Evaluating the Ratio of Vegetative and Reproductive Buds of Pistachio Trees in Rafsanjan Area to Determine the Yield Potential of the Next Year

Pistachio is one of Iran's most important agricultural products, whose export has a special economic and commercial value. Biennial and alternate bearing are among the problems that cause severe fluctuations in this product production and export. Indeed, in the high-yield year of pistachios, the reproductive (flower) buds fall off, leading to alternate bearing and crop decreasing in the next year (off). This year (2021) was a low crop year for pistachios in Rafsanjan; however, reports indicate a reduction in flower bud for next year, contrary to the flowering regulation.

In the present study, four commercial cultivars of pistachio (Fandoghi, Kaleghoochi, Ahmad Aghaei, and Akbari) in different areas of Rafsanjan were sampled. Then, the percentage of vegetative and reproductive buds was determined by their cutting, staining, and microscopic examination.

The results showed that reproductive buds decreased this year and reached about 33% of the total buds, especially for Kaleghoochi and Ahmad Aghaei cultivars.

Considering that only about 10% of flower buds in a cluster turn into fruit each year, it is recommended that pistachio orchards be managed properly with careful planning to prevent a reduction in crop production as much as possible next year.