فهرست مطالب khosro parvizi

AbstractConducting various studies on potato cultivation in relation to the effects of cultivar on yield and water use efficiency has a long history and in this regard has been associated with dispersion and many differences in thier results. With the aim of investigating the effects of the cultivar on the yield and water consumption efficiency of potatoes, the research conducted in different regions of the country, in the 20-years period from the beginning of 2000 to 2019 AD or from the beginning of 1379 to the end of 1398 SH, was extracted and analyzed through the meta-analysis model. Studies on cultivar type were divided into early to mid-early and mid-late to late groups and in the early group Sante cultivar and in the late group Agria cultivar were considered as controls. The results of meta-analysis of cultivars in the studies showed that in the group of mid-late to late cultivars there was no statistically significant difference between the cultivars used and the control Agria cultivar in yield (P≥0.05). The mean yield of other mid-late to late cultivars and control Agria cultivar were very close with a slight difference (0.61 t / ha). In the early to mid-early group, although the difference between other early and control cultivars of Sante was not statistically significant in general studies, but Sante cultivar had a higher average yield (2.93 tons per hectare) compared to other cultivars in its group. In general, in all the studies, although mid-late to late cultivars had a yield increase of 2.3 tons per hectare compared to early to semi-early cultivars, but due to the long growing period and the number of times of irrigation (at least 2 up to 3 times), they have less ability in water consumption efficiency. IntroductionAchieving food security and preventing price fluctuations requires the introduction of suitable potato cultivars for reliable production in all seasons and for different uses (Hassan-panah and Hassan-Abadi, 2018). So far, a lot of research has been done on the effect of cultivar on the yield and water efficiency of potato crops in order to achieve maximum production with minimum water consumption in a scattered manner and with different goals. However, there are always differences of opinion regarding the amount of water consumed during the growth period of different potato cultivars, which hinders the determination to promote specific cultivat or cultivars for better adaptation in the region and to achieve the improvement of water consumption efficiency in the region. Therefore, performing a meta-analysis (meta-analysis) by combining the results of comparison tests of cultivars (with identical control cultivars) in different regions of the country provides access to a single guideline that can draw a more specific and regular model. Materials and MethodsIn this research, firstly, researches were conducted in different regions of Iran, in a period of 20 years from the beginning of 2000 to 2019 from WOS foreign data bank and internal data bank and official websites of Iran DOC. , Fipak, Magiran.Com and SID were searched. In the following, screening was done among the searched researches. Then, the final sources were extracted which had a lot to do with the issue of cultivar and its effects on yield and water efficiency. In the investigation of the cultivar type in the conducted studies, it was found that the set of studies could be separated into two evaluation groups of early and late cultivars in potato. For this purpose, the full text of the extracted sources was fully examined and the required statistical data from each of the studies including mean, standard deviation and sample size were extracted from the control cultivar and other experimental cultivars in each independent studies. Finally, the resulting data were combined and subjected to meta-analysis using Stata/SE version 11.1, StataCrop., Lp, Station, TX software. To evaluate the homogeneity of the study results, the I2 index and the Q test (Hedges et al, 1999; Higgins and Thompson, 2002) were used.Results and DiscussionThe results of the meta-analysis of cultivars in the studies showed that in the group of late cultivars, there was no statistically significant difference in yield between Agria control cultivar and other used cultivars. The yield average of other late cultivars and the control cultivar of Agria were very close with a slight difference (0.61 tons per hectare). In the early group, although the difference between the other early cultivars and the Sante control was not significant in the total of studies, the Sante cultivar had a higher average yield (2.93 tons per hectare) compared to other cultivars in its group. totally, in all studies, although the late cultivars had a yield increase of 2.3 tons per hectare compared to the early cultivars, they were less capable in terms of water consumption efficiency as compared with early ripening cultivars. Usually, in late cultivars, the length of the irrigation period and the amount of water consumption is two to three times higher than that of early cultivars. This amount is usually 10 to 15% of the water requirement of potatoes. If we consider the efficiency of water consumption in the sprinkle irrigation system of 250 liters and in the drip system of 150 liters per kilogram of potato production (Gadami Firouzabadi and Parvizi, 2017), in this case, in late cultivars, on average, 594 cubic meters per hectare more water is consumed compared to early ripening cultivar.ConclusionBased on the results of this meta-analysis and in order to achieve the optimal yield and water efficiency in terms of the type of potato cultivar, it is necessary to cultivate cultivars with a shorter growing period and with High functional capacity and resistant to stress and water deficiency such as Sante should be prioritized. In addition, the superiority of Sante variety among the studied early ripening cultivars was higher than the average in all studies, therefore, it can be considered in breeding programs to produce new cultivars.

Potato, as one of the strategic crops, plays an important role in the economy of the country. The potato golden cyst nematode (Globodera rostochiensis), was reported from Hamedan province in 2007. In present study, the reaction of 19 commercial potato cultivars and 23 advanced potato clones together with resistant and susceptible cultivars were evaluated against potato golden cyst nematode Globodera rostochiensis in greenhouse and field conditions. As the result, the cultivars Savalan, Jili, Sagita, Panamera and the clones 5/25, 870787, 1/27, 870861, 13/75, 1 were evaluated as susceptible. The cultivars Anosha, Banba, Kolomba, Kaiser, Fabula and clones 24/24, 19/75, 8701125, 11 and KSG613 were evaluated as resistant which could be introduced as the new resistant cultivars. The cultivars Khavaran, Boren and the clone 8708133 were evaluated as tolerant. The cultivars Challenger, Georgia and Taurus (commonly cultivated in Iran) were evaluated as susceptible. Besides the phenotypic evaluations, the molecular approches were also employed to amplify two TG689 and 57R markers linked to the H1 resistance gene in studied cultivars and clones.

Hamedan province, characterized by an average annual rainfall of less than 340 mm, faces significant limitations in potato production)Solanum tuberosum(, primarily due to the scarcity of irrigation water and the occurrence of drought stress during critical growth stages. In order to address these challenges, the utilization of aqueous superabsorbent materials and the inoculation of mycorrhizal fungi have emerged as highly suitable approaches. These methods aim to optimize the utilization of water and soil resources (Khadem et al., 2011). Previous studies have indicated that the inoculation of arbuscular mycorrhizal fungi in various plant species, apart from potatoes, can reduce the impact of drought stress and enhance nutrient uptake (Bolannazar et al., 2007; Subramanian et al., 2008). However, limited research has been conducted on the effects of superabsorbents and mycorrhizae, particularly under conditions of moisture stress and deficit irrigation in potato crops. Consequently, this experiment aims to investigate the effects of applying these methods under stress conditions.

The experiment was arranged in strip factorial based on randomized complete block design with three replications. Three irrigation levels containing optimal irrigation (100, 75 and 50% of water requirement based on evapotranspiration from Pan Class A) in horizontal plots and factor 2 using Trawat200A superadsorbent (0 and 80 kg.ha-1) and four mycorrhiza and superabsorbent levels including no application of these material (control), superabsorbent, mycorrhiza as a bio-fertilizer and their combination were considered as sub plots. The Agria potato cultivar was selected. Superabsorbent material was applied adjacent to the tubers at planting time. Mycorrhizal inoculum containing the active propagules (CFU 120 /g) was inoculated to the tubers. The concentration of nutrients in the shoot and in the tubers were determined by using Kjeldahl apparatus for Nitrogen (Waling et al., 1989), spectrophotometer for phosphorus (Jones, 2001), flame photometry for Potassium and atomic absorption spectroscopy for Iron, Zinc, and Manganese (Ryan et al., 2001). the produced tubers were divided, weighed and counted based on their size in three groups (small, medium and larg). Water use efficiency was determined as the amount of dry matter produced per cubic meter of water consumption in different treatments.

The results of combined analysis of variance showed that the main effects of irrigation rate, application of mycorrhiza and superabsorbent on tuber yield and percentage of dry matter, nutrient uptake in stem, leaf and tuber were significant. Comparison of means showed that with the application of low irrigation and increasing the intensity of water deficiency (reducing the amount of irrigation water), total yield decreased, but this decrease was significantly less in conditions of inoculation with mycorrhiza and the use of superabsorbent polymer. Mycorrhiza and superabsorbent increased the absorption of nutrients, especially under severe water deficiency. In this study, there was a significant difference in the uptake of phosphorus and other low-consumption and high-consumption nutrients at normal irrigation levels and stress in mycorrhizal plants, so that their uptake increased in proportion to the increase in stress intensity and in mycorrhizal inoculation conditions. It seems that by creating stress conditions, the ability and efficiency of mycorrhiza in nutrient uptake is increased and thus in the conditions of lack of moisture with the coexistence mechanism in the relationship of the plant more effectively helps the survival and durability of the plant. Mycorrhizal fungi can increase the uptake of phosphorus from the soil by increasing the relative water content and ultimately play an effective role in increasing plant growth (Krishna et al., 2005). In this study, it was found that the use of superabsorbent in potatoes helps to increase the absorption of nutrients. The reason for this can be increasing the storage capacity of water and nutrients for a long time in the soil, reducing nutrient leaching, rapid and optimal root growth with better nutrient storage and aeration of the soil.

In this study, it was found that the application of superabsorbent and mycorrhiza in potato helps to increase nutrient uptake as well as tuber yield. The positive effects of combined application  of mycorrhiza and superabsorbent on nutrient uptake and yield were more evident especially in conditions of severe water deficiency.
Acknowledgements
We are grateful for the efforts of Dr. Bakhtiari and Mr. Abdolreza Mordai in coordinating and equipping irrigation equipment and land preparation.

In order to investigate the role of nutrients on yield and quality of two commercial cucumber cultivars, Royal and Hike, the effect of poultry manure at levels of 0, 6, and 12 tons per hectare and chemical fertilizers in four different combinations including the one-time application of 50 kg of urea without micronutrient fertilizer; one-time application of 109 kg ammonium sulfate without micronutrient fertilizer; application of urea, phosphorus, and potassium fertilizers as well as complete micronutrient fertilizer according to soil test; and ammonium sulfate, phosphorus, and potassium fertilizers as well as complete micronutrient fertilizer according to soil test, were studied at three harvesting time. Total yield increased in both cultivars by using fertilizers consisting of poultry manure in the amount of 6 tons per hectare in combination with urea, phosphorus, potassium, and complete micronutrient fertilizers based on soil tests. With increasing poultry manure, the quantity of nitrate accumulation increased, but it was below the allowed threshold in all treatments. In most treatments, tissue firmness in the first and second harvests was higher than in the third harvest and its amount decreased with more nitrogen application. In the Hike cultivar, at all levels of chemical fertilizers, the amount of chlorophyll accumulation in the first and third harvests was higher than in the second harvest. The green color index in the Royal cultivar increased with the application of ammonium sulfate and poultry manure fertilizers. In total, the consumption of six tons of poultry manure with chemical fertilizers based on soil tests and also foliar application of the micronutrient fertilizers improved the yield and quality of cucumber fruit..

In order to investigate the effects of mycorrhizal fungus and superabsorbent on growth traits and yield components of maize under water stress conditions, this study was conducted in Hamadan province in the crop year 2019. In this experiment, low irrigation treatments including optimal irrigation (irrigation at 3-bar soil water potential), moderate drought stress (irrigation at 7-bar soil water potential) and severe drought stress (irrigation at 11-bar soil water potential) as the main factor and Mycorrhizal and superabsorbent polymer biofertilizer and their combination with non-consumption of mycorrhiza and superabsorbent as a sub-factor, were studied in factorial split plot experiment based on a randomized complete block design. The studied traits included plant height, leaf area index, ear length, ear periphery, row number per ear, number of seeds per row, 100 seed weight, grain yield, biological yield and harvest index. The results showed that all growing traits and yield were significantly affected by superabsorbent and mycorrhizal application. By increasing the drought stress intensity, the growth and yield components decreased, but the decrease was significantly lower in comparison to application of mycorrhiza and superabsorbent polymer. The use of mycorrhiza and superabsorbent in severe stress condition could increase biological yield by about 12% and 22% as compared with control. Lowest grain yield (4.25 t/ha) was obtained by severe stress without application of bio-fertilizer and superabsorbent.

To investigate the effect of superabsorbent polymer (SAP) and planting depth on total and marketability tuder yield of three potato cultivars, an experiment was conducted during 2016 and 2017 at Agricultural and Natural Resources Research and Education Center of Hamadan, Iran. The experiment was conducted as split split plot based on a randomized complete block design (RCBD) with three replications. The main plot included a planting depth at four levels (10, 15, 20 and 25 cm), subplot was consisted of a potato cultivar at three levels (Sante, Fontine and Agria) and sub-subplot comprised a SAP application at two levels (application and non-application of SAP). The results of this research showed that there is a significant interaction effect of cultivar and sowing depth with SAP on the number and weight of small tubers, deformed tubers and total yield (p<0.01) and on the number and weight of medium tubers (p<0.05). In this regard, the highest number and weight of medium tubers obtained at depth of 20 cm along with SAP usage in all cultivars. In general, the results revealed that SAP usage in all of the cultivars led to an increase in marketable tubers and total yield.

In order to investigate the effect of superabsorbent and mycorrhizal fungi on reducing water consumption, growth traits and potato yield, an experiment with strip-factorial design was performed. In this study, the amount of irrigation water at three levels (100, 75 and 50% of water requirement based on evapotranspiration) in horizontal plots and the use of Trawat200A super absorbent with two levels (0 and 80 kg / ha) and mycorrhiza on two levels (inoculation and non-inoculation with Glomus etunicatum) were placed in vertical plots. The results of combined analysis of variance showed that effect of irrigation and the use of mycorrhiza and superabsorbent were significant in most vegetative traits as well as yield. Means comparison showed that vegetative traits and total yield decreased by application of low irrigation, but this decrease was significantly less in mycorrhizal inoculation conditions and with the application of superabsorbent polymer. Under moderate and severe stress conditions, the combined use of mycorrhiza and superabsorbent increased the total yield compared to non-consumption (control) by about 9.5% and 10.15%, respectively.

Achieving an efficient combination of sucrose and benzyl adenin (BA) concentration is one of the success factors in potato microtuber production. In this experiment in order to study the effect of different concentrations of BA and sucrose on plantlets growth traits and their production of microtubers, healthy plantlets of Arinda cultivar were treated with different concentrations of BA and sucrose in MS culture medium in vitro. This research was conducted as a factorial experiment based on a completely randomized design. BA was used as the first factor with the concentrations of 0 (control), 50, 100 and 150 μM, and the second factor was sucrose at three concentration levels (30, 45 and 60 grams per liter). Some plantlets growth traits including stolon length, leaf number, root fresh and dry weight, stem fresh and dry weight, number of microtuber, fresh microtuber weight and its dry matter percentage were measured. The results showed that the effect of BA on all traits was significant, while sucrose effect was significant on some of traits only. The effect of BA and sucrose interaction was significant only on stolon length and microtuber weight. In most of the growth traits, as well as the number of microtuber and its percentage of dry matter, the concentration of 50 μM BA had the better results compared to the two other concentrations (100 and 150 μM). Nevertheless, there were the same results between 150 µM BA and control treatment in the most traits as well as microtuber productions. Growth traits of plantlet and their yield improved by the change in sucrose concentration, from 30 to 60 grams per liter.

An study was conducted in order to investigate the effect of poultry and chemical fertilizers on vegetative and reproductive traits and the total yield in field cucumbers in Hamedan province of Iran. The research project was conducted in a strip factorial experiment based on randomized complete block design with three replications. The treatments were Haiek and Royal cultivars, poultry manure including 0, 6 and 12 tons per hectare and chemical fertilizer including 1- 50 kg urea without micronutrient fertilizer (regional custom), 2- 109 kg ammonium sulfate without micronutrient fertilizer, 3- combination of urea, phosphorus, potassium and micronutrient fertilizers according to the soil test and 4- combination of ammonium, phosphorus, potassium sulfate and micronutrient fertilizers according to soil test. Analysis of variance of the data showed that the interaction effect of different levels of poultry manure with different levels of chemical fertilizer and cultivar was significant on male to female flower ratio, number of pickling cucumber yield, fresh cucumber yield and length of fruiting period. The mean comparison of the data showed that the use of six tons poultry manure cause a significant increase in total yield by 4.68 tons per hectare in both cultivars only when urea, phosphorus, potassium and complete micronutrient fertilizers were applied according to the soil test. However, with the use of poultry manure at the rate of 12 tons per hectare in all levels of chemical fertilizers, there was a significant increase in the yield with average of 4.29 tons per hectare in both cultivars. Totally, the use of poultry manure at two levels of 6 and 12 tons per hectare increased the production of cucumber fruit by 3.09 and 4.13 tons per hectare, respectively. Chemical fertilizer application based on soil test and in combination with micronutrient-complete fertilizer by spraying solution enhanced the growth traits as well as cucumber yield (at the rate of 2.02 tons per hectare) as compared to consumption of 50 kg urea without micronutrient fertilizer.

In order to investigate the effect of two growth regulators of gibberellic acid (GA3) and benzyl adenine (BA) on meristems regeneration and their vegetative characteristics in new potato clones, this study was conducted as a factorial experiment based on a completely randomized design. Factors that were investigated included the effect of gibberellic acid and benzyl adenine on four levels including 1- complete MS medium (control), 2- MS medium + 0.2 mg. L-1 gibberellic acid, 3- MS medium + 2 mg. L-1 gibberellic acid and 4- MS medium + 1 mg. L-1 benzyl adenine medium and the second factor included five potato clones named KSG302, KSG82, KSG48, KSG31 and KSG64. The number of growing meristems (the regenerated meristem) and some vegetative traits of reproduced plantlets including plantlet height, plantlet weight, leaves number, internode and number of nodes, number and length of the roots were measured. Results of analysis of variance showed that main effects of growth regulator, clone and their interaction were significant on meristem regeneration rate and also on all growth characteristics of the regenerated plantlets. The studied clones showed different status in the terms of plantlet growth traits in different treatments of two growth regulators. The highest plantlet weight was obtained in KSG64 clone with an average of 0.654 g in two MS mediums of 1 mg. L-1 benzyl adenine and 2 mg. L-1 gibberellic acid. Totally, the results of the experiment showed that the use of growth regulator especially benzyl adenine increased the growth vigor of plantlet, but also had a significant effect on meristem regeneration in most clones. Also, the effects of low concentration of gibberellic acid was similar to those at higher concentrations on meristem regeneration and growth vigor of the plantlets and even better in some cases.

this research was carried out to investigate the effects of the use of nitroxin and superabsorbent alone and in combination in moisture stress conditions on growth and yield of the corn. The experiment was arranged in split plot based on randomized complete block design with three replications. Three irrigation levels containing optimal irrigation (irrigation at soil water potential -3 bar), moderate drought stress (irrigation at soil water potential -7 bar) and severe water stress (irrigation at soil water potential -11 bar) were allocated to main plots and four bio fertilizer Nitroxin and superabsorbent levels including no application of these material (control), superabsorbent, Nitroxin as a bio-fertilizer and a combination of Nitroxin and superabsorbent were considered as sub plots. The studied traits included plant height, leaf area index, ear length, ear periphery, and row number per ear, number of seeds per row, 100 seed weight, grain yield, biological yield and harvest index. The results showed that more growing traits and yield were significantly affected by superabsorbent and Nitroxin application. This effectiveness was less under mild but more under severe stress conditions. The combined application of superabsorbent and Nitroxin in both mild and sever stress conditions created a better situation in growth traits and yield components. Total yield in severe stress treatment increased by 35%, 60% and 68%, respectively, under using of Nitroxin superabsorbent and their composition compared to non-use. Lowest grain yield (4.75 t/ha) was obtained by severe stress and no use of both of type of bio-fertilizer and superabsorbent

This experiment had been carried out to evaluate the potential of mycorrhiza fungus on growth rate and performance of plantlets derived minituber in water deficiency condition. The test was conducted in a factorial experiment based on completely randomized design with four replications. The factors included four level irrigation regimes (100%, 85%, 75% and 65% of water field capacity), inoculation of potato minituber by mycorrhiza sp. Glomus intraradices and non-inoculated ones. Growth indices such as stem length and diameter, internode number and length, stem and root fresh weight, leaf area and chlorophyll content were measured. Analysis of variance showed that the main effect of mycorrhiza and water irrigation regimes had significant effect by probability of 1% α level on stem length, leaf area, chlorophyll content, colonization percentage, fresh and dry stem weight, fresh and dry root weight and number of minituber. Interaction effect of two factors was significant only in leaf area, chlorophyll content and dry root weight. By mean comparisons demonstrated that the highest internode and stem length, fresh and dry stem weight, fresh root weight, leaf area and chlorophyll content were accomplished in mycorrhizal inoculation with 85% FC providing water. Totally, the results demonstrated that mycorrhization of minituber in two lower water available levels produce plantlets that had same situations as compared with non-inoculated of 100% FC providing water.

In this research, the effect of different concentrations of Paclobutrazol (0, 200, 300, 400mg.L-1) and different application times of paclobutrazol (beginning of tuberization, 10, 20 and 30 days after tuberization) on some qualitative and quantitative traits of ‘Sante’ potato cultivar were investigated. Test was performed in a factorial experiment based on randomized complete blocks design with two factors by 3 replications. Paclobutrazol (Culture commercial suspension with 250gr.L-1 active ingredient of PBZ) was used as foliar spray on potato plants. Conclusion of analysis variances demonstrated that effect of paclobutrazol application time was significant (p≤0.01) on large, small and seed tuber size production. The effect of Paclobutrazol concentration showed significant difference on tuber dry matter percentage, large, small, potato seed tuber, total number, mean weight of tuber and tuber number per plant. Comparison means results showed that use of poclobutrazol with concentrations of 300 and 400mg. L-1 increased amount of tuber in potato plants. As a result, number of total tubers per plant and number of tuber seeds have been increased by 9.8% and 13.2% respectively. Although application of paclobutrazol in these two levels significantly increased mean number of tuber per plant but had no significant effect on total yield comparison with control treatment. By results of this experiment we can conclude that application of paclobutrazol on potato plant will be considerably able to increase percentage of seed tuber size. Consequently, this situation leads to more efficiency of tuber production per area unit in potato seed farms.

In order to screen and induce the resistance of the potato stocks to the Colletotrichum coccodes, firstly, healthy seed tubers from two potato cultivars (Marfona and Agria) were placed in suitable conditions to produce sprout and single node. Then, segments of sprouts and single node of 5 to 7 mm were prepared. These segments were transferred to sterilized culture media containing MS and Nitsch & Nitsch mixed with three-dosage mixture of the fungus extract. Flasks of sprouts and nodal segment cuttings transferred into the chamber growth under appropriate temperature and light period until shoots were regenerated. This test arranged by factorial experiment based on randomized complete design with four replications. The factors were selected by cultivar in two level (Agria, Marfona), three concentration of fungus extract; low concentration (Six cc pure fungus extracts plus one volume of sterilized distilled water), Medium concentration (Six cc pure fungus extract plus one third volume of distilled sterilized water) and high concentration (Six cc pure fungus extract), distilled water as control treatment and culture medium in two levels (MS and Nitch & Nitch). After regeneration and production of new plantlets, their contamination and their health were evaluated. The result of the experiment showed that regeneration was not observed in sprout segments in both culture media and in both cultivars with all three concentrations of fungal extract, and only in the control treatment, the sprout segments were able to regenerate. However, regeneration was performed in the single nodes in both cultivars with a low concentration and average fungus extract.

Mycorrhiza can be used as an efficient tool to increase nutrients productivity to achieve sustainable agriculture. This experiment conducted to investigate the interaction of phosphorus and mycorrhiza on growth characteristics and production of mini-tuber and nutrients uptake of seedlings under greenhouse condition. The experiment was arranged as factorial in completely randomized design with three replications in agricultural and natural resource research center of Hamadan in 2015. First factor included of inoculation with mycorrhizal fungi, Rhizophagus irregularis, (inoculated and non-inoculated) and the second factor was the amount of phosphorus (0.965, 0.482, 0.241 and 0.12 mM phosphorus according to H2PO-4 in Hoagland solution (100, 75, 50 and 25 percent of Hoagland complete phosphorus concentration (HCPC), respectively). The results showed that the maximum values of seedling establishment (98.3%), number of leaves (13.3), the number of mini-tubers (8.9), the total weight of mini-tubers per plant (53.2 g), shoot height (54.6 cm), phosphorus in mini-tubers dry matter (%0.38) and leaves (%0.363) observed in phosphorus 75% HCPC and inoculation treatment and no significant differences was seen relative to phosphorus 100% HCPC and inoculation treatment. Inoculation with mycorrhizal fungi significantly increased the mini-tubers and leaves nitrogen, dry matter and weight of mini-tuber relative to non-inoculated treatments. Generally, respect to that there was no significant difference between 75% and 100% phosphorus in inoculation treatment, the applying of mycorrhizal fungi can reduce agricultural inputs consumption without any significant decrease in yield.

Potato crop requires substantial amount of water and is extremely susceptible to water stress. Therefore, irrigation management is particularly important for its cultivation. In order to study of yield and biochemical properties of potato leaves under deficit irrigation, a field split-plot experiment was carried out based on a completely randomized block design with three replications. Main plot included six irrigation regimes [100%, 90%, 80%, 70%, 60%, and 50% of water requirement] and sub-plots included cultivars Sante and Savalan. Irrigation treatments had significant effects on leaf soluble proteins and sugar, leaf relative water content, and yields and dry weights of tubers per plant. Severe water deficit stress reduced leaf soluble proteins content, leaf relative water content, yields and dry weights of tubers per plant. Irrigation regime × cultivar interaction was significant for concentrations of leaf potassium and proline. Results also indicated that the highest values of soluble sugar (2.8 µmol.g-1of FW) and soluble proteins (3 µmol.gr-1of FW) were related to 50% and80% irrigation regimes, respectively. The lowest yield (204.9 gr.plant-1) and dry weight (46.8 gr.plant-1) of tubers were observed in 50% of complete irrigation. Maximum concentrations of potassium(43 mg.gr-1of DW) and proline (2.2 µmol.gr-1 of FW) in leaves belonged to 50% irrigation regime in cv. Sante. Result from the present research indicated that, under drought conditions, adverse effects of water stress can be reduced and desirable product can be attained by managing irrigation (deficit irrigation) appropriately.

The advantages of plastic mulches have been known in production of agricultural crops. Their capability have been demonstrated to help nutrition uptake, precocity and yield of fruit trees, and decreasing of aphid population as viruses pest vectors. It is also demonstrated some advantages of plastic mulch on some traits in potato such as increasing growth rate, yield and number of medium tuber size. Also, the effects of combined use of straw, chopped and polyethylene as well as different levels of irrigation (60, 80, 100, 120% water requirement) on yield and water use efficiency in potato have been investigated. In previous studies, it is concentrated on the effect of the special type of plastic on growing aspect of potato and there is no comparative assessment between different types of the mulches. So that in this research we evaluated the responses between types of plastic mulches.
Material and this research was conducted under field conditions. A factorial experiment was designed based on randomized complete block design with three replications. The experimental treatments consisted of mulch in five levels (clear, white, black, double layer and control (without mulch)) and two cultivars (Agria and Sante). Each plot was designed in 4 m2. For every plot, ridges were divided into complicated double rows with 50 × 150 centimeters wide. Irrigation tapes were placed between every duplicated row. Water requirement was calculated through corrected evapotranspiration (ETo) by Penman-Monteith equation with considering 90% water use efficiency. During the growing season some characteristics such as requirement time to 80% emergence, tuberization time, plant height in flowering time, number of stems and leaf area have been measured. Harvesting time was recorded along with measurement of tuber weights. Total yield was measured by random selection of one m2 in each plot. Harvested tubers were separated based on three sizes; edible tuber (large tuber), average tuber and small tuber size. Tow-way analysis of variance (ANOVA) of data was carried out using SAS software and means were compared byDuncan’s Multiple Range Test at probability level of 5%
The results of the experiment showed that application of plastic mulch and cultivar had significant effect (P≤ 0.01) on most of growing traits. Effect of cultivar and plastic mulch had no significant different on tuber dry matter. Mean comparison of 80% emergence date, number of main stem, growth duration, ranking of tubers size and total yield showed significant effect between cultivars and plastic mulches. Sante cultivar with clear mulch reach in shortest time to 80% emergence (11.3 days) and tuberization time (46.46 days). Significant difference between polyethylene mulches in emergence date is due to the effect of mulch characteristics on soil temperature and moisture. Consequently, soil microclimate would be changed and growth habits of potato plant inclined to suitable responses. Clear plastic mulch had highest plant height and number of main stem compared to other mulches and control treatment. Leaf area also affected by mulches; so that four types of plastic mulches had more leaf area comparison to control. Significant effect of mulch treatments on leaf area can be related to conservation of moisture and reduction of water stress. Meanwhile, increasing of uptake and transferring of mineral nutrient can be promoted growth rate. All this reaction can increase leaf area in plastic mulch treatments. Totally, application of plastic mulches could improve growth rate, growth duration and total yield of potato.
The result of this research showed that polyethylene mulch can obviously increase growth rate as well reduce growth duration. Also, plastic mulch can significantly increase total yield and positive reaction effect on tuber size. Different types of plastic mulches showed different responses on growth traits and total yield. It seems clear mulch be more capable in the most traits and total yield compared with other plastic.

cold resistance has been studied and evaluated by several methods; visional observation after natural cold injury, establishing of freezing condition by transported micro chamber in native places of trees, cold treatment of detached tree segments in laboratory examination. Most physiological traits correlated with cold resistance have multi gene characteristics and have controversial relationships. Russia researchers evaluated cold injury on 30 cultivars of grapevine. Their results showed that only hybrids that accomplished by crossing between Asian and vinifera had more cold resistance as compared with other cultivars. Up to now some researches have been conducted in Iran. Malakooti evaluated the capability of cold injury in some clones. He concluded that only two clones had cold resistance property when treated with -21 OC in 24 hours by duration of cold. All grapevines that have been cultivated in Iran belong to vinifera species. Therefore there is no absolute cold resistance in the most of them. But some clones and cultivars may be showed more cold tolerance comparison with others since they have been selected and acclimated trough the time. By entrance of cold weather that was overwhelming in all of the country in 2011, there had been suitable condition for this survey. In this regard, this research had been conducted to distinguish and evaluate this characteristic.
Material and this study was conducted to evaluate the effect of cold injury on grapevine cultivars and assessment of tolerance to cold injury in the grapevine cultivars. This research was done in a field evaluation in three part of Hamadan province namely, Razan city, Malayer city and collection cultivars in the Agricultural research center of Hamadan. In three regions we collected and evaluated the canes of eight Cultivars, namely, Red Tompson seedless, White Tompson seedless, Askari, Fakhri, Yaghooti, Mehdikhani, ghazne and dozool. After that the winter passed (early spring), we collected the canes and some corsons. Then the canes were separated in three segments. Buds were observed by microscopic detection and survived buds were counted in different segments of the cane. That is a criterion to evaluate the effect of cold injury on buds in this expectation. As we have limited samples in some regions, therefore the experiment was conducted in non-complete randomized design. Tow-way analysis of variance (ANOVA) of the data was carried out using SAS software (v. 8.02, SAS Institute, Cary, NC) and the means were compared through the Duncan’s Multiple Range Test.
result of analysis variance showed that cultivars have significantly different in respecting to bud growth. There were the most number of activated buds in the first third zone of canes (basal side of the cane). This activation had been decreased comparison with the apical zone. Means comparison showed that two cultivars (Mehdikhani and Yaghooti) had highest number of survived buds in three segments of cane as compared to other cultivars. These two cultivars are early ripening cultivar. It is estimated that less injury of cold in these cultivars might be correlated with their precocity besides inclining with inherits and genetic specifications. These cultivars were harvested 25 to 30 days sooner than other cultivars, so they have more time for repletion of starch and biomass. Other six cultivars had more injured buds as compared with these two cultivars. There were not significant different between these six cultivars, although ghazne and dozool had less survived buds as compared with four other cultivars in three segment of the cane. In comparison between three regions of Hamadan province, Hamadan itself and Razan city had more cold injury than Malayer.
It was demonstrated that in this research two cultivars of grapevine (Yaghooti & Mehdikhani) had more cold tolerance in three regions compared with other cultivars. But red and white Thompson seedless is more widespread in Hamedan. So it is recommended that we have good monitoring on horticultural techniques for preventing and reducing cold injury in these cultivars. These precautions or tactics can be concluded as establishing of better nutrition program, prevention of early harvesting, prevention of any leaf injury and defoliation, good pruning performance and prevention of sever pruning especially in late season, using of resistant rootstock, using of absorbent light mulches in winter, application of some material for inducing cold resistance.

Microplants derived from tissue culture of two potato cultivars (Agria and Sante) were inoculated with two species of mycorrhizal fungi. Inoculation was being done when microplants transferred in to the greenhouse. A pot experiment was conducted using a factorial based on randomized complete blocks design with four replications. The factors were mycorrizal inoculation (non-inoculated and inoculated with Glomus mosseae، Glomus etunicatum and mixture of them) and two cultivars of potato. Eight weeks after inoculation، colonization percentage was assayed. In addition، plant growth regulators including Auxin، Cytokinin and Gibberellin were measured. After harvesting، minitubers were separated and total yield was estimated. In addition، dry matter of minituber was determined. Results showed that inoculants of mycorrhizae had significant effect (p≤0. 05) on colonization، minituber production and level of all plant growth regulators. Interaction effect of cultivar and inoculants in minituber size and weight was significant by probability of α= 0. 01 but was significant by probability of α= 0. 05 in Gibberellins levels and colonization percentage. By mean comparisons، it was demonstrated that inoculation with G. etanicatum and mixed inoculants had more positively effect on colonization severity، minituber production، and level of all plant growth regulators comparison with G. mosseae. The highest amount of minituber (13. 81 No and 40. 59 gr in mean weight per plantlet) was achieved in mixed inoculants that significantly (p≤0. 05) was different with two separated inoculants and control treatment. Dry matter of minituber was increased significantly (p≤0. 05) by application of mixed inoculant and separately mycorrhizal inoculants comparison with control treatment in two cultivars.

Effects of different Paclobutrazol concentrations (0, 250, 350 and 450 mgL-1) and plantlet density (80, 100 and 120 plantlet/m2) on minituber production per plantlet in potato cultivar ‘Sante’ were investigated in a factorial experiment based upon a randomized complete block design of 4 replications. Paclobutrazol (Cultar with 250 g/L of active ingredient) was used as foliar application at early stolon initiation. The results indicted that Paclobutrazol increased chlorophyll a and b contents of the leaf tissue as well the ratio of the tuber fresh mass to shoot fresh mass. Paclobutrazol significantly reduced the internode,s, stem and stolon length, also reduced stem diameter. While plantlet density increased internode, stem and stolon length, yet reduced tuber fresh mass to shoot fresh mass ratio. The interaction between the two factors was significant on internode, stem and stolon lengths. The study clearly showed that Paclobutrazole is effective in suppressing excessive vegetative growth in high plantlet densities. It could also improve the minituber average weight through an increase of assimilation to the minituber and as well an increase of chlorophyll a and b contents of the leaf tissue. Means related to weight and number of minituber production were recorded as 3.27, 3.74 and 5.69, 6.16 in control and Paclobutrazol treatments, respectively. In total, for producing the highest numbers of minituber of higher weights, it is recommended to apply higher plantlet densities along with lower concentrations of Paclobutrazol