Agriculture Reference
In-Depth Information
clones. In some cases the incidence of mutation has been increased by ir-
radiation and desirable clones produced (Lacey and Campbell,
). Some
'sports' also differ from the parent cultivar in time of harvesting and in chilling
requirement (Gonzalez-Cepeda,
; Hauagge and Cummins,
). The
data given in Table
include 'sports' within each cultivar even though many
of the 'sports' have been patented and given individual names.
There is little comparative data on changes over time in the global produc-
tion of different cultivars (O'Rourke,
.
). However, the total production and
market share of cultivars introduced after
('Fuji', 'Gala', 'Jonagold' and
'Elstar'), together with that of 'Braeburn' (discovered in
) has increased
very rapidly, whereas that of 'Jonathan', 'Rome Beauty' and 'McIntosh' has
declined in relative terms. The continued predominance of 'Red Delicious' in
large part follows the steady introduction of new strains of this cultivar.
The key attributes of apple cultivars concern those characteristics which
give them customer and marketing appeal and those which determine their
adaptability to different environments.
Apple cultivar fruit quality
In common with some other tree fruits, but in sharp distinction from many
other crops, apples are marketed to the end-purchaser, the consumer, by cul-
tivar name. Surveys in the United States in
) showed
'Red Delicious', followed by 'Golden Delicious', to be the favourite cultivars
but with 'McIntosh' in second place in Pennsylvania. Freedom from bruise
or blemish, juiciness and crispness, and firmness were universally regarded as
the most important quality factors; others were colour, shape and size. Fukuda
(
-
(O'Rourke,
) noted that 'Ralls Janet' and 'Jonathan' had been the top two cultivars in
Japan until the 'economic takeoff' in the
s when consumers shifted their
choice to sweeter and larger apple cultivars. As a result these were replaced by
'Delicious' strains and 'Fuji'. 'Delicious' became the top cultivar in the
s
but then lost popularity because, as grown in Japan, it quickly became mealy
and also developed internal breakdown. By
'Fuji' occupied
%ofthe
planted area and 'Delicious' only
) concluded that the
relative sales of 'Red Delicious' and 'Granny Smith' indicated that more con-
sumers prefer a red sweet apple than a green and tart one, but regarded these
as separate markets.
Fruit flavour is dependent on the combination of acids, sugars, tannins and
aromatic compounds, but consumer acceptability is basically determined by
the balance between acidity and sweetness. The main sugars are fructose, suc-
rose and glucose; the acid in the mature fruit is almost all malic acid, although
Hong
et al
.(
.
%. O'Rourke (
% of citric acid in 'Fuji'. Sweetness and
acidity are inherited independently, so all combinations are possible. Table
) reported
-
.
