EFFECT OF HYDROGEN CYANAMIDE ON BUD BREAK, FLOWERING AND FRUIT GROWTH OF TWO PEAR CULTIVARS (PYRUS COMMUNIS) UNDER TUNISIAN CONDITION

Under Mediterranean condition, the lack of chilling constitutes a limiting factor for deciduous fruit production. To induce dormancy breaking; several chemicals were used by growers but their application effect depend on the spraying time. This work evaluated the consequence of a late application of hydrogen cyanamid on flowering, bud abortion and fruit growth of two pear cultivars, under the climate condition of Tunisia. The experiments were conducted on ‘Dr Jules Guyot’ and ‘Santa Maria’ cultivars, known for their middle chilling requirements. The chemicals tested were Dormex applied at 1 and 2%. The control trees were spayed with water. The parameters evaluated were: flowering, bud abortion and fruit growth. Cyanamid treated trees showed varying degrees of advanced and grouped bud breaking in comparison with the control trees. Very satisfactory improvement in synchronization of blossoming was also observed which can increase the chances of effective cross-pollination inducing a positive effect on yield potential.