Complete Irrigation Research Articles

EFFECT OF PLANTING DATES AND DRIP IRRIGATION RATES ON GROWTH, YIELD AND ITS COMPONENTS OF COWPEA (VIGNA UNGUICULATA L. WALP) PLANTS UNDER SANDY SOIL CONDITIONS

Two field experiments were carried out in privet farm at Bani Mazar region, North Al-Minia Governorate, Egypt, during the two fall seasons of 2016 and 2017, respectively under drip irrigation system, in sandy soil conditions. The objectives of this experiment were to study the effect of two factors i.e. determine the proper planting date from three planting dates i.e. at middle of July (as a control), 7th and 28th of August at twenty one days interval as well as two water schedule regimes treatments i.e. 80 and 60 % from water requirements/ fed. as compared with the control treatment i.e. 100 % from the cowpea (Vigna unguiculata L. Walp) plants irrigation requirements/ fed. and their interactions on growth, yield, its components, water use efficiency as well as some chemical constituents of the leaves and dry seeds under the condition of the newly reclaimed soil on the cowpea Kaha 1 cv. The experimental design was split–plot, i.e. the three planting dates devoted in the main plots and the water schedule regimes randomly distributed in the sub plots with three replications per treatment. The results indicated that, the best planting date under this investigation was at middle of July as compared with the two other planting dates i.e. 7th and 28th of August which occurred the highest significantly increased in vegetative growth characters, dry seeds yield (ton/ fed.), its components, water use efficiency, total chlorophyll content in the fresh leaves, proline contents in the dry leaves, protein, nitrogen, phosphorus and potassium (%) in the cowpea dry seeds. Concerning to the influence of schedule water regime, it was found that, the cowpea plants received the complete irrigation treatment (100 %/ fed.) as compared with increasing water deficient from 80 % to 60 % from the cowpea plants irrigation requirements/ fed. produced no significant increases in some characters i.e. plant height, dry weight of the foliage/ plant, average weight of dry pods, number of dry seeds/ pod, weight of 100 dry seeds and total chlorophyll content in the fresh leaves. Whereas, the cowpea plants irrigated with the moderate irrigation treatment (80 % from the cowpea plants irrigation requirements/ fed.) led to no significant increases in number of branches, dry seeds yield, number and weight of dry pods/ plant, proline contents in the dry leaves, protein, nitrogen and potassium (%) contents in the dry seeds. The lowest results of all previous characters were obtained when the plants were irrigated with the lowest water amount i.e. 60 % from the cowpea plants irrigation requirements/ fed. as compared with the two other water schedule regimes. On the other hand, water use efficiency significantly increased with irrigation the cowpea plants with 60 %/ fed. followed with irrigation with 80 % and 100 % from water requirements / fed. Regarding to the results of the interactions between the two studied factors used in this study showed that, the distinguished interactions treatment which led to the highest antecedent means values over all the other interactions was obtained with the interaction between the 1st planting date at the middle of July and irrigation the cowpea plants by the moderate irrigation regime (80 % from the cowpea plants irrigation requirements/ fed.) specially, its produced significant increases in dry seed yield and its components as well as water use efficiency as compared with the rest of the two interactions, these findings were true in the both fall seasons.

Yield, antioxidant activity and shelf-life of cauliflower inflorescences under drought stress and foliar spraying of selenium

ABSTRACT The ability of antioxidant compounds in vegetables to prevent disease is important for the pharmaceutical and food industries. In addition, water stress can enhance the existing antioxidant capacity of plants. As such, this study aimed to assess the effect of different irrigation depths and selenium application on the postharvest characteristics of cauliflower. A randomized block design was used in a 3 x 2 factorial scheme, with four repetitions. The first factor consisted of three irrigation depths with regulated deficit irrigation (RDI): severe (50% ETc) and moderate RDI (75% ETc) and complete irrigation (100% ETc), performed after inflorescence initiation, and the second of foliar spraying of selenium (with and without the element). Selenium application increased cauliflower yield under moderate RDI and no water/drought stress. Moderate RDI was the most effective strategy for maintaining yield and increasing the antioxidant capacity and phenolic compound content of cauliflower. Foliar spraying of selenium raised total polyphenol content under drought stress. Severe RDI extended the shelf life of cauliflower florets.

The effects of water stress on yield performance of drip-irrigated pepper (Capsicum annum L. cv. Capya var. Yalova yağlık 28) in the Central Anatolian region of Turkey

The aim of this study is to investigate the effects of conventional deficit irrigation strategy on yield components and water use efficiency in the red pepper. The field study was performed in Cumra, a town in the province of Konya in the years of 2012 and 2013. The irrigation treatments were applied as follows: (i) full irrigation regime (100% of water requirement for plant, I100) and (ii) two conventional deficit irrigations regime at the rate of 80% (I80) and 60% (I60) of I100 at 5-day intervals. The irrigation water was used based on soil water content measurement through the gravimetric method where evaporation was measured by a class A pan cup simultaneously. The maximum marketable yields were obtained in the treatment of I100 with 22.0 and 24.0 t ha−1 for the years of 2012 and 2013, respectively. The seasonal crop water requirement was calculated as 454, 591, and 726 mm for 2012 and as 498, 652, and 806 mm for 2013, respectively. The values of crop yield response factors (ky) at I80 and I60 were found as 1.03 and 1.37 in 2012 and 0.66 and 1.54 in 2013, respectively. The highest levels of water use efficiency (WUE) and irrigation water use efficiency (IWUE) were determined for the treatment of 20% deficit during the period of study. The complete irrigation levels (FC) were calculated through 0.87 times the pan A evaporation. The results reveal that full irrigation strategy is the best choice to obtain maximum yield or net return while 20% deficit irrigation is a viable solution for water poor environments.

Model for management of an on-demand irrigation network based on irrigation scheduling of crops to minimize energy use (Part I): Model Development

A tool implemented in MATLAB®, called GREDRIP, has been developed to simulate the behavior of an on-demand irrigation network, taking into account crop distributions in an irrigable area. It was applied during two complete irrigation seasons (2015 and 2016) for weekly irrigation scheduling. This tool portends to be useful as a decision support system tool to manage on-demand collective irrigable areas with minimum energy costs at the pumping station and by performing an irrigation schedule to guarantee crop water requirements. Hence, it is possible to go from an on-demand irrigation management system to a restricted arranged operation, carried out with centralized management, where the manager of the irrigation network satisfies the demand of farmers within a short period of time. The main novelty of this paper is to show a simulation tool which integrate the energy efficiency of the pumping station taking into account irrigation events distribution according to the crop irrigation scheduling at each plot. In this regard, this tool respects the irrigation scheduling of farmers, and it controls the starting time for each hydrant to minimize the energy cost. It was applied considering two types of pressure regulations, i.e., fixed and variable pressure heads. The distribution of open hydrants and the starting times of the irrigation events at each case performed by this tool led to optimization of the flow discharge distribution in the irrigation network, guaranteeing adequate flow discharge and pressure to all hydrants, which affected the uniformity of irrigation in the plot. Although the regulation using fixed pressure management represented energy costs 10% higher than the regulation using the variable pressure head, this difference would not compensate for the implementation of variable pressure management given the complexity of managing a variable pressure head in a pumping station. The actual irrigation network management, which does not consider the energy efficiency at the pumping station, showed higher energy consumed and energy costs at the pumping system in comparison with the results using GREDRIP. This fact suggest that it is necessary to improve the technical advisory system for irrigation scheduling at the plot scale and irrigation network management.

Are matching funds for smallholder irrigation money well spent?

Groundwater irrigation can dramatically affect agricultural production and productivity. Despite its potential as an agricultural development tool, little credible evidence exists for the impacts of groundwater development on smallholder agriculture. We add to the evidence on the benefits of irrigation investments for small producers by evaluating the Rural Business Development (RBD) program of the Millennium Challenge Corporation in Nicaragua for small plantain producers. The RBD program offered matching funds covering up to 30% of the cost of two years of inputs, extension services, and diesel-powered micro-sprinkler irrigation for individual farms. In order to estimate the average impact of the RBD program on its beneficiaries, we combine model selection via the LASSO with doubly robust treatment effect estimation as applied to two years of panel data for 146 producers. We find that the program had substantial impacts on plantain revenue and production, while achieving nearly complete irrigation coverage of plantain land among beneficiaries. We find no discernible impact on household expenditure.

A Self-Powered and Autonomous Fringing Field Capacitive Sensor Integrated into a Micro Sprinkler Spinner to Measure Soil Water Content.

We present here the design and fabrication of a self-powered and autonomous fringing field capacitive sensor to measure soil water content. The sensor is manufactured using a conventional printed circuit board and includes a porous ceramic. To read the sensor, we use a circuit that includes a 10 kHz triangle wave generator, an AC amplifier, a precision rectifier and a microcontroller. In terms of performance, the sensor’s capacitance (measured in a laboratory prototype) increases up to 5% when the volumetric water content of the porous ceramic changed from 3% to 36%, resulting in a sensitivity of pF per unity change. Repeatability tests for capacitance measurement showed that the sensor’s root mean square error is 0.13%. The average current consumption of the system (sensor and signal conditioning circuit) is less than 1.5 A, which demonstrates its suitability for being powered by energy harvesting systems. We developed a complete irrigation control system that integrates the sensor, an energy harvesting module composed of a microgenerator installed on the top of a micro sprinkler spinner, and a DC/DC converter circuit that charges a 1 F supercapacitor. The energy harvesting module operates only when the micro sprinkler spinner is irrigating the soil, and the supercapacitor is fully charged to 5 V in about 3 h during the first irrigation. After the first irrigation, with the supercap fully charged, the system can operate powered only by the supercapacitor for approximately 23 days, without any energy being harvested.

Surface Water and Groundwater Interactions in Traditionally Irrigated Fields in Northern New Mexico, U.S.A.

Better understanding of surface water (SW) and groundwater (GW) interactions and water balances has become indispensable for water management decisions. This study sought to characterize SW-GW interactions in three crop fields located in three different irrigated valleys in northern New Mexico by (1) estimating deep percolation (DP) below the root zone in flood-irrigated crop fields; and (2) characterizing shallow aquifer response to inputs from DP associated with irrigation. Detailed measurements of irrigation water application, soil water content fluctuations, crop field runoff, and weather data were used in the water budget calculations for each field. Shallow wells were used to monitor groundwater level response to DP inputs. The amount of DP was positively and significantly related to the total amount of irrigation water applied for the Rio Hondo and Alcalde sites, but not for the El Rito site. The average irrigation event DP using data for the complete irrigation season at each of the three sites was 77.0 mm at El Rito, 54.5 mm at Alcalde and 53.1 mm at Rio Hondo. Groundwater level rise compared to pre-irrigation event water levels ranged from 3 to 1870 mm, and was influenced by differences in irrigation practices between sites. Crop evapotranspiration estimates averaged across irrigation events were highest in Rio Hondo (22.9 mm), followed by El Rito (14.4 mm) and Alcalde (10.4 mm). Results from this study indicate there are strong surface water-groundwater connections in traditionally irrigated systems of northern New Mexico, connections that may be employed to better manage groundwater recharge and river flow.

MANAGING FURROW IRRIGATION METHOD IN CORN SMALL HOLDINGS

A field study on corn using furrow irrigation was carried out in northern Egypt on a clay loam soil with 1.2 g cm-3, average soil bulk during 2015 season in Shibin El-Kom area, Egypt. The main aim of this work is to study the changing of irrigation rate (10.71 and 5.35 m3 h-1) and fertilizer application (in complete irrigation time and half wave) on two different slopes (0.05 and 0.1%) of corn field in order to improve furrow irrigation method in small holdings. Corn seeds (Hi-Tech 2031) were planted on May 13, 2015 and received eight irrigations during the growing season. Application efficiency (Ea) was highly achieved by applying 10.71 m3 h-1 and improved by all treatments in second irrigation due to increasing initial soil moisture content compared to first irrigation. Storage efficiency (Es) was properly achieved by applying all treatments except 10.71 m3 h-1 inflow rate under 0.05% furrow slope because 7% deficit was occurred. The results showed that, average of corn yield, green forage yield, 100-grain weight, number of rows per ear and number of grains per row increased by decreasing furrow slope, decreasing inlet flow rate, and nitrogen application after offering half wave. Nitrogen application after offering half wave was achieved high nitrogen (N) concentration in corn root zone. The results indicated that corn yield increased by 8.90, 0.39 and 5.74% by applying furrow slope 0.05% relative to 0.1%, 5.35 m3 h-1 inlet flow rate relative to 10.71 m3 h-1 and nitrogen application after offering half wave along furrow relative to nitrogen application with the beginning of irrigation, respectively.

Dynamic Evaluation of Lavage Efficacy in Upper Compartment of the Temporomandibular Joint

The aim of this study was to determine the most efficient temporomandibular joint (TMJ) lavage technique for complete irrigation and removal of synovial fluid. The corresponding total lavage fluid volume needed also was investigated. Three-dimensional TMJ lavage models of the classic double- and single-needle techniques with modified cannula sizes (diameters, 2.4 and 0.8mm) were generated based on a constructed upper compartment model. Models were integrated with 2-phase flow models to predict fractional fluid volume (α value) changes of lavage saline and synovial fluid within the upper compartment of the TMJ. Fluid flow diagrams, velocity vectors, and intra-articular pressure data were collected and compared among the models. Models were validated by clinical synovial fluid concentration analyses, with vitamin B12 used as an internal standard. In all 8 models, lavage fluid initially gathered around the inflow portal, with a stable mixture of synovial and lavage fluids eventually being established in the compartment. Use of the double-needle technique with a large inflow portal resulted in thorough lavage (α= 100%). When the single-needle or Shepard cannula technique was used, some areas within the upper compartment remained devoid of brisk flow. The 2.4-mm inflow model coupled with a 0.8-mm outflow portal resulted in a stably and persistently high intra-articular pressure (>2.7 × 104Pa). A minimum volume of 109mL of lavage fluid was necessary for complete replacement of synovial fluid by saline. When a 2.4-mm inflow portal needle was applied, a lavage rate of 100% was obtained with a minimum lavage volume of 109mL. Using a small inflow portal could lead to inadequate flow, residual synovial fluid, and, ultimately, treatment failure.

Effect of exogenous salicylic acid under irrigation withholding at different growth stages in wheat (Triticum aestivum L.)

Salicylic acid (SA), an endogenous plant growth regulator has been found to generate a wide range of metabolic and physiological responses in plants affecting their growth and development. In order to study effect of salicylic acid foliar application and limited irrigation on quantitative and qualitative characteristics of wheat, this experiment was conducted at Varamin, Iran during 2014 growing season. The experimental design was laid out in a randomized complete block with a split plots arrangement of treatments in three replications. Main plots included four different levels of irrigation (complete irrigation, irrigation withholding at stem elongation stage, irrigation withholding at flowering stage and irrigation withholding at seed filling period stage) and different concentration of foliar application of salicylic acid (0, 150 and 300 ?M) were allocated to subplots. The results showed that irrigation withholding conditions in different growth stages significantly decreased seed yield, RWC and total chlorophyll but by contrast increased membrane stability, proline content, SOD and CAT enzymes activity and also lipid and protein peroxidation. Salicylic acid foliar application had positive effect on all attributes in this experiment. In general, the results of the present study indicate that usage of salicylic acid reduces the harmful effects of water deficit stress and increases resistance to drought stress in wheat plant.International Journal of Natural Sciences (2014), 4(2) 28-33

The study of humic acid foliar application on physiological and biochemical changes in wheat under irrigation withholding at different growth stages

In order to study effect of humic acid (HA) foliar application and limited irrigation, on physiological and biochemical characteristics of wheat an experiment was conducted in research field of Varamin, Iran during 2012 growing season. The experimental design was laid out in a randomized complete block with a split plots arrangement of treatments in three replications. Main plots included four different levels of irrigation (complete irrigation, irrigation withholding at stem elongation stage, irrigation withholding at flowering stage and irrigation withholding at seed setting stage) and three different concentration of HA foliar application (0, 150 and 300) was allocated to subplots. The results showed that irrigation withholding conditions in different growth stages significantly decreased seed yield and total chlorophyll content but by contrast increased electrolyte leakage, antioxidant enzymes activity and lipid and protein peroxidation. It appears that HA act in plants via a specific form of stress that is detected by anti-stress defense systems in plants. These HA applied to plants can protect against water stress in degraded soils.International Journal of Natural Sciences (2015), 5(1) 1-7

Interrogating the Functional Correlates of Collateralization in Patients with Intracranial Stenosis Using Multimodal Hemodynamic Imaging.

The importance of collateralization for maintaining adequate cerebral perfusion is increasingly recognized. However, measuring collateral flow noninvasively has proved elusive. The aim of this study was to assess correlations among baseline perfusion and arterial transit time artifacts, cerebrovascular reactivity, and the presence of collateral vessels on digital subtraction angiography. The relationship between the presence of collateral vessels on arterial spin-labeling MR imaging and DSA was compared with blood oxygen level-dependent MR imaging measures of hypercapnic cerebrovascular reactivity in patients with symptomatic intracranial stenosis (n = 18). DSA maps were reviewed by a neuroradiologist and assigned the following scores: 1, collaterals to the periphery of the ischemic site; 2, complete irrigation of the ischemic bed via collateral flow; and 3, normal antegrade flow. Arterial spin-labeling maps were scored according to the following: 0, low signal; 1, moderate signal with arterial transit artifacts; 2, high signal with arterial transit artifacts; and 3, normal signal. In regions with normal-to-high signal on arterial spin-labeling, collateral vessel presence on DSA strongly correlated with declines in cerebrovascular reactivity (as measured on blood oxygen level-dependent MR imaging, P < .001), most notably in patients with nonatherosclerotic disease. There was a trend toward increasing cerebrovascular reactivity with increases in the degree of collateralization on DSA (P = .082). Collateral vessels may have fundamentally different vasoreactivity properties from healthy vessels, a finding that is observed most prominently in nonatherosclerotic disease and, to a lesser extent, in atherosclerotic disease.

Investigation of growth analysis in chickpea (Cicer arietinum L.) cultivars under drought stress

A field experiment performed in order to evaluate the effects of drought stress on growth indices of chickpea cultivars. This experiment was performed in factorial using randomized complete block design with three replications. Treatments were drought stress treatment in in three levels consisting of no drought stress (control), moderate drought stress (irrigation at planting and early flowering) and severe drought stress (no irrigation) and cultivar treatment (three cultivars Azad, Grit and ILC482). Results showed that LAI, CGR, RGR and NAR reduced with increased in drought stress level. Also, LAR decreased after short time increasing. Non stress condition caused to improve growth stages and increase accumulation of dry matter and yield in chickpea. Maximum LAI, LAR and CGR obtaind at 56 days after sowing under non irrigation condition, but under complete irrigation they were observed at 77 days after sowing. RGR and NAR reduced with increasing the age of the plant. Thus we concluded that drought stress decreased growth of chickpea and final yield of it.DOI: http://dx.doi.org/10.3126/ijls.v9i5.12705

Changes in Yield and Yield Components of Wheat Cultivars under Water Stress Condition

A field experiment was laid out in order to evaluation of effects water stress on yield and yield components of wheat cultivars in Lorestan province in Islamic Azad University, Boroujerd branch, Iran at 2014. The experiment was laid out in a split-plot design based on randomized block design with three replications. Treatments were irrigation in five levels such as 1: four period irrigation after anthesis, 2: three period irrigation after anthesis, 3: two period irrigation after anthesis, 4: one period irrigation after anthesis and 5: control in main plots and three wheat cultivars (Shiraz, Pishtaz and Bahar) in sub plots. The results showed that, the effect of water stress, cultivar and interaction between them on all parameters were significant at 1% level. The height of Pishtaz cultivar was taller than other cultivars. The Pishtaz cultivar with one period irrigation after anthesis had the highest number of spike per square and Bahar cultivar with one period irrigation after anthesis had the lowest number of spike per square. However, 1000- grainwas decreased in water deficit treatment. However, the Pishtaz cultivar with four period irrigation had the highest plant dry weight and grain yield and Bahar cultivar non irrigation treatment after anthesis had the lowest plant dry weight and Shiraz cultivar in non-irrigation treatment had the lowest grain yield. The results showed that yield and yield components of common wheat decreased with increasing of water deficit and for increasing in grain yield of wheat complete irrigation are needed. However, Pishtaz cultivar had a highest grain yield and dry matter production. Then we can increase grain yield and production of wheat with cultivation of Pishtaz cultivar and avoid of water stress.DOI: http://dx.doi.org/10.3126/ijls.v9i5.12707

Effect of zinc and sulfur foliar applications on physiological characteristics of sunflower (Helianthus annuus L.) under water deficit stress

In order to study effect of zinc and sulfur foliar applications on quantitative and qualitative characteristics of sunflower under water deficit stress, an experiment was conducted at Varamin, Iran during 2013 growing season. The experimental design was laid out in a randomized complete block with a split plots arrangement of treatments in three replications. Main plots included three different levels of irrigation (complete irrigation, irrigation withholding at flowering stage and irrigation withholding at seed filling period stage) and sub plots were included four different zinc and sulfur application (untreated zinc and sulfur application, zinc foliar application, sulfur application and both zinc foliar application and sulfur application). The results showed that irrigation withholding at different growth stages significantly decreased seed number in cap, thousand seed weight, seed yield, biological yield, oil yield and total chlorophyll but by contrast increased proline content, membrane stability, super oxide dismutase enzymes activity. Both zinc foliar application and sulfur application treatment had positive effect on all attributes in this experiment. In general, the results of the present study indicate that usage of zinc foliar application reduces the harmful effects of water deficit stress and increases resistance to drought stress in sunflower plant.

Effect of irrigation and planting date on the selected morphophenological and quality traits of ajowan (Carum copticum Benth. & Hook. F.).

In order to study the effects of irrigation and planting date on selected traits of ajowan (Carum copticum BENTH. & HOOK.F.) an experiment was conducted in two successive conducive seasons of 2009/2010 and 2010/2011 in Birjand. The experimental design was a split plot based on randomized complete block with three replications. In the present study, two irrigation treatments (irrigation termination with flowering onset and complete irrigation) and six planting dates (Dec 6th, Dec 21st, Jan 5th, Feb 29th, Mar 30th and Apr 30th) were considered as main plot and subplot, respectively. As results indicated, the drought stress significantly reduced seed and essential oil yield, but had a non significant effect on the germination percent. Moreover, there was a nil effect on the morphological characteristics of the plants. It was interesting to note that the late planting date caused seed yield, number of umbels per plant, number of umbellules per inflorescence, plant height, number of branches per plant, essential oil percentage and the length of the vegetative growth period to decrease, but there was nil effect on the essential oil yield and the germination percent. In fine, the results indicated that water stress not only caused the essential oil percent and plant performance to decrease, but also influenced early plantings to have more seed yield and essential oil percent.

Stochastic Analysis of Wind Energy for Wind Pump Irrigation in Coastal Andhra Pradesh, India

The rapid escalation in the prices of oil and gas as well as increasing demand for energy has attracted the attention of scientists and researchers to explore the possibility of generating and utilizing the alternative and renewable sources of wind energy in the long coastal belt of India with considerable wind energy resources. A detailed analysis of wind potential is a prerequisite to harvest the wind energy resources efficiently. Keeping this in view, the present study was undertaken to analyze the wind energy potential to assess feasibility of the wind-pump operated irrigation system in the coastal region of Andhra Pradesh, India, where high ground water table conditions are available. The stochastic analysis of wind speed data were tested to fit a probability distribution, which describes the wind energy potential in the region. The normal and Weibull probability distributions were tested; and on the basis of Chi square test, the Weibull distribution gave better results. Hence, it was concluded that the Weibull probability distribution may be used to stochastically describe the annual wind speed data of coastal Andhra Pradesh with better accuracy. The size as well as the complete irrigation system with mass curve analysis was determined to satisfy various daily irrigation demands at different risk levels.

Precision irrigation based on wireless sensor network

The main purpose of this study is to present a complete irrigation solution for the farmer based on wireless sensor network. The challenge is to create an automated irrigation system which can reduce in the same time the water's waste and is cost effective. Different parameters are important to measure in order to calculate the efficient quantity of water needed by plants. In this study, the proposed solution is the use of low-cost sensor nodes having reduced power consumption able to realise necessary requirements. The system is composed of different types of nodes. Each node consists of a TelosB mote and adequate sensors or actuators. Soil nodes are used to detect the level of moisture and temperature in soil. Weather nodes monitor the climatic changes. Other nodes are connected to actuators which are able to control the opening of the irrigation valve if necessary.

Effect of Water Stress and N Fertilizer Levels on Yield and Water Use Efficiency of Forage Millet

Aims: This study was conducted to study effect of irrigation deficit and N fertilization on yield and water use efficiency (WUE) of forage millet cv. Nutrifeed. Study Design: Experimental design was split-plot based on randomized complete block with three replications. Place and Duration of Study: The experiment was carried out in research field of Islamic Azad University, Birjand branch, Birjand, Iran in 2011. Methodology: The factors included irrigation levels (100 and 50% supply of plant water requirement) and N fertilizer levels (0,75,150 and 225kg.ha) were the main and subplots, respectively. Results: The results showed that the decrease in irrigation level from 100 to 50% supply of PWR decreased forage fresh yield 38.8% and total dry yield by 40.1%, significantly. The effect of N on total forage fresh and dry yield and yield components was significant. As N level was increased from 0 to 225kg.ha, forage dry yield increased by 81.2%. The complete irrigation treatment with the application of 225kgN.ha had the highest production potential with total forage fresh yield of 49.3t.ha. WUE was significantly affected by N levels. As N level was increased to 225kg.ha, WUE was 67.52, 35.09 and 13.56% higher than that at N levels of 0, 75 and 150kg.ha. Conclusion: In total, according to the results, complete irrigation with the application of 225kgN.ha increased forage and protein yield per unit area.

Effect of Irrigation and Planting Date on Yield and Water Use Efficiency of Ajowan (Carum copticum)

Aims: This study was conducted to evaluate the effect of irrigation regimes and different planting dates on yield and water use efficiency of ajowan. Place and Duration of Study: The study was carried out during 2009/2010 and 2010/2011 seasons in Birjand, Iran. Methodology: Experimental design was split plot based on randomized complete block with three replications. Irrigation intervals (irrigation cut at the beginning of flowering and complete irrigation) as the main factor and six planting dates (December 6, December 21, January 5, February 29, March 30 and April 30) as sub factors. Results: Results showed that the highest and lowest seed yields and number of seeds per plant was from planting dates of February 29 and March 30, respectively. Results showed that late planting decreased seed yield, number of umbels per plant and number of seeds per plant; but increased number of seeds per umbel and 1000-seed weight. Winter planting had higher yield and biomass water use efficiency compared to spring planting but seed water use efficiency and harvest index were not affected by planting date. The effect of the water stress treatment on plants’ reproductive structures caused Original Research Article Annual Research & Review in Biology, 4(12): 1968-1979, 2014 1969 decreases to seed yield, seed water use efficiency and seed harvest index. Conclusion: In general, these showed that winter planting in conditions of drought stress resulted in higher biomass water use efficiency.