Irrigation Treatments Research Articles

Comparison of the AquaCrop and CERES‐Maize models for simulating maize phenology, grain yield, evapotranspiration and water productivity under different irrigation and nitrogen levels

AbstractThe CERES‐Maize and AquaCrop models were evaluated for their performance in simulating maize (Zea mays L.) phenology, evapotranspiration (ETc), grain yield and crop water productivity (CWP). Model input data for calibration, validation and simulations were obtained from field experiments conducted from 2011 to 2014 that imposed three different irrigation levels (full irrigation treatment [FIT], limited irrigation treatment [75% FIT] and rainfed control) and five nitrogen (N) management treatments. Both models performed well in simulating the maize phenological stages, with simulated values being within 1–4 days of measured values for both models. Both models simulated grain yield well during the calibration with a normalized root mean squared error (RMSEn) of 5% (0.6 t ha⁻1) for CERES‐Maize and 8% (0.80 t ha⁻1) for AquaCrop. The model error for ETc varied from −2 to +14% for CERES‐Maize and ranged from −3 to +11% for AquaCrop. High N levels resulted in higher accuracy in predicting ETc. The AquaCrop model performed better than CERES‐Maize in simulating irrigated crop production under different N levels under rainfed conditions. The performance of both models for rainfed systems was poorer than their performance in irrigated systems, indicating that both models need further improvements in simulating rainfed maize production systems.

Wick irrigation improves seed yield and water use efficiency in mung bean

AbstractDrought is a serious threat to crop growth, and finding new irrigation methods can save water. This study was conducted to investigate water use efficiency and seed yield in mung bean under wick irrigation. Irrigation treatments consisted of the wick irrigation method, surface irrigation (common irrigation) with water equivalent to wick irrigation, and surface irrigation with the double water use of wick irrigation. The results showed that the wick irrigation had a seed weight per plant, 100‐seed weight, seed number per pod, pod number per plant, seed yield, biological yield, water use efficiency of seed, water use efficiency of biomass and net income increase of 164, 14, 28, 80, 164, 128, 164, 128 and 300%, respectively, compared to surface irrigation with an equivalent water volume of wick irrigation. Wick irrigation resulted in increases in plant height, internode length, leaf number per plant, node number per plant, branch number per plant, leaf length and leaf width of 60, 59, 65, 91, 91, 52 and 52%, respectively, compared to surface irrigation with an equivalent water volume of wick irrigation. In conclusion, the wick irrigation method, as a new method, can save water and improve seed yield and net income.

Knowledge level of pomegranate growers about recommended pomegranate production technologies of UAS Dharwad

The present study was conducted with specific objective to study the knowledge level of pomegranate growers about recommended pomegranate production technologies in Vijayapura and Bagalkot districts of Karnataka, respectively. Total of 8 villages were selected for the study and 15 pomegranate growing farmers from each village were randomly selected to constitute a total sample of 120 farmers. It was noticed that almost two fifth (39.17 %) of the pomegranate farmers belonged to medium knowledge level category, 32.50 per cent of them belonged to low knowledge level category and 28.33 per cent of them belonged to high knowledge level category, respectively. Cent per cent of the pomegranate growers had knowledge about the varieties, planting material, spacing, time of planting, frequency of pruning and mode of irrigation. Large majority of them had knowledge about chemicals to control pests (90.00%), size of the pit (85.00 %), chemicals to control diseases (80.00 %) and diseases of pomegranate (78.33 %). Majority of them had knowledge about the type of soil (71.67%), frequency of fertilizer application (66.67%) and pests of pomegranate (60.00 %). More than half (59.17 %) of them had knowledge about the frequency of irrigation and Bahar treatment (55.83 %). About 45.83 per cent of them had knowledge about the pit filling process with FYM, 43.33 per cent of them had knowledge about the growth regulators used, 41.67 per cent of them had knowledge about the proportion of NPK application per tree and 39.17 per cent of them had knowledge about the rest period given during Bahar treatment. Equal percentage of them (33.33 %) had knowledge about types of Bahar treatments and average yield per tree. About 30.83 per cent of knew about the quantity of FYM application and 23.33 per cent knew about intercropping in pomegranate and 19.16 per cent of them knew about the weedicides.

Performance of hydrogel and salicylic acid on productivity and economics of yellow sarson (Brassica rapa) in new alluvial zone

A field experiment was conducted under new alluvial zone to evaluate the performance of hydrogel and salicylic acid for increasing the productivity of Indian mustard in restricted irrigation condition. The experiment consisting of ten treatment combinations, viz., hydrogel @ 2.5 kg/ha, hydrogel @ 5 kg/ha, salicylic acid (SA) @ 100 ppm at flowering and siliqua formation, SA @ 200 ppm at flowering and siliqua formation, two irrigations at pre-flowering and siliqua development stage, hydrogel @ 2.5 kg/ha + SA @ 100 ppm at flowering and siliqua formation, hydrogel @ 2.5 kg/ha + SA @ 200 ppm at flowering and siliqua formation, hydrogel@ 5 kg/ha + SA @100 ppm at flowering and siliqua formation, hydrogel @ 5 kg/ha + SA @ 200 ppm at flowering and siliqua formation and control, was laid out in randomized block design with three replications. Among treatment combinations, application of hydrogel @ 5 kg/ha with two sprays of salicylic acid either 100 or 200 ppm at flowering and siliqua formation stage significantly increased various yield-attributing parameter. More seed yield obtained with two irrigation at pre-flowering and siliqua formation (1838 kg/ha) stage and showed parity with hydrogel @ 5.0 kg/ha + salicylic acid @100 ppm (1794 kg/ha) and hydrogel @2.5 kg/ha + salicylic acid @ 200 ppm (1719 kg/ha) and statistically superior to all other treatments. These treatments registered 128.6, 123.5and 113.2%, respectively, more grain yield over the control plot. Increased stover production was observed with hydrogel @2.5 kg/ha + salicylic acid @ 200 ppm and was closely followed by hydrogel @5.0 kg/ha + salicylic acid @ 200 ppm and hydrogel @2.5 kg/ha + salicylic acid @100 ppm. Furthermore, significant and highest improvement in growth, yield attributes, and economics was recorded under irrigation treatment applied at pre-flowering and siliqua formation stage over control and alone application of hydrogel and SA. Thus, the result showed that application of hydrogel either 2.5 or 5 kg/ha with two sprays of SA 100 ppm at flowering and siliqua formation was found beneficial for obtaining high seed yield as well as net returns. Application of hydrogel @ 2.5 kg/ha + salicylic acid 100 ppm at flowering stage and siliqua formation stage with maximum average benefit: cost ratio (2.66) may be recommended for mitigation of moisture stress in rainfed situations for obtaining higher crop yield in new alluvial region

Precision agricultural technology for advanced monitoring of maize yield under different fertilization and irrigation regimes: A case study in Eastern Hungary (Debrecen)

Precision agricultural (PrA) technology relies on the utilization of special equipment to access real time observations on plant health status, chlorophyll, nitrogen content, and soil moisture content. In this research new PrA technology (i.e., SPAD (Soil Plant Analysis Development), and UAV-based NDVI (Unmanned Aerial Vehicle-based Normalized Difference Vegetation Index) were used to monitor maize yield based on different filed trials in eastern part of Hungary. Our study aimed to examine the utilization of PrA technology specifically SPAD and UAV-based NDVI measurements for monitoring maize GY under irrigated and rainfed experimental setups in Hungary with varied nitrogen treatment for the year 2022. The results showed that the SPAD increased in all treatments (14.7 %; p < 0.05) from V6–V8 in the rainfed treatments, decreased significantly (p < 0.05) by 13.9 % (R1) and 30.6 % (R3). However, implementation of irrigation significantly increased the SPAD values in majority of treatments. Also, results reveal that, under irrigated and rainfed conditions the highest UAV-based NDVI value (0.703, 0.642) was obtained in V12 (A120 treatment) and highest NDVI value (0.728, 0.662) was obtained in Vn (A120 treatment). Remarekedly, irrigation led to significant differences (p < 0.05) of UAV-based NDVI values compared with none irrigated. On the other hand, implementation of 120 kg N ha−1 before sowing led to highest GY, especially under irrigated conditions (8.649 Mg ha−1). The overall mean GY under rainfed treatment was 6.256 Mg ha−1, while under irrigated treatment it increased by 37.2 % and reached 8.581 Mg ha−1 (p < 0.05). In conclusion, PrA technology will support farmers in making informed decisions regarding fertilization strategies and timing, which will in turn maximize yield and minimize risk.

Effects of saline-fresh water rotation irrigation on photosynthetic characteristics and leaf ultrastructure of tomato plants in a greenhouse

To reveal the mechanisms of saline-fresh water rotation irrigation that affect the leaf ultrastructure and photosynthetic characteristics of tomato plants and to optimize the strategy of saline water irrigation of greenhouse tomatoes, a two-season tomato experiment with four treatments of saline-fresh water rotation irrigation was conducted in a greenhouse in southern Xinjiang. The four treatments consisted of rotation irrigation with four times saline-fresh water (W1), rotation irrigation with two times saline water and two times fresh water (W2), rotation irrigation with two times fresh water, four times saline water, and two times fresh water (W3), and freshwater irrigation as a control (CK). The three rotation patterns had the same amount of saline water and fresh water, but the rotational interval was different. The results indicated that the saline-alkali stress introduced by saline water significantly reduced the gas exchange parameters of tomato leaves and water use efficiency at the leaf scale, and both stomatal and non-stomatal factors played a key role in limiting leaf gas exchange. The chloroplast granular lamellae structure was disrupted in tomato leaves treated with W1 and W2. Compared with CK, W1 and W2 decreased leaf chlorophyll content by 4.59% and 10.89%, net photosynthetic rate by 26.82% and 40.11%, and yield by 60.62% and 67.63%, respectively. In contrast, W3 presented a relatively intact mesophyll cell structure and relatively high chlorophyll content and photosynthetic efficiency. In W3 treatment, no significant differences were found in the number of fruits per plant (only increased by 8.16% and the yield by 4.03%), while with better quality compared with CK. The results suggested that tomato growth and yield were neither poor nor detrimental when rotated with saline water during the flowering and fruiting stage-fruit expansion stage and freshwater irrigation during other growth stages. W3 can be used as a saline-fresh water rotation pattern for tomato production in greenhouses in arid and saline areas.

Effect of salinity and drip fertigation on maize (&lt;i&gt;Zea mays&lt;/i&gt;) and water use efficiency

Climatic variability is immensely pressurised on freshwater availability in arid and semi-arid ecosystems, leading to poor quality water for crop production not becoming uncommon, especially in coastal ecosystems. A field experiment was conducted during winter (rabi) season of 2022–23 at the Saline Water Scheme at Agricultural College Farm, Acharya N. G. Ranga Agricultural University, Bapatla, Andhra Pradesh to assess the impact of saline water on maize growth, yield and water use efficiency under drip fertigation. The experiment consisted 8 treatments laid in randomized block design (RBD) with 4 replications. The utilization of the BAW irrigation method, together with the application of a prescribed quantity of fertilizer, resulted in the highest plant height and dry matter accumulation during all phases of crop growth. These outcomes were comparable to those achieved by using a combination of fresh water and saline water with an electrical conductivity of 2 dS/m. The maximum values for the number of kernels per cob (451), cob length (17.2 cm), cob weight (164.4 g), kernel yield (7.38 t/ha), stover yield (9.61 t/ha) and water use efficiency (18.5 kg/ha mm) of maize were observed under the irrigation treatment T4. The parameters exhibited their minimum values when irrigation was conducted using water with a salt level of 4 dS/m and no fertilizers were used. However, there was no statistically significant difference observed in the number of cobs per plant and harvest index of maize when saline water was used in conjunction with drip fertigation. In the context of maize cultivation, employing a cyclic irrigation technique that alternates between salty (EC 2–4 dS/m) and freshwater sources, in conjunction with recommended dose of fertiliser (RDF) has the potential to deliver comparable crop development, productivity, and economic benefits when compared to the use of freshwater sources alone.

Integration of genome-wide association studies, metabolomics, and transcriptomics reveals phenolic acid- and flavonoid-associated genes and their regulatory elements under drought stress in rapeseed flowers.

Biochemical and metabolic processes help plants tolerate the adverse effects of drought. In plants accumulating bioactive compounds, understanding the genetic control of the biosynthesis of biochemical pathways helps the discovery of candidate gene (CG)-metabolite relationships. The metabolic profile of flowers in 119 rapeseed (Brassica napus) accessions was assessed over two irrigation treatments, one a well-watered (WW) condition and the other a drought stress (DS) regime. We integrated information gained from 52,157 single-nucleotide polymorphism (SNP) markers, metabolites, and transcriptomes to identify linked SNPs and CGs responsible for the genetic control of flower phenolic compounds and regulatory elements. In a genome-wide association study (GWAS), of the SNPs tested, 29,310 SNPs were qualified to assess the population structure and linkage disequilibrium (LD), of which several SNPs for radical scavenging activity (RSA) and total flavanol content (TFLC) were common between the two irrigation conditions and pleiotropic SNPs were found for chlorogenic and coumaric acids content. The principal component analysis (PCA) and stepwise regression showed that chlorogenic acid and epicatechin in WW and myricetin in DS conditions were the most important components for RSA. The hierarchical cluster analysis (HCA) showed that vanillic acid, myricetin, gallic acid, and catechin were closely associated in both irrigation conditions. Analysis of GWAS showed that 60 CGs were identified, of which 18 were involved in stress-induced pathways, phenylpropanoid pathway, and flavonoid modifications. Of the CGs, PAL1, CHI, UGT89B1, FLS3, CCR1, and CYP75B137 contributed to flavonoid biosynthetic pathways. The results of RNA sequencing (RNA-seq) revealed that the transcript levels of PAL, CHI, and CYP75B137 known as early flavonoid biosynthesis-related genes and FLS3, CCR1, and UGT89B1 related to the later stages were increased during drought conditions. The transcription factors (TFs) NAC035 and ERF119 related to flavonoids and phenolic acids were upregulated under drought conditions. These findings expand our knowledge on the response mechanisms to DS, particularly regarding the regulation of key phenolic biosynthetic genes in rapeseed. Our data also provided specific linked SNPs for marker-assisted selection (MAS) programs and CGs as resources toward realizing metabolomics-associated breeding of rapeseed.

Quinoa growth and yield, soil water dynamics, root growth, and water use indicators in response to deficit irrigation and planting methods

To address the growing issue of scarce water in the arid and semi-arid areas, it is essential to investigate the potential of drought tolerant crops and implement promising farm management strategies to improve water productivity and yield production. Therefore, a split plot experiment to investigate how different irrigation levels (I-1:100% water requirement (WR), I-2:75%WR, and I-3: 50%WR) and planting methods (P-1: basin, P-2: on-ridge, and, P-3: in-furrow) interact and affect quinoa water use, yield, root growth, and water productivity in southern Iran over two growing seasons. The results showed high seasonal crop evapotranspiration (993–1030 mm) in I-1 as a result of the high advection ratio (α), which ranged from 1.02 to 1.46 from the early vegetative to the seed filling stages. The P-3 increased transpiration rate by 4.5% and 7.7%, and decreased soil evaporation by 17% and 29% compared to P-1 and P-2, respectively. Single (Kc) and dual (Kcb + Ke) crop coefficients varied between 0.41 and 1.38 over the two growing seasons. Grain yield in P-3 were 25%, 34%, and 44% higher compared to P-1 and P-2 under I-1, I-2 and I-3, respectively. The study revealed that nearly 67% and 80% of the total root dry matter was in the 0–30 cm and 0–60 cm of the soil profile in all experimental treatments, respectively. Regardless of irrigation treatment, root length density (RLD) and root mass density (RMD) were found to be 18.9% and 15.7% lower in P-1’s top 0–20 cm of the soil profile than those obtained in P-2 and P-3, respectively. Analyses showed that the increased root length in deeper soil layers contributed to higher soil water uptake, and consequently higher crop water productivity. In addition, root-to-shoot ratio increased as the amount of the applied irrigation water was decreased. Quinoa exhibited the highest acclimation to water stress in P-3 based on water stress sensitivity coefficients (λi) and yield response factor (Ky) values. Crop water productivity (WPC) and irrigation water productivity (WPI) for grain yield varied between 0.17 and 0.28 kg m−3. In conclusion, in terms of grain yield, shoot and root dry matter and water productivity, I-2 and P-3 (75% WR irrigation level and in-furrow planting method treatment) is recommended as the optimum water and planting management strategy for quinoa cultivation in the study area as a measure to address water scarcity and food sustainability. Still, to improve yield and irrigation water efficiency, the effect of soil management practices such as mulching and organic amendments on soil water retention and nutrient availability for quinoa should be investigated.

The Effect of Water Availability on the Carbon Content of Grain and Above- and Belowground Residues in Common and Einkorn Wheat.

The carbon (C) fixed by crops, which is exported with harvest and retained as postharvest residues in a field, is important for calculating the C balance. The aim of this study was to determine the effect of water availability on the C content in whole wheat plants. In a three-year field trial, the weights of grain, straw, chaff, stubble, and roots of two cultivars of winter wheat (Triticum aestivum L.) and one cultivar of einkorn wheat (Triticum monococcum L.) and their carbon contents were determined in water stress, irrigation, and rain-fed control treatments. The water availability, year, and cultivar had a significant influence on the C content in aboveground plant parts, but the effect of water on grain C was weak. The C content decreased with irrigation and increased with drought, but the differences were small (at most, 3.39% in chaff). On average, the C contents of grain, straw, chaff, and roots reached 45.0, 45.7, 42.6, and 34.9%, respectively. The amount of C exported with grain and left on the field in the form of postharvest residues depended on the weight of the total biomass and the ratio of grain to straw and residue. Whole plant C yield reached 8.99, 7.46, and 9.65 t ha-1 in rain-fed control, stressed, and irrigated treatments, respectively, and 8.91, 9.45, and 7.47 t ha-1 in Artix, Butterfly, and Rumona, respectively. Irrigation significantly increased the C content in grain and straw (but not in chaff, stubble, and roots) in comparison with water shortage conditions. On average, a grain yield of 1 t ha-1 corresponded to an average export of 0.447-0.454 t C ha-1 in the grain of all cultivars and inputs of 0.721, 0.832, and 2.207 t C ha-1 of residue to the soil in the form of straw and postharvest residue in the two cultivars of common wheat and one of einkorn. The results of the study provided reliable data for the calculation of the C balance of wheat under conditions of different water availability.

Assessment of the Performance of Drip-Irrigated Green Pepper (Capsicum annum L.) under Poly-House and Open-Field Conditions

Sweet pepper (Capsicum annum L.) is one of an important group of vegetables grown extensively, widely cultivated and used as foods in almost every country of the world. It is a high productivity crop, it has high remunerative and nutritive values. Sweet pepper consumption in Nigeria is growing recently because of increasing demand by rural and urban consumers as a result of rapid population growth and water scarcity calls for an alternative means of production system for sustenance of the human race. The experiment was carried out during the dry seasons of 2020.2021 and 2021/2022 at the Teaching and Research Field of Federal Polytechnic, Ado-Ekiti, Nigeria. The beds were prepared, nursery was raised, drip irrigation system was installed and fumigation was carried out before transplanting. The experimental design was a randomized complete block (RCBD) with nine replications in each environment. The same design was applied to both poly-house and open-field conditions. The factors are environment (poly-house and open-field) and irrigation intervals of 5, 6 and 7 days (I5, I6 and I7). Data obtained were subjected to analysis of variance and Tukey’s Honestly Significant Difference (HSD) was used for multiple comparison. Drip irrigation was applied to all plots at different irrigation intervals. Number of leaves (NL), plant height (PH), stem girth (SG) and weight of fresh fruit (WFF) were recorded. The respective results of performance of green pepper at different irrigation treatments under poly-house and open-field in the 2020/2021 and 2021/2022 growing seasons were: NL-I5: 180, I6: 185, I7: 171 and I5: 120, I6: 139, I7: 122 in 2020/2021 growing season while I5: 157, I6: 173, I7: 160 and I5: 108.3, I6: 118.3, I7: 118 during 2021/2022 growing season. PH-I5: 128.7, I6: 139.3, I7: 125.3 and I5: 108.3, I6: 118.3, I7: 104.7 cm in 2020/2021 growing season while I5: 117.7, I6: 129.7, I7: 120 and I5: 102, I6: 115, I7: 99.3 cm during 2021/2022 growing season. SG-I5: 30, I6: 29.7, I7: 29.6 and I5: 25.1, I6: 26, I7: 25 mm in 2020/2021 growing season while I5: 20.3, I6: 23.3, I7: 21.3 and I5: 18.5, I6: 20, I7: 17.9 mm during 2021/2022 growing season. WFF-I5: 20.3, I6: 29.2, I7: 19.8 and I5: 13.3.1, I6: 21, I7: 14.2 kg/m2 in 2020/2021 growing season while I5: 14.6, I6: 23.5, I7: 14.7 and I5: 9.5, I6: 17.8, I7: 8.8 kg/m2 during 2021/2022 growing season. The controlled conditions provided by the poly-house resulted in best overall performance compared to the open field environment. It is recommended that the assessment of long-term sustainability and economic viability of poly-house cultivation for green pepper production be conducted.

Estimation of Plant Height and Biomass of Rice Using Unmanned Aerial Vehicle

Plant height and biomass are important indicators of rice yield. Here we combined measured plant physiological traits with a crop growth model driven by unmanned aerial vehicle spectral data to quantify the changes in rice plant height and biomass under different irrigation and fertilizer treatments. The study included two treatments: I—water availability factor (i.e., three drought objects, optimal, and excess water); and II—two levels of deep percolation and five nitrogen fertilization doses. The introduced model is extreme learning machine (ELM), back propagation neural network (BPNN), and particle swarm optimization-ELM (PSO-ELM), respectively. The results showed that: (1) Proper water level regulation (3~5 cm) significantly increased the accumulation of spike biomass, which was about 6% higher compared to that under flooded conditions. (2) For plant height inversion, the ELM model was optimal with a mean coefficient of determination of 0.78, a mean root mean square error of 0.26 cm, and a mean performance deviation rate of 2.08. For biomass inversion, the PSO-ELM model was optimal with a mean coefficient of determination of 0.88, a mean root mean square error of 3.8 g, and a mean performance deviation rate of 3.29. This study provided the possible opportunity for large-scale estimations of rice yield under environmental disturbances.

Impact of Low Tunnel Heights and Irrigation Regimes on Growth Parameters of Capsicum

The cultivation of Capsicum, commonly known as sweet pepper, is a critical component of global agriculture. As the demand for high-quality peppers continues to rise, there is a growing need to explore innovative cultivation practices that enhance yield and resource efficiency. Extensive experimental work was conducted at the research farm of Soil and Water Engineering, Punjab Agricultural University, Ludhiana from October 2008 to June 2009. This manuscript delves into the intricate interplay between low tunnel heights and irrigation regimes, seeking to unravel their collective impact on the growth parameters of capsicum. From the experiments, the data clearly revealed that plant height, leaf area index and dry matter accumulation was highest in 75 cm tunnel height followed by 90 cm and 60 cm tunnel height treatments throughout the crop season. Among all the irrigation treatments drip irrigation with 0.90 IW/CPE ratio gave the highest plant height and leaf area index than other irrigation treatments. Whereas drip irrigation with 0.75 IW/CPE ratio gave the highest dry matter accumulation than the other irrigation treatments.

Effect of irrigation levels on the physiological responses of petunia cultivars for selection

The selection of drought-tolerant varieties is essential to address the anticipated water stress in plants. This study assessed the drought tolerance of two petunia cultivars (Petunia Grandiflora and Falcon F1 (white). A pot experiment was conducted with the four irrigation levels, which included the irrigation interval of one day (control, T0), three days (T1), five days (T2), and seven days (T3). Under T1, the Grandiflora cultivar produced the tallest plants (43.0 cm). The plant height gradually decreased as the irrigation interval grew longer. Overall, the size of the Grandiflora was observed to be higher than the Falcon F1 cultivar. The Grandiflora cultivar produced the longest roots (6.2 cm) in T0, followed by the Falcon, which had roots with a length of 5.6 cm. The root length of Grandiflora was found to be 5.5 cm and 5.0 cm in T1 and T2, while Falcon F1 produced 5.2 and 4.6 cm roots, respectively. Petunia Grandiflora surpassed Falcon F1 (white) regarding root dry weight for all treatments. In addition, when water was provided after a 3-day gap (T1), the Petunia Grandiflora cultivar produced the highest root-shoot ratio (3.52) using fresh weight. Petunia Grandiflora had the highest chlorophyll concentration of 2.68 mg g−1, followed by the Falcon F1 (white) cultivar in T1. The Grandiflora produced the highest total chlorophyll levels (4.04 mg g−1) when water was added after a one-day break, followed by Falcon F1 (white), which had total chlorophyll values of 3.42 mg g−1 under control compared to other irrigation treatments. Hence, Grandiflora performed the best; therefore, this study will help the cultivators adapt to drought environments using drought-resistant cultivars. Due to this fact, most people buy these flowers as seedlings rather than starting them from seeds, and this research is significant for flower nurseries.

Growth and Yield Response of Pea (Pisum sativum L.) Crop to Classical and Regulated Deficit Irrigation along with Nitrogen Fertilization under Drip Irrigation

Background: The conventional methods of applying water and nutrient results lot of wastage and negatively affect the soil, environment and crop response of pea. Methods: The experiments were conducted at Lovely Professional University, Punjab during two years. The five drip irrigated treatments having full irrigation, classical deficit irrigation and regulated deficit irrigation in combination same level of nitrogen fetigation @90% recommended dose of nitrogen (RDN) were taken in 4 replications. One control plot (having flood irrigation with soil application of nitrogen @100% RDN through broadcasting) was taken for comparison. Result: Plant growth, yield contributing parameters, pod yield and water use efficiency (WUE) were significantly affected by drip irrigation in combination with 90% RDN through fetigation over conventional method of irrigation and fertilizer application. Among all the drip irrigated treatments, the increment in crop yield, WUE and irrigation water saving varied from 27.6 to 65.7%, 63.6 to 99.7% and 26.1 to 44.6%, respectively over control plot. In case of same nitrogen fertigation level, the yield and water use efficiency of drip irrigated pea crop can be improved by adoption of moderate water deficit level (which is 15% less than full IWR) under regulated deficit irrigation approach over full irrigation approach. The findings of the work can be utilized by farm managers for irrigation planning and nitrogen management for pea crop and by policy makers to conserve available fresh water resources in water scares regions.

Zeolite application and irrigation during ripening reduced berry sunburn damage and yield loss in cv. Sangiovese (Vitis vinifera L.).

Climate change poses significant challenges to the grapevine cultivation for wine production. In the last years, the occurrence of extreme weather events such as intense heat waves and prolonged period of drought increased sunburn damage with negative consequences to yield and berry composition. Short-term adaptation strategies are urgently needed to mitigate these effects. In this light, our study aimed to evaluate the efficacy of zeolite application on the canopy and irrigation during ripening on sunburn damage, yield, and berry composition in cv. Sangiovese (Vitis vinifera L.). Over 3 years (2021-2023), canopy management and irrigation treatments were arranged in a strip-plot design. Canopy management treatments included leaf removal on the cluster zone, with and without zeolite application, and no defoliated control; irrigation treatments comprised irrigation from berry softening and no irrigation. Both zeolite application and irrigation reduced sunburn damage, thus mitigating yield loss. Regarding berry composition, zeolite application did not alter the main parameters whereas irrigation led to reductions in sugar and anthocyanin concentrations. These findings suggest that zeolite application and irrigation during ripening represent promising and cost-effective solutions for grape growers facing climate change-induced challenges. However, further studies are necessary to optimize timing of irrigation to avoid detrimental effects on anthocyanin accumulation.

Increasing cotton lint yield and water use efficiency for subsurface drip irrigation without mulching.

Planting without mulching can eliminate the residual film pollution caused by the long-term use of plastic film covers, but it will increase soil moisture evaporation and heat loss and severely reduce water use efficiency and cotton productivity in cotton (Gossypium hirsutum L.) fields in arid regions. It is unclear whether the advantages of subsurface drip irrigation and nighttime irrigation can be leveraged to reduce the amount of irrigation applied in fields, improve the soil and leaf hydrothermal environments, and increase the synchronicity of yield and water use efficiency (WUE). Therefore, in a two-year field experiment (2019-2020), cotton was grown under different irrigation treatments (I5, 3753 m3 ha-1; I4, 3477 m3 ha-1; I3, 3201 m3 ha-1; I2, 2925 m3 ha-1; and I1, 2649 m3 ha-1). The soil volumetric moisture content, soil temperature, leaf relative water content (RWC), daily changes in gas exchange parameters, lint yield, and WUE were evaluated. The results showed that reducing irrigation can reduce the soil volumetric moisture content (0-40cm soil layer), increase the soil temperature and soil temperature conductivity, and increase the leaf temperature, intercellular carbon dioxide concentration (Ci), and WUE; however, reducing irrigation is not conducive to increasing the leaf RWC, net photosynthetic rate (Pn), stomatal conductance (Gs), or transpiration rate (Tr). There was no significant difference in WUE between the I3 and I4 treatments from 8:00 to 20:00, but the lint yield in these treatments increased by 2.8-12.2% compared to that in the I5 treatment, with no significant difference between the I3 and I4 treatments. In addition, a related analysis revealed that the positive effects of the leaf hydrothermal environment on the Pn and soil temperature on the WUE occurs during the same period (10:00-16:00). Overall, an irrigation amount of 3201-3477 m3 ha-1 applied with a subsurface nighttime irrigation system without mulching can enhance the soil moisture content and soil temperature, maintain a high photosynthetic capacity, and increase the lint yield and WUE. These results revealed that the negative impacts of plastic film contamination in arid areas can be alleviated.

Push-Out Bond Strength of Fiber-Reinforced Post Using Various Post Space Irrigation Treatments.

Objective: This study aims to provide the impact of different endodontic irrigation treatments after post space preparation on the push-out bond strength of fiber posts to dentin using self-adhesive cements. Methods and Materials: A total of 180 extracted premolar teeth were selected. The canals were instrumented by and then were filled. After preparing the post space, teeth were divided into 12 groups according to irrigants (normal saline solution; 17% EDTA [ethylenediaminetetraacetic acid] + 5.25% NaOCl [sodium hypochlorite]; 17% EDTA; 5.25% NaOCl; and 1.2% chlorhexidine [CHX]) and irrigation technique (conventional syringe irrigation [CSI] and passive ultrasonic irrigation [PUI]). After cementation, the samples were sectioned to obtain 1-mm disks from coronal and apical parts, a push-out test was performed using a universal testing machine (Z050, Zwick/Roell, Ulm, Germany) at a speed of 1 mm/min. The data were analyzed using one-way analysis of variance (ANOVA) and Mann-Whitney U tests. Results: The push-out bond strength was higher in coronal segment in comparison to apical segment. The highest push-out bond strength value was related to NaOCl + EDTA using PUI (12.39 ± 1.08). There are significant differences when comparing NaOCl + EDTA group with EDTA group using CSI or PUI technique (p < 0.05) except in coronal region with CSI technique. In both apical and coronal regions, phosphoric acid irrigation was found to be similar to normal saline solution and CHX groups regardless of activation technique. Conclusion: The push-out bond strength values were significantly affected by the irrigation protocol. Using PUI and 17% EDTA + 5.25% NaOCl in apical region could be an effective irrigant for smear layer removal after post space preparation.

The effect of ascorbic acid and bio fertilizers on basil under drought stress.

Evaluate the effect of ascorbic acid application and coexistence of Mycorrhiza fungus and Azospirillium on basil (Ocimum basilicum L.) under drought stress. This experiment was performed as a split factorial in a randomized complete block design with three replications in the crop year 2017-2018 in Shahriar, Iran. In this experiment, irrigation was the main factor in three levels, including drought stress based on 40-70-100 mm from the evaporation pan of class A. Biofertilizer including growth-promoting bacteria (Azospirillium) and mycorrhiza fungus in four levels, including a(Non-consumption) B (Seeds of growth-promoting bacteria (Azospirillium)) C (Consumption of mycorrhiza fungus as seeds) D (Concomitant use of growth-promoting bacteria Azospirillium with mycorrhiza fungi as seeds) and ascorbic acid in two levels of foliar application, including A (Absence Application of ascorbic acid) and B (Application of ascorbic acid (two days after irrigation treatment)) was considered as a factorial factor. The results showed that the highest biological yield was obtained in drought stress of 40 mm and application of biological fertilizers in the form of mycorrhiza application with an average of 3307.1 kg/ha, which was about 70% more than 100 mm evaporation stress and no application of biological fertilizer. The use of ascorbic acid under drought stress conditions improved by 10%, the essential oil using ascorbic acid evaporated under drought stress conditions of 100 mm. As a general conclusion, the use of ascorbic acid and Mycorrhiza + Azospirillium biological fertilizer improved the quantitative and qualitative characteristics of basil under drought stress.

Water productivity and growth parameters of Fawn-tall fescue and Tekapo-orchard grass under deficit irrigation in arid zones.

This study aimed to determine the drought stress response of Fawn-tall fescue and Tekapo-orchard grass and investigate a drought stress resistance marker. Grass genotypes were grown under four Irrigation treatments I1 equivalent to 0.3 standard crop evapotranspiration (ETc), I2 equivalent to 0.65 ETc, I3 equivalent to 0.75 ETc, and I4 equivalent to 1.2 ETc. Plant height, fresh weight, dry weight were measured and the Water productivity (WP) were calculated. The results showed a reduction in the growth of both grass genotypes as the drought stress increased as indicated by the shorter plants and reduction in fresh and dry weight. However, the WP results showed that the Fawn-tall fescue endured the drought stress better than the Tekapo-orchard grass as indicated by the constant values of the plant WP across the tested irrigation treatments. The results was confirmed by the amplification of dehydrin genes where Fawn-tall fescue was found to be homozygous for dehydrin genes.