Study On The Effect Of Different Pollen Sources, Multiple Pollination Methods, And Pollination Frequency In Khastaawi Date Palm On Quantitative And Qualitative Traits Of Yield

Abstract

Date palm cultivation is one of the fundamental crops in Iraq, due to its economic, nutritional, and strategic importance within the national food security system. Given that climate changes in Iraq have had negative effects, this study aimed to investigate the impact of pollination sources, pollination methods, and pollination frequency on the chemical and productive traits of this cultivar. The study also measured the anatomical characteristics of pollen grains by assessing shape, polarity, germination opening, wall thickness, and surface ornamentation, in addition to measuring the seed germination percentage of pollen in the laboratory for the three cultivars. The main factors included: First, pollen source (A), consisting of Red Ghnamee (A1), Green Ghnamee (A2), and Khakri (A3). Second, pollination method (B), consisting of: pollen suspension (B1), dry pollination (B2), and using four male catkins (stamens) (B3). Third, number of pollination repetitions (C), consisting of pollination one time (C1) and pollination twice (C2). The experiment was conducted according to a randomized complete block design (RCBD) in a factorial arrangement with three replications. Across all pollen sources, fruit set generally increases as it moves from B1 to B3 and from C1 to C2, as in figure 1a.  For instance, B3C2 tends to yield the highest fruit set, while B1C1 tends to yield the lowest. By pollen source (A1, A2, A3); A1 values rise from B1C1 (70.00) to B3C2 (77.08); A2 (Green Ghnamee): values rise from B1C1 (65.52) to B3C2 (69.40); A3 (Khakri): values rise from B1C1 (60.35) to B3C2 (65.14). Across pollination methods and repetitions, fruit drop percentages decline from B1C1 to B3C2; For A1 drop goes from 30.00% (B1C1) down to 22.91% (B3C2); For A2 drop goes from 34.48% (B1C1) down to 30.26% (B3C2); For A3 drop goes from 39.65% (B1C1) down to 34.85% (B3C2). There were also significant differences for the main factors and the two-way interactions among the study variables. The results showed that the pollen source type, pollination method, and pollination repetition have clear significant effects on the productive and chemical traits of the date palm cultivar Khastaawi. The use of the Red Ghnamee pollen with repeated pollination using the traditional method contributed to improved fruit set percentage and reduced fruit drop, positively affecting the weight of the spike and the overall palm yield. The pollination treatments also increased total sugars percentage and reducing sugars percentage in the fruits, indicating the possibility of using these treatments to improve the fruit’s chemical quality. The study recommends adopting effective pollen source materials and pollination repetition according to a studied schedule to enhance production efficiency in the Khastaawi date palm cultivar under similar environmental conditions.