Apple tree endodormition

Apple production represents the largest production of deciduous fruit trees accounting for 49% of the production area and 60% of total production in tonnes (DIEA 2007). In the last decade growth has been strongly associated with fruit exports which have increased from 52 tonnes worth US$28000 in 1998 to 10921 tonnes worth US$4900000 in 2007 (Tambler 2007). These exports are mainly destined for Europe and although the quality demanded by this market is met Uruguay's climatic conditions present some limitations. These limitations range from difficulties in stabilising high yields to problems related to the quality of the fruit produced. Spring frosts environmental conditions that are not conducive to pollination excessive solar radiation in summer thermal limitations that determine unattractive shapes or colour deficiencies in some apple varieties together with the irregular availability of winter cold are some examples and have in common the difficulty of modifying them in fruit production systems.