جستجوی مقالات مرتبط با کلیدواژه "آبیاری بارانی" در نشریات گروه "زراعت"

Weeds are the main factor limiting cumin production. Hand weeding is used as the most important and common method of weed management in cumin fields, which, in addition to spending a lot of time, takes a large part of the production cost. Cumin is weak in competition with weeds because it has a low and weak initial growth and establishment speed, and its biomass and height of its aerial organs are low, in addition, its root expansion is not very notable. The amount of weed damage in cumin cultivation is reported from 40 to 90 percentage depends on the type of weed species and density, the length of the competition period, cultivation conditions, control time and management of nutrients and in different conditions. Trifluralin (Treflan) is used by some farmers at planting time of cumin as a foliar spray in the soil or with irrigation water. Interviews conducted with farmers confirm that the use of this herbicide at the time of planting cumin affects the seeds of the plant to some extent and reduces the germination percentage of this plant, although some farmers also believe that there is no side effect in this case. Another challenge to successful cumin production, particularly in rainy years, is plant diseases. Wilt, leaf burn, and surface powdery mildew, caused by *Fusarium oxysporum*, *Alternaria burnsii*, and *Erysiphe polygoni*, respectively, are among the most significant diseases affecting cumin worldwide. Therefore, this study was carried out with the following objectives 1) Investigating the effect of trifluralin herbicide abuse at different intervals until planting, on the percentage of cumin seedling emergence.2) The effect of using trifluralin herbicide at different intervals until planting, on the population and growth of weeds.3) The effect of irrigation method on cumin yield4) Investigating the effect of irrigation method on the percentage and yield of cumin essential oil5) The effect of irrigation method on the contamination of cumin plants with Fusarium fungus6) Studying the water use efficiency in different irrigation and weed management

Therefore, in order to evaluate the effect of the weed management method and the type of irrigation on the control of weeds, an experiment was conducted as split-plot based on a randomized complete block design with 3 replications in the research farm of the Agricultural Faculty of Bardsir, Shahid Bahonar University of Kerman in 2022-2023. The experimental treatments include the type of irrigation in two levels (flooded and sprinkler) and weed management in seven levels (hand weeding, time of planting the cumin seeds after 3, 7, 14 and 21 days trifluralin herbicide application and no weed control).

The type of irrigation showed a significant effect on weeds density and dry weight, the percentage of plant wilt, the number of umbrellas per plant, biological yield, seed yield, essential oil percentage, essential oil yield and water use efficiency at the level of 1% and the harvest index at the level of 5%. The method of weed management showed a significant effect on the density and dry weight of weeds, the number of emerged plants, plant height, the number of umbrellas per plant, biological yield, seed yield, essential oil yield and water use efficiency at the level of 1% and harvest index at the level 5%. The interaction effect of irrigation and weed management methods showed a significant effect on the density and dry weight of weeds, the of essential oil percentage and yield at the level of 1%, and the biological yield and yield of seeds at the level of 5%. The results of this experiment showed that sprinkler irrigation had better conditions in terms of weed and disease control as well as seed and essential oil yields compared to flood irrigation. Among the herbicide treatments, the application of trifluralin 3 days before planting had better weed control results. By increasing the distance of cumin planting from the time of herbicide application, despite the increase in weed dry weight and density, cumin seed yield improved. In both irrigation methods, treatments of hand weeding and cumin planting after 21 days of herbicide application had the highest yield of seed and essential oil.

In general, cumin planting 21 days after trifluralin application and using sprinkler irrigation were able to reduce the weed density and biomass to an acceptable level and on the other hand, they produced a good seed and essential oil yield which is recommended.

This research was conducted using questionnaires and the analysis of soil samples (the content of organic matter, nitrogen, phosphorus and potassium) obtained from saffron fields of Torbat-Heydariyeh, Iran, during 2020-2021. In this research, saffron irrigation and nutrition management methods among three farmer groups (progressive farmers, skilled farmers and ordinary farmers) were investigated and compared with the recommendations of saffron researchers. The classification of farmers in the mentioned three classes was based on the stigma yield in relation to the field age. The results showed that most of the progressive and skilled farmers used the combined nutrition management method (organic fertilizer + chemical fertilizer with frequency of about 65%), while the single application of chemical fertilizer was the most common method among ordinary farmers (47.5%). The mean amount of organic manure application for ordinary, skilled and progressive farmers was 5.0, 6.3 and 10.7 ton ha-1year-1, respectively (less than the amount of 19.2 tons recommended by researchers) and the mean amount of nitrogen application was 49.5, 56.5 and 87 kg ha-1 (compared with 93.3 kg recommended by researchers). The application of phosphorus and particularly potassium was not a common practice among all three groups’ farmers. The average content of organic matter in the fields was 0.68%, nitrogen 0.041%, phosphorus 16.1ppm and potassium 292 ppm, which indicates the poverty of soils in terms of organic matter and to some extent nitrogen. The foliar application of nutrients for the fields of ordinary, skilled and progressive farmers was 0.23, 0.65 and 1.00 times per year, respectively, and the average irrigation times was 3.2, 3.6, and 4.6 times per year, respectively, which is less than the recommended values by experts (2.55 and 5.8 times per year, respectively). Summer irrigation (44.4% of farmers) and sprinkle irrigation method (26.8% of farmers) were more common among progressive farmers. In general, the poverty of organic matter and lack of nitrogen in the soil, low foliar application of nutrients and lack of use of modern irrigation methods were among the most important reasons for the high gap yield of saffron fields.

In order to investigate the agronomic characteristics of Potato under water deficit stress conditions using line-source sprinkler irrigation method and potassium fertilizer amounts an experiment was done in Khorasan Razavi Agricultural and Natural Resource Research Center during 2015-2016 as split plot design based on completely randomized blocks design. Water deficit levels at 0.75m from line-source (control), at 3.75m from line source (very light), at 6.75m from line-source (light), at 9.75m from line-source (severe deficit), at 12.75m from line source (very severe deficit) were considered as main factor and potassium levels included 0, 90, 180, and 270 kg.ha-1 K2O were as subfactor. Studied traits were included, tuber yield, percent of small, medium and big tuber yield, number of tuber per plant, average of tuber weight, plant height and stem number per plant. The results showed that water deficit stress levels had significant effects on total traits and potassium nutrition levels had same effects except percent of small and medium tuber yield and stem number per plant. Higher water deficit levels significantly decreased the tuber yield, tuber number per plant and average of tuber weight that in very severe deficit these traits reduced 92.29, 84.32, and 53.81 percent respectively. The highest tuber yield (17.92 ton.ha-1), tuber number per plant (7.94) and average of tuber weight (38.73 g) resulted in 270 kg.ha-1 K2O. The highest and lowest tuber yields were in control with 270 kg.ha-1 K2O and very severe deficit with 0 kg.ha-1 K2O.

Background and Objectives:

 Potato is extremely sensitive to water stress, both from inadequate or excess water, resulting in reductions of tuber yield and quality. The plant has a relatively shallow root system, locating about 85% typically in the upper 30 cm of soil, which increases the sensitivity of the crop to water stress. Variation in soil moisture conditions can also lead to the occurrence of tuber physiological disorders such as brown center, hollow heart, growth cracks, bruise susceptibility, and heat necrosis, typically during the bulking period. A direct relation between low moisture conditions of soil and misshapen tubers has been reported. The aim of study was to assess the growth, yield, yield components, and water productivity of some conventional potato varieties in Bardsir region of Kerman.  

Materials and Methods:

 In order to evaluate the effect of various irrigation methods on growth, yield and yield components of potato varieties, an experiment was conducted as the split-plot based on the randomized complete block design with three replications at experiment station of the Agricultural Faculty of Bardsir, Shahid Bahonar University of Kerman during 2015 and 2016. The experimental treatments were irrigation

1- Furrow (flooding), 2-sprinkler and 3- drip assigned to main plot and potato varieties: 1- Marfona, 2- Sante, 3- Agria and 4- Banba as the subplot.   Results The results showed that the effect of irrigation method was significant (P≤0.01) on all the studied traits except in water productivity and percentage of tuber dry mater. The highest mean of tuber weight (71.55 g), number of marketable tuber (6.99), tuber yield (36.98 t ha-1), and shoot dry weight (5.97 t ha-1) were recorded in the furrow irrigation method. The lowest values of the traits were observed using the sprinkler method. The effect of variety treatment on all traits was significant (P≤0.01). For drip and sprinkler irrigation methods, the largest tuber was related to Sante variety, and regarding the surface method, it was gained at Marfona. The highest number of tuber per plant belonged to Sante variety (9.50) followed by Marfona (8.89) which had a significant difference with Banba (7.15) and Agria (6.88) varieties. Tuber percentage of dry weight for Agria variety (27.22) was significantly higher than other varieties (19.93-22.74). The tuber yield for Sante, Marfona, Banba, and Agria was 34.84, 28.91, 26.14, and 21.57 t ha-1, respectively. The maximum level of water productivity (5.93) was gained for santé variety using the sprinkler irrigation method.  

Discussion :

In general, the results indicated that Marfona variety was justly appropriate for flooding irrigation conditions, and santé variety is best for low water supply (drip and sprinkler irrigation methods).

A two years’ field experiments was conducted to determine the cotton water need at Hashemabad cotton research Station. The Hashemabad Cotton Research Station is located in north of Iran at 36° 51' N latitude and 54° 16' E longitude at the south-east corner of Caspian Sea and its height from sea level is 13.3 meters. That station has a Mediterranean climate with relatively mild winters and dry summers. In this project, five Irrigation treatments contains T1= 100%, T2= 75%, T3= 50%, T4= 25%, T5= 0% at three replications on Randomized complete bloke design using sprinkler Irrigation system were studied. By analysis of variance indicated that there was no significant difference between T1, T2 and T3, in terms of seed cotton yield. However, in term of numerically, the yield of T3 had 22 and 16 percent over T1 and T2, respectively. The relative water use efficiency of this treatment was over others. According to this research project, the recommended of cotton Irrigation water is 50 and 80 percent at wet and drought years respectively. The amount of cotton water needed in the humid region is 3200 and 4600 m3/ha at wet and drought years, respectively. Based on the results of this study, it seems necessary that reduce of the amount of cotton irrigation requirement in northern of Iran.

Various studies have investigated the response of crops and pasture plants to water for non-saline waters and their reaction to salinity in full irrigation. A set of such studies can determine water-yield or salinity-yield relationships. However, quantitative research has been done to study the effects of salinity and drought stress. However, we are proposing perpendicular system as a new alternative to learn wheat yield under simultaneous water and salinity stresses. Response of grain and straw of wheat, Back Cross Roshan 6611 cultivar, to combined effects of quantity and quality of water was traced under crossed sprinkler line source irrigation. The field area was 3232 m2 which was located in the west of Birjand city in southeast of Iran. The soil was sandy loam (=1.41 gr/cm3) and two different sources of water, normal (EC=1.5 dS/m) and saline (EC=5.5 dS/m) were adopted for two line sources, respectively. Crops located in the center of the field, were fully irrigated without any stress. While the other crops far beyond irrigation lines, were under water stress. Water salinity was differ among different points of the field and varied between 1.5 and 5.5 dS/m, based on the quantity of water received. After each irrigation procedure, the volume and salinity of water collected in 256 cans, which were placed in 2'2 square meters, were measured. At the end of the growing season, one square meter around the cans was taken to measure yield and yield components. General form of yield function for different salinities and irrigation water is Y=f (AW, EC) in which Y is the wheat yield in kg/hectare, AW is irrigation water depth during growth period in cm and EC is mean salinity of irrigation water in dS/m. Five types of production function (Linear, Cobb-Douglas, Quadratic, Laty-Dinar, and Transcendental) were evaluated using field data. Slide Write software was used for calculating R2, F-statistics, t-statistics and constant parameters of the equations. All statistics were tested at significant levels of 1% and 5%. The best function was selected based on goodness of fit and significance of factors. The results showed that yield prediction of wheat and straw was better than other functions under the influence of combined conditions of drought and salinity with Cobb Douglas function. Datta et al. used second polynomial non-linear function among three linear, power and Second polynomial functions. Rosso and Baker concluded that Second polynomial function estimates the relationship between yield, salinity and water better than Maximum and Hoffman function. Kiani used transducer function for result analysis. The marginal rate of technical substitution indicated that each one of the factors can be substituted for the other one for a wide range in order to achieve equal amount of yield (grain/straw). These results are consistent with results of Rosso and Baker, Dota et al. and Letti and Dinar. Also, the results showed that in lower performances, the effect of water content on reduction of crop was higher than that of salinity. 1-Regarding this research, reduction of grain and straw weight due to the reduction of irrigation water and increase in water salinity follows Cobb-Douglass function and outperforms other functions in predicting changes of grain and straw weight due to the effect of changes in two abovementioned factors.
2-Results showed that changes in grain and straw weights are more sensitive to changes of irrigation water than water salinity.
3-Using substitution rate curve, it is possible to substitute salinity and water content in order to achieve same yield.

In order to compare the effect of irrigation levels and methods on leaf area and replacement corm production of saffron during 2013-2014 growing season, a split plot experiment was conducted in randomized complete block design with three replications in the Jolgeh Rokh District, in 35 km Torbat Heydarie. The main plot basin irrigation, drip and sprinkler irrigation and sub plot was three levels of irrigation (100, 75 and 50 percent water requirement of saffron). The traits studied were including dry weight, number, diameter and length of leaf, dry weight, size and number of replacement corms, weight and length sheath. Sampling for determining the characteristics of leaf and sheath was done on April 30, and for corm it was done on May 31, 2014. The results showed that in the irrigation method treatments, the most dry weight of corm, leaf and sheath weight, size and number of replacement corm, number, diameter and length of leaf were observed in the case of drip irrigation. In addition, the best yield was observed in drip irrigation and the lowest amount was seen in basin irrigation. Saffron irrigation with the drip method resulted in an increase of the number of replacement corms compared to the sprinkler and basin methods (10 and 34 percent, respectively). The effect of irrigation levels was significant on some of the traits that were studied and the most yield was related to 100 percent irrigation level and the lowest one was in the 50 percent water requirement. Reducing irrigation from 100 to 50% crop water requirement severely reduced replacement corms number and their weight (62 and 86 percent, respectively). Consequently, the most photosynthesis level of Saffron and also the maximum amount of total number and total weight of replacement corms were obtained in the drip irrigation case and 100 percent irrigation level

Rapeseed shows great sensitivity to farm management and agronomic operations. Specially, planting method, seeding rate and row spacing have big effects on yield. The seeding rate and row spacing are critical factors for achieving optimum plant density and this is one of the most important factors affecting the seed yield of rapeseed. In addition, uniform distribution of plants per unit area is required for yield sustainability. Rapeseed is planted in narrow and wide row spacing. With decreasing in row spacing and increasing of distance between plants, plants distribution becomes more uniform, competition between plants is reduced and finally, seed yield increases. In cold and semi-cold areas of Iran, rapeseed is planted as an irrigated crop. Plants arrangement and distribution in surface area are affected by irrigation system, too. In furrow irrigation, rapeseed is planted only on the upper level of the ridges and thus plant distribution is non-uniform. With the using of sprinkler systems, flat planting is possible and plant arrangement becomes more uniform.
In order to compare the flat with ridge planting and to determine the best row spacing and seeding rate in flat planting of winter rapeseed, a field experiment was conducted in Hamedan Agriculture and Natural Resources Research Center in 2011-2013 cropping seasons. Combination of four row spacing (15, 20, 25 and 30 centimeters) with three seeding rates (6, 8 and 10 kg ha-1) in flat planting method and check treatment (ridge planting with two rows on each ridge using 8 kg ha-1 seeding rate), totally 13 treatments, were studied in a Randomized Complete Block design with three replications during the growing season and in harvest time, some agronomic traits such as number of plants per m2, plant height, number of branches and pods per plant, seeds per pod, 1000-seed weight, biological and seed yield and harvest index were measured. RCBD and factorial analysis of variance were done using SAS software and mean comparison was carried out using Duncan's multiple range test 5% probability level.
The plant densities between flat and ridge planting, seeding rates and row spacing were different because of difference in plant arrangement. Ridge planting (check treatment) had the highest plant height, number of branches and pods per plant, and the lowest 1000-seed weight and seed yield in comparison with flat planting treatments. In flat planting, seed yield and yield components significantly affected by row spacing. Row spacing of 15-20 centimeters produced the highest seed yield. In flat planting, using of 6-10 kg seeds per hectare had not significant effects on biological and seed yield. Narrower than the wider row spacing increased grain yield due to more uniform distribution of plants in the ground, Which leads to better absorption of solar radiation in plant canopy and consequently reduce competition between plants.
The results of this experiment showed that in ridge planting, competition between plants increased and final plant density reduced. In contrast, flat planting had more uniform arrangement that decreased inter and intra row competition, increased plant density per unit area and finally produced higher biological and seed yield. Average seed yield in flat planting method was 4381 kg ha-1 which was about 18% higher than ridge planting. Based on these results, it seems that flat planting with 15-20 cm row spacing and 6-10 kg ha-1 could be used for winter oilseed rape.

In order to evaluate the effect of three irrigation methods including surface irrigation (I1), daily sprinkler irrigation (I2), post-irrigation sprinkling with fresh water (I3), and different levels of salinity including 2.9 (control), 3.5, 4.1, 4.7 and 5.3 dS.m-1 on agronomic and physiological traits of maize, a field experiment as factorial was carried out based on randomized complete block design with three replications during 2013-2014 in College of Irrigation science, Shahid Chamran University of Ahvaz. To apply salinity, a sprinkler irrigation system was used to establish minimum and maximum salinity levels on two parallel pipelines on both sides of field. Overlapping sprinklers led to establish a linear salinity gradient. Irrigation methods I3 and I2 with 4750 and 4160 kg h-1 had higher and lower amounts of grain yield, respectively. Water salinity significantly decreased stomatal conductance, chlorophyll index, leaf area index, K concentration and ratio of potassium to sodium, and higher reductions in these traits was observed in sprinkler irrigation. Daily sprinkler irrigation and surface irrigation showed the higher and lower Na concentration, 18.2 and 15.1 mg kg-1, respectively. These findings showed that, the threshold value of salinity for most traits and all irrigation methods was found to be ~4.1 dS.m-1. With the given water resources limataion and saline water resources in Iran, post-irrigation sprinkling with fresh water might be used for irrigating row crops such as maize with a lower yeild loss.

In order to investigate the effect of nitrogen fertilizer on tea yield and yield components in supplemental irrigation and rain fed conditions an experiment was conducted at Feshalam Tea research station in Fouman (Guilan) during (2008-2010). In this study, line-source irrigation technique and the strip plot experiment on randomized complete block design was used. Six levels of nitrogen, zero, 100, 200, 300, 400 and 500 kg ha-1 (N0 to N5) from urea as the main plots and five contiguous irrigation levels consist of full irrigation (I4), deficit irrigation (I1, I2, I3) and no-irrigation (I0) in four replications as sub-plots were arranged. The results showed that supplementary sprinkler irrigation and nitrogen fertilizer increased the number of harvested shoots in the months of water shortage during growing season. Full irrigation (3424 m3) with less nitrogen uptake increased dry matter of tea shoots. The highest yield (3928 kg ha-1 of made tea) was obtained with consumption of 200 to 300 kg N ha-1 under full irrigation condition and the lowest yield (788 kg ha-1 without irrigation and fertilizer. Application of 100 to 200 kg N ha-1 produced the highest yield (1672 kg ha-1) in rainfed conditions.

Water crisis as a main factor of agronomy limitation exists in all over the arid and semiarid regions such as Isfahan, province which is located in the central part of the Zayandehrud River Basin (ZRB). Due to the increase in the cultivated area of potato in Fareidan Region located in the west of Isfahan province, it will be necessary to use pressurized irrigation systems to achieve the highest irrigation application efficiency and water productivity.
The ZRB (41,500 km2) is a closed basin with no outlet to the sea. The research was conducted in the Fareidan region of Isfahan, which is located in the west part of the ZRB. The Rozveh Agricultural Research Station (32°, 58' N, 50°, 25' E) is located at the altitude of 2390 m above the sea level. This study was conducted as a randomized complete blocks design as a split strip plot layout with three replications and during two years (2007-2008). Three irrigation systems (Drip tape, Sprinkler and furrow) were considered as main plots, two planting methods (one - row planting and two-row planting) as split subplots and two potato cultivars (Marfuna and Agria) as split-split subplots. Production (Tuber-yield), the consumption water and cultivars reactions to common diseases were evaluated in different treatments. The soil of the experimental area, according to USDA Soil Taxonomy 1994 is of silty loamy. At the soil depth of 1m, soil salinity (1.1-2.0 dS m-1), water salinity (1.24 dS m-1), soil moisture at field capacity (23 Vol. %), and bulk density (BD = 1.44 g/cm3) at the field site were measured or experimentally obtained in the Isfahan Soil and Water Laboratory. The results were subjected to an ANOVA to analyze the effects of the treatments and their interactions. The data obtained were analyzed using the compound variance analysis and the averages of different treatments were separated using the Duncan multiple range test using the statistical software (SAS Institute, Inc., Cary, NC). The probability level of 0.05 (Duncan's test) also was selected.
An analysis of variance (ANOVA) was conducted on the irrigation systems and planting methods using PROC GLM (SAS 9.1, SAS institute Ltd., USA). Duncan’s multiple range tests at 0.05 probability level was used for paired mean comparison. The Results provided in two years show that the effect of irrigation systems × year (P≤0.05) and cultivars × year (P≤0.01) on (Tuber-yield), the consumption water and cultivars reactions to common diseases were found to be significant. There is no interaction between irrigation and planting methods, Variety × planting methods, Variety × irrigation, irrigation × Variety × planting methods and irrigation × Variety × planting methods × Year for (Tuber-yield), the consumption water and cultivate reactions to common diseases. On the contrary, the effects of the irrigation system treatments on the Tuber-yield and water productivity were significant (p≤0.05). The effects of variety on Tuber-yield and water productivity were not significantly (P≥0.05) detected.
Sprinkler irrigation method with 26152 kg ha-1 of production mean was preferred significantly to tape irrigation method with 23974 kg/ha of production mean. Tape irrigation leaded to the highest mean of WP equal to 4.69 kg m-3. Two years comparison of yield mean showed no significant difference between Agria and Marfuna potato cultivars. The two year comparison results of yield means using different planting methods indicated that one row planting method (24839 kg ha-1) was preferred significantly comparing to two row planting methods (22927 kg ha-1). Evaluation of tuber infection by ordinary scab and rhizoctonia showed that the highest mean of infection way observed in furrow method and the lowest one was observed in tape method of irrigation. Scab infection in furrow irrigation was 47% higher than sprinkler irrigation and 78% higher than tape irrigation.
During the three (2) years of the experiments with the three (3) irrigation treatments imposed on the potato crop, it was found that the drip type irrigation system, despite its lower yield than sprinkler irrigation, increased water productivity. A lowest pollution tuber to scab infection and rhizoctonia was determined by Drip type method. Thus, using this method, particularly in water restrictions on potato planting is required. The highest tuber yield was obtained in sprinkler irrigation, as well as from the point of view of the intensity and the infection rate of diseases on the tuber to Scab and rhizoctonia there was significant advantage compared to furrow irrigation. Therefore, in the lack of water restriction and the high speed wind can be used. The results showed that the one row planting method for all treatments is desirable therefore highly recommended for agricultural potato production.

Due to water deficit in Golestan, it is necessary to optimize use of water which means to find relation between water use and yield. For this reason, this experiment was conducted by sprinkler irrigation as line source. Six irrigation treatments as I1, I2, I3, I4, I5 and I6 is assumed in two hand of sprinkler line because of sprinkler water triangular distribution, so that I1 and I6 treatments received the highest and the lowest water, respectively and I2 treatment received as water requirement as. Three cotton cultivars of Sahel, Sepid and 818–312 were planted by 20 × 80 centimeter. Experimental design was strip split plot with three replications. The results showed that the highest yield was I3 treatment that with I4, I5 and I6 treatments in the first year and all treatments in the second year had significant difference. Sepid cultivar yield was 17.9 % higher than two cultivars in the first year and 15 % higher than Sahel cultivar in the second year. Difference between three cultivars on view of earliness was not significant and on view of boll weight in the first year was not significant but in the second years was significant. The highest boll weight belonged to I3 Treatment and also I6 Treatment was the highest earliness. Sahel cultivar during two years had the lowest micronairy. Treatment of I3, received on view of water use received 30% less water than water requirement. Ultimately, on view of yield, quality properties and less water use, the best irrigation treatment and cultivar were I3 treatment and Sepid cultivar.

To determine sugar content and root yield variation of new sugar beet hybrids under different irrigation levels, an experiment was carried out at Zarghan Agricultural Research Station ofFars Agricultural and Natural Resources Research Center, Shiraz, Iran. The study was conducted as split block based on a randomized complete block design with three replications for two years, 2009-10, using line source sprinkler system. The treatments consisted of six cultivars including 28064, 28058, 28928, Zarghan, Jaam, and Rasoul (susceptible check) in main plots, and three irrigation levels viz. control, medium stress, and severe stress in subplots. Irrigation levels were set according to the distance from lateral tube and 4 m distance was considered for imposition of irrigation levels. Combined analysis results showed that hybrid 28928 had the highest root yield. It also showed higher than average yield stability in both optimum and water deficit conditions. Zarghan cultivar had lower yield in water deficicit condition while in normal irrigation the result was opposite. Regression analysis showed a quadratic equation between sugar content and water consumption so that sugar content was decreased in the range of about 400-900 mm irrigation but increased in less than 400 mm and more than 900 mm. In spite of increasing sugar content, water deficicit cannot be recommended for sugar production owing to yield reduction.. Considering the positive response of root yield to water use, 1100 mm irrigation level is suggested for increasing both root yield and sugar content.

In order to study the yield and growth indix of potato under water deficit, an experiment was conducted with line-source sprinkler irrigation in Khorasan Razavi Agricultural and Natural Resource Research Center. Water deficit levels were included, at 0.75m from line-source (control), at 3.75m from line source (very mild deficit), at 6.75m from line-source (mild deficit), at 9.75m from line-source (severe deficit), at 12.75m from line source (very severe deficit).The yield were 26.47, 22.3, 17.31, 9.88 and 2.04 ton per hectare in control, very mild, mild, sever and very sever deficit respectively. Water deficit had very effects on root, shoot and tuber dry matter, total dry matter (TDM), relative growth rate (RGR), crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD), and net assimilation rate (NAR). The maximum LAD (478) was in control in 1600 GDD and maximum RGR was calculated between 0.004 and 0.005 g/g GDD in water deficit. In sever and very sever deficit, maximum CGR showed very soon (1300 and 1200 GDD respectively).

To evaluate the effects of different levels of sprinkler irrigation and plant density on yield, yield components and water use efficiency of grain maize KSC 302, an experiments was carried out in field station of Seed and Plant Improvement Institute, Karaj, Iran in 2006 and 2007 growing seasons. Split-plot arrangements in randomized complete blocks design with three replications was used. Main plots were three irrigation levels: 75%, 100% and 125% ET and sub-plots were three plants densities: 80000, 90000 and 100000 plant per hectare. Results showed that increasing irrigation levels from 75% to 125% had significant effect on grain yield and yield components, however, its effect on water use efficiency was not significant. 100% ET level had the highest WUE (1.03 Kg/m3). Effect of different plant densities on grain yield, yield components, and water use efficiency was not significant. Results revealed that 125% ET level and 90000 plant density had the highest yield and yield components, and 100% ET level and 100000 plant density had the greatest WUE. Therefore, under non-limited irrigation water resources the best option is application of 12000 m3.ha-1 of irrigation water and 90000 plant density, and under limited irrigation water conditions the best option is application of 10000 m3.ha-1 of irrigation water and 100000 plant density are suitable for areas similar to Karaj conditions.

This study was conducted to compare the effects of sprinkler and furrow irrigation methods on sucking pests’ population، yield and water use in Hamedan region during two years. The results showed that density of thrips in sprinkler irrigation system was lower than the furrow irrigation. Also it was found that population of leafhopper decreased and the two-spotted spider mite was removed completely. The results of effects of irrigation systems on crop biomasses showed that in sprinkler irrigation it was very higher than furrow irrigation. This could be due to decreased pests’ population، decreased use of pesticides and good availability of the crop to water and fertilizer. Growth Trend and storage of potato tubers after 100 days in furrow irrigation was more than sprinkler irrigation. With decreasing shoot’s growth in sprinkler irrigation due to enough moisture and fertilizer، root’s growth increased. Harvesting at the same time indicated that yield of potato in furrow irrigation was 12. 04 % higher. It seems that delay in cutting time in sprinkler irrigation increases the yield. In general، the results indicated that water use in sprinkler irrigation was 50. 70 % less than furrow irrigation. Sprinkler system by decreasing need for chemical control could act as a part of integrated pest management. Also Sprinkler system could increase efficiency of irrigation by decreasing water resources demand، chemical control and the costs.

In the water-limited areas, the great challenge of the agricultural sector is more production from less water that it can be achieved by increasing water productivity. A field study was conducted to compare various cultivars of wheat to water using line source sprinkler irrigation at Gorgan Research Station in 2005-2006. The effect of variable water supply on yield and WUE of six wheat cultivars were determined. Four locations with distance from the laterals were monitored all of the irrigations. Four irrigation treatments (W1, W2, W3 and W4) were provided by the reduction of irrigation water with distance from the line source. The experiment used a strip plot design to examine the effect of fixed irrigation rates on six cultivars (C1=Tajan, C2=N-80-6, C3=N-80-7, C4=N-80-19, C5=N-81-18, C6=Desconcido) with four replications. Each irrigation treatment of each strip was divided into six cultivars treatments, along the length of the laterals. Result indicated that the grain yield was affected by irrigation treatment and genotypes. Due to suitable rainfall during the growing season, soil moisture depletion was high in deficit irrigation treatment (W4) as compared to W1 treatment. Generally, the WUE was increased with decreasing applied water under supplementary irrigation. The optimum amount of water to achieve maximum WUE was a range of 290 to 320 mm in the above-mentioned cultivars. The highest and the lowest WUE was related to C5 (1.48 kg m-3) and C1 (1.3 kg m-3) respectively. The optimum yield to achieve the highest WUE was found between 4100 kg ha-1 (in C1 cultivar) up to 4900 kg ha-1 (in C3 cultivar).

This study was conducted to determine the effect of water salinity in sprinkler irrigation on yield of different wheat cultivars, using different mixtures of saline and fresh water. The experiment was conducted in a Randomized Complete Block with split plot arrangement with four replications in 1998-1999 growing season at Roodasht Agricultural Research Station in Isfahan. The main plots were four water quality treatments (average 5, 7, 9 and 11 ds/m) and the sub plots were four cultivars of wheat (Mahdavi, Cross Sorkhtokhm, Ghods and Niknezhad). Each replication was 15x30 meters. The sprinkler effective radius was 15 meters and spraying angle was 360. The comparison of treatment means with LSD method at P=0.05 revealed that different water qualities affected grain yields of cultivars significantly. The grain yield in 11 ds/m water quality treatment decreased by 50 percent, compared with that of the 5 ds/m water quality treatment. Effects of different cultivars on grain yield were not significant, although Mahdavi and Niknezhad had the highest and the lowest grain yields, respectively. The mean dry weight in earing and physiological maturity stages were significantly different. Mahdavi produced the highest and Niknezhad the lowest dry weight. The mean 1000-grainweight of the varieties had significant difference. Mahdavi and Ghods had the highest and the lowest 1000-grain weight, respectively. The mean Na+ and K+ ions concentrations in flag leaf at flowering (GS=65) had significant difference. Mahdavi had the highest K+ and the lowest Na+ concentrations in its nag leaf.