Irrigation Treatments Research Articles

Water Use Efficiency in a Deficit-Irrigated Orange Orchard

Citrus is a subtropical fruit tree with high water requirements. This study aimed to determine the effects of water deficit on an orange orchard subjected to different water-saving strategies. The study was realised in an orange orchard in a semiarid area by adopting four different water management techniques: 100% crop evapotranspiration (control); SSDI—subsurface sustained deficit irrigation; RDI—regulated deficit irrigation; PRD—partial rootzone drying treatment during five growing seasons. The experimental design foresaw a randomised block design with six replicates per treatment (24 index plants). The results of the study showed that the water-saving strategies reduced irrigation water consumption by 25% (SSDI), 33% (RDI), and 49% (PRD) compared to the fully irrigated treatment without yield reduction, thus increasing water use efficiency. Mineral nutrition of the trees was slightly affected by irrigation treatments; element concentration in leaves was generally in the optimal range; only potassium showed values below the recommended leaf concentrations. Regarding fruit quality parameters, the vitamin C concentration in RDI showed significant differences with a value of 62.7 mg 100 mL−1 compared to 58.5 mg 100 mL−1 in the control. Plants subjected to SSDI and PRD strategies showed increased levels of pulp colour index with significant values of 10 and 9.90, respectively, compared to the control (8.44). By implementing targeted water management, citrus growers could save water and increase the ascorbic acid and sugar concentration in the fruits; anthocyanins also increased but not significantly. These findings open new market opportunities for citrus growers in marginal areas, where they cannot rely solely on producing citrus fruits to remain competitive.

Using spectral vegetation indices and machine learning models for predicting the yield of sugar beet (Beta vulgaris L.) under different irrigation treatments

Yield prediction is essential for production planning, resource management, and competitive advantages. The use of vegetation indices and machine learning for yield prediction is rapid, practical, and accurate and contributes to the development of digital agriculture. Although many studies have been carried out on yield estimation, the number of studies on sugar beet and irrigation applications is limited. To solve this problem, in this study yield prediction of sugar beet under different irrigation treatments was carried out using spectral reflection-based vegetation indices obtained by proximal measurements and developed machine learning models. The multilayer perceptron (MLP), random forest (RF), k-nearest (kNN), bagging (BAG), support vector regression (SVR), gaussian processes (GP), and CustomNet (CN) predictors were used in yield prediction. The irrigation treatments included I100 (application of irrigation to increase the available moisture to field capacity by around 45–50% of the water holding capacity at the root depth), I75 (75% of the water applied in the control group), I50 (50% of the water applied in the control group), and I125 (25% of the water applied in the control group). The combinations of vegetation indices were determined using Pearson correlation and principal component analysis. OSAVI, SAVI, and NDVI had the most significant influence on the yield prediction of sugar beet. Among the combinations used, the kNN1 model (including all attributes as input) showed high R2 values of 0.99 for training and 0.64 for testing. In addition, the kNN3 model (including Treatment, NDVI, NWI, and OSAVI as inputs) had R2 values of 0.97 for training and 0.65 for testing, indicating successful outcomes. However, the MLP1 and SVR1 models had lower results with test R2 values of 0.53 and 0.56, respectively. The results demonstrate the successful application of machine learning and vegetation indices for yield prediction. The proposed approaches could encourage agricultural experts and researchers in future work for yield mapping and identification.

Tomato genotype but not crop water deficit matters for tomato health benefits in diet-induced obesity of C57BL/6JRj male mice

Several studies have linked the intake of lycopene and/or tomato products with improved metabolic health under obesogenic regime. The aim was to evaluate the differential impact of supplementations with several tomato genotypes differing in carotenoid content and subjected to different irrigation levels on obesity-associated disorders in mice. In this study, 80 male C57BL/6JRj mice were assigned into 8 groups to receive: control diet, high fat diet, high fat diet supplemented at 5 % w/w with 4 tomato powders originating from different tomato genotypes cultivated under control irrigation: H1311, M82, IL6-2, IL12-4. Among the 4 genotypes, 2 were also cultivated under deficit irrigation, reducing the irrigation water supply by 50 % from anthesis to fruit harvest. In controlled irrigation treatment, all genotypes significantly improved fasting glycemia and three of them significantly lowered liver lipids content after 12 weeks of supplementation. In addition, IL6-2 genotype, rich in β-carotene, significantly limited animal adiposity, body weight gain and improved glucose homeostasis as highlighted in glucose and insulin tolerance tests. No consistent beneficial or detrimental impact of deficit irrigation to tomato promoting health benefits was found. These findings imply that the choice of tomato genotype can significantly alter the composition of fruit carotenoids and phytochemicals, thereby influencing the anti-obesogenic effects of the fruit. In contrast, deficit irrigation appears to have an overall insignificant impact on enhancing the health benefits of tomato powder in this context, particularly when compared to the genotype-related variations in carotenoid content.

Development and validation of a sunflower crop growth module for the Daisy model

The objective of this study was to develop a crop model for sunflower in Daisy. For this intent, the field experiment data of two full irrigation treatments for 2 years, 2012 and 2013, were used to develop the crop model. The average RMSE of the dry matter (DM), leaf area index (LAI), height of plant (H), and water content parameters in the treatments utilized for calibration was calculated 0.093 Ton/ha, 0.198 cm2/cm2, 2.25 cm, and 1.035%, respectively. The average RMSE of the parameters of DM, LAI, H, and water content in the treatments utilized for validation were estimated 0.207 Ton/ha, 0.272 cm2/cm2, 4.22 cm, and 1.123%, respectively. The results of the validation showed that the developed crop model had good accuracy making it useful for simulation of sunflower agroecology. It is suggested to use the developed crop model in the information library of Daisy and survey and calibrate it for other areas with different climates and sunflower varieties.

Effects of Wind Exposure and Deficit Irrigation on Vegetative Growth, Yield Components and Berry Composition of Malbec and Cabernet Sauvignon.

The impact of global warming on Argentine viticulture may result in a geographical shift, with wine-growing regions potentially moving towards the southwest, known as one of the windiest regions in the world. Deficit irrigation is a widely used strategy to control the shoot growth and improve fruit quality attributes, such as berry skin polyphenols. The present study aimed to assess the effects of different wind intensities and irrigation levels, as well as their interactions, on field-grown Vitis vinifera L. cvs. Malbec and Cabernet Sauvignon. The experiment was conducted during two growing seasons with two wind treatments (sheltered and exposed) and two irrigation treatments (well-watered and moderate deficit irrigation) in a multifactorial design. Vegetative growth, stomatal conductance, shoot biomass partition, fruit yield components and berry skin phenolics were evaluated. Our study found that, generally, wind exposure reduced vegetative growth, and deficit irrigation increased the proportion of smaller berries within the bunches. Meanwhile, deficit irrigation and wind exposure additively increased the concentration of berry skin phenolics. Combined stressful conditions enhance biomass partition across the shoot to fruits in Malbec, increasing the weight of bunches and the number of berries. Our findings offer practical implications for vineyard managers in windy regions, providing actionable insights to optimize grapevine cultivation and enhance wine quality.

The Impact of Deficit Irrigation on the Agronomic Performance and Chemical Composition of Scolymus hispanicus L.

In the current study, the effects of drought stress on the growth and phytochemical profile of Scolymus hispanicus L. (a.k.a. golden thistle) were evaluated. Plants were treated with three irrigation regimes, e.g., plants that received only rainwater (Control; C), deficit irrigation (I1; 50% of field capacity (FC)), and full irrigation (Ι2; 100% of FC). The fresh weight of the rosette of leaves was not negatively impacted by deficit irrigation, whereas root development was severely restrained compared to control and I2 treatments. Drought stress conditions had a positive effect on the nutritional properties of the golden thistle since the treatments of control and deficit irrigation showed the highest content of macronutrients and energy. Oxalic acid was the richest organic acid, especially under the I1 regime. Similarly, α-tocopherol was the only identified vitamin E isoform, whose content was also doubled in I1 treatment. Raffinose, glucose, and sucrose were the most abundant free sugars in amounts that varied among the irrigation treatments, while the total and distinct free sugar content was the highest for the I1 treatment. The most abundant detected fatty acid compounds were α-linolenic acid, followed by palmitic and linoleic acid, with the highest amount being detected in C, I1, and I2 treatments, respectively. Flavonoids were the only class of polyphenols detected in golden thistle leaves, including mostly kaempferol and quercetin derivatives. The greatest antioxidant potency was shown for the control and I1 treatments (for OxHLIA and TBARS methods, respectively). The evaluated leaf samples recorded a varied antimicrobial effect for the different bacterial strains and fungi, whereas no cytotoxic, hepatotoxic, and anti-inflammatory effects against the tested cell lines were recorded. Finally, the mineral content of leaves was significantly affected by the irrigation regime, with Ca, Mg, Cu, and Zn being the highest for the I1 treatment, while the I2 treatment had the highest content of K, Fe, and Mn and the lowest Na content. In conclusion, deficit irrigation showed promising results since it improved the phytochemical content without compromising the fresh weight of leaves, and thus it could be suggested as a sustainable agronomic practice for producing high-added value products without significant constraints in growth development and yield parameters of golden thistle.

Effects of Vancomycin/Tobramycin-Doped Ceramic Composite (Polyvinyl Alcohol Composite–Vancomycin/Tobramycin–Polymeric Dicalcium Phosphate Dihydrate) in a Rat Femur Model Implanted With Contaminated Porous Titanium Cylinders

BackgroundPeriprosthetic joint infection (PJI) remains common and problematic. We hypothesized that using a bioceramic that provided rapid release of the antibiotics (vancomycin [VAN] or VAN and tobramycin [VAN and TOB]) from a polyvinyl-alcohol-composite (PVA) combined with a delayed and sustained antibiotic release from polymeric-dicalcium-phosphate-dihydrate (PDCPD) ceramic would inhibit S. aureus-associated implant infections. MethodsA total of 50 male Sprague Dawley rats were randomly divided into 5 groups—I: negative control; II: bacteria only; III: bacteria + saline wash; IV: bacteria + PVA-VAN-PDCPD, and V: bacteria + PVA-VAN-TOB-PDCPD. A porous titanium (Ti) implant was press-fit into the rat knee. S. aureus-containing broth was added into the joint space creating a PJI. After 1 week, the joints from groups III to V were washed with saline and the fluid collected for bacterial quantification. This was followed by saline irrigation treatment (groups III to V) and application of the antibiotic-loaded PVA-PDCPD bioceramic (groups IV and V). On day 21, joint fluid was collected, and the implants harvested for bacterial quantification. ResultsNo bacteria were isolated from the negative control (group I). The positive control (group II) was positive on both days 7 and 21. Bacteria were still present on day 21 in the fluid and implant in group III. Groups (IV and V) showed a decrease in the bacterial burden in the fluid and implant on day 21. There were significant differences in bacteria levels in the collected wash fluid and on the implant at day 21 between the saline wash (group III) and treatment groups (IV and V). ConclusionsIn this animal model of acute periprosthetic infection, treatment with PVA-VAN-PDCPD and PVA-VAN/TOB-PDCPD reduced bacterial load in the infected joint and the infected Ti implant. Application of PVA-VAN-PDCPD and/or PVA-VAN/TOB-PDCPD after saline irrigation could be used as an addition to the treatment of PJI.

Response of grain amaranth (Amaranthus hypochondriacus) to irrigation schedules under sprinkler irrigation

A field experiment was conducted during winter (rabi) seasons of 2019–20 and 2020–21 at the Centre for Crop Improvement, Sardarkrushinagar Dantiwada Agricultural University, Banaskantha, Gujarat to study the response of grain amaranth (Amaranthus hypochondriacs L.) to irrigation schedules under sprinkler irrigation system. The experiment was conducted in a randomised block design (RBD) comprised of 6 irrigation treatments, viz. I0 , Surface irrigation; I1 , Control (only pre-sowing irrigation); I2 , Sprinkler irrigation at 0.2 IW: CPE; I3 , Sprinkler irrigation at 0.4 IW: CPE; I4 ,Sprinkler irrigation at 0.6 IW: CPE; and I5 ,Sprinkler irrigation at 0.8 IW:CPE with 4 replications. The results revealed that application of irrigation at IW: CPE ratio of 0.8 had significant effect on plant height, inflorescence length (83.4 cm), grain yield (1,625 kg/ha) and straw yield (7,497 kg/ha) compared with control treatment (surface irrigation). Treatment 0.8 IW: CPE resulted in the 28.15% higher grain yield than the control. The highest water-use efficiency (WUE) (12.8 kg/ha-mm) was achieved by the treatment I1 (only pre-sowing irrigation). Consumptive use (mm) was found increased with increase in irrigation scheduling from I0 to I5 . The highest consumptive use of 179.3 mm was recorded under the treatment of 0.8 IW: CPE ratio. Irrigation at 0.8 IW: CPE ratio fetched highest net returns of `54,701/ha, with benefit: cost (B:C) ratio 3.06 during both the years in pooled analysis.

Impact of different irrigation & trace metals treatments on onion (Allium cepa L.) plant growth cultivated in rural and urban soils

AbstractThe present research attempts to evaluate the response of Allium cepa L. to different irrigation treatments and to indicate the optimum scheme along with plant growth, throughout a pot experiment during Spring 2021. The experimental procedure consisted of two different soil types, three treatments of irrigation and two levels of Cu and Zn (low and high), in four replications each. Irrigation events started when the lower allowable limit (LAL) reached a defined percentage of filed capacity (FC): 40% FC, 60% FC, and 75% FC and an irrigation event occurred with irrigation doses (Dn) equal to 60% FC, 40% FC, and 25% FC, respectively, to reach the value of FC. According to the results, the minimum yield was achieved by both soil types when Cu and Zn solution concentration and water stress were at their highest levels, although light texture soil (loamy sand—LS) allowed for superior growth. The optimum scheme was: the lower concentration of Cu and Zn solution along with LAL equal to 60% FC at the loamy sand soil. The outcomes suggest that frequent short irrigation doses at light-texture soils can result in yield response indicators when planted in pots. Furthermore, the influence of Cu and Zn cations at low concentrations can be advantageous for onions because Cu cations provide protection against fungal diseases, while Zn cations serve as nutrient support reducing the risk of metals deficiency.

Evaluating the precise grapevine water stress detection using unmanned aerial vehicles and evapotranspiration-based metrics

AbstractPrecise irrigation management requires accurate knowledge of crop water demand to adequately optimize water use efficiency, especially relevant in arid and semi-arid regions. While unoccupied aerial vehicles (UAV) have shown great promise to improve the water management for crops such as vineyards, there still remains large uncertainties to accurately quantify vegetation water requirements, especially through physically-based methods. Notably, thermal remote sensing has been shown to be a promising tool to evaluate water stress at different scales, most commonly through the Crop Water Stress Index (CWSI). This work aimed to evaluate the potential of a UAV payload to estimate evapotranspiration (ET) and alternative ET-based crop water stress indices to better monitor and detect irrigation requirements in vineyards. As a case study, three irrigation treatments within a vineyard were implemented to impose weekly crop coefficient (Kc) of 0.2 (extreme deficit irrigation), 0.4 (typical deficit irrigation) and 0.8 (over-irrigated) of reference ET. Both the original Priestley-Taylor initialized two-source energy balance model (TSEB-PT) and the dual temperature TSEB (TSEB-2T), which takes advantage of high-resolution imagery to discriminate canopy and soil temperatures, were implemented to estimate ET. In a first step, both ET models were evaluated at the footprint level using an eddy covariance (EC) tower, with modelled fluxes comparing well against the EC measurements. Secondly, in-situ physiological measurements at vine level, such as stomatal conductance (gst), leaf (Ψleaf) and stem (Ψstem) water potential, were collected simultaneously to UAV overpasses as plant proxies of water stress. Different variants of the CWSI and alternative metrics that take advantage of the partitioned ET from TSEB, such as Crop Transpiration Stress Index (CTSI) and the Crop Stomatal Stress Index (CSSI), were also evaluated to test their statistical relationship against these in-situ physiological indicators using the Spearman correlation coefficient (ρ). Both TSEB-PT and TSEB-2T CWSI related similarly to in-situ measurements (Ψleaf: ρ ~ 0.4; Ψstem: ρ ~ 0.55). On the other hand, stress indicators using canopy fluxes (i.e. CTSI and CSSI) were much more effective when using TSEB-2 T (Ψleaf: ρ = 0.45; Ψstem: ρ = 0.62) compared to TSEB-PT (Ψleaf: ρ = 0.18; Ψstem: ρ = 0.49), revealing important differences in the ET partitioning between model variants. These results demonstrate the utility of physically-based models to estimate ET and partitioned canopy fluxes, which can enhance the detection of vine water stress and quantitatively assess vine water demand to better manage irrigation practices.

Analysis of Microbial Diversity in Rhizosphere Soil of Panax notoginseng under Different Water and Microbial Fertilizer Conditions

Panax notoginseng is a highly regarded medicinal plant that has obstacles associated with continuous cropping. Understanding soil microorganisms is crucial, as they play a major role in this regard. However, soil microorganisms are affected by multiple factors; therefore, we need to conduct more in-depth research. This study investigated the combined effects of irrigation and microbial fertilizer treatments (J1F1, J1F2, J2F1, J2F2, J3F1, J3F2, and CK) on the diversity of bacterial and fungal microbial communities in the rhizosphere of Panax notoginseng. The bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) sequences were sequenced using Illumina HiSeq. The results showed that, without microbial fertilizer (CK), the microbial community abundance and diversity were significantly lower than in the other treatments; moreover, among the microbial fertilizer treatments, the microbial abundance in F1 was higher than that in F2. Under the same microbial fertilizer application, the incidence rate of Panax notoginseng root rot was J2 > J1 > J3, and the yield of Panax notoginseng was J3 > J2 > J1. Under the same irrigation conditions, the incidence rate of Panax notoginseng root rot was F1 > F2, and the yield of Panax notoginseng was F2 > F1. This study provides important guidance for Panax notoginseng plant microbiota and sustainable agriculture.

Improving prediction accuracy of CSM-CERES-Wheat model for water and nitrogen response using a modified Penman-Monteith equation in a semi-arid region

Context or problemThe implementation of crop models for water and nitrogen management are important in preserving water resources and reducing groundwater pollution. The Decision Support System for Agrotechnology Transfer (DSSAT) is a collection of field-scale process-based crop models that simulate crop growth and yield in response to water and nitrogen management as well as many other factors. Objective or research questionThe objective of this study was to improve the simulation of irrigation and nitrogen fertilizer effects on growth and yield of winter wheat using locally modified Penman-Monteith (PM) equation. Specifically, we focused on improving the estimation of ETo using a locally modified Penman-Monteith (PM) equation in the CSM-CERES-Wheat model. MethodsField measured data from a two-year experiment (2009–2010 and 2010–2011) in a semi-arid region were used to calibrate and evaluate the CSM-CERES-Wheat model in a region with strong advective condition. In this experiment, the irrigation treatments were 1.2, 1.0, 0.8, 0.5 times by full irrigation requirements and rain-fed, and nitrogen treatments were 0, 46, 92, and 136 kg N ha−1. ResultsUsing the CSM-CERES-Wheat model with the unmodified PM equation resulted in some growth variables such as: aboveground dry matter, grain yield, and grain nitrogen uptake with high normalized root mean square error (NRMSE) of 0.51, 0.35, and 0.32, respectively. However, using the modified PM equation for ETo module under semi-arid condition improved the soil water content estimation and the model outputs, such as the above ground dry matter, grain yield and grain nitrogen uptake with NRMSE of 0.2, 0.15 and 0.16, respectively, that are accurate. This modification provided more accurate estimations, particularly in our experimental site in semi-aid region with strong advective conditions. ConclusionsThe findings of this study indicated that the locally modified PM equation in the CSM-CERES-Wheat model enhanced the accuracy of estimating irrigation and nitrogen fertilizer on the growth and yield of winter wheat. By improving the estimation of ETo value, the model's performance in simulating crop responses to water and nitrogen management was significantly enhanced. Implications or significanceThe utilization of the accurately estimated ETo value of the modified PM equation has significant importance in the practical application of the CSM-CERES-Wheat model. Furthermore, this modification greatly enhances the accuracy of model outputs, particularly at our experimental site located in a semi-arid region with robust advective conditions.

Production of Moringa variety PKM-1’s seed and oil in the Subhumid Chaco, Santa Cruz, Bolivia

Moringa oleifera Lam. (M. pterygosperma Gaertn.) is native to northwestern India. The goal was to study its adaptation to commercial cropping for seed and oil in the Bolivian Sub-humid Chaco. During the first six months of the trial, twenty rows of 61.5 m long placed 4 m apart were planted with Moringa. Irrigation was applied to half of them chosen at random. The seeds collected in periods I and II in the first year showed that the treatment with irrigation produced a significantly (P < 0.05) greater amount of seed in both cases, compared to the treatment without irrigation. This production meant 300 % and 213 % more for the first and second harvest respectively, and 211 % for the total of irrigated treatments. The oil content was 35.9 % and 35 % for the first and second year of the trial, which means 100 and 196 kg of oil/ha/year for the first and second year, respectively.

Influence of crop rotation, irrigation, fertilization, and tillage on the aggregate property and soil wind erosion potential in the floodplain of the Yellow River

The floodplain of the Yellow River (FPYR) is threatened by severe soil erosion. Soils are often susceptible to wind erosion owing to their coarse-textures and weak aggregation, yet studies are yet to describe the ability of soils to resist wind erosion in this region. Accordingly, this study aimed to quantify how soil wind erosion potential is affected by soil aggregate properties, such as dry aggregate geometric mean diameter (GMD), aggregate geometric standard deviation (GSD), aggregate stability, and soil bulk density, and to assess the effects of soil type, crop rotation, irrigation, fertilization, and tillage treatments on these aggregate properties in the main wind erosion area across the FPYR. Significant differences in GMD and aggregate stability were found between crop rotation treatments, whereas crop rotation marginally affected the soil bulk density. Further, the impact of management practices on aggregate properties differed for each soil type. The soil aggregate erodible fraction (EF) in the FPYR ranged from 1.14 to 82.73% across sites, with a mean of 26.14% across soil types and management practices, which was lower than that previously reported in other wind erosion regions. We incorporated these measured EFs into the Revised Wind Erosion Equation (RWEQ) to evaluate the wind erosion risk of the FPYR. The results indicated that the central FPYR was more susceptible to wind erosion than the other regions, although the total wind erosion potential in the FPYR was small. Adoption of soil conservation practices could help minimize wind erosion and improve atmospheric quality in the region.

Enhancing drought tolerance in Indian mustard (Brassica juncea) through microbial inoculants under varying irrigation regimes

A field experiment was conducted during the winter (rabi) seasons of 2020–21, 2021–22 and 2022–23 at College of Agriculture, Sri Karan Narendra Agriculture University, Jobner, Rajasthan to identify the appropriate bacterial strains and irrigation levels to enhance drought tolerance and productivity in Indian mustard [Brassica juncea (L.) Czern.]. The experiment was laid out in a split plot design assigning irrigation treatments (no irrigation, 50% deficit irrigation and normal level of irrigation) in main plots and microbes (MRD-17, MKS-6, Biophos and Biophos+, CRIDAMI-I, CRIDA MI-II and control) in sub plots. Results demonstrated that normal level of irrigation (2 irrigations) yielded superior outcomes in terms of plant height, dry matter accumulation, yield attributes, viz. seed yield (1542 kg/ha), stover yield (3677 kg/ha), relative water content (70.72%), protein content (18.1%), oil content (38.7%), water use efficiency (7.50 kg/ha-mm), net returns (₹52529/ha) and B:C ratio (2.07). This was significantly higher compared to 50% deficit irrigation and no irrigation treatments. Among microbial inoculants, CRIDA MI-II exhibited the highest impact on growth and yield attributes, viz. seed yield (1312 kg/ha), stover yield (3262 kg/ha), protein content (17.2%), water use efficiency (5.88 kg/ha-mm), net returns (₹42294/ha) and B:C ratio (1.72). Notably, it was statistically comparable to the effects of CRIDA MI-I and Biophos and Biophos+ across most parameters. The comprehensive results of this study advocated the strategic implementation of both optimal irrigation practices and microbial inoculants as a sustainable approach to enhance productivity and drought tolerance in Indian mustard, particularly in the arid and semi-arid regions of Rajasthan.

Enhancing drought tolerance in Indian mustard (Brassica juncea) through microbial inoculants under varying irrigation regimes

A field experiment was conducted during the winter (rabi) seasons of 2020–21, 2021–22 and 2022–23 at College of Agriculture, Sri Karan Narendra Agriculture University, Jobner, Rajasthan to identify the appropriate bacterial strains and irrigation levels to enhance drought tolerance and productivity in Indian mustard [Brassica juncea (L.) Czern.]. The experiment was laid out in a split plot design assigning irrigation treatments (no irrigation, 50% deficit irrigation and normal level of irrigation) in main plots and microbes (MRD-17, MKS-6, Biophos and Biophos+, CRIDAMI-I, CRIDA MI-II and control) in sub plots. Results demonstrated that normal level of irrigation (2 irrigations) yielded superior outcomes in terms of plant height, dry matter accumulation, yield attributes, viz. seed yield (1542 kg/ha), stover yield (3677 kg/ha), relative water content (70.72%), protein content (18.1%), oil content (38.7%), water use efficiency (7.50 kg/ha-mm), net returns (₹52529/ha) and B:C ratio (2.07). This was significantly higher compared to 50% deficit irrigation and no irrigation treatments. Among microbial inoculants, CRIDA MI-II exhibited the highest impact on growth and yield attributes, viz. seed yield (1312 kg/ha), stover yield (3262 kg/ha), protein content (17.2%), water use efficiency (5.88 kg/ha-mm), net returns (₹42294/ha) and B:C ratio (1.72). Notably, it was statistically comparable to the effects of CRIDA MI-I and Biophos and Biophos+ across most parameters. The comprehensive results of this study advocated the strategic implementation of both optimal irrigation practices and microbial inoculants as a sustainable approach to enhance productivity and drought tolerance in Indian mustard, particularly in the arid and semi-arid regions of Rajasthan.

Exogenous Application of Gamma Aminobutyric Acid Improves the Morpho-Physiological and Biochemical Attributes in Lavandula dentata L. under Salinity Stress

Saline water has been proposed as a solution to partially supply plants with their water requirements due to a lack of fresh water for cultivation in arid and semi-arid sites. Gamma-aminobutyric acid (GABA) is a non-protein amino acid participating in numerous metabolic processes to mitigate the undesirable effects of salinity. A pot experiment was carried out during 2021 and 2022 at Sakha Horticulture Research Station to investigate the effect of foliar application of GABA at 20 and 40 mM on vegetative growth and biochemical changes in French lavender under increasing levels of sea water salinity irrigation treatments (0, 1000, 2000, and 3000 ppm). Results indicated that increasing salinity concentration noticeably decreased plant height, number of branches, herb fresh and dry weight, root length, root fresh and dry weights, photosynthetic pigments, relative water content, and essential oil percentage. On the other hand, accumulation of proline and antioxidant enzymes was increased under increasing salinity concentrations. We conclude that foliar application of GABA acid at 40 mM can alleviate the adverse effects of salinity on the abovementioned French lavender plant characteristics by improving vegetative growth and root characteristics, as well as diminishing chlorophyll degradation, maintaining high leaf relative water content, increasing proline accumulation and antioxidant activity.

Effects of Selenium on the Lignin Deposition Pattern and Stem Mechanical Properties of Alfalfa (Medicago sativa L.).

Lignin provides structural support to plants; however, it reduces their utilization rate. According to our previous studies, selenium (Se) reduces lignin accumulation in alfalfa, but the specific mechanism involved remains unclear. Therefore, at the seedling stage, four root irrigation treatments using 2.5, 50, and 5 μmol/L sodium selenite (S-RI), selenomethionine (SS-RI), Se nanoparticles (SSS-RI), and deionized water (CK-RI) were performed. At the branching stage, four treatments of foliar spraying with the three Se fertilizers described above at a concentration of 0.5 mmol/L (S-FS, SS-FS, and SSS-FS) and deionized water (CK-FS) were administered. The results revealed that all Se treatments chiefly reduced the level of deposition of syringyl (S) lignin in the first internode of alfalfa stems. SS-FS and SSS-FS treatments mainly reduced the deposition of S and guaiacyl (G) lignins in the sixth internode of alfalfa stems, respectively, while S-FS treatment only slightly reduced the deposition of G lignin. S, SS, and SSS-RI treatments reduced the level of deposition of S and G lignins in the sixth internode of alfalfa stems. Se application increased plant height, stem diameter, epidermis (cortex) thickness, primary xylem vessel number (diameter), and pith diameter of alfalfa but decreased primary xylem area and pith parenchyma cell wall thickness of the first internode, and SS(SSS)-FS treatment reduced the mechanical strength of alfalfa stems. Therefore, Se application could decrease lignin accumulation by regulating the organizational structure parameters of alfalfa stems and the deposition pattern of the lignin monomers.

Water Use Strategies and Shoot and Root Traits of High-Yielding Winter Wheat Cultivars under Different Water Supply Conditions

Drought is the most important factor limiting winter wheat yield in the North China Plain (NCP). Choosing high-yielding cultivars is an important measure to minimize the negative effects of drought stress. Field studies were conducted with 10 cultivars in the 2020–2022 seasons under three irrigation treatments (I0, without irrigation; I1, irrigated at jointing stage; I2, irrigated at jointing and anthesis stages) in the NCP to examine the water use strategies and root and shoot traits of high-yielding cultivars under different water supply conditions. The results showed that yield variation among cultivars was 21.2–24.6%, 23.7–25.9% and 11.6–15.3% for the I0, I1 and I2 treatments, respectively. Under water deficit conditions (I0 and I1), high-yielding cultivars reduced water use during vegetative stages and increased soil water use during reproductive stages, especially water use from deeper soil layers. Those cultivars with higher root length density (RLD) in deep soil layers exhibited higher water uptake. Each additional millimeter of water used after anthesis from the 100–200 cm soil layers increased grain yield by 23.6–29.6 kg/ha and 16.4–28.5 kg/ha under I0 and I1, respectively. This water use strategy enhanced dry matter accumulation after anthesis, decreased canopy temperature (CT) and increased relative leaf water contents (RLWC), which ultimately improved grain yield. For winter wheat grown under I2, cultivars that decreased water use after anthesis had higher water productivity (WP). Root length (RL), root weight (RW) and root:shoot ratio were each negatively correlated with grain yield, while above-ground biomass was positively correlated with grain yield. Therefore, higher dry matter accumulation and smaller root systems are two important traits of high-yielding cultivars under sufficient water supply conditions (I2) in the NCP.

Effect of Irrigation Cuttings at Different Growth Stages and Spraying with Citrullus Colocynthis Extract on the Leaf Water Balance of two Cultivars of Zea Mays L.

A study in the real world with a Randomised Complete Block Design (R.C.B.D.) utilising a split-split diagrams layout with three separate replicates was carried out at the research facility of the college's water resources and soil sciences department at the Agriculture faculty / University of Diyala in the autumn season 2022. The experiment included three stages of cutting off irrigation: male flowering, milky stage, and three concentration levels of Citrullus Colocoynthis extract. Two cultivars of Zea mays L. were used: AGN720 and JAMESON. The concentration levels were 50 ml L-1 and 100 ml L-1, respectively, and two cultivars were used: AGN720 and JAMESON Citrullus Colocoynthis extract has an anti-transpiration effect on the water balance of leaves and water use efficacy of Zea mays L. grown under water stress conditions. The most important results are as follows: the AGN720 variety recorded the best water use efficiency, with an increase of 9.04% compared to the JAMESON variety. Spraying the extract of Citrullus Colocoynthis as anti-transpiration at a concentrate level of 100 ml L-1 increased the capability of water retention, relative water content, and water use efficiency. The irrigation cut-off treatment in the milky phase stage had the best water use efficiency, saving 2.559 kg of grain m-3 water compared to the no-cut irrigation treatment.