جستجوی مقالات مرتبط با کلیدواژه "fruit-set" در نشریات گروه "باغبانی"

In order to the evaluation of the effects of Canary Island palm pollen on the fruit characteristics of commercial date palms cvs ‘Medjool’ and ‘Barhee’ and the possibility of use of the pollen of this specie for date palm pollination, the current study was conducted for two consecutive years in Date palm and Tropical fruits Research Center. The research was conducted as two separate experiments in a randomized complete block design with three treatments of pollen type (Canary Island palm including ‘G1’ and ‘G2’ and date palm cv ‘Red Ghanami’ as control) and three replications (18 trees that were 15 years old). Each palm has considered as an experiment unit. Results showed, traits of percentage of fruit set, parthenocarpy, and fruit drop in ‘Barhee’ cultivar were not affected by pollen source and no significant difference was obsereved between Canary Island palm pollinizers and ‘Red Ghanami’ pollinizer regarding these traits, but these traits were affected by pollen source in ‘Medjool’ cultivar. Canary Island palm pollinizers reduced seed weight, seed length and seed diameter of ‘Barhee’ cultivar significantly. While seed characteristics of ‘Medjool’ cultivar were not affected by Canary Island palm pollens. Qualitative characteristics of ‘Medjool’ and ‘Barhee’ fruits were also affected by Canary Island palm pollens. Overall, at the conditions of date palm pollen deficiency, the use of Canary Island palm pollens (3 g per spathe) for the pollination of ‘Barhee’ cultivar is recommended and for other cultivars more research is needed.

This study was conducted in order to investigate the changes in the growth regulators related to fruit setting in the pollination season on both tissue culture-derived and offshoot-derived date palms cv. Barhee (10 years old) in the Date Palm and Tropical Fruit Research Center of Ahvaz city. At the beginning of spring, palm trees were selected from each group of tissue culture and offshoot trees and sampling of flowers and fruits was done in the three stages including: spath appearance, ripe spath and 2 weeks after pollination in three replications. In order to evaluate fruit setting, three spathes in each palm (1-2 days before natural opening) were pollinated with Ghanami cultivar pollen by traditional method. The plant hormones including auxin (IAA and IBA), gibberellin (GA1, GA3, GA4, GA9), cytokinin (Zeatin and Kinetin), abscisic acid and jasmonic acid were measured in the flower or fruit samples collected from tissue culture and offshoot trees. Five weeks after pollination, fruit set percentage, parthenocarpic fruits percentage and flower and fruit drop percentage were recorded. The results showed that tissue culture derived plants had less fruit set percentage and more seedless fruit and fruit drop percentages compared to off shoot derived plants. Also, the fruit yield in the tissue culture plants was lower than off shoot derived plants.  The levels of gibberellin, auxin, and cytokinin hormones in the off shoot derived plants were higher than tissue culture plants in most of the measured stages.  The tissue culture plants had a higher amount of abscisic acid and jasmonic acid than offshoot plants. By using multiple linear regression analysis and superior model selection, the amount of abscisic acid and jasmonic acid of flower and fruit had a negative relationship with the amount of fruit set. The fruit setting was positively correlated with the amount of kinetin, indole acetic acid, GA3, GA4 and GA9 of flowers and fruits, while had a negative correlation with the amount of abscisic acid and jasmonic acid.

Tomato (Solanum lycopersicum L.) is an important commercial food plant. Several factors affect the growth of tomatoes in the greenhouse, and one of them is proper planting density. Investigating and suggesting the best density in hydroponic cultivation can have a significant effect on production efficiency. Therefore, a factorial experiment was conducted in the hydroponic cultivation system based on completely randomized design with three replications and two treatment of cultivar (Dafnis, Izmono and Hirad) and density (at four density levels of 2, 2.5, 3 and 3.5 plants per m2) in the greenhouse of Gorgan Agricultural and Natural Resources Research and Education Center. Characteristics of number of clusters per plant, number of flowers per cluster, percent of blossom drop, number of fruits per cluster, fruit yield per plant and per m2, number of fruits per plant, number of fruits per m2, average fruit weight, fruit diameter, fruit length, pericarp thickness, uniform fruit ripening, distance between clusters, marketable yield, total soluble solids and pH of fruit juice were measured. According to the mean comparisons, the average yield per m2 at high plant density (3.5 plants per m2) in all three cultivars was significantly higher than others. With the increase of density from 3 to 3.5, from 2.5 to 3.5 and from 2 to 3.5 plants per m2, respectively, relative increases in yield per m2 of 2.4%, 28.6% and 43.1% in Hirad, 6.8%, 21.75%, 23.4% in Dafnis and 22.7%, 35% and 51% in Izmono were observed. With the increase of plant density, the percentage of blossom drop of plants decreased significantly. The highest total soluble solids content of one cultivar (Hirad) was observed in the highest density and two other cultivars were not affected. The pH of fruit juice of Dafnis and Izmono at a density of 3.5 plants per m2 was significantly lower than other treatments, but there was no difference for this trait in Hirad cultivar between different densities. The results of this study suggest to increase the density of tomato in hydroponic greenhouse in Golestan province up to 3.5 plants per m2.

Pollen and Pollination is a critical process in date fruit production that may affect the quality, quantity and yield of the fruit. Application of compatible pollen can lead to an acceptable level of fruit set. Five pollinator genotypes including 7001 (as control), 7004, 7013, 7030 and Boyer 11 (derived from tissue culture) were selected to investigate the effect of pollen source on the commercial production of tissue culture-derived Medjool cultivar. This research was performed on 15 twelve- year- old trees of Medjool cultivar derived from tissue culture in a randomized complete block design with three replications. The experiment was carried out in Jahrom Research Station during 2019 and 2020. Pollen source had a significant effect on the percentage of fruit set and characteristics of the fruit. Bunches pollinated with pollens from genotypes 7030 and 7013 showed the highest percentage of the fruit set (56.80 and 56.10%, respectively), while bunches pollinated with pollen from genotype 7004 showed the lowest percentage of the fruit set (about 49.38%).The results indicated that the bunches pollinated with pollens obtained from genotype 7013 showed the highest fruit and seed length, fruit weight, fruit flesh, fruit volume, bunch weight and yield. Based on the results, the best pollen for Medjool cultivar in terms of fruit set and quantitative characteristics is pollen from genotype 7013. This study made it possible to identify the fruit characteristics, according to the pollen used. These results can be used to achieve high yield in Medjool dates.

Olive (Olea europaea L.) is an important horticultural crop for oil production. This study was conducted to evaluate the flowering characteristics of more than 90 native olive genotypes and cultivars. It was performed for two years (2011-2012) at Tarom Olive Research Station. The studied traits included the flowering time, number of flowers per inflorescence, percentage of perfect flowers, fruit set in self-pollination and open pollination and pollen germination rate. The results showed that the earliest opening time of flowers was related to genotypes Qg13, Qg28 and cultivar of Koroneiki and the latest flowering time was in Bash genotype. Flowering time interval between the first and last genotype lasted 18 days. The average number of flowers per inflorescence was 20.52 flowers. Among the olive genotypes and cultivars, the number of perfect flowers varied from 0.7% to 50.9%. The effect of canopy direction was significant on number of flowers in inflorescence and percentage of perfect flowers. Most of genotypes and cultivars had high self-compatibility in pollination and 12% of genotypes had severe self-incompatibility. In open pollination, the lowest final fruit set was related to genotype Tmo1 with 0.1% and the highest was related to cultivar Arbequina with 4%. In pollen germination, the genotype Tmo1 with 4.8% had the lowest and genotypes of D1, Qg18 with 88% had the highest pollen germination. The genotype Tmo1 had abnormal flowers with without filament of stamens and attached anthers.

In order to investigate the role of different pollen grains on the qualitative and quantitative characteristics of 'Clementine' mandarin (Citrus clementina), an experiment was carried out based on a randomized complete blocks design with six treatments and four replications. The 'Clementine' mandarin was subjected to the open-, self-, and cross-pollination with the pollen grains of sweet lemon (Citrus limetta), grapefruit (Citrus paradisi), Lisbon lemon (Citrus limon) and sour orange (Citrus aurantium). The compatibility and incompatibility of pollinators were determined using controlled pollination methods and the microscopic analyses of pollen tube growth. The microscopic evaluations revealed that 'Clementine' mandarin is a self-incompatible cultivar but it is compatible with all studied species. The fruit set in the flowers that were pollinated with sweet lemon (73.75%), Lisbon lemon (71.25%), grapefruit (70%) and sour orange (70%) were not significantly different, while the self- and open- pollinated flowers produced a lower leve of fruit set. The highest viable seeds (13.2) were recorded in the fruits that were pollinated with sour orange, while the self-pollinated ones had no seed. In addition, the pollens of sour orange were the most successful for penetration to the basal portion of style and into ovary of ‘Clementine’ mandarin. Evaluation of genetic affinity among Citrus species revealed that sour orange is the most genetically similar species with 'Clementine' mandarin. Results of this investigation showed that the source of pollen grain substantially affect the fruit set as well as qualitative and quantitative attributes of 'Clementine' mandarin. By considering all of the fruit-related factors, the pollens of C. paradisi and C. limon are suggested as the best choice for improving qualitative and quantitative characteristics of 'Clementine' mandarin.

Pollination is very important for achieving an economical production in hazelnuts. This study was conducted as a factorial randomized complete block design with three replications. In this study, the effects of three pollinizers (Pashmineh, Gercheh and Shastak) on nut and kernel characteristics of some hazelnut cultivars (Rounde, Fertilede coutard and Gerdeshkvarat) were investigated. The results of the flowering phenology showed that all cultivars were protanderious. The time of the male flowers opening in Ronde and Fertilede coutard was from early January to late January and in Gerd Eshkvarat was from mid-January to late January. The opening time of the female flower was variable from mid-January in Ronde to late February in Fertilede coutard. The results showed that the quantitative traits of nut and kernel were strongly influenced by pollen sources. Using stronger and more viable pollen grains of Gercheh pollinizer, the heaviest nut and kernels, the highest percentage of kernel production, and the lowest percentage of blankness kernels were 3.64, 1.48, 48.69, and 13.94, respectively. However, using Shastak pollen grains, the weight of the nut and kernel was decreased by 2.44 % and 1.22 %, respectively, and the blankness percentage of kernel was increased by 26.48 %. The amount of blankness increased dramatically to 87.51 % in self-pollination and nut and kernel weight significantly reduced to 1.27 and 0.22 g, respectively. In general, pollen grain had effects on some fruit characteristics such as nut and kernel weight, percentage of blankness and kernel production, and pollen grain had no significant effect on nut and kernel shape. The highest overlap of male flowers opening in pollenizer genotypes with female flowers of Rounde, Fertilede coutard, and Gerdeshkvarat was observed in Gercheh.

Boron deficiency can be a limiting factor for flowers and fruits formation in some olive orchards. The appropriate time of boron foliar application in different areas and cultivars needs more investigations. This study was conducted to investigate the effects of spraying with an optimum concentration of boron (350 mg/l) at different phenological stages: after fruit harvest in autumn (first stage), the onset of flower bud formation in winter (second stage), during anthesis in spring (third stage), alone or in combination, on flowering  and fruit formation in three olive cultivars (Bella di, Mission and Koroneiki). The characteristics such as inflorescences number, total flowers number, complete and incomplete flowers percent, final fruit-set, percentage of pollen germination, and leaf and inflorescence boron content were evaluated. Boron spraying increased the percentage of pollen germination in all three cultivars compared to control. Spraying  in first stage and in combination of the first and the second stages increased the total number of flowers and inflorescences in Koroneiki and in combination of all three stages increased these characteristics in Mission. Bella di with spraying in second stage and in combination of second and third stages, and Koroneiki in third stage had the highest percent of complete flowers. The highest percent of fruit-set was observed in combination of the first and the third stages, and in combination of the second and the third stages in Koroneiki and then in combination of all three stages in Mission. Spraying in combination of the second and the third stages increased leaf and inflorescence boron contend in all three cultivars.

The effect of seasonal changes pattern of internal carbohydrates of trees on flowering, fruit set, and fruit development is an important subject for orchard management and physiology of fruit production. With the aim of alternate bearing control, a research was performed based on RCBD design under dry farming condition at Ramsar on 24 years old of Satsuma mandarin trees. Main purposes of this research were to investigate the partitioning of soluble and insoluble carbohydrates of trees during on and off years, evaluating the relation between carbohydrate reserves, flowering and fruit set, effect of 2,4-D foliar application on carbohydrate partitioning, abscission enzymes activity, control of alternate bearing and crop quantity and fruit quality. Results showed that bearing level had a meaningful effect on carbohydrate partitioning and its seasonal fluctuations. Activity of abscission enzymes were affected by crop load as well as exogenous 2,4-D application. Results also showed that 2,4-D could regulate alternate bearing of Satsuma mandarin trees and improve fruit weight. Based on obtained information, the leaf starch content at the end of June-drop is a reliable biochemical index for predicting of final individual fruit weight at the same year as well as the flower density in the next year.

In order to study the effect of polyamins (PAs) including putrescine (Put) and spermidine (Spd) on growth and quality of olive fruit (Olea europae L. cv. Dezful) an experiment was conducted in Shiraz, Iran (2014 and 2015). Putrescine (0, 2.5 and 5 mM L-1) and Spermidine (0, 1.25 and 2.5 mM L-1) were sprayed on branch units at full bloom (FB) and two weeks after full bloom (AFB). Factorial experiment was conducted in a randomized complete block design with three replications. Fruit number, physical characteristics such as fruit and pit size, weight, length and diameter, fruit color and chemical characteristics such as total phenol content, total carbohydrate and chlorophyll a, b were evaluated. The results showed that Put was very effective on decreasing abscised fruits and increased fruit set at FB. Fruit skin color was affected by the type of PAs applied. Total phenol was generally reduced in fruits obtained from PAs treated trees. Total carbohydrate, N, chlorophyll a and b contents and total chlorophyll increased in PAs treated fruit as compared with control. Applications of Put and Spd significantly increased fruit growth characters such as size, weight, length and diameter but decreased weight, length and diameter of the pits compared with control. The highest effect on physical and chemical characters was observed in Put at 5 mM L-1 treatment.

Assessment of the germination behavior of pollen is effective on increasing yield and quality and also selection of suitable cultivars. This study was carried out to evaluate the germination of different age pomegranate pollen in perfect and male types flowers as well as determinate fruit set with pollination of ‘Malas Yazdi’, ‘Rabab-e-Neyriz Fars’, ‘Poost Siah’, ‘Bihaste Dane Ghermez Ravar Kerman’, ‘Bihaste Kam Bar Najaf Abad’, ‘Bihaste Sangan Khash’, ‘Goroch Tafti’ and ‘Pishva Varamin’. The highest pollen quantity obtained in perfect flowers of ‘Goroch Tafti’. The highest pollen germination percentage and rate were observed in ‘Pishva Varamin’, ‘Goroch Tafti’, ‘Bihaste Sangan Khash’, ‘Malas Yazdi’, ‘Rabab-e-Neyriz Fars’ during first-six hours after releasing from anthers, although about ‘Goroch Tafti’, germination percentage unaffected up to 12 hours after release. Regarding to study of cultivar and flower type, the highest germination percentage obtained in male flowers of ‘Goroch Tafti’. Simple effect of pollen age, showed that germination percentage significantly reduced 6 h after release. Evaluation of effect of cultivar on germination rate showed the highest value in ‘Pishva Varamin’, ‘Goroch Tafti’, ‘Bihaste Sangan Khash’ and ‘Malas Yazdi’. The results indicated that ‘Malas Yazdi and ‘Rababe Neyriz’ flowers pollinated with ‘Bihasteh Ravar Kerman’ and ‘Goroch Tafti’ were led to 65 to 80 percent fruit set from fertilization fruits, respectively. Free pollination (control) with 90 percent fruit set in comparison with self-pollinated of commercial cultivars was significantly different at 1% level of probability. Therefore, it is concluded that some cultivars had low germination percentage and in some others pollen age had most effect on germinability that could be respected in variety selection for plantation. So compatibility pollen can affect fruit set and yield.

Almond is one of the most important Prunus species. Most almond cultivars and genotypes are self-incompatible and some others are cross-incompatible. However, recently self-incompatible cultivars developed by breeding are available. Therefore self-incompatible cultivars for pollination, fertilization and production require compatible pollen of other cultivars. In this regard the study of pollen and pistil compatibility of the three cultivars of ‘Tuono’, ‘Shokofeh’, ‘Sahand’ and promising five selected genotypes of A1.16, A9.7, A8.39, A10.11 and A230 was made using method controlled pollination and determined the fruit set percentage in the field. Crosses were performed based on flowering overlap among the three groups. Results showed that crosses of Tuono × A9.7 (60.52 % fruit set), A9.7 × A10.11 (79.20% fruit set) and Shokofeh × Sahand (77.52 % fruit set) had the highest of fruit set percentage and maximum compatibility on crosses were used in mentioned groups. Furthermore crosses of Tuono × A230 (42.45 % fruit set) and Tuono × Sahand(39.52 % fruit set) showed 50 percent incompatibility.

In order to study the effects of foliar application of NAA and plant thinning on growth, yield and fruit quality of melon genotype Khatooni, the experiment was conducted in a randomized complete block design with three replications at Research field of Faculty of Agriculture, University of Zanjan. Treatments consisted of foliar application of NAA at three levels (25, 50 and 100 mg.L-1 at 4-6 true leaf and fruit set stages), pruning (pruning against nonpruning) and plant thinning. Treatment with NAA increased the total soluble solids content of fruit. An obvious gradient of TSS was detected, ascending from pedicel to umbilicus part of mesocarp. The maximum leaf area, fruit width and mesocarpe thickness was observed in NAA (100 mg.L-1 at fruit set stage). NAA caused a significant decrease in time to ripening. Among the treatments, the highest number of fruits per plant and total yield was recorded by using NAA (50 mg.L-1 at 4-6 leaf stage). Also maximum mean fruit weight and marketable yield was obtained in plant thinning treatment. According to the results, foliar application of NAA (100 mg.L-1 at fruit set stage) can be proposed instead of plant thinning practice that require too much time and labor for the farmers.

To study the impact of supplementary pollination with pollen suspensions enriched with boric acid on quantity and quality of pistachio fruit cv. ‘Owhadi’, an experiment was conducted with 6 treatments at two different locations. Parameters, including the fruit set percentage, dehiscent nut percentage, blankness percentage, deformities percentage, fresh and dried fruits weight and kernel, ounces, oil and protein percentage were measured. The results showed that the highest percentage of final fruit set and the lowest fruit drop was obtained with treatments containing 0.02% boric acid. The highest mean percentage of dehiscent nut was obtained with treatments containing 0.01% boric acid (SAB1). The least percentage blankness was obtained with treatments containing pollen and boric acid 0.02%.

Influences of pollination methods and plant growth regulators spraying; gibberllic acid (GA3) or naphthalene acetic acid (NAA) on some quantitative and qualitative parameters of date fruit (Phoenix dactylifera cv. ‘Kabkab’) was investigated in two years (2009 2010). The experiment was conducted based on randomized complete block design with eight treatments including embedded male inflorescence in spadix (EM), hand pollination (HP), hand duster (HD), motorized duster (MD), hand pollination + GA3 (100 mg l-1) (HP + GA100), hand pollination + GA3 (100 mg l-1) (HP + GA150), hand pollination NAA (150 mg l-1) (HP + NAA) and free strand (FS). Results showed that the highest fruit set percent, the lowest fruit abscission, the greatest fruit number per strand, the highest strand weight, the greatest fruit weight, the highest yield, the greatest fruit length, the greatest fruit diameter, the greatest fruit volume, the greatest pulp/seed ratio and the highest fruit growth rate were obtained by HP+GA150 treatment application. The highest fruit abscission and the lowest fruit number per strand were measured by MD treatment application. The lowest fruit weight was obtained in control (EM), HP and HD treatments. Control (EM), FS, HP, HD and MD treatments showed also the lowest yield. Treatment of HP+NAA150 had the lowest seed length and HP+GA100 treatment had the greatest seed length. The greatest and the lowest seed diameter were obtained by usage of HP+NAA150 and HP treatments, respectively. Seed weight was not influenced by exerting treatments. The highest and the lowest TSS were obtained by HP and HP+NAA150 treatments application, respectively. The highest pH was obtained by usage of HP+GA100. The lowest fruit moisture was observed in HP treated fruit and the highest moisture was observed in HP+NAA150 treated fruit. It can be concluded that application GA3 and NAA have a significant effect on yield increasing, quantitative and qualitative parameters of date fruit cv. Kabkab and HP+GA150 may be recommended.

Effects of foliar application of boron (B) and calcium (Ca) was investigated on fruit set and some quantity and quality characteristics of pistachio trees cv. ‘Owhadi’ in two consecutive seasons, 2011 and 2012. A factorial experiment was conducted in randomized complete block design whith nine treatments and three replicates at a pistachio orchard in Kusarriz region of Rafsanjan. Treatments include B as boric acid (0, 1000 and 2000 mg l 1) and Ca as calcium chlorid (0, 1 and 2%). Results of the first year showed that foliar application of 1000 mg l-l B increased the initial and final fruit set by 11 and 2l %, respectively, compared to controls. However, by application this level of B, some qualitative traits such as splitting rate, nut weight and rate of blankness significantly increased. In the second year, the highest rate of initial and final fruit set was obtained with application of 1000 mg l-1 boric acid. At the second year, concentration of Ca and B in the flower buds and leaves were increased by foliar spary of these elements, compared with controls. In general, the results of the present study showed that B application in concentration of 1000 mg l-1 after harvesting and swollen buds stages improved fruit set and some qualitative and quantitative characteristics of pistachio trees but foliar application of Ca reduced some of these parameters.

The level of self-compatibility of the 48 pre-selected apple cultivars، using their own pollen، the genetic capacity of flowering، flower-fruit conversion ratio، multiple fruit fall and bearing preservation during 4 successive biological growth stages were examined through two main treatments of self and cross pollination، in Horticulture Research Station of Kamalshahr in Karaj (Iran). The fruit samples were analyzed via 43 pomological traits and physiological disorders. Six to 10 branches carrying flower buds were labeled within the canopy of the existing، 3 to 6، trees. The labeled branches were isolated by bags، and 5 other open pollinated branches were marked as control for each cultivar or genotype. All branches were submitted to a precise recording of flower buds، young fruits، June drop and mature fruit numbers in 4 different biological stages including 1. bud swelling phase، before balloon stage، 2. two weeks after bloom end، 3. June drop and 4. maturity time. The results showed that there were significant differences between all genotypes and cultivars in the number of produced flowers، flower-fruit conversion ratio، fruit fall and fruit set percent during growth stages and particularly for the self- compatibility level among and within the cultivars. Inbreeding pressure caused appearance of physiological disorders at different levels (based on cultivar)، changing the expression of fruit weight، fruit length، fruit diameter، seed number، seed abnormality and other traits. The mean comparisons made by Duncan test confirmed that the promising genotype IRI6، with 6. 49% of efficiency in fruit retaining capacity، surpassing the open pollinated treatment as control with 4% of fruit set at the end of the 4th stage of fruit growth or at harvest time، confirming itself as a completely self-fertile apple genotype. Among the pre-selected self-compatible cultivars، except the 12 off cultivars، all other cultivars demonstrated different and considerable levels of self-compatibility. Complete pomology test of 30 traits was worked out on 10 fruit samples taken from each self and cross treatment belonging to each cultivar and genotype، based on national guideline for the conduct of tests for apple (UPOV)، and ulterior biochemical characteristics.

A group of morphological, pomological traits and fruit set percent were studied for two years in two different groups of coetaneous healthy and infected trees of ‘Jonagold’, ‘Gala’ and ‘Golden Delicious’ pruned in spindle form and grown in Horticultural Research Station and Post-harvest Laboratory of Horticulture Department under Seed and Plant Improvement Research Institute. Evaluations made on flower production per cultivar and its relative conversion coefficient to fruit in successive biological growth stages including 1 week after bloom end, June drop stage and 2 weeks before ripening time to study preservation of fruit produced demonstrated that fruit set percent and yield per tree were both higher in control than infected ones. Analysis of variances of the data regarding the traits of fruit length and fruit length/diameter ratio, stalk length, eye cavity depth, stalk cavity depth, lenticels number, TSS, TA in ‘Jonagold’; Internode number of annual branches and TA in ‘Golden Delicious’, (2010); Internode length of annual branches in ‘Gala’ (2011) were always higher in healthy trees and these differences were statistically significant for all the mentioned traits. Although a virus control certificate had already been issued to the healthy trees, ELISA test was performed randomly for TmRSV and ApMV on the relative leaf extracts, confirming the plants’ health status four years after transplantation in the experimental orchard.

The present research was conducted with the purpose of studying self and cross-compatibility in some commercial cultivars of peach through field and microscopic studies in order to increase the quantity and quality traits of the product. The study was carried out in years 2010 and 2011. In a first experiment, the pollen germination of 10 cultivars of peach was studied in culture medium. The results showed that the pollen from all cultivars, except that from G.H.Hale had sufficient germination. The highest percentage of pollen germination belonged to Suncrest with 91.85% and the lowest to G.H.Hale with a germination rate of 0%.In the second experiment, the effect of self and open pollination on fruit set in 9 cultivars (Red Haven, Springcrest, Early Red, Early Gold, Suncrest, Dixi Red, Anjiri, Spring Time and Elberta) were investigated. The results showed that fruit set, following open pollination (at all the three counting stages) was higher than fruit set, resulting from self-pollination, indicating that self-pollination significantly reduces the fruit set. In addition, in third counting stage (80 days past from pollination), the highest level of fruit set of 24.96%, belonged to Spring Time, while the lowest of 14.93%, to Anjiri peach. In a third experiment, the effect of self pollen and three types of cross pollen on the level of fruit set were studied. The results revealed that in all the four treatments, the level of fruit set from self pollination was higher than that from cross pollination. In a fourth experiment, a microscopic study, flowers were harvested and fixed in F.A.A. solution within 24, 48, 72, 96 and 120 hrs after self and cross pollination. Results showed that 24, 48 and 72 hrs were not enough times for pollen tube to reach the base of the style, but 96 and 120 hrs were suitable time intervals. The number of pistils having pollen tubes at the base of their style increased for 120 hrs following self and cross pollination in some of the crosses as compared with 96 hrs following self and cross-pollination. Results finally indicated that in some crosses, 96 hr and in others 120 hr. past self and cross-pollination, were the proper time intervals for pollen tube to reach the base of the styles.