Depletion Of Available Water Research Articles

Impacts of Kaolin and Pinoline foliar application on growth, yield and water use efficiency of tomato (Solanum lycopersicum L.) grown under water deficit: A comparative study

Abstract The impacts of Kaolin particle film (KPF) and Pinoline (P) Antitranspirants (ATs) on growth, yield components (marketable and unmarketable), fruit quality and on-farm irrigation water use efficiency (WUE) of tomato plants ( Solanum lycopersicum L. ) grown under water deficit of 40%, 60%, and 80% depletion of available water (DAW) were studied, to determine if ATs application would mitigate water deficit stress and increase WUE. The field experiments were elaborated in the open field for two seasons under the drip irrigation system. The results revealed that deficit irrigation (DI) significantly reduced the relative water content of the leaves (RWC), CO 2 assimilation rate (P-net), marketable yield, while canopy temperature (CT) and WUE were increased. Results indicated that KPF under DI effectively enhanced the physiological activities and marketable yield production, while reduced sunscald fruits and those with blossom-end rot symptoms (unmarketable yield), particularly under 60%DWA, but it did not compensate the negative effects under 80%DWA. Also, the effect was null under non-limiting water conditions. Generally, P had no significant effects under different water stress severities. Under 60%DWA, application of KPF increased the marketable yield to 93% of the unstressed-unsprayed plants, while conserving 25% of irrigation water, leading to an increase in WUE by 26.24% with respect to unstressed-unsprayed plants.

Partial Relief of Drought-Stressed Fennel (Foeniculum vulgare Mill.) in Response to Foliar-Applied Zinc

Few attempts have been made to explore the effect of Zn fertilization on the performance of medicinal plants in general and fennel in particular, under adverse conditions. This study was conducted to examine the efficacy of zinc (Zn) in correcting physiological responses of fennel to water deficit. Twelve field-grown fennel genotypes were subjected to two levels of irrigation (irrigation after 25%–35% and 75%–85% depletion of available soil water) and two levels of foliar-applied Zn (0 and 4 g kg−1). Water deprivation had significant effects on all characteristics; i.e., in contrast to seed essential oil concentration, harvest index, and superoxide dismutase (SOD) and catalase activities, it led to decreases in the rest of the attributes. Varietal differences in response to drought were meaningful for most of the traits. Genotypic variations for dry mass and seed yield were consistent with differences among the genotypes in leaf water potential, relative water content, proline concentration, and chlorophyll concentrations. Zinc led to significant increases in all physiological attributes, including activation of antioxidant defense responses manifested in ascorbate peroxidase and SOD activities and carotenoid concentration. The Zn-effect tended to be more notable in drought-stricken fennel plants in a majority of the traits. Based on our findings, Zn could be considered an effective micronutrient for ameliorating, at least in part, the stressful effects of water deficit on fennel.

EFFECT OF WATER STRESS ON YIELD AND YIELD COMPONENTS OF BREAD WHEAT GENOTYPES.

A field experiment was conducted during 2014 -2015 and 2015-2016 seasons at the Field Crops Research Station Abu Ghraib, to study the effect of water stress, on yield and yield components of bread wheat genotypes .The water stress treatment were 25% (S1) and 75% (S2) depletion of soil available water . The experiments was conucted using a split plot with in arrangement Randomized Complete Block Design with three replications. Water stress treatments were assigned to the main-plot, while, 27 wheat genotypes were assigned to sub-plots. The results indicated that water stress treatment (S2) significantly decreased the number of spikes m-2, number of grain.spike-1, 1000 grain weight and grain yield. The genotypes showed a differences in all characters studied. The genotype 26 produced the highest number of spikes m-2(355.8) and did not significantly differ from Bohooth10 347.2 spike.m-2.The Bohooth10 gave highest in the number of grain spike-1 (62.07) . The genotype 25 produced the highest weight of 1000 grains (40.05,37.09 gm)The genotype 26 produced highest grain yield (6.117 and 5.074 ton h-1 ) for two seasons, respectively but differed significantly from IPA99 which gave lowest grains yield ( 3.395 and 3.020 Tun.h-1) for two seasons respectively.

Erratum to: Variation in Seed Oil Content and Fatty Acid Composition of Globe Artichoke Under Different Irrigation Regimes

Seed oil content of globe artichoke and its composition were assessed under three irrigation regimes, including irrigation at 20, 50, and 80 % depletion of soil available water. Water deficit affected the phenological characteristics, amount and the quality of the oil as well as the phenolics and antioxidant activity of the leaves and capitula. The seed oil content ranged from 18.7 % in 80 % to 22.8 % in 20 % treatment. The fatty acid composition of oil was determined using gas chromatography (GC). The predominant fatty acids in the oil were linoleic (51.68 %), oleic (34.22 %), palmitic (9.94 %), and stearic (3.58 %). Water deficit leads to reduced oil content, linoleic acid, the unsaturated/saturated fatty acid ratio and the iodine value. On the other hand, some other fatty acids such as palmitic and oleic acid and also the ratio of oleic/linoleic acid were elevated due to water deficit. Higher antioxidant activity was observed in capitula (IC50 = 222.6 μg ml−1) in comparison to the leaves (IC50 = 285.8 μg ml−1). Finally, the severe drought stress condition caused to gain higher oil stability, while the highest seed oil content and unsaturated fatty acids in the oil was obtained in non-stress condition. Moreover, high phenolics, flavonoids and antioxidant activity as well as appreciable dry matter content were obtained in the moderate water stress condition.

Response of Vitis vinifera L. cv. Barlinka/Ramsey to Soil Water Depletion Levels with Particular Reference to Trunk Growth Parameters

Vitis vinif era L. cv Barlinka/Ramsey was irrigated with micro sprinklers at 10 % , 40 % and 60 % depletion of plant available water (PAW) in a field trial on a sandy soil in the Hex River Valley. A fourth treatment was trickle-irrigated at 40% PAW depletion. Irrigations were scheduled with tensiometers. A system which measures trunk diameter was used for automatic trickle irrigation of a fifth treatment. Measuring trunk growth continuously using linear variable differential transformers revealed no increase in diameter between budbreak and bloom. From bloom until veraison trunk diameter increased, whereafter it decreased slightly. Average seasonal trunk diameter increases were 0,8 mm, 1,2 mm and 2,1 mm, for the 60%, 40% and 10% PAW depletion levels, respectively. When well supplied with water, diurnal trunk contraction ranged between 0 mm and 0,01 mm per day. As water stress increased, trunk contraction increased curvilinearly to a maximum value of ca 0,1 mm per day. The most acceptable combination of growth, yield, berry size and eating quality was obtained by irrigation using micro sprinklers at 40% PAW depletion. Irrigation at 10% as well as 60% PAW depletion reduced berry taste and colour significantly. Root studies by means of the profile wall method showed that irrigation at 10 % PAW depletion limited fine root development in comparison to 40 % PAW depletion. Trickle irrigation stimulated development of fine roots within 500 mm of the grapevine as opposed to micro sprinklers. Trickle irrigation at 40% PAW depletion tended to increase water stress in comparison to micro sprinklers. This tended to improve grape quality, but reduced production and berry size. Although automatic irrigation held no significant advantages regarding yield and quality in comparison to manual scheduling with the aid of tensiometers, it did simplify irrigation management.

Identifying Irrigation Strategies for Improved Agricultural Water Productivity in Irrigated Maize Production through Crop Simulation Modelling

Identifying irrigation strategies that improve agricultural water use efficiency (WUE) have a pivotal role to play in sustainable water development. In this study, the AquaCrop model was used to examine the impact of different irrigation scheduling options on yields to identify viable strategies to enhance WUE for irrigated maize. Two scheduling scenarios at water application depths ranging from 20 to 50 mm were investigated: schedules based on allowable depletion of total available water (TAW) in the root zone and interval schedules based on irrigating at predefined daily intervals. For both scenarios, simulated yields, seasonal water applied and percent percolation loss were within the range of 9.16 to 10.22 ton/ha, 180 to 950 mm and 0–61%, respectively. The WUE in terms of water applied (WUEIrr) and crop evapotranspiration (WUEET) ranged from 1.07 to 5.48 kg/m3 and 2.42 to 4.42 kg/m3, respectively. The results revealed that depletion levels of 40–50% TAW at water depths of 20–40 mm could be used to obtain high WUE without significant yield penalty. Moreover, a good balance between yield, improved WUEET and percolation reduction was observed at water depths of 30–40 mm for daily intervals with water applied during the vegetative-reproductive stage of 7–5, 10–5 and 10–7. The identified strategies can contribute to the development of best management practices for water conservation.

Dry Matter Production and Seed Yield of Soybean as Affected by Post-Flowering Salinity and Water Stress

The experiment was conducted in a vinyl house of the Agronomy Division, Bangladesh Agricultural Research Institute (BARI), Joydebpur, Gazipur, during rabi season of 2015-2016 to evaluate the sensitivity of different post-flowering growth stages of soybean to salinity (100 mM NaCl) and water stress (70% depletion of available water) imposed at 4th to 6th, 6th to 8th, 8th to 10th and 10th to 12th wees after emergence. Shoot dry weight wa found more sensitive to salt and water stress than root dry weight at all the post flowering growth stages. The highest relative shoot dry weight (91.47%) and relative root dry weight (95.58%) were recorded from salt and water stressed plants, respectively when both the treatments imposed at 4th to 6th weeks after emergence. The highest seed yield (10.47 g plant-1 ) was obtained from the control treatment followed by that (8.68 g plant-1) under salt stress treatment imposed at 10th to 12th weeks after emergence. Contrary, the lowest seed yield of 0.69 g plant-1 was obtained from the salt stress treatment imposed at 4th to 6th weeks after emergence. Among the stages, 4th to 6th weeks after emergence of soybean was found the most sensitive to salt stress in relation to seed yield reduction. The salt stress imposed at 6th to 8th weeks after emergence was also found damaging for seed yield production.Bangladesh Agron. J. 2016 19(2): 21-27

Application of biochemical markers for the assessment of drought tolerance in alfalfa (Medicago sativa L.) cultivars

AbstractAlfalfa (Medicago sativa L.) cultivars respond differently to drought stress levels and oxidative injury. This may provide us with an important tool to identify the chemical mechanisms operative in drought tolerant genotypes. The present experiment was conducted to determine catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POX) activities; malondialdehyde (MDA) content; herbage yield; stress susceptibility index (SSI); and drought tolerance index (DTI) of 10 alfalfa cultivars under four irrigation regimes (55, 65, 75 and 85% depletion of available soil water). Drought stress was observed to reduce herbage yield but increase CAT, APX and POX activities as well as MDA content; however, such alterations were cultivar‐drought level‐specific. With a few exceptions, Baghdadi had the highest CAT, POX and APX activities and lowest MDA content, lowest reduction in herbage yield and the lowest SSI and the highest DTI under all irrigation regimes suggesting that it was the most adapted and drought‐tolerant cultivar. Herbage yield had a significant and positive correlation with POX and a significant and negative correlation with MDA under all irrigation regimes indicating that they could be used as markers for selecting more drought‐tolerant cultivars in alfalfa. Catalase and APX also had a significant and positive correlation with herbage yield, thus they could be used as markers for selection of more drought‐tolerant cultivars. The results suggested that a wide variation in drought tolerance exists within alfalfa cultivars, thus selection for more drought tolerance is possible. In addition, chemical markers such as POX, CAT and APX activities and MDA content may be used to assist in selection for more drought tolerance cultivar in this species.

Measurement of water consumptive use, growth, and yield of potato (Solanum tuberosum L) under drip irrigation system

A field experiment was conducted during the spring of 2015 in the Al- Chaksaliah village in Hit district - Anbar province in sandy Loam soil texture, to study water consumptive use in different ways under the drip irrigation system, style of addition on growth and yield of potatoes. Water consumption measured in four methods, depending on climatic data using Najib Kharofah equation, depending on evaporation pan and water tensiometer and moisture sensor, water added in two ways firstly addition depth once, for Added half the depth and the addition of the second half after 12 hours of The first add-on, the study treatments distributed in accordance with the randomized complete block design (RCBD) of three replicate. Potatoes were planted on 05/02/2015, was given five irrigations before germination and then was irrigation scheduling, where perfusion has operations at 40% depletion of available water using of tensiometer and moisture sensor with an irrigation intervals of three days when using Najib Kharofah and pan evaporation equation. The water consumption calculation and measurement of plant height, root length, dry weight, total yield and calculated the efficiency of water use. Results showed, that Water consumption values increased with advancing stages of plant growth, and decreased in the mature stage, with the highest water-consumption reached in the swollen tubers stage as it reached values of 533, 405, 360 and 337 mm for the way Najib Khrovh, pelvis, tensiometer and sensors humidity, respectively, while the total is less watery consumption to plant potatoes in the vegetative stage of growth, reaching 85, 74, 60 and 30 mm for the way Najib Khrovh, evaporation pan, tensiometer and moisture sensors, respectively. The Najib Kharofah equation gave the highest value for the consumption of water in comparison with the rest of seasonal treatments reaching 996, 772, 668 and 595 mm Season-1 for the treatment of Najib Kharofah and evaporation pan, tensiometer and moisture sensors, respectively. The Najib Kharofah treatment prevailed for both ways of addition to give a higher yield of tubers and higher dry weight and height of the plant amounted and length of the roots to 40.75 Ton h-1 and 96.74 g Plant-1 and 41.83 cm and 31.31 cm, for complete treatments, respectively. And amounted to 43.19 Ton h-1 and 98.5 g Plant-1 and 43.4 cm and 32.56 cm, for the mid-term treatments, respectively. While the lowest values of the tuber yield, dry weight and length of the roots and plant height under the treatment of moisture sensors amounted to 29.28 Tun h -1 and 65.56 g Plant-1 and 25.93 cm and 28 cm full of treatments, respectively. And 30.46 Tun.h-1 and 65.81 g Plant-1 and 27.6 cm and 29.88 cm for the mid-term treatments, respectively. Tensiometer treatment gave midterm best efficiency of water use for tubers to reach an average of 8.53 kg m-3 compared with other treatments.

Apple Tree Responses to Deficit Irrigation Combined with Periodic Applications of Particle Film or Abscisic Acid

The objective of this study was to determine if the application of two antitranspirant compounds would moderate water deficit stress effects on physiological responses of “Granny Smith”, “Royal Gala” and “Golden Delicious” apple (Malus domestica Borkh.) trees on MM106 rootstock that occur during deficit irrigation. Uniform trees were grown in pots under water supply regimes of 30%, 60%, and 80% depletion of available water (DAW) before irrigation to runoff and received applications of kaolin particle film (PF) or abscisic acid (ABA) at 0, 30 and 60 days. At 120 days, genotype and deficit irrigation affected nearly all leaf traits, but antitranspirant treatment had no significant effects. As the % DAW increased, the net photosynthetic rate (Pn), transpiration rate (T), stomatal conductance, leaf water and pressure potential, variable-to-maximal chlorophyll fluorescence, leaf number, and leaf N, P and K contents were reduced. A significant genotype by deficit irrigation interaction was evident on T, water use efficiency (WUE), and leaf osmotic pressure potential. A significant deficit irrigation by antitranspirant interaction was evident on only leaf Pn, with PF and ABA reducing it at 30% DAW and only PF reducing it at 80% DAW. However, the periodic use of PF or ABA during deficit irrigation did not alleviate most physiological effects of water deficit stress due to deficit irrigation.

Study of self-pollination and capitula characteristics in globe artichoke ( Cynara cardunculus var. scolymus Hayek L.) under different irrigation regimes

In order to estimate the drought effects on capitula characteristics and self-pollination of globe artichoke ( Cynara cardunculus var. scolymus Hayek L.), the randomized complete block design was carried out with three irrigation regimes (20 %, 50 % and 80 % depletion of soil available water) and six replicates. The artichoke is mostly open-pollinated, however, after covering the buds and isolation of flowers to prevent cross pollination, 1.79 % self-pollination was observed and this amount was not affected by different irrigation regimes. In stress conditions (50 % and 80 % water depletion) as well as non-stress condition (20 % water depletion), plants with respectively one and two medium capitula and without small capitula had most relative frequencies in the population and drought stress increased these relative frequencies by reducing the number of medium and small capitula in plants. In addition, Capitula size and dry weight were significantly affected by water stress. Water shortage induced severe decrease in length and dry weight of all capitula including large, medium and small, although capitula width was less affected by water deficit and only slight decline in medium (12.5 %) and small capitula (23.7 %) was observed under severe stress condition.

Iron supplement ameliorates drought-induced alterations in physiological attributes of fennel (Foeniculum vulgare)

This study was conducted to examine the response of fennel to foliar applied Fe under contrasting moisture conditions. Twelve fennel genotypes were subjected to two levels of irrigation (irrigation after 35 and 85 % depletion of available soil water) and two levels of Fe solution (0 and 4 g kg−1). Plants subjected to drought showed notable reductions in leaf chlorophyll a (Chl a), Chl b, relative water content (RWC), water potential (ψw), carotenoids, ascorbate peroxidase (APX), seed yield and plant dry mass (DM). Though, drought-treated plants indicated notable increases in proline concentration, super oxide dismutase (SOD) and catalase activities and seed essential oil concentration. Genotypic variations for DM and grain yield were consistent with differences among the genotypes in ψw, RWC, proline, Chl a and Chl b concentrations. Fe led to significant increases in APX and SOD activities and carotenoids, Chl a and Chl b concentrations. The mitigative effect of Fe tended to be more notable on the drought-stricken plants for a majority of the traits. From our findings, Fe could be appreciated as a micronutrient effective in ameliorating at least in part the stressful effects of drought on plants.

Variation in Seed Oil Content and Fatty Acid Composition of Globe Artichoke Under Different Irrigation Regimes

AbstractSeed oil content of globe artichoke and its composition were assessed under three irrigation regimes, including irrigation at 20, 50, and 80 % depletion of soil available water. Water deficit affected the phenological characteristics, amount and the quality of the oil as well as the phenolics and antioxidant activity of the leaves and capitula. The seed oil content ranged from 18.7 % in 80 % to 22.8 % in 20 % treatment. The fatty acid composition of oil was determined using gas chromatography (GC). The predominant fatty acids in the oil were linoleic (51.68 %), oleic (34.22 %), palmitic (9.94 %), and stearic (3.58 %). Water deficit leads to reduced oil content, linoleic acid, the unsaturated/saturated fatty acid ratio and the iodine value. On the other hand, some other fatty acids such as palmitic and oleic acid and also the ratio of oleic/linoleic acid were elevated due to water deficit. Higher antioxidant activity was observed in capitula (IC50 = 222.6 μg ml−1) in comparison to the leaves (IC50 = 285.8 μg ml−1). Finally, the severe drought stress condition caused to gain higher oil stability, while the highest seed oil content and unsaturated fatty acids in the oil was obtained in non‐stress condition. Moreover, high phenolics, flavonoids and antioxidant activity as well as appreciable dry matter content were obtained in the moderate water stress condition.

ROLE OF PROLINE ACID IN IMPROVING SUNFLOWER YIELD AND YIELD COMPONENTS UNDER DEFICIT CONDITIONS WATER

A field study was conducted during the spring and autumn seasons of 2014 at the experimental farm of Field Crop Department, College of Agriculture (Abo-Ghraib) - University of Baghdad, to study the effect of Irrigation deficiency quantities and concentrations of Proline acid on yield , its components, water consumptive and water use efficiency of sunflower (Helianthus annus L. ) for Luleo hybrid. Randomized Complete Block Design (RCBD) in arrangement of a split-plot with three replications were used. Irrigation treatments, control (depletion 50% of available water) and 60% , 50% 40% of control treatment, were assigned as a main plots. while proline acid concentrations of 0, 30, 60 and 90 mg.L-1 were assigned as a subplots. The results showed that there is no significant differences between the control treatment and 60% of the control for the period from planting to 50% flowering, number of leaves, relative water content, nitrogen concentration in leaves, fertilization percentage, number of seeds in the head,100 seed weight and seeds yield reaching 3.90, 2.46 t.ha-1 and 3.78 , 2.41 t.ha-1 for spring and autumn seasons respectively. which indicates the possibility of saving 40% of the water consumption which is estimated 1920.00, 2960.00 m3. ha-1. Season-1 for two seasons respectively without any yield reduction. While the percentage of decline in seeds yield for treatments 50% and 40% from the control treatment for spring season were 14.61% , 19.74% respectively and 21.95 % , 33.33% for autumn season comparing with control. Irrigation treatment 40%, 60% of the control treatments gave the best water use efficiency for both seasons respectively. a concentrations of Proline acid affect significantly most of studied traits. Increasing of Proline to 60mg.L-1 gave the to increase in fertilization percentage was و70.2081.% 100 seed weight7.12 و7.52 gm, seed yield 3.75, 2.21 t.ha-1 and water use efficiency 0.84 و0.29 kg seed.m-3 water comparing with control for two seasons respectively .The interaction between irrigation and Proline acid showed a significantly effect on all characteristics seeds yield components traits in both seasons. We therefore recommend that in case of limited irrigation water by %60 by the need of the full irrigation (50 % depletion of available water) without a significant decrease in product seed yield, in addition to possibility treatment of sunflower plants with Proline acid with 60 mg .L-1 to improvement capacity of water stress.

Yield and net return from alfalfa cultivars under irrigation in Southern Alberta

Field studies with two types of alfalfa (Medicago sativa L.) cultivars were conducted at Lethbridge in 2012 and 2013 and at Picture Butte in 2012 to determine the effects of irrigation on the dry matter (DM) yield and on net returns. The irrigated cultivars (Longview and Blue J) and dryland cultivars (Rangelander and Rambler) were arranged on plots in a randomized complete block design with four irrigation treatments and replicated five times. For the optimal irrigation treatment (W1), soil water content was maintained between 60 and 90% of available water in the designated root zone. Other irrigation treatments received 75% (W2), 50% (W3), and 25% (W4) of the irrigation water applied to the optimal treatment. The mean DM yields of irrigated alfalfa cultivars were greater than one of the dryland cultivars in both locations. The mean total DM yields for W2and W3at Lethbridge for Blue J, Longview and Rambler were greater than those of W1, although the differences were not always significant. The net returns, calculated by using the same price for all alfalfa harvests were similar across the cultivars and irrigation treatments excepting Rangelander, where the returns were lower. The results obtained from this study indicated a trend towards comparable yields and net returns between the optimal and the 75% irrigation treatment with 40% depletion of available water at the root zone, for the irrigated alfalfa cultivars and a dryland type Rambler.

Optimizing Tillage and Irrigation Requirements of Sorghum in Sorghum-Pigeonpea Intercrop in Hamelmalo Region of Eritrea

Sorghum (Sorghum bicolor L. Moench) is cultivated as monocrop in Eritrea. Efforts were made to grow sorghum-pigeonpea (Cajanus cajan L. Millspp.) intercrop on the tillage, fertilizers and supplementary irrigations necessary for sorghum. Experiments were conducted in terraced fields at Hamelmalo during 2013-15 to evaluate growth and yield of sorghum-pigeonpea intercrop in split plot design with conventional tillage (CT), reduced tillage (RT) and zero tillage (ZT) in main plots and rainfed (I0), 50% of full irrigation (I1), 75% of full irrigation (I2) and 100% of full irrigation (I3) in subplots. All irrigations were stopped 15 days before sorghum maturity. Full irrigation was 60 mm applied at 50% depletion of available soil water in 1 m profile. Sorghum growth was faster than pigeonpea until 85 days from planting and pigeonpea growth accelerated only after sorghum harvesting. About 80% of sorghum roots were within 0.6 m profile but more than 75% of pigeonpea roots were below 0.60 m depth. This showed a weaker competition between the two crops for nutrients, water and light. Both grain and stover yields of sorghum were optimum in RT + I2 during the 2 years. Highest grain yield was 6900 kg·ha-1 in RT + I3 in 2013, which was at par with that in RT + I2. Mean residual soil moisture at sorghum harvesting was 74 mm·m-1, which decreased to 8 mm·m-1 by pigeonpea harvesting. Residual moisture was more in the irrigated than non-irrigated plots. Pigeonpea yields were optimum (1363 kg·ha-1) in RT + I3 and lowest (297 kg·ha-1) in ZT + I0. Average water use by sorghum-pigeonpea was 374 mm by sorghum harvesting and 438 mm by pigeonpea harvesting, producing total sorghum equivalent yield of 7475 kg·ha-1. This raised average water use efficiency from 12.6 kg·ha-1·mm-1 at sorghum harvesting to 17.1 kg·ha-1·mm-1 at pigeonpea harvesting. Benefit was doubled at 50% of full irrigation and >4 times at 75% of full irrigation.

Seed Priming Wheat Triticum aestivum L. to improve water use efficiency under different moisture levels

A field experiment was carried out in the experiments of field crops Department field - Faculty of Agriculture - University of Baghdad, during the season 2013 -2014 .The objective was to investigate the effect of seed priming wheat before sowing on the wheat plants tolerance to the drought compared with the non- priming seeds and its relationship with the growth and grain yield. Use the R.C.B.D design in the arrangement of split- plot with three replicates. The drought treatment (50, 70, and 90%) depletion of available water of occupied the main plots. While seed priming treatments (gibberellins, Kinetin, cycocel, salicylic acid, kcl, Ascorbic acid, distilled water and Dry seedss). The results of experiment revealed that there were significant differences between seed priming treatments with emergence. The results of the trial showed that, the moral effect of the seed priming in the proportion of emergence. The average emergence field rate of 78.4% for the treatment of Dry seed to 87.4% using the seed priming with Gibberellin, with increase ratio 11.47%, so as with KCL and Salicylic acid is the other significant increases amounted to 9.31% and 8.62 % compared to the treatment comparison Dry seed . Moisture depletion treatment 90% with seed priming by Salicylic acid increase in water use efficiency of grain reached quotient 1.850 kg. M3 increase exceeded 100% compared to the treatment comparison Dry seed at the same level of attrition 90% causing moisture depletion at 90% with no motivation Dry seeds in the reduction of water use efficiency of cereal quotient 0.8381 kg M3 as the table itself, that moisture depletion at 90% with Gibberellin has achieved an increase in the efficiency of water use for the quotient with biological efficiency 3.8823 kg. M3 compared to treatment comparison Dry seed at the same level of 90% and an efficiency recorded 3.143 kg M3. Seed priming with Gibberellin and Salicylic acid gave the highest values of water use efficiency. The interaction between depletion levels and seed priming was significant for all studied traits.

Effectiveness of exogenous salicylic acid on root and shoot growth attributes, productivity, and water use efficiency of water-deprived fennel genotypes

This study was carried out to investigate the response of fennel (Foeniculum vulgare Mill.) to water deficit and exogenous application of salicylic acid (SA). Six fennel genotypes, from Iran (namely ‘Urmia’, ‘Hamadan’, ‘Kerman’, ‘Shiraz’, ‘Birjand’ and ‘Yazd’) were subjected to two levels of irrigation consisting of either irrigation after 35% (control) or 75% depletion of available soil water (water deficit) and 3 levels of treatment with SA (0.0, 0.5 and 1.0 mM). Root growth attributes, yield and yield components as well as irrigation water use efficiencies for seed, oil and dry masses of the shoot and whole plant were studied. Shoot dry mass, grain yield and essential oil yield were decreased due to water deficit. Furthermore, root growth attributes were decreased under water deficit, except for root diameter and dry mass, and root/shoot ratio. With the exception of irrigation water use efficiency for seed yield, all irrigation water use efficiency aspects were increased when fennel was subjected to water deprivation. Fennel genotypes were grouped according to their stress susceptibility indices (SSI) into drought-tolerant, moderately drought-tolerant and drought-sensitive groups. The largest drought-induced decreases in root length, root dry mass, root length density, number of fruits per umbel, seed yield, 1000-seed weight, seed essential oil yield, and irrigation water use efficiency for seed and oil yield were observed in genotype ‘Hamadan’ from the drought-sensitive group. Salicylic acid led to increases in root growth and yield attributes, seed essential oil content and yield, and irrigation water use efficiency aspects under both moisture conditions. Overall, foliar application of SA appeared to attenuate the negative effects of drought stress on fennel through increases in most of the root growth and yield attributes and the attenuation was more substantial in the drought-tolerant set of fennel genotypes.

Osmoregulation-mediated differential responses of field-grown fennel genotypes to drought

This study was aimed at examination of physiological and agronomic responses of fennel (Foeniculum vulgare Mill.) to water deficit. Twelve fennel genotypes namely ‘Kashan’, ‘Urmia’, ‘Hamadan’, ‘Kerman’, ‘Shiraz’, ‘Birjand’, ‘Mashhad’, ‘Ardabil’, ‘Bushehr’, ‘Avicenna’, ‘Isfahan’, and ‘Yazd’ were subjected to four levels of irrigation (irrigation after 35%, 55%, 75%, and 85% depletion of available soil water) in a field study in two years. Leaf water potential, relative water content (RWC), proline, total soluble sugars, chlorophyll a (Chl a), b (Chl b), total (Chl a+b), a/b (Chl a/b) along with dry mass (DM), seed yield and its attributes and seed essential oil content were measured. Water deprivation left significant effects on all characteristics, i.e. in contrast to seed essential oil content and harvest index, the rest of the attributes were decreased significantly with drought intensification. Varietal differences in response to drought were meaningful for most of the traits; i.e. genotypic variations for DM, grain yield and stress susceptibility index (SSI) were consistent with differences among the genotypes in physiological traits such as leaf water potential, RWC, proline, soluble sugars and chl content. Genotypes were discriminated according to their response to drought and SSI. Drought tolerant genotypes (‘Yazd’, ‘Kerman, ‘Mashhad’ and ‘Shiraz’) exhibited a greater capacity for accumulation of osmotic solutes associated with higher leaf water potential and RWC, compared to drought sensitive genotypes (‘Ardabil’, ‘Avicenna’, ‘Hamadan’ and ‘Birjand’). From our findings, fennel could be appreciated as a promising species in potentiating alternative industrial-medicinal crops in the face of the eminent challenge of water scarcity in arid and semi-arid climatic regions.

English

Water scarcity is a global concern, as the demand for water is increasing tremendously and poor management of water resources will accelerates dramatically the depletion of available water. The precise prediction of evapotranspiration (ET), that consumes almost 100% of the supplied irrigation water, is one of the goals that should be adopted in order to avoid more squandering of water especially in arid and semiarid regions. The capabilities of feedforward backpropagation neural networks (FFBP) in predicting reference evapotranspiration (ET0) are evaluated in this paper in comparison with the empirical FAO Penman-Monteith (P-M) equation, later a model of FFBP+Genetic Algorithm (GA) is implemented for the same evaluation purpose. The study location is the main station in Iraq, namely Baghdad Station. Records of weather variables from the related meteorological station, including monthly mean records of maximum air temperature (Tmax), minimum air temperature (Tmin), sunshine hours (Rn), relative humidity (Rh) and wind speed (U2), from the related meteorological station are used in the prediction of ET0 values. The performance of both simulation models were evaluated using statistical coefficients such as the root of mean squared error (RMSE), mean absolute error (MAE) and coefficient of determination (R2). The results of both models are promising, however the hybrid model shows higher efficiency in predicting ET0 and could be recommended for modeling of ET0 in arid and semiarid regions.