Agriculture Reference
In-Depth Information
Maturation
Climacteric
100
100
10
75
50
1.0
0.1
25
Ethylene
0
0
0
30
60
90
120
150
180
Time after anthesis (Days)
Ripening
Cell enlargement
Cell division
Figure 5.6 Relative changes in physiology during growth, development, maturation and ripening in apple
fruit. (Figure by Dr. Ekman, 2006.)
have a very profound effect on fruit quality, and some of
these instances are described below.
rapidly increasing fruit cell numbers. This period is followed
by a more or less linear growth phase until harvest maturity,
during which fruit size increases through cortical expansion
(Figure 5.6).
Research has found that the total fruit cell number
determines the potential maximum fruit size. The total
number of cells in an apple is produced during the initial
cell-division growth phase during the first 60 days after
full  bloom (DAFB) (Stanley et al . 2000). Given no
limitations, these cells would expand to their optimum size
to  provide the maximum fruit weight achievable for that
total  cell number. A reduction in fruit weight would be
expected from trees with a higher crop density (Volz et  al .
1998) or from late thinning of the crop (McArtney et  al .
1996) due to competition for total carbohydrate. Low
temperature during the initial 60 DAFB extends the cell
The influence of seasonal climate on fruit growth
and maturity
The classic apple growth curve is illustrated in Figure 5.6,
and shows the three stages of apple fruit growth; cell
division, cell expansion, growth and ripening. Seasonal
growing temperatures impose many effects on apple
production and most obviously set limits on apple produc-
tion areas (Palmer et al . 2003). Growing temperatures
determine the length of the growing season and alter the
rate  of physiological processes, including cell division,
growth and  respiration (Palmer et al . 2003). Apple fruit
growth is defined by an initial 35-60-day period of
exponential growth following fertilisation coinciding with
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