Comparison of Reproductive and Physicochemical Characteristics of Fruit in the Four Date Palm Cultivars `Qasb, Zahidi’, `Piyarom’ and `Medjool’ in Kerman Province

Date cultivars (Phoenix dactylifera L.) in this experiment are the best cultivars of dried and semi-dry dates in Iran and the world. In many areas, their cultivated area is increasing. The low cost of harvesting, transportation and storage has made farmers want to cultivate these cultivars. In this experiment, important morphological and physicochemical traits of the fruit of these cultivars in Normashir region were studied and compared.

This experiment was carried out in a randomized complete block design with four treatments (Qasb, Zahedi, Pyarom and Medjool date cultivars) in 3 replications for 2 years (2017-2017). Twelve 15-year-old palm trees (Phoenix dactylifera L.) were selected. It was done in the collection of the Research Institute of Tropical Dates and Fruits located in Narmashir city. In this study, number of clusters, number of strands per cluster, percentage of fruit set, parthenocarpy and fruit drop, cluster yield, fruit flesh to kernel ratio, fruit flesh percentage, length, diameter, weight and volume of fruit and kernel, moisture content, total sugar reducing sugar, non-reducing sugar and soluble solids were measured.

Qasb cultivar has more clusters (8 clusters) than other cultivars. The number of strings in the cluster was more in Qasb (61.16) and Pyarom (60) cultivars than other cultivars. The highest percentage of fruit set (76.73%) was observed in Zahedi cultivar and the highest percentage of fruit drop (53.45) was observed in Qasb cultivar. The highest yield per bunch (5547 g), weight (13.77 g), length (4.27 cm), diameter (2.22 cm) and fruit volume (12.74 cm3) were observed in Medjool cultivar. The cultivars were the same in Seed diameter. Zahedi cultivar had the lowest length (2.1cm) and kernal weight (0.8 g) and parthenocarpy (0.47%). Medjool had the highest seed weight (1.09 g) and Pyarom (2.61 cm) and Qasb (2.60 cm) cultivars had the highest seed length. Medjool cultivar had the highest pulp to kernel ratio (11.86), highest percentage of pulp (92.2%) and highest moisture content (18.12%). Zahedi cultivar had the highest total sugar content (77.85), reducing sugar (73.7) and non-reducing sugar (3.15) and total soluble solids content (77.85).

The results of this study showed that under the same managerial and climatic conditions, the top cultivars of dates are different in terms of reproductive characteristics. The high percentage of fruit set and the low percentage of fruit loss and parthenocarpy in Zahedi cultivar indicate the high success of cultivation of this cultivar in the region and similar climates. Cultivars also differ greatly in physicochemical properties of the fruit. In suitable managerial and climatic conditions at the time of pollination, Medjool cultivar with high yield and superior characteristics of fruit in terms of weight, length, diameter and volume of fruit for cultivation with the aim of export seems appropriate. Qasb and Pyarom cultivars with suitable appearance characteristics and lower sugar content are welcomed by some consumers. It is better for gardeners to cultivate and develop cultivars based on market demand in each region and export goals.