جستجوی مقالات مرتبط با کلیدواژه « دور آبیاری » در نشریات گروه « باغبانی »

Water-deficit and consecutive droughts have led to drought stress in most parts of the world. We need to prepare a good program to use better the available water. Different materials can be used to increase water use efficiency. Mineral superabsorbent is one of the materials used around the world. These materials absorb water in the soil so that reserved water is usable by plant in the time of drought stress and they can reduce stress and lead to yield loss prevention. So that, an experiment was conducted to evaluate effects of different mineral superabsorbent and irrigation cycles on tall fescue. An experiment based on randomized block design with three replication was used. Two irrigation periods (3 and 10 days) and two kinds of mineral superabsorbents (polymer and mineral) with amounts of 160 and 240 g kg-1 were used as experimental treatments. No mineral superabsorbent was used as control. Results showed that mineral and polymer superabsorbent amounts in 3 days irrigation period had significant effect on root fresh and dry weights and shoot fresh and dry weights at 5% level, in greenhouse test. Likewise, both superabsorbents, had significant effect on proline amount. Furthermore, polymer amounts had significant effect at 5% level, in field test. In general, it can be concluded that the use of mineral superabsorbents can be a good solution to save water consumption in green space. Also, it can enhance tall fescue growth under drought condition.

Supplementary irrigation in the fig orchards of the shores of Bakhtegan Lake in Estahban is done with saline water. This research was carried out to investigate the effect of saline water on vegetative and reproductive characteristics of fig trees. The randomized complete block design was performed with irrigation water salinity treatments (2, 4, 6 and 8 dS.m-1) in two irrigation intervals (once every 15 and 30 days) with a non-irrigation treatment (control) on Sabz cultivar in three replications at Khanehkat village in the years 2018 to 2021. The results showed that irrigation with 8 dS.m-1 salinity had adverse effects and it was an unsuccessful treatment compared to the other treatments with lower salinity irrigation. The highest abnormality symptoms in vegetative and reproductive factors were observed in the control treatment. Also, this treatment has the lowest relative water content (58.6%), diameter (26.6mm) and weight (4.3g) of fruit, the least yield (4935g) and the percentage of first-class commercial fruits (Open ostiole, white and large fruits) and the highest leaf ionic leakage (27.1%), which was significantly different from most of the treatments. There was a great similarity in the characteristics of trees treated with 8 dS.m-1 saline water and without irrigation. Therefore, supplementary irrigation with this salinity is not recommended. In conclusion, supplementary irrigation with saline water less than 6 dS.m-1 had suitable quantity and quality of fruit and the least abnormality signs. So, Sabz cultivar can tolerate until this amount of salinity.

Drought stress in tomatoes reduces fruit quality and yield, also fall leaves and cause of blossom rot. It has been reported that drought stress reduces cell division and causes the stomata to close, followed by a decrease in the flow of carbon dioxide to the mesophyll cells of the leaf. Several methods have been proposed to overcome the drought stress in tomato plants, which can be mentioned the use of drought tolerance genotypes, genetic engineering to identify drought resistant genes and transfer them to sensitive plants, as well as the use of tolerancet rootstocks. It has reported that type of rootstock can effected on tolerance of tomato plants to drought stress. For this reason, the present study was conducted to investigate the effect of wild eggplant rootstock on the drought tolerance of two tomato cultivars.

In order to find the effect of the wild eggplant rootstock on the tolerance of two tomato cultivars, a factorial experiment was conducted as completely randomized design with two factors. Factors were included irrigation period three levels of 3 (control), 6 and 9-day and grafting combination at 6 levels involved non-grafted Dafnis, non-grafted Isabella, self-grafted Dafnis, self grafting Isabella, Isabella grafted on wild eggplant rootstock (S. torvum), and Dafnis grafted on wild eggplant rootstock. The plants were exposed to drought for 54 days. At the end of experiment growth and physiological parmeters including leaf specific, plant height dry weight of shoot as well as photosynthesis parameters, RWC and plant nutrients were measured. The amount of leaf proline was measured according to Paquin and Lichasur methodusing a spectrophotometer at a wavelength of 515 nm. The phenolic compounds of the leaves were measured at a wavelength of 725 nm using a spectrophotometer (Isfendiyaroglu and Zeker, 2002). Also, the membrane stability index (ion leakage percentage) was measured according to Lutts et al.'s method (Lutts et al., 1996).

The results showed that with increasing irrigation period decreased the most of vegetative parameters, photosynthesis pigments, and mineral nutrients, so that, the highest value was showed at the 3-day irrigation period and the lowest value was at the 9-day irrigation period. Shoot weight decrese is probably due to morphological changes in plant roots, which is a plant response to drought stress. The results also showed that the interaction of irrigation period and grafted combination on some vegetative and ecophysiological parameters was significant. The lowest dry weight of shoot was observed at 9-day of irrigation period in plants of Dafnis grafted on torvum rootstock., Tthe highest dry weight root volume, leaf potassium and phosphorous concentration were at the 3-day irrigation period in self-grafted Dafnis plants.The results also showed that the amount of phenolic compounds in plants of Isabella grafted on torvum rootstock was the highest in 9 days irrigation period which may be due to the rootstock effect on the synthesis of these compounds in the scion. According to the results, the concentration of leaf magnesium in non-grafted plants increased with the increase of the irrigation cycle from 3 days to 9 days, althougth no significant difference was observed between self-grafted and non-grafted plants. In the 9-day irrigation period, the highest concentration of leaf magnesium was observed to non-grafted Daphnis plants, which was significantly different from other grafting combinations compounds except Daphnis self-grafted plants.

The results of the present study showed that drought stress had the greatest effect on dry matter, and the amount of photosynthetic indices and pigments in tomato plants. Based on the results of the present study, it was found that the most of the reduce vegetative and physiological parameters was observed in Daphnis cultivar grafted on the thorum rootstock, were significantly reduced compared to self-grafted or non-grafted plants, which it was due to the dwarfing effects of this rootstock or grafting incompatibility. According to the results of the present study, it can be postulated that in drought stress Isabella cultivars grafted on the wild eggplant rootstock had more growh than other combination grafting. Hence it proposed more studies in this case.

The deficiency of organic matter in the soil is one of the factors limiting cultivating and growing of plants. While the organic matter is the main factor of soil fertility and the ideal organic matter content of agricultural soils is about 4-6% according to the experiments performed, this amount is very low in arid and desert areas such as those  in Iran. The significant capability of humic fertilizers in the rapid improvement of soil fertilization level is quite recognizable. Humic acid has a direct role in determining the producing potential of the soil. Humic substances can have a positive effect on plant growth in different ways. Humic acid results in an increasing nitrogen uptake by plants and stimulates and enhances the uptake of Ca, Mg, P, and K. By enhancing the resistance to environmental stresses, increasing chlorophyll concentration and thus affecting photosynthesis, amino acids are effective in plant growth and yield. Given the conditions that agriculture faces, drought is the main limiting factor of agricultural production in the present and future. Research has reported that the improvement of plant growth under stress conditions by application of humic substances and amino acid. The use of these factors that increase plant growth in stressful conditions and improve yield is a useful and effective method. The aim of this study was to investigate the effect of organic fertilizers on growth traits of cucumber plants under drought stress.

In order to explore the effect of drought stress on cucumber plant, an experiment was carried out in the research field of agriculture faculty of Ferdowsi University of Mashhad in 2015-2016. This study was performed as a factorial design in a completely randomized block design with three replications. The first factor was fertilization at four levels (control, humic acid application (200 ppm), glycine amino acid and glutamic acid application (6 liters per hectare), and combined application of humic acid (200 ppm), glycine amino acid and glutamic acid (6 liters per hectare), and the second factor was irrigation at three levels of 3, 5 and 7 days. Furrows with 2 m apart, 40 cm deep, 50 cm wide and 20 m long were created. Following the soil irrigation, the cucumber seeds were planted on the edge of the experimental hills (4-5 seeds per hill) that were spaced 50 cm apart. The treatments were applied via irrigation at specified concentration. At the end of the experiment Morphophysiological traits were measured.

The results showed that drought stress reduced fresh and dry weights of plant, a number of branches, root length, stem length, and internode length. The amount of available water to plants affects their growth traits. Increasing irrigation interval decreased vegetative growth parameters in this plant, which is undoubtedly due to the lack of water available to the plant. Drought stress leads to stomata closure, plant wilt, swelling reduction, and reduced water content and total potential of the leaf, resulting in decreased cell division, especially in shoots and leaves. As a result, the first effects of dehydration in plants can be seen in their smaller leaf size and lower height than normal conditions. The highest level of drought stress (7 days) decreases all the traits. Unfortunately, the use of humic acid and acid amine had no effect on the highest levels of stress (7 days). The application of humic acid alone could improve the effects of drought stress on the plant. Humic acid enhances plant growth by affecting plant cell metabolism as well as chelating power, increasing nutrient uptake, and increasing nitrogen content. Experimental studies have shown that glycine betaine strengthens enzymatic structures and activities and protein components, and cell wall stability against the damaging effects of environmental stresses is considered to be one of its activities. It seems that organic matter and humic compounds including humic acid through positive physiological effects including effects on plant cells metabolism, increased leaf chlorophyll concentration, increased metabolism within cells, and increased durability of photosynthetic tissues (Increasing leaf durability) leads to increase of production performance and biomass production in plants.

The use of humic acid alone led to improved leaf area, root length, and other traits. These factors caused an improvement in the photosynthetic rate in the plant, resulting in improved yield and growth under drought stress conditions (increased irrigation intervals). The protective and moderating role of the humic acid application under drought stress is one of the reasons for growth improvement by these compounds. In general, the combined application of humic acid and amino acid in the form of irrigation fertilizer in cucumber under drought stress improved growth traits and prevented yield reduction.

The present study was conducted to evaluate the efficiency of the HYDRUS model in simulating soil water movement and redistribution of moisture around the roots of maize in homogeneous and heavy soils. This study was carried out in the Agricultural Research Center of Khuzestan Province under drip strip irrigation with three irrigation regimes of 2, 3 and 4 days with three replications during two cropping years. In order to monitor the moisture around the roots, dig a soil profile to a depth of 75 cm perpendicular to the drip irrigation strip. Observed and simulated moisture values were compared byR2,EF, MAE and RMSE statistics. The results showed that the average moisture distribution in each irrigation regime is in the range of crop capacity. RMSE values for different diets ranged from 1.29 to 2.40% and MAE values for different diets ranged from 1 to 2%. Moisture simulations were classified as excellent based on MAE and RMSE values.Also, the results of the coefficient of explanation are between 60 to 90% and the efficiency of the model is between 40 to 90%. Based on the results, the lowest efficiency of the model was in the simulation 24 hours after irrigation and the best simulation was 72 hours after irrigation. The results show the high capability of the model in simulating soil volumetric moisture.

In order to investigate the effect of humic acid and irrigation interval on yield and yield components of corn seed of Single Crusher 704 cultivar in Zabol, a split plot experiment (split plot) in a randomized complete block design with 3 replications. Experimental treatments include main plots three levels: 6 days (A1), 9 days (A2) and 12 days (A3), and and sub plots of research include humic acid in four levels including control or weekly (B1) Biweekly (B2), Triweekly (B3) and Monthly (B4). The results of analysis of variance showed that the effects of irrigation and spraying of humic acid on their harvest index, plant height, number of ear per plant and number of seeds per ear were significant. The highest Harvest index (51.42%), plant height (190 cm), number of ear per plant (3.6 N.o) and number of grain per ear (612 N.o) were obtained irrigated conditions for 6 days and Biweekly Humic acid spray treatment. According to the results of the experiment, the best irrigation interval for corn seed is recommended for 6 days irrigation, with the use of Biweekly for humic acid solution for cultivation in the area.

Olive (Olea europaea L.) is one of the drought tolerant ever green fruit trees. Olive is an economically important species of the Mediterranean area, so understanding the mechanisms by which olive plants face drought stress under environmental conditions is essential for the improvement of olive yield and oil quality. Olive is one of the fruit trees which become important in the Iranian fruit industry at the near future. Mulch is an optimizing strategy under which crops are allowed to sustain some degree of water deficit and yield reduction. Increasing crop water-use efficiency (WUE) through water conservation in the soil is an important component of dry land farming. Mulching is among the water management practices for increasing WUE. Mulch is referred to as any material that is spread onto the surface of the soil for protection against solar radiation or evaporation. Different materials, such as wheat straw, rice straw, plastic film, grass, wood, and sand, are used as mulches.
This experiment was conducted to study the effect of irrigation interval and mulch on Pomological characteristics and yield of 11-years old Sevillana olive cultivar. A factorial experiment was carried out in Dallaho Olive Research Station at Sarepole located in Kermanshah province. Field experiment based on randomized complete block design with three replications and two factors (irrigation interval and mulch) were conducted in 2015. Each experiment unit consists of 4 trees and 108 trees were used. Irrigation treatments period for experiment were 3, 6 and 10 days interval and mulch treatments for experiment were polyethylene, organic materials and non-mulch (control). Geographical characters was longitude of 45˚, 51΄ E and latitude of 34˚, 30΄ N and the height of sea level 581m. The measured tree characteristics were: Fruit Weight, Pulp Fresh Weight, Pulp Dry Weight, Dry matter, Pulp/Pit ratio, Pit Length, Pit Diameter, Fruit Yield (kg/ tree) and Fruit Yield (kg/ hectare). Reproductive traits were determined by the methods of I.O.O.C.(2002). Collected data were analyzed using SAS program.
Obtained results showed that mulch and interval irrigation treatments had significant differences in Pomological traits so that mulch and 3 days interval irrigation treatments increased fruit weight, pulp fresh and dry weight, fruit moisture percent, fruit yield kg/ tree and kg/ hectare but fruit weight, pulp fresh and dry weight, fruit moisture percent and Fruit yield kg/ tree and kg/ hectare reduced by drought stress. Mulch application increased fruit weight, fruit length and diameter, pulp fresh and dry weight, fruit moisture percent and fruit yield. Mulch application improved Pomological characteristics such as fruit weight, pulp fresh and dry weight, fruit moisture percent, Fruit yield kg/ tree and kg/ hectare of olive Sevillana cultivar under drought stress and helped to save irrigation water in olive orchards. In the arid and semi arid as well as sub-tropical regions, water shortage is a normal phenomenon and seriously limits the agricultural potential. Therefore, under irrigation or rain-fed conditions, it is important for the available water to be used in the most efficient way. The proper irrigation interval can play a major role in increasing the water use efficiency and the productivity by applying the required amount of water when it is needed. On the other hand, the poor irrigation interval can lead to the development of crop water deficit and result in lower yield due to water and nutrient deficiency. Early in the season when plants are small, it is beneficial to encourage the roots to explore as much of the soil profile as possible. This maximizes nutrient uptake and stress tolerance later in the season. The effect of mulch on yield and its components have been reported in various studies. The effect of mulch on plant yield through changes in soil conditions that can change the soil temperature and soil moisture that influence on the growth and yield. The effect of mulch can be done through weed control, make favorable conditions of temperature and soil moisture, reduce leaching of nutrients and soil fertility, increase the efficiency of water use, increase availability of absorption of nutrients, increased root growth and control of diseases and pests.
According to the results of this research, it can be concluded that mulch and interval irrigation had a significant effect on reproductive characteristics. Using mulch improved Pomological characteristics of olive including fruit weight and yield per tree and hactar, fruit length and diameter, pulp fresh and dry weight, fruit moisture percent Under drought stress and helped to save irrigation water in olive orchards.

In order to evaluate the effect of irrigation and plant density on the extinction coefficient grain corn delayed, the trial was conducted in the summer of 1390 in the field of Shahid Shalemi in Ahwaz city, This experiment using a split plot design with three replications.Irrigation intervals (I) in three levels, including intervals of five (I1), eight (I2) and 10 (I3) on the main plots and plant density (P) on three levels: 6.7 (P3), 7.8 (P2) and 9.5 (P1) per square meter, or 67, 78 and 95 thousand plants per hectare were in sub plots. Evaluations consisted of leaf area index and light penetration into the canopy in order to calculate K (light depreciation coefficient), respectively. Results showed that irrigation on light extinction coefficient was significant at the one percent level, so that with increasing irrigation intervals, the coefficient is increased. The stress concentration factor and irrigation density and interactions were significant at the one percent level. The highest density of 65000 plants per hectare was obtained extinction coefficient in other words by reducing the leaf area index, light extinction coefficient increased.

In order to study the effects of irrigation interval and nitrogen on yield and some physiological characteristics of Fenugreek (Trigonella foenum-gracum L.), an experiment was carried out as split plot in randomized complete block design with three replications at Islamic Azad University of Birjand, 2009. Treatments included irrigation intervals (4, 8 and 12 days) as main plot and nitrogen fertilizer (0, 50, 100 and 150 kg.ha-1 urea) as subplot. Results showed no significant differences for seed yield in irrigation treatments after 4 and 8 days. Increasing N also led to the increase of seed yield but no significant difference was found for seed yield between 100 and 150 kg.ha-1 urea. Decreasing in water use led to the increase of Na, proline and carbohydrate and decrease of K, Cha, carotenoids and total pigments, but it had no significant effect on Chb. Nitrogen significantly increased chlorophyll a, carotenoids, total pigments, and K. Increasing N up to 50 kg ha led to the increase of carbohydrates but then reduced the carbohydrates of leaf. According to the results obtained in this experiment, it can be stated that Fenugreek is somewhat drought tolerant and considering the importance of this medicinal plant, it can be used in conditions of water scarcity as an alternative for the species that have lower economic value under water deficit.

To study the effects of irrigation interval and nitrogen level on yield and yield components of Fenugreek medicinal plant، an experiment in split plot arranged in randomized complete block design with three replications conducted at the Azad University of Birjand in 2009. Treatments included; irrigation intervals (4، 8 and 12 day) as main plot and nitrogen fertilizer (none fertilizer، 50، 100 and 150 kg/ha) as subplot. Results showed that the difference between 4 and 8 days of irrigation intervals for seed yield wasn’t significant، but the highest amount of forage yield achieved from irrigation after 4 days. Rising of nitrogen level led to increase of yield and yield components and the difference between 100 and 150 kg/ha nitrogen for seed and forage yield wasn’t significant. Irrigation interval has a considerable effect on all yield components except of pod length. Nitrogen also has a significant effect on plant height and number of pod per plant but it was insignificant on number of seed per pod، seed weight and pod length. Interaction effect of irrigation and nitrogen indicates that in 4 and 8 days of irrigation intervals، amounts of 100 and 150 kg/ha nitrogen have the highest effect on yield and yield components، but with increase of irrigation intervals to 12 days، 100 kg/ha nitrogen have the highest effect on all traits.

Lack of sufficient water resources and drought stress is one of the main problems for crop production in arid and semi-arid regions of the world، such as Iran. The use of water absorbing polymers (hydrogels) improves water retention capacity of soils and can lead to optimal use of the restricted water resources. In this research، the effects of four levels of Aquasorb water-absorbing polymer (0، 2، 4، and 8 grams Aquasorb per kg of soil) and three irrigation frequencies (3، 6 and 9 day intervals) on growth indices، yield and water use efficiency (WUE) of greenhouse cucumber، cultivar Negar، were investigated. The results showed that yield and growth indices of the cucumber were affected by the application of hydrogel and increased as compared with control. Also، water consumption by cucumber decreased significantly as the irrigation interval increased. The highest yield (196. 3 g/plant) was obtained when the hydrogel was used at the rate of 2 g/kg of soil and irrigation interval was 6 days. Although the use of hydrogel increased water consumption of the cucumber، but its application at the rate of 2 g/kg soil significantly increased WUE (17. 0 g/L) of this plant.

In order to determine the effect of irrigation interval and mulch on growth of olive an experiment was carried out in Dallaho Olive Research Station at Sarepole. A split plot experiment was used based on a completely randomized design with three replications and two factors (mulch and irrigation interval). Each experiment unit consists of 4 trees. Land preparation was done in February 2005 in a 6048 squared meter area then tree planted. Pruning operation was done in next year. Mulch treatments for experiment were control، polyethylene and organic materials and irrigation treatments period for experiment were 3، 6 and10 days interval. Some growth traits including height، trunk diameter and current season growth were measured at the end of growth season. Collected data were analyzed with MSTATC program. Results showed that organic materials mulch and interval irrigation treatments had significant differences in height، trunk diameter and current season growth so that organic materials mulch and 3 days interval irrigation treatments increased height، trunk diameter and current season growth of olive trees. The interaction effect between mulch and irrigation treatments was significance. So that 3 days interval irrigation and organic materials mulch had the highest height، trunk diameter and current season growth. 6 days interval irrigation supplemented with mulch treatment had more significant effect on these traits compared to 3 days interval irrigation alone.

Using mulch to decrease and optimize water use is known as a practical method. For this purpose, a split-factorial experiment based on complete block design with three replications on two melon cultivars was conducted in spring season of 2010 in Torbat-e-Jam. Interval irrigation treatments in three levels (6, 8 and 10 days) were considered as main plot and mulch (straw plus paddy rice, plastic and no mulch) and cultivar (Khatooni and Ghasri) were considered as sub plots in a factorial design. Results showed that there was a significant difference between plactic mulch and the control and also between interval irrigation treatments for fruit yield, ripening period, suger percentage, fruit weight and number of fruits on plants. Interaction effect observed between interval irrigation and mulch for number of fruits on plants, marketable fruit, yield and ripening period traits. The shortest period of ripening was observed for the 8 and 10 dey interval irrigation together with plastic mulch. Plactic mulch caused the suger percentage of both cultivars to increase as well. Plactic mulch for 6 day interval irrigation caused yield and fruit quality to decrease, but it caused yield and fruit quality to increase for more than 8 day interval irrigation. Regarding the advantages of plactic mulch which is the decrease of water use and the improvement of yield and fruit quality, using plactic mulch is recommended for dry land.

In order to investigate seed pre-treatment and irrigation interval effects on quantity and quality yield of the primed seeds of cumin (Cuminum ciminum L.), an experiment was carried out in research field of Vali-e-Asr University of Rafsanjan in 2009. The study was conducted as a Factorial experiment based on RCBD with four levels of seed pre-treatment (Control or without pre-treatment, seed pre-treatment with distilled water, seed pre-treatment with -0.3 and -0.9 Mpa PEG solution) and different irrigation intervals (5, 7, 9 and 11 days). The results indicated that the seed yield was significantly decreased with increasing of irrigation intervals which was related to more decrease of umbel number and seed number per umbel. The results also indicated that the percentage of the essence was increased with increasing irrigation interval however it was decreased in 11-day irrigation interval. Thousand seed weight and harvest index were not affected by seed pre-treatment and irrigation intervals. The highest umbel number in plant (14.62) and seed number per umbel (13.16) were obtained in seed pre-treatment of -0.3 Mpa PEG (P3), and in 5 and 7-day irrigation intervals. Totally, the highest seed yield (628.7 kg.ha-1) was obtained in seed pre-treatment of -0.3 Mpa PEG (P3) and 5-day irrigation interval and the highest essence content (3.62 %) was obtained in pre-treatment of distilled water (P2) and 7-day irrigation interval.

Turf grass as a main grown cover plant has a unique place in green space planning. In order to study the effect of hydrogel and paclobutrazol on water requirement of turfgrasse (Lolium perenne L. Barbal) a factorial experiment based on a BRCD with 3 replication was conducted in the summer of 2010 in Mashhad. The factors under study were 4 levels of hydrogel (0, 3, 6, 9 gr/kg soil), 3 levels of irrigation (2day, 4day, 6day intervals), 2 levels of paclobutrazol (control and preplanting seed treated, with 30mg/lit) on Lolium perenne. Results showed that the best density obtained using 6 g hydrogel and irrigation intervals of 2 days. The turf quality in soils with hydrogel application was better than the control. In general, the results showed that the plot with hydrogel had 33, 44 and 48% higher value in traits of color, density and chlorophyll content, respectively. Also the plot treated with paclobutrazol as compared with the control had 2, 7.5 and 11% more value in traits of density, cutting weight and root dry weight respectively. It is concluded that using 6 gr/kg hydrogel and paclobutrazol in soils with similar texture could reduce water consumption.

Water deficit and consecutive droughts have lead to drought stress in most parts of the world recently. We need prepare a good program to use better available water. Different material can be used to increase water use efficiency. Super absorbent is one of the materials used around the world. These materials absorb water in the soil so that reserved water is usable by plant in the time of drought stress and they can reduce stress and lead to prevent yield loss. So that an experiment was conducted to evaluate effects of different super absorbent and irrigation cycles on lawn. A split plot experiment based on randomized block design with three replication was used so that irrigation cycles and super absorbent amounts used as main plots and subplots respectively. 4 irrigation periods (1, 2, 4 and 6 days) and 4 super absorbent amounts (0, 20, 25 and 30 g/m2) were used as experimental treatments. One day irrigation interval and zero super absorbent amounts were used as control. Lawn water requirement calculate by evaporation from a pan class A. Results shown that super absorbent amount had significant effect at 1% and 5% level on shoot height, total chlorophyll and plant density but had significant effect on root fresh and dry weight, shoot fresh and dry weight, root developing. Rigidity, Elasticity and performance quality was higher for 30 g/m2 of super absorbent amount at one and two day's irrigation cycle interval in compare to other treatments. Experiment results showed that lawn performance was higher in 30 g/m2 of super absorbent amount at two days irrigation cycle than the others and had 50% water saving in compare to one day irrigation interval.

This study was carried out in the Agro-industry Complex of Gohar Kouh, Khash in Iranshahr. A split-plot experiment based on RCBD was employed with three irrigation intervals including 1: 30 day interval 2: 40 days of irrigation interval 3: 60 day irrigation interval along with three levels of nitrogen application including 1: no nitrogen fertilizer 2: 750 grams of nitrogen fertilizer per tree 3: 1500 grams of nitrogen fertilizer per tree as a sub plots. The results showed the highest yield was 4349 grams per tree that belonged to trees irrigated in 30 day intervals, and with the highest nitrogen application level. The lowest yield was obtained from I40N0, I40N750, I60N0 treatments. Each of the irrigation interval treatments with N0 level showed the lowest vegetative growth. Vegetative growth was improved by increase in nitrogen application level in most of the treatments. The most vegetative growth rate was obtained from the treatments of I30N1500 and I40N750 namely 13 and 12.4 centimeters of growth respectively while the lowest vegetative growth was obtained from treatments of I60N0 and I40N0 namely an average of 7.2 centimeters of vegetative growth. Results indicated that, the most nitrogen concentration resulted in leaf growth of 1.9 percent (I60N1500 treatment) while the lowest nitrogen concentration (I30N0 treatment) ended up with a leaf growth of 1.4 percent.

Growth indices are useful for interpreting plant reaction to environmental factors. In order to study the effects of arbuscular mycorrhizal fungi (AMF), P2O5 fertilizer and irrigation according to physiological growth indices of coriander, this experiment was conducted at Iran Research Institute of Forest and Rangelands in 2006. Field experiment was carried out in split factorial based randomized complete block design with 4 replications. The factors studied included application and non-application of mycorrhiza (Glomus hoi), 0, 16 and 32 kg/ha P2O5 fertilizer (triple super phosphate) and two levels of irrigation, irrigation after 30 mm water evaporation from evaporation pan (without drought stress conditions) and irrigation after 60 mm water evaporation (drought stress conditions). The results of 7 sample stages showed that applications of mycorrhiza and 70 kg/ha phosphorus without drought stress conditions increased dry matter, leaf area index, relative growth rate, net assimilation rate and crop growth rate and these characteristics decreased under drought stress conditions sorely. The results showed that mycorrhiza fungi could increase absorb of phosphorus by symbiosis between fungi and coriander root. This condition can reduce application of phosphorus fertilizers in fields, without reducing of yield and quality yield.

The aim of this study was to investigate the effect of irrigation period on the quality andquantity of yield and some morphological and physiological traits of three multigerm sugarbeet genotypes named BP Mashhad، BP Karaj and 191. The experiment was in a split plotbased on randomized complete block design، carried out at Motahari Research Station ofSugar beet Seed Research Institute in Kamalabad، Karaj in 2005. The main plots consisted of three irrigation periods، non-stress، medium stress and sever stress (80، 130 and 180 mm evaporation from class A pan، respectively) and the sub plots consisted of three genotypes. Irrigation treatments were applied at 6-8 leaf stage. The amount of irrigated water in each treatment was measured by WSC flom. Based on the results، the mean root yield of each treatment was 37. 97 (non-stress)، 17. 78 (medium stress) and 15. 46 (severe stress) tha-1، and dry root weight of each treatment was 850 (non-stress)، 459 (medium stress) and 15. 46 (severe stress) gm-2. All the factors used affected yield، leaf area index، dry root and shoot weight in severe stress condition compared to the non-stress condition. The severe stress condition decreased root yield but increased sugar contents. Drought stress also decreased other measured traits such as root dry weight، total dry weight and leaf area index. Two genotypes BP Mashhad and BP Karaj were evaluated as drought tolerant genotypes.