Experiments were conducted during 2000 and 2001 to determine the effects of floral and foliar application of the bacterial strain Bacillus OSU 142 on the yield, growth and nutrient element composition of leaves of the apricot cultivar Hacihaliloglu grown in the Malatya province of Turkey. In 2000, trees were sprayed with a bacterial suspension at full bloom, and 30 and 60 days after full bloom. This experiment demonstrated significant differences in yield, shoot length and nutrient element composition of leaves only on trees treated at the full bloom stage. In view of this, the bacterial application was performed only at full bloom in 2001. The average increase in yield in 2000 and 2001 was 30% and 90%, respectively, compared with the untreated control Shoot length development was significantly higher when trees were treated with OSU 142 at full bloom stage in both years. Similarly, N, P, K, Ca and Mg contents of leaves were higher on OSU 142-treated trees than on the untreated control. The results of this study suggest that OSU 142 has the potential to increase the yield of apricot trees.