Abstract:
This study was carried out on Uzun and Siirt pistachio cultivars present at the
Pistachio Research Institute orchards. After the most suitable pruning, fertilization
and irrigation practices, different plant growth regulators were sprayed on entire
trees at the different doses, and effects of plant growth regulators on alternate
bearing were investigated.
In the study, 10, 25 and 50 ppm 1-Naphthaleneacetic acid (NAA), 25 ppm Nbenzyl-9-(2-tetra-hydropyranyl) adenine (BA) and 0.25% urea were used, and 0.25%
urea was added to all plant growth regulators’ doses. Plant growth regulators were
sprayed to the fruits, buds and leaves to the point of drip. Applications were done
two times in year. First application was done at starting kernel development, and
second application was done 20 days after the first application.
According to the results, the highest yield was obtained from 25 ppm
benzyladenine + 0.25% urea in Uzun (4.98 kg per tree) and 47.29% of inflorescence
buds retained in this application. The lowest yield was obtained from control as 4.05
kg per tree and 47.56% of inflorescence buds retained in control.
At the Siirt, the highest yield (8.26 kg per tree) was obtained from 0.25% urea
application and 51.58% of inflorescence buds retained in this application. The lowest
yield was obtained from 50 ppm naphthalene acetic acid application (5.16 kg per
tree) and 58.49% of inflorescence buds retained in this application. At the Siirt , 5.53
kg yield per tree was obtained from control and 6.01 kg per tree obtained from 25
ppm benzyladenine + 0.25% urea.
