Coffee trees, particularly arabica, have a biennial
bearing cycle that can result in alternate heavy and light crops.
This of course affects farmers' annual incomes but the overall
impact is very difficult to measure…
Depending on the overall supply and demand situation at the time
a really low 'off-year' crop in Brazil (arabica) or Vietnam
(robusta) could well affect global output and, therefore, also
prices. It should be remembered however that coffee production is
spread over a large number of countries, each with individual
production patterns. Therefore, one cannot really speak of global
'on' or 'off' years but, biennial bearing in important producing
countries certainly features in global coffee production and
pricing discussions.
Some background to the biennial bearing phenomena
itself:
In a year of heavy cropping most of the available carbohydrate
produced by photosynthesis is used by the developing crop, and
little is available for the formation of new wood (suckers) to bear
the next crop. In the following year that situation is reversed,
with only a small proportion of the available carbohydrate being
required for the crop and most of it being available for new
extension growth. This then results in a heavy crop in the
following year and so on. This pattern of overbearing followed by
poor fruit setting is particularly evident in unshaded coffee and
occurs independently of climatic conditions. However, changes in
rainfall patterns can produce similar effects: heavy crop this year
- little next year..
Careful pruning can minimise the impact of biennial bearing by
maintaining an acceptable ratio of leaf to crop and ensuring that
sufficient new suckers are produced. Shaded coffee, grown under
ideal conditions in the tropics or near the Equator, will present
much less of a problem (if any) than coffee grown under more
stressful conditions. As already mentioned however, coffee
production conditions vary greatly throughout the coffee producing
world and many individual factors affect crop yields. And, none are
unique to all growing areas…
Biennial bearing and production *
The table below clearly shows 'on' and 'off' years in Brazil,
whereas there is no discernable pattern for either Colombia or
Vietnam. To note however that Brazilian production of Conillon
robusta is relatively unaffected by biennial production changes -
the fluctuations shown below are mostly due to fluctuations in
Brazilian arabica production. * Only the three most important
producing countries are reviewed with particular emphasis on Brazil
- the world's largest producer.
Coffee production by crop year
Year | 2002/03 | 2003/04 | 2004/05 | 2005/06 | 2006/07 | 2007/08 | 2008/09 |
World | 122.1 | 104.0 | 115.5 | 109.6 | 126.7 | 118.5 | N/A |
Brazil | 48.5 | 28.8 | 39.3 | 32.9 | 42.5 | 36.1 | 45.9 |
Vietnam | 11.6 | 15.2 | 14.2 | 13.5 | 19.3 | 18.0 | N/A |
Colombia | 11.9 | 11.2 | 12.0 | 12.3 | 12.2 | 12.4 | N/A |
Source ICO - millions of bags - see also topic 01.05.04 of the
Coffee Guide.
Of course, other issues, for example low prices causing trees to be
poorly maintained, also play a role. Indeed, global prices were at
their lowest for many years in the period 2000/2004.
As regards the impact of biennial bearing on pricing we would
suggest that when coffee inventories in both consuming and
producing countries are high, then the phenomena is relatively
irrelevant for prices. But, in low inventory cycles the impact can
be considerable.So, does the market take into account the biennial pattern? Yes
- but only nominally in that it knows the cycle is a fact of life
but it reacts more to actual short-term forecasts, or changes in
the flow of coffee on to the market, than to the fact that it will
be an on or off year. Can that be disentangled? Not really -
it is an ever-present consideration and thus must be factored into
the market at some point but it is a bit like background noise - it
may always be there but one only really notices it when it is
significantly different.
To end, we would summarise that, yes, biennial bearing does
impact on the global coffee scene but - the overall impact is
extremely difficult to quantify. To do so with any accuracy
requires far more statistical and analytical resources than are
available to www.thecoffeeguide.org.
Posted 21 January 2009