only two did not produce fruit ‘Snow Picked’ mandarin 54 ab 100 a the previous year as well (ichang papeda ‘Sinton’ citrangequat 23 ab 81 ab and nansho daidai, data not shown). ‘Mr. John’s Longevity’ citrangequat 18 ab 71 ab Procimequat produced by far the most Ichang papeda 15 ab 79 ab fruit per tree, estimated at up to 700 in ‘Changsha’ mandarin 8 b 69 ab the 2000 season. Fruit size was small- Nansho daidai 6 b 80 ab est in procimequat, and tended to be ‘Owari’ satsuma 0 b 50 ab smaller in the kumquat hybrids than Razzlequat 0 b 16 b the mandarins or other citrus species. zData were not normally distributed; analyzed by analysis of variance on ranks with Dunn’s mean separation. Means Eating quality was deemed best by followed by the same lower case letter are not signifi cantly different, P < 0.05. the authors for ‘Owari’, ‘Changsha’, and ‘Mr Johns Longevity’. ‘Nippon’ Table 3. Cold hardiness rankings for citrus and related cultivars with three or produced a tart, but edible fruit. more individuals surviving after 3 years (2001), Coastal Gardens Research Farm, Thorniness was lowest in ‘Owari’, Savannah, Ga. which was thornless, and greatest in Stem nansho daidai and razzlequat (Table dieback Defoliation 5). These ratings were based on thorn Taxon (%) (%) length, not thorn density (number per unit length of stem) or fi rmness. How- ‘Eustis’ limequatz 100 ay 100 a ever, the ratings shown should provide ‘Meyer’ lemonz 100 a 100 a an indication of diffi culty in pruning Procimequat 28 ab 90 ab and picking fruit, and perhaps other Ichang papeda 21 ab 71 ab practices affected by the presence of Razzlequat 5 ab 91 ab thorns. ‘Owari’ satsuma 4 b 77 ab ‘Changsha’ mandarin 3 b 65 b Discussion ‘Nippon’ orangequat 3 b 43 b Our primary objective was to ‘Sinton’ citrangequat 0 b 74 ab evaluate the suitability of several cold Nansho daidai 0 b 79 ab hardy citrus (and related) cultivars as ‘Mr. John’s Longevity’ citrangequatx 0 b 72 ab fruiting landscape trees for regions of z‘Meyer’ and ‘Eustis’ were replanted in 2000 after complete kill of trees originally planted in 1998; these trees were the southeastern U.S. that experience fi rst leaf in fi eld, whereas others were third leaf. annual freezes in the 15 to 20 °F range. yData were not normally distributed; analyzed by analysis of variance on ranks with Dunn’s mean separation. Means followed by the same lower case letter are not signifi cantly different, P < 0.05. Despite low replication due to plot size xFive of seven ‘Mr. John’s Longevity’ citrangequat were planted in May 2000, thus data are averaged over 1- and limitations, the temperature and har- 3-year-old trees. diness data presented is quantitative and objective, as opposed to anecdotal freezing in December and January. no stem dieback whatsoever, but was reports from nurseries or homeown- Defoliation ranged from 43 to 91% defoliated about 30% to 35% (data not ers who have made observations on on the nine surviving cultivars, but all shown). Only procimequat, which was single trees. Thus, the data should be showed signs of new leaf production considerably damaged, showed more interpreted cautiously, but serve to es- in March 2001. than 1% stem dieback. Defoliation was tablish a baseline for choosing among 2002. Seven cultivars remained less than 30% in ‘Changsha’, razzle- the cultivars studied. available for analysis following the win- quat, and nansho daidai, but severe As a group, the kumquats ter of 2001–02 (Table 4). Three of the in the other cultivars. (‘Meiwa’, ‘Nagami’, ‘Longevity’) did fi ve remaining ichang papeda trees were GROWTH AND FRUITING CHARACTERIS- not survive freeze conditions of this killed by freezing, eliminating it from TICS. Six of the nine cultivars evaluated study. This was somewhat unexpected, analysis. Two of three ‘Nippon’ orange- in November 2001, after four seasons since they are known to be more cold quat trees died during the late fall of of growth, had heights of 6 ft (1.8 m) hardy than commercially important 2001 from root rot, not from freez- or greater (Table 5). Procimequat and citrus species, and exhibit prolonged ing; the single remaining tree showed ichang papeda are reportedly small in quiescence in spring that reduces the
542 ● July–September 2003 13(3) Table 4.Cold hardiness rankings for citrus and related cultivars that survived thorny. This cultivar may have potential through 4 years in the fi eld (2002) with three or more individuals remaining, as a security screen or hedgerow. Coastal Gardens Research Farm, Savannah, Ga. The mandarin group contained Stem two of the best overall cultivars in the dieback Defoliation study, ‘Changsha’ and ‘Owari’. The Taxon (%) (%) satsumas are known to be among the most cold hardy commercially Procimequat 82 ay 96 a cultivated citrus in the world (Fergu- ‘Mr. John’s Longevity’ citrangequat 0.9 b 69 a son, 1996), and have been cultivated ‘Owari’ satsuma 0.7 b 93 a successfully in relatively cold areas of Nansho daidai 0 b 17 b the U.S. such as southern Mississippi, Razzlequat 0 b 13 b Alabama, Louisiana, and southern ‘Sinton’ citrangequat 0 b 88 a Georgia (McClendon 2001b). ‘Owari’ ‘Changsha’ mandarin 0 b 28 b probably has the best quality fruit of all zAll taxa planted in 1998 except fi ve of seven ‘Mr John’s Longevity’ citrangequat, which were planted in May studied, being bright orange in color 2000. yData were normally distributed; analyzed by analysis of variance with Tukey’s mean separation. Means followed and nearly seedless, and has the added by the same lower case letter are not signifi cantly different, P < 0.05. advantage of being thornless. The au- thors have observed several-year-old Table 5. Growth and fruit characteristics of selected cultivars at the end of the ‘Changsha’ growing and fruiting near fourth season, November 2001. Tifton and Augusta Ga, so this cultivar was expected to perform well. ‘Snow Fruit/ Wt/ Thorniness, Ht tree fruity mature Picked’ mandarin, touted as hardy to 0 Taxonz (ft) (no.) (g) woody to 10 °F (–17.2 to –12.2 °C), was killed outright in the fi rst year, raising doubts Nansho daidai 10.4 ax 1 ab 230 2 to 3w about the validity of those claims. Razzlequat 10.4 a 0 b 0 2 to 3 The four remaining cultivars, all ‘Sinton’ citrangequat 9.4 ab 0 b 0 1 to 2 species of Citrus, showed mixed re- ‘Changsha’ mandarin 8.4 ab 39 ab 117 0 to 1 sults. ‘Meyer’ was killed outright both ‘Nippon’ orangequat 7.2 abc 266 a 56 1 times tested (1999 and 2001), which ‘Mr. John’s Longevity’ citrangequat 6.5 bc 77 a 35 1 was surprising since there are reports ‘Owari’ Satsuma 5.5 bc 37 ab 146 0 of it grown in Coastal Georgia, and it Procimequat 4.6 c (hundreds) <5 0 to 1 is listed in catalogs as hardy to teens Ichang papeda 3.6 c 8 ab 124 1 °F (–11.7 to –7.2 °C). Observations zAll taxa planted in 1998 except fi ve of seven ‘Mr John’s Longevity’ citrangequat, which were planted in May in northern Florida also showed that 2000. yFruit weight and thorniness were not compared statistically. ‘Meyer’ had 0% survival after experienc- xMeans followed by the same lower case letter are not signifi cantly different, P < 0.05. ing 12 °F (Anderson, 2000). Nansho wThorniness rating (length of thorns on mature wood): 0 = no thorns, 1 = ≤¼ inch (6.4 mm), 2 = ¼ to ½ inch daidai exhibited greater cold hardiness (12.7 mm), 3 = ½ to 1 inch (25.4 mm), 4 = 1 to 2 inches (50.8 mm), 5 = >2 inches. Thorns on older wood or than several cultivars, but was relatively thorny and slow to bear fruit. Yuzu was likelihood of deacclimation in response ‘Nippon’ orangequat (half tangerine, eliminated from the study after the fi rst to fl uctuating temperatures in late half kumquat) performed relatively well year when two of three trees died. Based winter (Jackson and Fasulo, 1994). in terms of cold hardiness and fruiting on observations, and the use of yuzu Comparable results were obtained in through Fall 2001, when two adjacent in breeding other cold hardy cultivars northern Florida, where three of four trees succumbed to root rot (caused (e.g., yuzange, yuzuquat, ‘Clem-Yuzu ‘Meiwa’ trees were killed completely by Phytophthora, diagnosed by J. Wil- 3-3’), we expected this cultivar to be following a freeze on 23 Dec. 1989, liams-Woodward). This may have been more cold hardy. The single tree that with a minimum temperature of 12 °F due to unfortunate placement in the survived grew to over 6 ft by Fall 2001, (–11.1 °C) (Anderson, 2000). fi eld, or might suggest that this cultivar but was almost completely defoliated The kumquat hybrids displayed a should be grafted on a rootstock toler- each year. Ichang papeda, reported wide range of hardiness, probably re- ant of root rot fungi. The citrangequats, as one of the most cold hardy of the lated to their parentage. Complete kill ‘Sinton’ and ‘Mr Johns Longevity’, evergreen citrus (McClendon, 2001a), of ‘Eustis’ limequat, in both 1999 and proved to be among the hardiest of had relatively little stem dieback in 2 2001, was not surprising given the fact the original 16 cultivars. This was of 3 years evaluated, but was severely that limes are some of the least hardy expected, due to the trifoliate orange injured in the last year. Its poor qual- citrus (Jackson and Fasulo, 1994). parentage, and the fact that there is an ity fruit and undesirable growth habit Procimequat, also with lime parentage, old ‘Thomasville’ citrangequat tree at would likely render it undesirable to experienced substantial defoliation and the Coastal Gardens Research Farm the homeowner. 28% or greater stem dieback each year, that has grown and fruited reliably for A central question in relation to which also may be expected. However, over 20 years. Razzlequat, with desert this study is “what constitutes cold its survival compared to pure kumquat lime (Eremocitrus glauca) parentage, hardiness?”. In a landscape setting, aes- species is puzzling since one might ex- was probably the hardiest and one of thetics as well as fruit quality and yield pect partial lime parentage to reduce the most attractive trees in the study, become important. While the level of hardiness relative to pure Fortunella. but lacked precocity and was extremely damage tolerated by homeowners is
● July–September 2003 13(3) 543 VARIETY TRIALS likely to vary considerably, substantial Literature cited Krewer, G.A. and A.A. Powell. 1983. Citrus fruit for southern and coastal Georgia. Ga. annual stem dieback is unlikely to be Anderson, P.C. 2000. Cold hardy citrus Coop. Ext. Serv. Bul. 804. tolerated by most people. If defoliation for north Florida. N. Fla. Res. Educ. Ctr. is the main criterion, clearly none of News. vol. 2. Feb. 7 2000. Jackson, L.K. and T.R. Fasulo. 1994. the cultivars tested would be consid- Cold hardy citrus. Univ. Fla. Fact Sheet Davies, F.S. and L.G. Albrigo. 1994. Citrus. ered cold hardy, since all experienced HS 123. Crop production science in horticulture. at least some degree of defoliation in vol. 2. CAB Intl., Wallingford, U.K. McClendon, T. 2001a. Citrus for the south: most years. Alternatively, if one is will- Part 1 of 2. Rapidophyllum: J. S.E. Palm Ferguson, J.J. 1996. The satsuma tanger- ing to tolerate some defoliation and Exotic Plant Soc. (Spring 2001):5–8. minor stem dieback, as long as the ine. Univ. Fla. Fact Sheet HS 195. McClendon, T. 2001b. Citrus for the south: tree survives and fruits the following Hoogenboom, G. 2002. Georgia Part 2 of 2. Rapidophyllum: J. S.E. Palm season, then cultivars such as ‘Owari’ automated environmental monitor- Exotic Plant Soc. (Summer 2001):5–9. satsuma, ‘Changsha’ mandarin, ‘Mr ing network. 1 May 2002.
544 ● July–September 2003 13(3)