Quote:Today there are many white peach varieties which are highly colored and sufficiently
firm for shipping.

White-FleshedPeach and ApricotBreeding

Joseph C. Goffreda
Rutgers Fruit Research and Extension Center, Rutgers University
Cream Ridge, NJ

Presented at the 42n dAnnual IDFTA Conference, February 20-24, 1999, Hamilton, Ontario,
Canada.

ORIGIN OF PEACH CULTURE IN THE US
Peaches are not native to the western hemisphere.They are believed to have originated in
China where they were cultivated for at least 4,000 years.It is in this region where the greatest
genetic diversity still exists.The spread of peaches to the west followed along ancient trade
routes from China to Persia (hence the name for peach,Prunus persica) and from Persia into the
Mediterranean region including Greece, Italy and Spain.Peaches were not introduced into
North America until the late 1500s by Spanish explorers but they spread rapidly along the
eastern region.By the late 1600s, both white- and yellow-fleshed peach cultivars were being
produced commercially in the mid-Atlantic.

Since peach cultivars were derived from a relatively small subsample of the genetic diversity
available in China, the genetic base of cultivars in the United States (US) was limited.This
situation was greatly exacerbated by the introduction of Elberta in 1889, a chance open
pollinated seedling from Chinese Cling.When Elberta was introduced, it was an extraordinary
cultivar for the commercial shipping market because of its large fruit size and superior firmness.
Elberta rapidly became the most popular variety in the US, and varieties derived from Elberta
proved to be even better, further shifting the marketplace toward yellow-fleshed types.
Consequently, breeding programs in the eastern US have focused primarily on developing
commercial yellow-fleshed cultivars which are largely descendents of Chinese Cling (Scorza et
al., 1985).The lack of breeding effort with white-fleshed varieties resulted in cultivars which
lacked the size, color, and firmness of their yellow-fleshed counterparts.

Due to recent breeding efforts to develop white peaches for the commercial market, there is
renewed grower interest in planting white peaches in the US.The large number of attractive
white-fleshed varieties developed by Zeiger Genetics, CA, is particularly noteworthy.Today
there are many white peach varieties which are highly colored and sufficiently firm for
shipping.It has been my experience that the majority of white peaches being released today are
of a sub-acid type, possessing a dominant allele that reduces the malic acid content of the
mature fruit.In general, these varieties are especially well suited to regions with mild winters
and limited bacterial spot but have not been widely adapted to eastern growing conditions.
However, there are exceptions such as White Lady, which is being successfully grown
commercially in New Jersey (NJ).

NJAES TREE FRUIT BREEDING PROGRAM
The state of New Jersey is the most densely populated state in the US.Consequently,peach
production in NJ faces numerous challenges including high land costs, suburban sprawl, limited
seasonal labor, and various environmental issues such as ground water contamination.The
climate of the northeast also poses other risks.The moderating effects of the Atlantic Ocean
often result in chilling requirements being satisfied by the end of December.In January and
February, temperatures can rise as high as +20oC (68ºF), causing the fruit trees to lose their
hardiness.Then, with the passage of an arctic cold front, the temperatures may drop to -20oC
(-4ºF) in just a couple of days.Our summers are often quite humid and rainy, increasing disease
pressure.Nevertheless, NJ is a major peach producing state, ranked 4thor 5thin the US.New
Jersey peach growers are typically paid 2-3 times as much for their peaches as are peach
growers in California because NJ is centrally located near several large metropolitan areas
including Washington, DC, Philadelphia, New York and Boston.

The New Jersey Agricultural Experiment Station (NJAES) established a tree fruit program in
the early 1900s to help satisfy the specialized needs of growers in this region.Today we have
an active breeding program to develop new cultivars of peaches, nectarines, apricots, and
apples.The main objective of the peach breeding program is to develop varieties of peaches
and nectarines that are highly productive in our environment and tolerant of diseases such as
cytospora canker, fusicoccum canker, and bacterial leaf spot.The fruit should be highly colored
with an attractive ground color, large (preferably 6.3 cm [2 1/2 inches] or greater in diameter),
and suitable for shipping.Since NJ is becoming increasingly suburbanized, there is interest in
growing unique, high quality stone fruit for the roadside and local markets.Another objective
of the NJAES breeding program is the incorporation of novel characters into peach that may be
useful in expanding the market for peaches, especially for the roadside markets.Such
characters include white-fleshed types (Goffreda, 1998), exceptional quality peen tao (flat or
doughnut) peaches, and fruit with the nonmelting or stony hard fruit texture.

Listed below are a few of the most promising white peach and nectarine varieties and selections
that exemplify the diversity of types being developed by the NJAES breeding program.

COMMERCIALLYAVAILABLE NJAES WHITE PEACH VARIETIES
Raritan Rose(JH Hale x Cumberland)
A white peach variety released by the NJAES in 1936.It is a fairly attractive peach ripening in
Redhaven season.The fruit are 5.7 to 7 cm (2 1/4 to 2 3/4 inches) with 50% mottled red over a
green-cream ground color.The tree and fruit have moderate bacterial spot resistance and the
fruit have average quality.Raritan Rose is still offered in the nursery catalogs and is being
grown for roadside market.

Summer Pearl® (NJ252)
Peach released by the NJAES which ripens about 3 weeks after Redhaven.Fruit have 60% red
over color on a cream-green ground color.Its pubescence is quite short and the variety can be
attractive in some years.The fruit are approximately 6.3 cm (2 1/2 inches) and usually firm
enough for shipping short distances.Fruit quality is usually very good.However, Summer
Pearl has not been very productive and is susceptible to bacterial spot.

Lady Nancy®
A white limb mutation of Jerseyqueen that was selected by Medio DeMarco, a New Jersey
peach grower.It was introduced in 1989.Lady Nancy ripens with Jerseyqueen, about 4 weeks
after Redhaven.Fruit are very large with about 60% pink-red over color on a cream-green
ground color.Flesh color is white except at the suture which is yellow.This indicates that the
mutation is not present at all cell layers and can make the flesh color of the variety somewhat
less stable.Resistance to bacterial leaf spot and winter injury is similar to that of Jerseyqueen.

PROMISING NJAES WHITE PEACH SELECTIONS
K39-1(D87-88x J19-19)
An attractive semi-freestone peach which ripens about 2 to 3 weeks before Redhaven.Fruit are
90%+red over cream ground with short pubescence.The fruit are 5.7 to 6.3 cm (2 1/4 to 2 1/
2 inches) and have good firmness and eating quality.Trees are productive and have moderate
resistance to bacterial spot.

D80-8 (NJ318 x H3-76)
A firm, nonmelting, clingstone peach ripening about 1 to 2 weeks before Redhaven.Fruit are
very attractive with 75-90% red over color on a cream ground color.The fruit are 6.3 cm (2 1/
2 inches) and have short pubescence.The flesh has a nonmelting texture and it has a very good
sweet, sub-acid flavor.This variety is very firm and suitable for shipping. This is a recent
selection which has exhibited moderate bacterial spot resistance.It is too early to assess
productivity.

NJ312 (NJ293 x Jing Yu)
A semi-freestone peach ripening with Redhaven.Fruit can be attractive with 50-80% red over
cream green.Fruit are 6.3 to 7.0 cm (2 1/2 to 2 3/4 inches).This peach also has a mild, sub-
acid flavor.The fruit may soften rapidly limiting this selection to the roadside market.
However, it has some resistance to bacterial spot and has been fairly productive.

D89-9(NJ318x Flavorcrest)
A freestone peach ripening just after Redhaven.Fruit color very early attaining 90% pink red
blush on a cream ground color.Fruit are 5.7 to 6.3 cm (2 1/4 to 2 1/2 inches) and are bright and
very attractive.The fruit are also very firm and retain their firmness on the tree for over 1 week.
This peach has a mild, sub-acid flavor.This is one of several exciting selections recently made
from this progeny. At this time we do not have an accurate assessment of their level of disease
resistance and hardiness.

NJ318(NJ256x Biscoe)
A freestone peach ripening about 3 weeks after Redhaven.Fruit are attractive with 60% red
over a cream-green ground color.Fruit are 6.3 to 7.0 cm (2 1/2 to 2 3/4 inches) and size well
even when over-cropped.Fruit have a mild, sub-acid flavor.Trees have good bacterial spot
resistance, but the fruit may soften fast.Trees have also exhibited above average susceptibility
to fusicoccum canker.

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