Maturity, Ripening, and Quality Relationships 57
1975). Changes in firmness with advancing maturity in apples have been shown to
be related to deterioration of the cell wall structure of the fruits (Tu et al., 1997).
In general, a firmer fruit is assumed to be less mature and to have a more complex
cell wall structure than a softer fruit. Maturity is often defined as optimal firmness
in relation to a particular fruit. However, the actual threshold value for optimal
FIGURE 3.1Stages of development and senescence based on physiological processes and
usage of horticultural crops. (From Watada et al., HortScience, 19, 20, 1984. With permission.)
INITIATION DEVELOPMENT
GROWTH
MATURATION
RIPENING
SENESCENCE
PHYSIOLOGICAL
MATURITY
DEATH
INFLORESCENCES
artichoke, broccoli, cauliflower
cucumber, green bean, okra, sweet corn
PARTIALLY
DEVELOPED FRUITS
asparagus, celery, lettuce, cabbage
apple, pear, citrus, tomato
carrot, onion, potato
ROOTS & TUBERS
FULLY
DEVELOPED FRUITS
Ornamental Crops
SEEDLINGS
CUT & POTTED
FOLIAGE
NURSERY STOCK
POTTED
FLOWERING
PLANTS
CUT
FLOWERS SEEDS
HORTICULTURAL MATURITY
SPROUTS STEMS & LEAVES
SEEDS
dry bean