Grape tomato trials, 2001

10 Pages·2002·0.33 MB·English

by  Hill, David E. (David Easton), 1929-

77ze |
Connecticut p
Agricultural P
Grape Tomato
Experiment P
Trials
Station, P
2001
Afew Haven P
BY DAVID HILL
E.
Bulletin 978
March 2002
SUMMARY
In 2001, five cultivars ofgrape tomatoes were grown at Mt. Carmel on a loamy
upland soil. Total cumulative yield throughout the growing season was related to the
growth habit ofthe individual cultivars. Average estimated cumulative yield of
indeterminate cultivars Santa, Summer Sweet, and Tami-G was 47,270 lb/A compared to
27,940 lb/A for determinate cultivars, Chiquita and Sweet Olive. Cumulative yields of
Santa and Summer Sweet were greatest, each producing 15.5 lb/plant. Sweet Olive had
the lowest cumulative yield (6.7 lb/plant).
As the season progressed and the indeterminate plants became larger, the average
length and diameter ofthe fruit declined 0.1 to 0.3 inches and the average weight
declined 0.2 to 0.3 ounces. Little change in the size and weight offruit was noted in
determinate plants.
Harvest ofmost cultivars began July 23 and concluded October 9, a 12-week
period. Yields ofdeterminate cultivars Chiquita and Sweet Olive declined after 8 weeks.
Yields ofindeterminate cultivars Santa, Summer Sweet and Tami-G persisted 12 weeks
until frost.
Cracking offruit became more prevalent in upper clusters offruit in late
September. Cracking in the larger-fruited Summer Sweet and Chiquita ranged from 42-
50%, respectively. Cracking offruit was least in smaller-fruited Tami-G (12%) and Santa
(26%).
.
Grape Tomato Trials 2001
BY DAVID E. HILL
Grapetomatoes (Lycopersiconesculentum) have become Table 1. Cultivarstested in 2001
verypopularas anew category in tomato culture. Their Indeterminate Supplier
sweetness, small size, and oblong shape, resemblinggrapes, Santa Thompson and Morgan,
Holmes
makes them appealing as a salad ingredient orsnack food.
SummerSweet Hybrid Park
The sagasurroundingtheirdevelopment and use in the
produce industry is intriguing. Chu Farms in Floridacoined Tami-G (a.k.a. Agriset-8279) Stokes
theterm "grape tomatoes" fortheirproduct(Rosselle 2000). Determinate
They sought and received federal trademarkregistration for Chiquita(pink) Johnny's Selected Seeds
use oftheterm. Undertrademark laws, the term "grape SweetOlive Johnny"s Selected Seeds
tomatoes" could not be used foranyothervarieties that
resembled Chu's. The trademark not onlyrestricted the
term's use in the produce industry but also in seedcatalogue Inthis bulletin, I shall discussthe yield and qualityof
descriptions for fruit ofsimilar size and shape. Several five cultivars ofgrapetomatoesthatwere listed in2001
growers began using the name"grape tomatoes" as a generic catalogues. I shall also discuss strategiesto maximize yield
term. Procacci Bros. Sales Corp. challengedthe exclusive andprofitthrough cultivarselection andmanagement
rightforuse ofthe term, declaring it ageneric namerather techniques.
than acultivarname. Aftera lengthy court battle, Chu Farms
relinquished the exclusive rightstothe term, thus opening SOILAND RAINFALL
the doors fortheproduce industry and seed producers to
describe fruitofsimilar size and shape (Lister2000). Since Soil. The grapetomato trial was conducted atLockwood
then, thegrape tomato varietyhas been taking overthe Farm, Mt. Carmel on Cheshirefine sandy loam awell-
cherrytomato niche accordingto produce industrytabloids drained loamy upland soil with moderate moistureholding
(Harvey2001). Its small size, sweetness, thin skin, and capacity
firmness have been creditedto its success. Rainfall. At Mt. Carmel, totalrainfall throughoutthe
The cultivar, "Santa", the name that is most associated growing season(Junethrough October)was 16.8 inches
with grapetomatoes, was firstreleased from the University comparedto a30-yearaverage of 17.1 inches (Table2).
ofIdaho (Boe et all980). Named afterthetown ofSanta, Small deficits, upto 1.4 inches, occurredin July, September,
ID, itwas described as a semi-determinate varietythat and October. Althoughtherainfall in July (1.8 inches) and
produced abundant oblong fruit, 3-5 centimeters (1.2-2.0 October(2.0 inches)was below average, ithad little impact
inches) in diameter. These fruitare abouttwice as large as onthegrowth ofplants andyield. One irrigation was
the improvedvarietythatwas developed in Taiwan under required in late July.
the Santaname (Rosselle 2000). Procacci Bros, procuredthe
exclusive rightto the Santa variety in the United States. METHODS AND MATERIALS
Grapetomatoes sold in supermarkets are usually identified
asthe Santavariety on product labels. Because ofthe Cultivars. Most seeds were obtained from several
exclusion clause between Procacci Bros, andthe seed domestic suppliers (Table 1). Santawas obtainedfroma
developer, seed ofSanta is notreadily available frommost seedsman intheUnitedKingdom whohad adistribution
seedsmen. Two seedsmen, however, list Santa in their2002 center inthe United States. An indeterminate cultivar, Mini
catalogues (Table 1). Charm, was included inthetrial, butharvestoffruitwas
Connecticut Agricultural Experiment Station Bulletin 978
Table 2. Departure from normal rainfall (inches) duringthe compared to measurements ofcommercial fruit ofthe Santa
2001 growing season (May-October) at Mt. Carmel. variety purchased at a local supermarket. All fruit harvested
Rainfall 30-yearAvg. Departure in late-Septemberwere evaluated forcracking.
June 5.0 2.5 +2.5
July 1.8 3.2 -1.4 YIELD OF FRUITAND SEASONAL DISTRIBUTION
August 4.7 3.9 +0.8
September 3.3 4.2 -0.9 Yieldandsize offruit. Thetotal cumulative yield offruit
October 2.0 3.3 -1.4 was highly dependentupon the growth habit ofthe
individual cultivars (Table 3). The average cumulativeyield
Total 16.8 17.1 -0.4 ofindeterminate cultivars Santa, Summer Sweet, and Tami-
G was estimated at47,270 lb/A compared to 27,940 lb/A for
determinate cultivars Chiquita and Sweet Olive. Cumulative
abandoned in late August because the rank growth ofthe yields ofSanta and Summer Sweetwere greatest, each
planthidthe clusters offruitwithin the dense foliage and producing 15.5 lb/plant. The high cumulative yield of
made ittoo difficultto harvesteconomically. Despite its Summer Sweetwas due to heavierfruit (0.55 oz/fruit)
sweet flavor, the fruit, smallest among those tested (0.4 oz), comparedto Santa (0.30 oz/fruit). Santa's high cumulative
had ahigh incidence ofcracking and did not separate well yield was dueto more numerous fruit (est. 810/plant)
from the calyx. comparedto Summer Sweet(est. 440/plant). Numberoffruit
Culture. Seeds were sown March 10 in Promix BX-filled was estimated from total cumulative yield/plant divided by
36-potpacks (3601). Pots measured 2-5/8 x 2-1/4 x 2-5/16 the average weightoffruit on August 8 and September9.
inches andwere placed in a greenhouse maintained at 70F at Sweet Olive hadthe lowest cumulative yield (6.7 lb/plant).
night and vented at 90F during the day. On April 15, all The size andweightoffruitdiminished duringthe
transplants were moved to a cold frame forhardening. growing season. The determinate cultivars, Chiquita and
Water-soluble 20-20-20 fertilizerwas addedtothe pots 1 SweetOlive, changed leastbecause the fruitwere borne on
weekbefore transplanting in the field. On June 4, seedlings plants whose vegetative growth ceasedasthe first fruit
ofeach cultivarwere transplanted 2 feet apart in rows 6 feet began tomature. Weight, length, anddiameter oflate fruit
apart. Theplanting consisted ofsix 10 X 6-foot blocks, seldom decreased morethan 0.1 ounce or0.1 inch compared
replicated three times. Each block contained five plants ofa to early fruit (Table 3). Fruitofthe indeterminate cultivars
single cultivar. The blocks were randomly placed within Santa, Summer Sweet, and Tami-G became progressively
each replication. Each cultivarwas represented by 15 plants. smaller in length and diameter, decreasing0.1 to 0.3 inches
Fertilizer. The soil wastreated with 10-10-10 fertilizerat comparedto early fruit. The smallerfruitweighed 0.2 to 0.3
arate of1300 lb/A before transplanting. The pH ofthe soil ounces less on September9 comparedto fruitharvested on
was 6.4; therefore, no lime was applied. August 8. As the plants became progressively largerduring
Pruningandtying. When the plants were about 15 inches the growing season, greaternumbers offruitwere being
tall, all suckers were removed up to the large lateral branch produced but their size and weightdecreased.
thatdevelopsjust below the first flowercluster. Basal No standards have been established forthe size and
shoots, often developing duringthe growing season, were weight ofgrape tomatoes. Commercial seed catalogues
also removed. Afterpruning, the branches ofall plants were generally distinguish them from cherrytomatoes largely by
tiedto 5-foot oak stakes. Additional tying was necessary as size and shape. The fruitofgrapetomatoes aregenerally
the plants extended theirbranches. Determinate plants were small and elongated (oval) comparedto cherrytomatoes
tied twice and indeterminate ones were tied threetimes by which are small andround. The degreeofelongation ofeach
the end ofJuly. At thethirdtying, strings were attached cultivar is shown in Table 3. In the cultivars tested, the
almosttothe top ofthe stakes. Thereafterthe lengthening length to diameterratio ranged from 1:1.2-1.4 in Augustand
branches cascaded toward theground. This configuration 1:1.1-1.2 in September, i.e. they became slightly more
made it more difficulttoharvest fruit from inner clusters rounded as the season progressed. A round cherrytomato
developing on ascending stems. Tallerstakes wouldhave would have a length to diameterratio of1:1. Fruit from the
made late harvests less difficult. commercial Santasample had an average ratio of1:1.3 and
Harvest. The first fruitwere harvested on July23 and weighed 0.4 ounces. Most seedcatalogues describe grape
continuedweekly until October9. Atharvest, the picked tomatoes as weighing 0.33 to 0.50 ounces.
fruitranged from full to halfmaturity. Fruitshowingthe first Grape tomatoes are the smallest ofthe elongated fruit
blush ofredremained unpicked until the nextharvest. types. The largerelongated types, which weigh between 1 to
During August 8 and September20 harvests, 25 fruit ofeach 4 ounces, include saladette (sliced fresh in salads) and plum
cultivarwere randomly selected formeasurements of orroma (used in sauces). Pink-skinned Chiquitaand red-
weight, diameter, and length. These measurements were skinned SummerSweet, with fruitweighing 0.6 to 0.7
.
Grape Tomato Trials 2001
Table 3. Yield and fruit characteristics ofgrape tomatoes grown at Mt. Carmel, 2001.
Fruit Characteristics
August 8 September20
Avg. Est. Avg. Avg. Avg. Ratio Avg. Avg. Avg. Ratio
Cum. Cum. Wt./ length Dia. Dia.: wt./ length dia. Dia.:
Yield* Yield** Fruit Fruit Length Fruit Fruit length
Lb/plant Lb/A Oz. In. In. Oz. In. In
Chiquita 8.7b 31,580 0.6 1.4 1.1 1:1.3 0.5 1.3 1.1 1:1.2
Santa 15.2a 51,120 0.4 1.2 1.0 1:1.2 0.2 1.0 0.8 1:1.2
Summer Sweet 15.2a 51,120 0.7 1.4 1.2 1:1.2 0.4 1.1 1.0 1:1.1
SweetOlive 6.7b 24,320 0.4 1.2 1.0 1:1.2 0.3 1.0 0.9 1:1.1
Tami-G 10.9ab 39,570 0.4 1.3 0.9 1:1.4 0.2 1.0 0.8 1:1.2
Santa-Commercia ... 0.4 1.2 0.9 1:1.3
* Mean separation within columns by Tukey's HSD multiple comparison test at p=0.05
Values in column followed by the same letterdid notdiffer significantly.
** Based on a plant spacing of2' x 6' or3630 plants/A
ounces, are listed as "grape tomatoes" in seed catalogues were heavier. Afterweek 8, the cumulative yieldofSanta
although theirsizes are largerthan normal. caught up with SummerSweet and keptpaceuntil the final
Seasonaldistribution ofharvest. Harvest ofmost yield on the week 12. Afterweek 8, cumulative yields of
cultivars began on July23 and concluded on October9, a Chiquita and SweetOlive slowed as the last fruitwere
12-weekperiod. The seasonal distribution is shown in Figure harvested. The cumulative yield ofTami-G keptpacewith
1. Upto week4, yields ofall cultivars were relatively low all cultivars uptoweek3, then laggedbehind in weeks4
with only 5-15% ofthe total yield harvested. A marked through 6. In week 7, itoutpaced determinate cultivarSweet
increase in the yield ofall cultivars was noted in weeks Olive and in week 9 it outpaced determinate cultivar
5 and 6. Up to week 8, cumulative yield ofChiquita and Chiquitawhose harvestconcluded after 1 1 weeks. The
Summer Sweet outpaced all others because their larger fruit yields ofChiquitaand Sweet Olive markedly decreasedafter
8 weeks. Bythis time nearly 90% ofthe fruithad been
harvested.
2001 GRAPETOMATOES
CRACKING OF FRUIT
Cracking oftomato fruit, aphysiological disorder, causes
-•-CHIQUITA
O SANTA serious economic loss in the field. Cracked fruitare less
-T—SUMMERSWEET
—V- SWEETOLIVE attractive andthe cracksprovide entry ofinsects and decay
— TAMI-G organisms. Crackingmay occurat anytime duringthe
r growing season, but it is more prevalent late in the season on
fruit from upperclusters (Peetand Willits 1995). Cracking
- i occurs when themovement ofwater into the fruit is rapid or
5 prolonged. Heavy rains following aperiod oflow soil
moisture causes rapid expansion ofthe interiorpulp. Ifthe
pericarp (skin) is inelastic, it suddenly ruptures. Cracking is
more prevalent late in theharvestseason becausethe
HARVESTWEEK pericarp becomesthinneron the more abundant developing
fruit. Cultivarsthatresistcracking generally have thicker
Figure 1. Cumulative distribution ofyield throughoutthe pericarps, a characteristic that may renderthe fruit less
growing season-2001 palatable.
Connecticut Agricultural Experiment Station Bulletin 978
In the experimental plots at Mt. Carmel, cracking in the thatdevelops immediately belowthe firstflowercluster. As
upperclusters offruit became more noticeable in late- the season progresses, additional pruningofbasal shoots at
September. Within individual maturing clusters offruit, only the soil line may be necessary.
those fruitthat were fully mature were prone to cracking. Mulching. Although no mulches were used on the
Among all cultivars, cracking in the larger-fruited Chiquita experimental plots, some growers use black plastic mulch to
(50%) and Summer Sweet(42%) were most prominent. At warm the soil, conserve moisture, reduce nitrate leaching,
the time ofmeasurement, Chiquita neared the end ofits and control weeds. Ifthe plants are not staked, plastic mulch
productive usefulness. Crackingwas least in small-fruited protects the fruit from directcontactwith the soil. Ifplastic
Tami-G (12%) and Santa(26%). Cracking in SweetOlive mulch is used, soil moisture should be near field capacity
was intermediate (35%). when the mulch is laid.
Harvest. To avoid excessive cracking, fruit should be
MANAGEMENT STRATEGIES harvested before they become fully mature. Fordirect
roadside sales or farmers markets, fruit should be harvested
Selection ofcultivars. Because the category ofgrape as they begin to ripen. Fully ripened fruitwill ship poorly,
tomatoes is new and initially suffered legal restrictions, few but ifslated fordirect sales on the day ofpicking, fully
cultivars were available for evaluation in 2001. In 2002, six ripened fruit should remain intact forseveral hours.
more cultivars have been released by seedsmen but are Containers forharvest should be shallow andnot allow more
untested in Connecticut. Santahas become the standard for thatthree layers offruitto accumulate. Ifthe fruit is fully
grape tomatoes but has limited availability because ofthe ripened, additional layers may cause cracking in the bottom
exclusive agreement between the developer ofthe cultivar layer. Ifthe colorofthe fruit is in the turning stage, deeper
and agrower-shipper. Among the othercultivars tested, containers may be used.
Tami-G mostclosely resembles Santa in fruit characteristics. Diseasecontrol. The experimental plots were freeof
Forsustained yields, indeterminate cultivars Santa and disease. The grape tomato plants appearedto have resistance
Summer Sweetprovide the longest harvest span (12 weeks). to early blightand Septoria leafspot. Standardtomatoes
Theyields ofdeterminate cultivars Chiquitaand Sweet grown in aplot30 feetaway, were severely infectedwith
Olive decline after 8 weeks. To increase late yields of both diseases which virtually denuded the vegetation ofall
determinate cultivars, one might considera second planting plants by late August.
in early July.
Transplants. Although direct seeding ofa crop is REFERENCES
possible in Connecticut, transplants will promote earlier
harvests. Transplants should be given adequate space to Boe, A.A., Pelofske, P.J., and Bakken, T.J. 1980. "Santa",
develop a stocky plantwith a well-developed root system. "Gem State", and "Benewah" tomatoes. Hort Science 15:
Cells measuring 2 to 3 inches are preferred (Ferro, et. al. 536-537.
1998). Ifthe containers are too small, the plant may become
Ferro, D.N., Bonnano, A.R., Howell, J.C., and Wick, A.C.
leggy and root bound. Transplants, grown in agreenhouse, 1998-1999. 1998 New England Vegetable Guide. Univ. of
shouldbe free ofaphids and white flies. Massachusetts, Amherst, MA. 98p.
Stakingortrellising. Eitherpractice is necessaryto
maintain the health ofthe plants and reduce rotting offruit in Harvey, C. 2001. Grapetomatoes taking overcherry niche.
contactwith the soil. Tyingthe branches in an upright The Packer- BusinessNewspaperofthe Produce Industry.
position increases aircirculation and may lessen the January 8, 2001. page 7.
development ofearly blight and Septoria leafspot. Untied
Lister, T. 2000. Shippers relieved by resolution ofgrape
plants have poor aircirculation and harvest offruit is more
tomato debate. The Packer- Business Newspaperofthe
difficult. The firsttying occurs when the plant can no longer
Produce Industry. September 18, 2000. page4.
support its weight. Determinate cultivars require a second
tying and indeterminate cultivars may require athird and Peet, M.M., and Willits, D.H. 1995. Role ofexcess water in
fourth tying to prevent the branches from touching the tomato fruitcracking. Hort Science 30:65-68.
ground. Six-foot stakes are preferred for indeterminate
Rosselle, T. 2000. Grape tomato market steady despite rising
cultivars while 4-foot stakes may suffice fordeterminate
acreage. The Packer- BusinessNewspaperofthe Produce
cultivars.
Industry. December 18, 2000. Page4.
Pruning (suckering) Pruning lower side shoots reduces
.
the mass ofvegetation developing duringthe growing
season and enables easier harvest oflower clusters offruit.
The lowershoots that develop between the main stem and
leafbranches should be pruned upto the first lateral branch
Digitized by the Internet Archive
in 2011 with funding from
LYRASIS members and Sloan Foundation
http://www.archive.org/details/grapetomatotrialOOhill
The Connecticut Agricultural Experiment Station (CAES) prohibits discrimination in all itsprograms and activities
on the basis ofrace, color, ancestry, national origin, sex, religious creed, age, political beliefs, sexual orientation,
criminal conviction record, genetic information, learning disability, present or past history of mental disorder,
mental retardation orphysical disability including but not limited to blindness, ormarital orfamily status. To file a
complaint ofdiscrimination, write Director, The ConnecticutAgricultural Experiment Station, P.O. Box 1106,New
Haven, CT 06504, or call [phone]. CAES is an equal opportunity provider and employer. Persons with
disabilitieswho require alternate meansofcommunication ofprogram information should contactthe Station Editor
at(203) 974-8446(voice); [phone] (FAX);[email protected](E-mail)
University of
Connecticut
_
:'.!\:'v'''
*M#k
39153028611459 mmm ' Wss
EBi
!3**S
I
W!s>KS
SBtt
S1&;
.'-",-'
n <H'-m'' -,,;r''-h''Hive'rvr-^-:' B
»8« IM
':':"•>*
£*
M'*,
'mSL