Shahid Chamran University of AhvazPlant Productions2588-543X33120100922The Effect of Sowing Dates on Yield, Yield Components and Oil Content of Different Spring Safflower (Carthamus tinctorius) Cultivars as Double Crop in Yasouj RegionThe Effect of Sowing Dates on Yield, Yield Components and Oil Content of Different Spring Safflower (Carthamus tinctorius) Cultivars as Double Crop in Yasouj Region11412213FAMAMMHFADMAJournal Article20081229In order to study the effects of sowing dates on yield, yield components and oil content of spring safflower, as double crop, an experiment was carried out in 2007 at the research field of agricultural college of Yasouj University. The experimental design was a factorial with randomized complete block with three replications. Four sowing dates (May 16, June1, June 16 and July 2) as a first factor and four cultivars (Arak 2811, Esfahan 14, IL111 and PI) as second factors were used. The results showed that May 16 and June 16 sowing dates had Minimum (1129 kgha<sup>-1</sup>) and Maximum (1372 kgha<sup>-1</sup>) seed yield respectively. Significant interactions were observed between cultivars and sowing dates for most of measured characters. Cultivars of Esfahan 14 at July 2 sowing date and IL111 at May 16 sowing date showed the highest and the lowest seed yield, oil yield, seed numbers per plant and seed numbers per head, respectively. Generally, with respect to these results it might be suggested that the Esfahan 14 cultivar at July 2 sowing date was the best option for double cropping of spring safflower in Yasouj region. However, because of the coinciding the harvest date of Esfahan 14, at July 2 sowing date, with the sowing date of some winter crops, such as canola, the June 16 sowing date for all cultivars is suggested as the second option.
<em> </em>In order to study the effects of sowing dates on yield, yield components and oil content of spring safflower, as double crop, an experiment was carried out in 2007 at the research field of agricultural college of Yasouj University. The experimental design was a factorial with randomized complete block with three replications. Four sowing dates (May 16, June1, June 16 and July 2) as a first factor and four cultivars (Arak 2811, Esfahan 14, IL111 and PI) as second factors were used. The results showed that May 16 and June 16 sowing dates had Minimum (1129 kgha<sup>-1</sup>) and Maximum (1372 kgha<sup>-1</sup>) seed yield respectively. Significant interactions were observed between cultivars and sowing dates for most of measured characters. Cultivars of Esfahan 14 at July 2 sowing date and IL111 at May 16 sowing date showed the highest and the lowest seed yield, oil yield, seed numbers per plant and seed numbers per head, respectively. Generally, with respect to these results it might be suggested that the Esfahan 14 cultivar at July 2 sowing date was the best option for double cropping of spring safflower in Yasouj region. However, because of the coinciding the harvest date of Esfahan 14, at July 2 sowing date, with the sowing date of some winter crops, such as canola, the June 16 sowing date for all cultivars is suggested as the second option.
<em> </em>https://plantproduction.scu.ac.ir/article_12213_4c9b4cde56eafeb71947d54a85a33460.pdfShahid Chamran University of AhvazPlant Productions2588-543X33120100922Effects of Chemical and Organic Fertilizers on Some Silage Chemical Properties of Globe Artichoke (Cynara scolymus)Effects of Chemical and Organic Fertilizers on Some Silage Chemical Properties of Globe Artichoke (Cynara scolymus)153112215FAEFM.RCHESHAADMJournal Article20081228To study the effect of three soil fertilizing systems (organic, integrated and chemical) on silage quality of globe artichoke (<em>Cynara scolymus</em>), an experiment was conducted using a Randomized Completed Block Design (RCBD) with four replications at the Research Farm of Agriculture College, University of Tehran, Karaj, Iran in 2007. The treatments included five levels of chemical fertilizers, four levels of manure, five levels of mixture of different ratios of chemical fertilizers and manure as integrated systems and a control treatment (no fertilizers or manures). The results have shown that soil fertilizing systems significantly affected silage quality of artichoke. The highest crude protein percent (12/7%) and lowest crude protein (8.2%) were obtained by treatment 15 (40 tones manure/ha) and control respectively. Water Soluble Carbohydrates (WSC) decreased during the silage process. Silage quality characteristics including crude protein (CP), water soluble carbohydrates (WSC), and dry matter digestibility (DMD) increased and acid detergent fiber (ADF) decreased by increment of cattle manure application. It was concluded that artichoke, as a forage crop, has a suitable yield and quality potential for livestock feeding in terms of soil fertilization systems. Artichoke silage quality was less than alfalfa silage but it is as much as corn silage with lower seed contents and was more than sorghum silage. Further studies would be needed to consider Artichoke as a source of forage and medicinal crop plant.
To study the effect of three soil fertilizing systems (organic, integrated and chemical) on silage quality of globe artichoke (<em>Cynara scolymus</em>), an experiment was conducted using a Randomized Completed Block Design (RCBD) with four replications at the Research Farm of Agriculture College, University of Tehran, Karaj, Iran in 2007. The treatments included five levels of chemical fertilizers, four levels of manure, five levels of mixture of different ratios of chemical fertilizers and manure as integrated systems and a control treatment (no fertilizers or manures). The results have shown that soil fertilizing systems significantly affected silage quality of artichoke. The highest crude protein percent (12/7%) and lowest crude protein (8.2%) were obtained by treatment 15 (40 tones manure/ha) and control respectively. Water Soluble Carbohydrates (WSC) decreased during the silage process. Silage quality characteristics including crude protein (CP), water soluble carbohydrates (WSC), and dry matter digestibility (DMD) increased and acid detergent fiber (ADF) decreased by increment of cattle manure application. It was concluded that artichoke, as a forage crop, has a suitable yield and quality potential for livestock feeding in terms of soil fertilization systems. Artichoke silage quality was less than alfalfa silage but it is as much as corn silage with lower seed contents and was more than sorghum silage. Further studies would be needed to consider Artichoke as a source of forage and medicinal crop plant.
https://plantproduction.scu.ac.ir/article_12215_750dc3dc928c9658283055e3ba698e75.pdfShahid Chamran University of AhvazPlant Productions2588-543X33120100922The Effect of Planting Dates and Different N-P-K Ratios on Grain Yield and N Use Efficiency in Wheat (Triticum aestivum L.) in AhvazThe Effect of Planting Dates and Different N-P-K Ratios on Grain Yield and N Use Efficiency in Wheat (Triticum aestivum L.) in Ahvaz334712217FAMVAAEFJournal Article20091103To study the effect of different N-P-K levels and planting dates on wheat yield and N-use efficiency, a field experiment was conducted in Agricultural Faculty of Shahid Chamran University at 2008-2009. Experimental design was split plot on RCB with 3 replications. Main plot was planting date in 3 levels (27 Oct, 16 Nov, 6 Dec) and sub-plot was different N-P-K levels including F<sub>1</sub>-control (0-0-0), F<sub>2</sub>- 40% lower than optimum (70-50-40), F<sub>3</sub>- optimum (110-90-80), and F<sub>4</sub>- 40% higher than optimum (150-130-120). Crop grain yield and yield components and also different N-use efficiency indices were measured. Results showed that best grain yield was obtained at range of optimum planting date (second and third planting date). Early planting date had the lowest grain yield for fertilizer treatments. Highest and lowest grain yield belonged to level of 150-130-120 and control plot (6.18, 3.27 t/ha) respectively. Seed 1000-weight and No. raceme per m<sup>2 </sup>had the best effect on the grain yield improvement, respectively. Best NUE (38/08 kg/kg) was obtained in the second planting date and N-P-K level of 40% lower than optimum treatment. In addition, NUE declined with increase in N application. Also, in all planting dates, 70-50-40 fertilizer level had the best NUE. In conclusion, the treatment which produced the highest grain yield had not the best NUE.
To study the effect of different N-P-K levels and planting dates on wheat yield and N-use efficiency, a field experiment was conducted in Agricultural Faculty of Shahid Chamran University at 2008-2009. Experimental design was split plot on RCB with 3 replications. Main plot was planting date in 3 levels (27 Oct, 16 Nov, 6 Dec) and sub-plot was different N-P-K levels including F<sub>1</sub>-control (0-0-0), F<sub>2</sub>- 40% lower than optimum (70-50-40), F<sub>3</sub>- optimum (110-90-80), and F<sub>4</sub>- 40% higher than optimum (150-130-120). Crop grain yield and yield components and also different N-use efficiency indices were measured. Results showed that best grain yield was obtained at range of optimum planting date (second and third planting date). Early planting date had the lowest grain yield for fertilizer treatments. Highest and lowest grain yield belonged to level of 150-130-120 and control plot (6.18, 3.27 t/ha) respectively. Seed 1000-weight and No. raceme per m<sup>2 </sup>had the best effect on the grain yield improvement, respectively. Best NUE (38/08 kg/kg) was obtained in the second planting date and N-P-K level of 40% lower than optimum treatment. In addition, NUE declined with increase in N application. Also, in all planting dates, 70-50-40 fertilizer level had the best NUE. In conclusion, the treatment which produced the highest grain yield had not the best NUE.
https://plantproduction.scu.ac.ir/article_12217_d23029862b2482dccf9fb99ace668b99.pdfShahid Chamran University of AhvazPlant Productions2588-543X33120100922Evaluation of Delayed Sowing Dates on Quantitative and Qualitative Traits and Dry Matter Remobilization in Three Winter Rapeseed Cultivars in Markazi ProvinceEvaluation of Delayed Sowing Dates on Quantitative and Qualitative Traits and Dry Matter Remobilization in Three Winter Rapeseed Cultivars in Markazi Province496612218FAMMAMJournal Article20090414In order to evaluate the effects of delayed sowing date on quantitative and qualitative traits of three winter rapeseed (<em>Brassica napus</em> L.) cultivars, two split plot field experiments, arranged in complete block designs with three replications, were carried out in Agricultural and Natural Resources Research Center of Markazi Province, Arak (Iran), during 2006-2008 growing seasons. Three rapeseed cultivars (Okapi, Modena and Licord) and three sowing dates (October 2, 12 and 22) were randomized in main plots and sub-plots respectively. The lowest grain yield (1723 kg/ha), 1000-seed weight (3.34 g), seed number per pod (22.01), pod number per plant (70.34), plant height (110.8 cm), second branch number per plant (2.92), days to end flowering (244.79), length of maturity (29.22), seed oil content (45.5%), oil yield (806 kg/ha), seed protein percentage (15.54), harvest index (24.94%), biological yield (6673 kg/ha), grain yield per plant (2.99 g) and dry matter remobilization (64 mg/plant) were obtained on third sowing date. The interaction effect between year and cultivar was significant for traits such as grain yield, 1000-seed weight (P<0.05) and pod number per plant (P<0.01). Also the interaction effect between year and sowing date for grain yield, seed number per pod and pod number per plant was significant at 1% probability level. The interaction effect between cultivar and sowing date was significant for 1000-seed weight (P<0.05), pod number per plant, seed protein percentage and harvest index (P<0.01). In addition, interaction effect between year, cultivar and sowing date was significant for grain yield and plant height at 1% probability level. Thus, it can be concluded that annual variability in the growth environment is responsible for the most of large year to year yield differences. There was positive and significant correlation between grain yield and the most traits such as 1000-seed weight, seed number per pod, pod number per plant, plant height, second branch number per plant, days to maturity, length of maturity, seed oil content (%), oil yield, seed protein percentage, harvest index, biological yield, grain yield per plant and dry matter remobilization except days to initial flowering and days to end of flowering but correlation coefficient between grain yield and length of flowering was negative but significant. In this research Licord cultivar had more grain yield than other cultivars that could be due to genetic diversity among cultivars for using growth sources in direction of grain yield enhancement per unit area.In order to evaluate the effects of delayed sowing date on quantitative and qualitative traits of three winter rapeseed (<em>Brassica napus</em> L.) cultivars, two split plot field experiments, arranged in complete block designs with three replications, were carried out in Agricultural and Natural Resources Research Center of Markazi Province, Arak (Iran), during 2006-2008 growing seasons. Three rapeseed cultivars (Okapi, Modena and Licord) and three sowing dates (October 2, 12 and 22) were randomized in main plots and sub-plots respectively. The lowest grain yield (1723 kg/ha), 1000-seed weight (3.34 g), seed number per pod (22.01), pod number per plant (70.34), plant height (110.8 cm), second branch number per plant (2.92), days to end flowering (244.79), length of maturity (29.22), seed oil content (45.5%), oil yield (806 kg/ha), seed protein percentage (15.54), harvest index (24.94%), biological yield (6673 kg/ha), grain yield per plant (2.99 g) and dry matter remobilization (64 mg/plant) were obtained on third sowing date. The interaction effect between year and cultivar was significant for traits such as grain yield, 1000-seed weight (P<0.05) and pod number per plant (P<0.01). Also the interaction effect between year and sowing date for grain yield, seed number per pod and pod number per plant was significant at 1% probability level. The interaction effect between cultivar and sowing date was significant for 1000-seed weight (P<0.05), pod number per plant, seed protein percentage and harvest index (P<0.01). In addition, interaction effect between year, cultivar and sowing date was significant for grain yield and plant height at 1% probability level. Thus, it can be concluded that annual variability in the growth environment is responsible for the most of large year to year yield differences. There was positive and significant correlation between grain yield and the most traits such as 1000-seed weight, seed number per pod, pod number per plant, plant height, second branch number per plant, days to maturity, length of maturity, seed oil content (%), oil yield, seed protein percentage, harvest index, biological yield, grain yield per plant and dry matter remobilization except days to initial flowering and days to end of flowering but correlation coefficient between grain yield and length of flowering was negative but significant. In this research Licord cultivar had more grain yield than other cultivars that could be due to genetic diversity among cultivars for using growth sources in direction of grain yield enhancement per unit area.https://plantproduction.scu.ac.ir/article_12218_34597913ef33812e66d505675e902410.pdfShahid Chamran University of AhvazPlant Productions2588-543X33120100922The Effect of Cultivation Depth and Variety on the Yield and Properties of Potato tuberThe Effect of Cultivation Depth and Variety on the Yield and Properties of Potato tuber677412220FAASJournal Article20070606In this study, the yield of three common varieties <em>Marfona</em>, <em>Agria,</em> and <em>Kosima</em> of Iranian grown potatoes in two sowing depths, 20 and 25 cm in Isfahan, Damaneh area were determined. A strip randomized complete block design was considered with three replications. Variety was considered as the main factor and depth as sub-factor. In addition, correlation of tuber dry matter percent, cumulative nitrate, and weight density of tubers that harvested from the sowing depth of 20 cm were measured and compared in three sizes of tubers: small, medium, and large diameters. ANOVA results showed that variety and sowing depth had significant effect on the yield of potato tubers (<em>P</em><0.05). The maximum yield for <em>Marfona</em> variety was 44 tons per hectare in the sowing depth of 20 cm. Tuber size and variety correlation had significant effect on dry matter at confidence level of 1% and 5%, respectively. <em>Kosima</em> variety and large tubers had more dry matter. Variety and tuber size had significant correlation on cumulative nitrate (<em>P</em><0.01). <em>Agria</em> tubers stored more amount of nitrate and <em>Kosima</em> stored the least. Large tubers stored more nitrate. Variety and tuber size did not have significant correlation on tuber weight density. <em>Marfona</em> tubers had more weight, so it can be good for export.<em> Kosima</em> tuber had more dry matter percent and stored less cumulative nitrate.In this study, the yield of three common varieties <em>Marfona</em>, <em>Agria,</em> and <em>Kosima</em> of Iranian grown potatoes in two sowing depths, 20 and 25 cm in Isfahan, Damaneh area were determined. A strip randomized complete block design was considered with three replications. Variety was considered as the main factor and depth as sub-factor. In addition, correlation of tuber dry matter percent, cumulative nitrate, and weight density of tubers that harvested from the sowing depth of 20 cm were measured and compared in three sizes of tubers: small, medium, and large diameters. ANOVA results showed that variety and sowing depth had significant effect on the yield of potato tubers (<em>P</em><0.05). The maximum yield for <em>Marfona</em> variety was 44 tons per hectare in the sowing depth of 20 cm. Tuber size and variety correlation had significant effect on dry matter at confidence level of 1% and 5%, respectively. <em>Kosima</em> variety and large tubers had more dry matter. Variety and tuber size had significant correlation on cumulative nitrate (<em>P</em><0.01). <em>Agria</em> tubers stored more amount of nitrate and <em>Kosima</em> stored the least. Large tubers stored more nitrate. Variety and tuber size did not have significant correlation on tuber weight density. <em>Marfona</em> tubers had more weight, so it can be good for export.<em> Kosima</em> tuber had more dry matter percent and stored less cumulative nitrate.https://plantproduction.scu.ac.ir/article_12220_4f3f6499b42223dcb33eb0b67332fc88.pdfShahid Chamran University of AhvazPlant Productions2588-543X33120100922A Study of Genetic Diversity in Iran of Most Important Sugarcane Varieties Based on RAPD Molecular MarkerA Study of Genetic Diversity in Iran of Most Important Sugarcane Varieties Based on RAPD Molecular Marker758612222FAMBBSHSHMSSJournal Article20070606This study was accomplished to study genetic variation of 35 cultivars sugarcanes using RAPD marker. The aim was to determine the genetic variation level and relation in some commercial varieties of S<em>.officinarum</em> and the two wild varieties of S<em>.spontneum</em> as well. Total genomic DNA of each cultivar was extracted from 1.5-2.5gr new germinated fresh young leaves and solved in the suitable amount of TE buffer. The concentration was determined by spectrophotometer. RAPD analysis was performed by use of 10bp randomized nucleotide primers. All genotypes were marked for presence or absence of band, and analyzed by use of statistical software NTSYS 2002. Among 65 applicated primers, 30 primers showed polymorphism between cultivars, and 464 polymorphic bands were produced. Cluster analysis lays varieties into the 2 separated groups through the Jacard coefficient and UPGMA methods. In this classification, 2 wild varieties from the S<em>.spontanenm</em> were separated completely and showed quite different band pattern in comparison with other varieties. On the whole, the results of this research showed that RAPD marker is a suitable tool to study genetic variation in sugarcane. It is recommended to increase the efficiency of breeding programs to study precise genetic variation and to determine the relationship among cultivars.
<strong><em> </em></strong>This study was accomplished to study genetic variation of 35 cultivars sugarcanes using RAPD marker. The aim was to determine the genetic variation level and relation in some commercial varieties of S<em>.officinarum</em> and the two wild varieties of S<em>.spontneum</em> as well. Total genomic DNA of each cultivar was extracted from 1.5-2.5gr new germinated fresh young leaves and solved in the suitable amount of TE buffer. The concentration was determined by spectrophotometer. RAPD analysis was performed by use of 10bp randomized nucleotide primers. All genotypes were marked for presence or absence of band, and analyzed by use of statistical software NTSYS 2002. Among 65 applicated primers, 30 primers showed polymorphism between cultivars, and 464 polymorphic bands were produced. Cluster analysis lays varieties into the 2 separated groups through the Jacard coefficient and UPGMA methods. In this classification, 2 wild varieties from the S<em>.spontanenm</em> were separated completely and showed quite different band pattern in comparison with other varieties. On the whole, the results of this research showed that RAPD marker is a suitable tool to study genetic variation in sugarcane. It is recommended to increase the efficiency of breeding programs to study precise genetic variation and to determine the relationship among cultivars.
<strong><em> </em></strong>https://plantproduction.scu.ac.ir/article_12222_0c7db21dcc1e5320b2d0c7cd9f79debb.pdfShahid Chamran University of AhvazPlant Productions2588-543X33120100922The Effect of Different Concentrations of IBA, NAA and Their Interactions on the Rooting of Semi-Hardwood Cuttings of Kiwifruit (Actinidia deliciosa CV. Hayward)The Effect of Different Concentrations of IBA, NAA and Their Interactions on the Rooting of Semi-Hardwood Cuttings of Kiwifruit (Actinidia deliciosa CV. Hayward)879612223FAMRVR0000-0003-4319-4223SHSJournal Article20080609This research was to evaluate the effect of different concentrations of Indole -3- butyric acid (IBA) “0, 2000, 4000, 6000 mg.l<sup>-1</sup>”, 1-naphtalene acetic acid (NAA) “0, 1000, 2000, 3000 mg.l<sup>-1</sup>” and their interactions on the rooting of semi-hardwood cuttings of kiwifruit (<em>Actinidia deliciosa</em>) Hayward cultivar. The experiment was carried out as factorial design with two factors (including Factor A= IBA levels and Factor B= NAA levels) by 3 replications in RCBD (Randomized Complete Block Design) with 16 treatments. The study was done at Islamic Azad University, Rasht Branch. The cuttings were planted in sand: perlite (1:1 v/v) rooting medium under mist. Results showed that the effect of auxins on callus production, root number, root length, fresh and dry weight, rooted cuttings percentage and rooting rate was significant (P≤1%). The highest root number, fresh and dry weight were obtained by 6000 mg.l<sup>-1</sup> of IBA + 2000 mg.l<sup>-1</sup> of NAA. The cuttings produced the longest roots at 6000 mg.l<sup>-1</sup> of IBA + 1000 mg.l<sup>-1</sup> of NAA. The highest level of IBA (6000 mg.l<sup>-1</sup>) increased rooted cuttings percentage (83.33%) and callus production. The highest rooting rate was obtained by 4000 mg.l<sup>-1</sup> of IBA + 3000 mg.l<sup>-1</sup> of NAA and 6000 mg.l<sup>-1</sup> of IBA + 2000 mg.l<sup>-1</sup> of NAA. Altogether, 6000 mg.l<sup>-1 </sup>of IBA + 2000 mg.l<sup>-1</sup> of NAA are the best treatment for rooting of semi-hardwood cuttings of kiwifruit. <br /> <strong><em> <br /></em></strong>This research was to evaluate the effect of different concentrations of Indole -3- butyric acid (IBA) “0, 2000, 4000, 6000 mg.l<sup>-1</sup>”, 1-naphtalene acetic acid (NAA) “0, 1000, 2000, 3000 mg.l<sup>-1</sup>” and their interactions on the rooting of semi-hardwood cuttings of kiwifruit (<em>Actinidia deliciosa</em>) Hayward cultivar. The experiment was carried out as factorial design with two factors (including Factor A= IBA levels and Factor B= NAA levels) by 3 replications in RCBD (Randomized Complete Block Design) with 16 treatments. The study was done at Islamic Azad University, Rasht Branch. The cuttings were planted in sand: perlite (1:1 v/v) rooting medium under mist. Results showed that the effect of auxins on callus production, root number, root length, fresh and dry weight, rooted cuttings percentage and rooting rate was significant (P≤1%). The highest root number, fresh and dry weight were obtained by 6000 mg.l<sup>-1</sup> of IBA + 2000 mg.l<sup>-1</sup> of NAA. The cuttings produced the longest roots at 6000 mg.l<sup>-1</sup> of IBA + 1000 mg.l<sup>-1</sup> of NAA. The highest level of IBA (6000 mg.l<sup>-1</sup>) increased rooted cuttings percentage (83.33%) and callus production. The highest rooting rate was obtained by 4000 mg.l<sup>-1</sup> of IBA + 3000 mg.l<sup>-1</sup> of NAA and 6000 mg.l<sup>-1</sup> of IBA + 2000 mg.l<sup>-1</sup> of NAA. Altogether, 6000 mg.l<sup>-1 </sup>of IBA + 2000 mg.l<sup>-1</sup> of NAA are the best treatment for rooting of semi-hardwood cuttings of kiwifruit. <br /> <strong><em> <br /></em></strong>https://plantproduction.scu.ac.ir/article_12223_b1e182a9375c181833fd28429431f701.pdfShahid Chamran University of AhvazPlant Productions2588-543X33120100922Effects of Storage Temperature on Date Palm Pollen ViabilityEffects of Storage Temperature on Date Palm Pollen Viability9710712225FAAMSMTTSAJournal Article20090113This research has been conducted to study the effects of near ambient temperatures occurring in drying process on date pollen viability (PV) and pollen viability declining rate (PVDR) as a factorial experiment with 3 factors namely: temperature in 3 levels (40, 50, and 60 <sup>o</sup>C), pollen type in 3 levels (Abadan Ghanami, Ahwaz Ghanami, and Shadegan Ghanami), and exposure time (ET) in 7 levels (0, 40, 120, 480, 1140, 4320, and 12960 minutes) in 3 replications. The results showed that the effects of all factors and their interactions except the interaction effects of pollen type and exposure time on pollen viability were significant. Maximum and minimum pollen viability was 84.6% for Abadan Ghanami in 40 <sup>o</sup>C at ET=0 minute and 0.03% for Shadegan Ghanami in 60 <sup>o</sup>C at ET=12960 minutes, respectively. On the other hand, the effect of temperature and ET on PVDR was significant and the others were not. Based on data analysis, most of the PV damages occur in the first moments of heat exposure of the pollen grains. Maximum and minimum PVDR were 0.6144 percent per minute in ET period of 0-40 minutes and 0.0003 percent per minute in the ET period of 4320-12960 minutes both for Shadegan Ghanami pollen respectively. In attempt to express this regular pattern, PVDR model as a power function of time variable (Vr=ct<sup>-k</sup>) with both coefficient and power factors of temperature have been defined. <br /><strong> </strong> <br /> This research has been conducted to study the effects of near ambient temperatures occurring in drying process on date pollen viability (PV) and pollen viability declining rate (PVDR) as a factorial experiment with 3 factors namely: temperature in 3 levels (40, 50, and 60 <sup>o</sup>C), pollen type in 3 levels (Abadan Ghanami, Ahwaz Ghanami, and Shadegan Ghanami), and exposure time (ET) in 7 levels (0, 40, 120, 480, 1140, 4320, and 12960 minutes) in 3 replications. The results showed that the effects of all factors and their interactions except the interaction effects of pollen type and exposure time on pollen viability were significant. Maximum and minimum pollen viability was 84.6% for Abadan Ghanami in 40 <sup>o</sup>C at ET=0 minute and 0.03% for Shadegan Ghanami in 60 <sup>o</sup>C at ET=12960 minutes, respectively. On the other hand, the effect of temperature and ET on PVDR was significant and the others were not. Based on data analysis, most of the PV damages occur in the first moments of heat exposure of the pollen grains. Maximum and minimum PVDR were 0.6144 percent per minute in ET period of 0-40 minutes and 0.0003 percent per minute in the ET period of 4320-12960 minutes both for Shadegan Ghanami pollen respectively. In attempt to express this regular pattern, PVDR model as a power function of time variable (Vr=ct<sup>-k</sup>) with both coefficient and power factors of temperature have been defined. <br /><strong> </strong> <br /> https://plantproduction.scu.ac.ir/article_12225_f6335abde7de8b27f354b0d71c01b8e8.pdf