1. PHASE 1
ENVIRONMENTAL IMPACTS ON BERRY
DEVELOPMENT PROCESSES
A minimum amount of light is required for enzyme
induction to drive the processes in Phase 1,
however, low temperatures slow down enzyme
activity and thus can prolong this phase.
Excess water or nitrogen availability can also result
in an extended Phase 1 influencing the activity of
enzymes and hormones, especially in relation to
cell-division in the developing pulp and skin, which
governs the eventual size and juice content of berries.
Conversely, low water levels can shorten this cell
division phase in berries. In this instance, abscisic
acid (ABA) is produced in roots when vines
experience water stress after flowering, shortening
the cell-division process and resulting in smaller
berries.Viticulturists exploit this process as a quality
management tool by the application of partial
rootzone drying (PRD) and regulated deficit
irrigation (RDI).
KEY GRAPE QUALITY DEVELOPMENTS
DURING THIS PHASE
Some of the traits that are crucial for many wine
styles develop very early during this phase.
• Important acids accumulate, eg. tartaric and
malic acid. These act as chemical stores of
energy and may also be involved in defence of
the berry against being eaten before the seed is
fully developed.
• The amount of tartaric acid remains constant
during ripening but the concentration decreases
as the berry increases in volume.
• Malic acid is used as an energy source for berry
metabolic processes.
• Minerals are imported into berries with sugar, as
are nitrogenous compounds.The import of nitrogen
peaks after berry set. In unripe fruit, ammonium
represents more than half of the total nitrogen.
• Phenolic molecules are made from fruit set
onwards, while the most important period for
phenolic development is 2-3 weeks before veraison:
• Many aroma characteristics develop during this
early phase of berry development, such as the
‘grassy’ methoxypyrazines which contribute to
the capsicum flavour in some wines.
UNDERSTANDING GRAPEVINE GROWTH NUMBER 4:
Viti-Noteswww.crcv.com.au 2005
The berry development process - Phases 1 and 2
Current Vitinote titles in this
Understanding grapevine
growth series include:
1. Dormancy and budburst
2. Spring shoot
and root growth
3. Flowering
4. The berry development
process – Phases 1 and 2
5. The berry development
process – Phase 3
6. Defining berry ripeness
7. Site factors influencing
berry ripening processes
and rates of ripening
THE FIRST STAGE OF BERRY
DEVELOPMENT STARTS SOON AFTER
FERTILIZATION OF THE FLOWER, AND IS
CHARACTERIZED BY STRONG GROWTH
OF THE SEED AND BERRY. AT THIS POINT,
THE FINAL NUMBER OF CELLS IN THE
BERRY IS DETERMINED AND ACIDS ARE
ACCUMULATED

2. THE CRC for Viticulture is a joint venture between the following core participants, working with a wide range of supporting partners.
www.crcv.com.au
• Similarly to acids, these may help defend the berry against herbivores.
The role of this aroma in repulsing animal predators generally
disappears as the berry matures, but it may be a desirable fruit
characteristic in some varieties, eg. Sauvignon Blanc.
• These compounds can be retained in fruits due to cloudy conditions,
shaded fruit, and no water stress.
PHASE 2
During Phase 2 the berry itself exhibits slow growth as energy is being
diverted to development of the seeds. This is vital in biological and
viticultural terms as the hormone abscisic acid (ABA) which eventually
triggers berry ripening is formed in the seed.
ABA is synthesized in the seed itself and incorporated into the embryo
where it inhibits the germination of the seedling at this time.
Late in Phase 2, ABA is exported into the fruit from the seed, where it
initiates the ripening of berries. Lignification of the seed begins at the
end of this stage.
Phase 2 lasts between 7 and 40 days and depends on variety and
temperature. It is the most temperature-sensitive stage, being delayed by
daytime temperatures below 18°C or above 35°C, or night time
temperatures below 13°C or above 30°C. These temperatures affect the
activity of the vast number of enzymes active in differentiating and
growing the seeds in the developing berry. Colour development is also
delayed when vines experience high temperatures during this phase.
Berries that contain an immature seed do not naturally accumulateABA and
do not undergo veraison.The start of veraison can be artificially postponed
by the application of cytokinin mimics orABA antagonists like salicylic acid.
FURTHER INFORMATION
Product or service information is provided to inform the viticulture industry
about available resources,and should not be interpreted as an endorsement.
USEFUL REFERENCES:
• Biology of the grapevine, 1992 by MG Mullins, A Bouquet and E
Williams published by Cambridge University Press.
• Soil, irrigation and nutrition, Grape Production Series No. 2, 2003
edited by P Nicholas.
• Viticulture and Environment, 1992 by J Gladstones.
• Viticulture, 1992 by BG Coombe and PR Dry.
Information in this Vitinote has been adapted from the CRCV Winegrape
quality management: Research to Practice® workshop manual. The
Viticulture Research to Practice®
workshops are training programs
whose delivery can be fine-tuned to suit each region.
• Enquiries to Peter Mansfield at Winetac on (08) 8373 7090 or visit
www.crcv.com.au for more information.
Visit the web site at www.crcv.com.au/viticare/vitinotes/ for updates and
more Vitinote titles.
©2005 Cooperative Research Centre for Viticulture
THIS IS ALSO KNOWN AS THE ‘LAG’ PHASE AS THE
BERRY ITSELF GROWS ONLY SLOWLY. DURING THIS
PERIOD THE EMBRYO WITHIN THE SEED MATURES
AND THE SEED COAT LIGNIFIES. TOWARDS THE END
OF THIS PHASE AS VERAISON (PHASE 3) APPROACHES,
COLOUR CHANGES OCCUR IN THE BERRY