effect of chemical thinning on characteristics of fruit and alternate bearing of dezfoul and fishomi olive cultivars

experiments were carried out in a commercial orchard during 1994, 1995 and 1996 to determine the influence of chemical thinning on characterisics of fruit and alternate bearing of native olive (olea europea l) cvs. dezfoul and fishomi at early fruitlet stage. in 1994, branch sprays of naphthalene acetic acid (100, 150 and 200 mg/l), naphthalene acetamide (200 and 300 mg/l) and urea (0.6 and 1.2%) were applied to limbs of dezfoul and fishomi when their fruitiets diameters were 6.43 and 6.28 mm, respectively. in the first experiment (1994), treatments had no considerable effect on characteristics of the fruits and alternate bearing in both cultivars, possibly due to late spraying. in the second year, same trealtments were applied to limbs of' dezfoul and fishomi when their fruitlets diameters were 3.80 and 3.73 mm, respectively. naa at 150 and 200 mg/l n dezfoul and 100, 150 and 200 mg/l in fishomi signjficantly induced fruit abscission, but nad and urea had no effect on fruit abscission in both cultivars. naa at 150 mg/l in fishomi and 200 mgll in dezfoul significantly increased fruit weight, length, diameter, volume, flesh weight and flesh to seed ratio. none of the treatments had significant effect on return bloom. in 1996, branch sprays of urea (1.2, 3 and 6%) and sevin (1200 and 2400 mg/l) had no considerable effect on abscission percent and characteristics of fruit in both cultivars.