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Increases in urban population and inadequate rainfall result in imbalanced water budgets in urban and sub-urban regions. Water conservation becomes important in urban landscapes because of increased water demands. Modern landscape designs require drought-resistant plants to maintain urban landscape greenness during water scarcity. Irrigating plants at their irrigation requirements, which is the minimum irrigation rate that can achieve acceptable aesthetic quality, can also conserve water. However, the drought tolerance and irrigation requrements of most landscape plants have not been widely evaluated. Shepherdia ×utahensis ‘Torrey’ (‘Torrey’ buffaloberry) and Penstemon species (beardtongues) are low-water-use landscape plants, but their drought resistance mechanisms are largely unknown. Despite garden roses (Rosa ×hybrida L.) being widely used in residential landscapes, their responses to reduced irrigation frequency and irrigation requirements are unclear. The objectives of this research were to determine the plant growth, morphology, and physiology of ‘Torrey’ buffaloberry, four penstemon species, and five garden rose cultivars under drought stress resulting from reduced substrate water content or irrigation frequency. Shepherdia ×utahensis ‘Torrey’ and the four penstemons were grown using an automated irrigation system to preciously control their substrate volumetric water contents at their setpoints between 0.40 to 0.05 m3·m-3 in a greenhouse for 50 days, whereas the five rose cultivars were irrigated at three irrigation frequencies (high, medium, and low) in an open field, where the irrigation frequency at the high, medium, and low levels was controlled using 80%, 50%, and 20% reference evapotranspiration (ETO), respectively. Under reduced substrate moisture levels, S. ×utahensis promoted root growth, closed stomata, and increased leaf trichomes density to regulate canopy temperature. Penstemon species native to arid regions, such as P. barbatus (Cav.) Roth ‘Novapenblu’ (Rock Candy Blue® penstemon) and P. strictus Benth. (Rocky Mountain penstemon), showed greater leaf reflectance, a higher volume of root system, and cooler canopy temperatures than the mesic penstemon species, including P. digitalis Nutt. ex Sims ‘TNPENDB’ (Dakota™ Burgundy beardtongue) and P. ×mexicali Mitch. ‘P007S’ (Pikes Peak Purple® penstemon). Rose cultivars were able to partially close their stomata to reduce water loss when irrigation frequency dereased or air temperatures increased. ‘MEIRIFTDAY’ and ‘Meibenbino’ roses, which showed reductions in the dry weights of leaves and stems and exhibited unacceptable overall appearance, were less tolerant to reduced irrigation compared with ‘ChewPatout’, ‘Overedclimb’, and ‘Radbeauty’ roses when irrigation events decreased from eight to one time during the growing season. Our research showed that landscape plants might change their morphology and physiology to allow them to tolerate water deficit and leaf overheating under drought conditions. Using plants with drought resilience could maintain acceptable visual quality with reduced irrigation water.

Deficit irrigation is critical to global food production, particularly in arid and semi-arid regions with low precipitation. Given water shortage has threatened agricultural sustainability under the dry-land farming system in China, there is an urgent need to develop effective water-saving technologies. We carried out a field study under two cultivation techniques: (1) the ridge and furrow cultivation model (R); and (2) the conventional flat farming model (F), and three simulated precipitation levels (1, 275 mm; 2, 200 mm; 3, 125 mm) with two deficit irrigation levels (150 and 75 mm). We demonstrated that under the ridge furrow (R) model, rainfall harvesting planting under 150 mm deficit irrigation combined with 200 mm simulated precipitation can considerably increase net photosynthesis rate (Pn), quantum yield of PSII (ΦPSII), electron transport rate (ETR), performance index of photosynthetic PSII (Fv/Fm′), and transformation energy potential of PSII (Fv/Fo). In addition, during the jointing, anthesis and grain-filling stages, the grain and biomass yield in the R model are 18.9 and 11.1% higher than those in the flat cultivation model, respectively, primarily due to improved soil water contents. The winter wheat fluorescence parameters were significantly positively associated with the photosynthesis, biomass and wheat production. The result suggests that the R cultivation model with irrigation of 150 mm and simulated precipitation of 200 mm is an effective planting method for enhancing Pn, biomass, wheat production, and chlorophyll fluorescence parameters in dry-land farming areas.

Deficit irrigation occurrence while maintaining acceptable yield represents a useful tool for vegetables production wherever irrigation water is limited. Lettuce (Lactuca sativa L.) 'Corsica' was grown in the field from May to July in order (1) to investigate the daily and seasonal evapotranspiration (ETc) of lettuce using drainage lysimeter, (2) to determine the crop coefficients (Kc) values, and (3) to study the effects of deficit irrigation on growth, marketable and water use efficiency (WUE). Treatments were: well-watered treatment receiving 100% of ETc (C), water-stressed treatment receiving 80% of ETc (WS1), water-stressed treatment receiving 60% of ETc (WS2), water-stressed treatment receiving 40% of ETc (WS3). Lysimeter measured crop evapotranspiration (ETc) totaled 422 mm, for total irrigation period of 81 days. Seasonal evapotranspiration (ET) of lettuce treatments, varied from 351 mm in the WS1 treatment to 305 mm in the WS2 treatment and 259 mm in the WS3 treatment, while in the control ET totaled 397 mm. The highest yield was recorded in C and WS1, with no significant differences between treatments followed by WS2, while the lowest value was recorded under the severe water stress treatment. A yield response factor (ky) value of 1.17 was determined, and lettuce was found to be sensitive to water stress. The highest values of water use efficiency (WUE), was recorded on WS1 (18.8 kg m-3), followed by the C (17.8), WS2 (16.3) and finally WS3 (15.5) treatment. Applying 80% of ETc resulted in water saving, with the least yield reduction, making more water available to irrigate other crops, and thereby considered optimal strategies for drip-irrigated lettuce in the semi-arid climate.

In this study, effects of deficit irrigations and leonardite treatments on water use efficiency (WUE), water consumption and agricultural productivity of Lactuva Sativa Var. Crispa were examined in a pot experiment under greenhouse conditions. Experimental treatments included: L0: (Control), L5: (5% leonardite + 95% soil), L10: (10% leonardite + 90% soil) and L20: (20% leonardite + 80% soil) with I100 (full irrigation, control) and I80 and I60 (deficit irrigation). Plant water depletions were determined by weighing the pots. The highest total amount of irrigation water (9.74 × 10−3 m3/pots) was observed in L0I100 control treatment and the lowest value (5.52 × 10−3 m3/pots) was obtained from L20I60 treatment. The highest WUE (41.63 kg/m3) was obtained from L10I80 treatment. The greatest yield (139 g), plant length (20.14 cm) and number of leaves per plant (28) were respectively obtained from L0I100 treatments. The greatest plant diameter (37.05 cm) was obtained from L10I100 treatment. Present findings revealed that L0I100 treatments were prominent for yield and L10I80 treatments for WUE and plant nutrient uptake. Lactuva Sativa Var. Crispa exhibited a strong dependence on water; yield and growth parameters were adversely influenced from I60 deficit irrigation treatments. Additionally, plant water consumptions decreased with Leonardite treatments.

Increased water scarcity necessitates the implementation of water-conserving irrigation management practices to sustain crop production, especially in water-limited areas. Field experiments were conducted to evaluate midday leaf water potential (LWP) of bell pepper (Capsicum annuum L. var. annuum) irrigated differentially using surface drip (DI) and subsurface drip irrigation (SDI) systems during 2016 and 2017 growing seasons in the eastern Mediterranean environmental conditions. The treatments considered were deficit irrigations (I-50, I-75), regulated deficit irrigation (RDI), partial root-zone drying (PRD50) and full irrigation (I-100) under DI and SDI systems. The experimental design was completely randomized in a split-plot system with four replicates per treatment. Deficit irrigation treatments of I-75 and I-50 received 75% and 50% I-100, respectively; RDI was supplied with 50% I-100 during vegetative growth stage until flowering, then received 100% of crop water requirement; PRD50 plots received 50% I-100. Bell pepper plant water status was estimated by LWP. Higher LWP values were determined in I-100 for two drip systems than the I-75, I-50, and PRD50; LWP correlated significantly (P < 0.01) and negatively with fresh pepper yield, DM yield, leaf area index (LAI), and mean soil water content and all these relations are best described with the curvilinear equations. In conclusion, bell pepper should be irrigated at mean LWP values between -0.89 and -0.95 MPa without any yield reduction. It is also concluded that RDI and I-75 treatments appear to be good alternatives to I-100 for sustainable bell pepper production under the Mediterranean environmental conditions.

Cactus pear is a dominant crop to arid lands with high nutritional value. Its fruits are used in food processing as add value to food products. The current study planted cactus pear under three irrigation regimes (T1, T2, and T3) where two of them (T2 and T3) implicated severe deficit irrigation conditions on the crop. The relationship between applied irrigation water regimes and fruit physical and chemical properties including antioxidants, pigment and vitamin C content was studied. The study also aimed to utilize cactus pear’s pulp (CPP), as additive value, in the processing of wheat flour cupcake. Samples of cupcake were made by adding 20%, 40%, 60% and 80% CPP based on wheat flour weight. Fruits obtained under T2 and T3 treatments had higher color concentration than T1. T2 irrigation regime yielded higher content of total phenolic and flavonoid content (TPC and TFC) than those produced under T3 and T1. Antioxidant activity was the highest in T2. Thus, fruit pulp obtained from T2 was selected for cupcake making. The content of soluble solids was ⁓18 Brix in all treatments. VitC. was significantly higher (P≤0.05) in T3 (56.04 g AA/kg) than T1 (55.42 g AA/kg) and T2 (51.01 AA/kg). The content of betacyanins in T1 was higher (0.47 mg100mg dry weight) in fruits pulp than T2 and T3 (0.44 and 0.54 mg100mg dry weight). Sensory evaluation showed that fortification with 60% cactus pear pulp had the best sensory characteristics meanwhile cupcakes fortified with 80% cactus pear pulp was not acceptable.

The profitable production of cabbage is primarily constrained by improper irrigation and fertilizer management. A field experiment comprising of four drip irrigation levels (0%, 25%, 50%, and 75% of ASMD) and four fertilizer levels (RDF @ 150:60:90, STCR50 @ 215:115:150, STCR55 @ 258:148:203 and farmers’ conventional dose @ 92:240:240 kg NPK ha−1) was conducted on cabbage in an inceptisol during rabi season in two consecutive years. The results revealed that drip irrigation at 0% ASMD with STCR55-based fertilization produced the tallest plant (27.39 cm), greatest leaf area per plant (4208 cm2), the highest LAI (1.75), and the greatest length of head (18.86 cm), diameter of head (17.78 cm), fresh weight of head (951 g), and head yield (73.9 t ha−1). Conversely, the lowest plant height (21.34 cm), leaf area per plant (3433 cm2), LAI (1.43), length of head (15.12 cm), diameter of head (14.33 cm), fresh weight of head (722 g), and head yield (51.4 t ha−1) were produced by drip irrigation at 75% ASMD and the farmers’ conventional dose. Irrigation water at 323.44 mm through the drip system was found to be optimal for water-yield production function. Deficit irrigation at 75% ASMD with STCR55-based fertilizers recorded the highest CWP (50.13 kg m−3). The crop yield response factor (Ky) for the total crop growing period was found to be 1.19 (R2 = 0.91). The maximum FUE (0.21 t kg−1 of nutrient applied) was obtained with drip irrigation at 0% ASMD with general RDF. The moisture component (volumetric moisture content) was introduced in TYE to enhance its predictability using machine learning algorithms. Based on higher yield, CWP, FUE, and economic analysis, the imposition of drip irrigation at 0% ASMD coupled with STCR55-based fertilization may be recommended to the cabbage growers of the Indo-Gangetic inceptisols of West Bengal, India or, those in similar agro-climatic condition.

Regulated deficit irrigation (RDI) is considered among the best water-saving techniques for supplementing Regulated water to fully achieve the water needs of the plant while maximizing water productivity with little or no substantial decrease in final produce compared to the conventional forms of irrigating crops. The aim of this paper is to review existing RDI approaches used in citrus production as well as plant-water stress indicators. Most of the approaches employed in citrus RDI scheduling require weather data for evapotranspiration calculations which is very technical, laborious and time consuming. Nonetheless, the time domain reflectometer (TDR) offers a simple way of scheduling RDI based on the soil-water status at any given time. This approach will help address the challenges in setting up on-farm synoptic stations to measure weather data to compute evapotranspiration or from using data from weather stations which might be different from the farm conditions. The pros and cons of all the approaches have been discussed and recommended that the TDR can be adopted as an alternative to schedule irrigation in citrus orchards to ensure that plants are supplied with adequate volume of water for maximum water use efficiency. Key words: Partial root-zone drying, plant-water requirement, plant-water stress, regulated deficit irrigation, remote sensing, subsurface irrigation.

BACKGROUND Based on the interrelationship among photosynthesis (Pn), water consumption and drought resistance physiology under water changes, this study aimed to explore whether easily measured Pn could be used to reflect the physiological state of winter wheat and soil moisture. The study was a greenhouse pot experiment, with three growth periods and four gradients of moisture. RESULTS The instantaneous water use efficiency of wheat improved significantly under short-term regulated deficit irrigation conditions. The photosynthetic parameters could effectively reflect the level of soil moisture (receiver operating characteristic curve analysis, area under the curve = 0.683-0.988). There was a significant correlation between Pn and yield under drought and rewatering (P 0.745, P 0.600, P

In this study, we assessed the efficiency of a deficit irrigation program (DIP) on groundnut (Arachis hypogaea L.) yield and economic profits. The DIP was designed to combine frequency and volume of irrigation to develop an appropriate irrigation water management (IWM) strategy for groundnut. Two field experiments were conducted at the Agricultural College and Research Institute, Madurai, Tamil Nadu, India, with a bunch variety of groundnut, VRI 2, under a randomized block design (RBD) with three replications. The treatments included DIP in combination with a foliar application of pink-pigmented facultative methylotrophic bacteria (PPFM). The irrigation frequencies adopted for the first set of treatments were high frequency (5/5), medium frequency (7/5), and lower frequency (7/7) starting from 14 days after sowing (DAS). The effects of early water stress on groundnut pod yield and water use efficiency were investigated in a second experiment by starting irrigation at 21 DAS. The number of irrigation frequencies and irrigation volume was fixed to develop an easily readable irrigation chart for end-users. The number of irrigation frequencies was fixed as three, and the volume of irrigation was fixed as a depth of 3 cm. In the first experiment, a mini mobile pumping unit was used for scheduling irrigation frequencies; in the second experiment, the surface drip method was used. In both experiments, we also assessed the effects of foliar application of PPFM, widely used as a growth stimulant for several crops, especially under drought conditions. Overall, we observed that DIP led to up to 25.6% water saving compared to surface irrigation. Use of the DIP at the medium frequency with PPFM spray had a significantly positive influence on water use efficiency (WUE) and irrigation water use efficiency (IWUE) compared to conventional drip irrigation (CDI). Compared to surface irrigation (SI), DIP had a positive impact on growth parameters, yield attributes, and economic profitability with a higher benefit-cost ratio. Additionally, there were only minor differences between deficit irrigation (DI) results starting from 21 DAS and 14 DAS. Irrespective of the irrigation techniques, PPFM application had a positive effect on the yield attributes and WUE. Our results indicated that DI at a medium frequency (7/5) with PPFM spray, starting from 21 DAS under drip fertigation, is the best irrigation management innovation (IMI) strategy for optimum utilization of irrigation water without significant reduction in pod yield. This management had a positive influence on WUE and IWUE of summer groundnut in sandy clay loam soil. However, the exact scheduling of the irrigation may differ in different environments as well as soil types. Nevertheless, we propose that the application and further optimization of the DIP devised in this study would help the farmers attain a similar yield using a lower amount of irrigation water and lead to significant economic profits for the farmers.

Investigating the effects of optimized fertilizer and irrigation levels on water use efficiency and productivity of wheat crop at small farms is of great importance for precise and sustainable agriculture in Pakistan's irrigated areas. However, traditional farmer practices for wheat production are inefficient and unsustainable. This study aimed to investigate the effects of deficit irrigation and nitrophos fertilizer levels on bread wheat grain yield, yield parameters, nutrient use and water use efficiencies in bed planting wheat compared to traditional farmers' practices in the flat sowing method. The two-year field experiment followed a randomized complete block design of three replications, taking three irrigation treatments according to the requirement of crop estimated by CROPWAT model (100% of ETC), deficit irrigation (80% of ETC), and deficit irrigation 60% of ETC and three nitrophos fertilizer treatments (farmer practice 120 kg N ha-1, optimized 96 kg N ha-1, and 84 kg N ha-1) at different growth stages. Crop ETC was calculated using the FAO CROPWAT 8.0 model from the last ten years (2003-2013) average climate data of the experimental station. The traditional farmer practice treatment was included as a control treatment with a flat sowing method compared with other sown-by-bed planter treatments. All treatments were provided with an equivalent amount of fertilizer at the basal dose. Before the first and second irrigation, top-dressing fertilizer was used in traditional farmers' treatment at the third leaf and tillering stages. It was applied in optimized treatments before the first, second, and third irrigation at the third leaf, tillering and shooting stages, respectively, under the bed planting method. The deficit level of irrigation (80% of ETc) and optimized fertilizer (96 kg N ha-1) showed the optimum grain yield, nutrient use, and water use efficiencies, with 20% reduced irrigation water and fertilizer levels than traditional farming practice. The results suggest that bread wheat should be irrigated with 80% of ETC and applied 96 kg N ha-1 nitrophos fertilizer at the third leaf, tillering, and shooting stages to achieve higher grain yield and water and nutrient use efficiencies under bed planting.

Water scarcity is increasing in the world, which is limiting crop production, especially in water-limited areas such as Southern High Plains of the United States. There is a need to adopt the irrigation management practices that can help to conserve water and sustain crop production in such water-limited areas. A 2-year field study was conducted during the summers of 2019 and 2020 to evaluate the effect of deficit irrigation levels and cultivars on root distribution pattern, soil water depletion, and water use efficiency (WUE) of cucumber (Cucumis sativus). The experiment was conducted in a split-plot design with four irrigation levels [100%, 80%, 60%, and 40% crop evapotranspiration (ETc)] as main plot factor and two cultivars (Poinsett 76 and Marketmore 76) as subplot factor with three replications. Results showed that root length density (RLD) was unaffected by the irrigation levels in 2019. In 2020, the RLD was comparable between 100% and 80% ETc, and it was significantly higher in 100% ETc than both 60% Eand 40% ETc. Root surface area density (RSAD) was not significantly different between 100% and 80% ETc, and it was significantly lower in both 60% and 40% ETc than 100% ETc in both years. Soil water depletion was the highest in 40% ETc followed by 60% and 80% ETc, and it was least in 100% ETc in both years. Evapotranspiration (ET) was the highest in 100% ETc followed by 80%, 60%, and 40% ETc. The WUE was not statistically different among the irrigation treatments. However, numerically, WUE was observed in the following order: 80% ETc > 100% ETc > 60% ETc > 40% ETc. The RLD, RSAD, soil water depletion, and ET were not significantly different between ‘Poinsett 76’ and ‘Marketmore 76’. However, fruit yield was significantly higher in ‘Poinsett 76’ than ‘Marketmore 76’, which resulted in higher WUE in Poinsett 76. It can be concluded that 80% ETc and Poinsett 76 cultivar can be adopted for higher crop water productivity and successful cucumber production in SHP.

espanolEl objetivo de este estudio es evaluar el efecto de una mezcla de alginato y ulvano sobre la productividad de uva de mesa cultivada bajo riego deficitario. En un predio agricola, se eligieron al azar 24 plantas de Vitis vinifera var Thompon Seedless. A la mitad de las plantas con riego normal y con riego deficitario se les adiciono mensualmente a sus suelos 500 g/m3 de la mezcla durante toda la temporada 2019-2020. Los resultados muestran que el riego deficitario mas la adicion de hidrogel algal aumentaron la produccion y el peso de los racimos de uva en un 18,5% y un 6,4%, respectivamente, en comparacion a las plantas solo con riego deficitario. La adicion de hidrogel algal mejoro la fertilidad de los suelos y estimulo el crecimiento de bacterias y hongos, principalmente, en los suelos sin restriccion hidrica. Se concluye que el uso de hidrogel algal en el cultivo de vides bajo riego deficitario mejora la productividad del cultivo. EnglishThe main objective of this research study was to assess the effect of an alginate and ulvan mixture on the productivity of table grapes grown under deficit irrigation conditions. Twenty-four Vitis vinifera var Thompon Seedless plants were randomly selected in a farm field. A mixture of algae polymers (500 g/m3) were added monthly (2019-2020 season) to the soils of half of the plants with normal irrigation and with deficit irrigation. The results show that deficit irrigation along with the addition of algal hydrogel increased grape bunch production and weight by 18.5% and 6.4%, respectively, when compared to plants with deficit irrigation only. The addition of algal hydrogel improved soil fertility and stimulated bacterial and fungal growth mainly in soils without water restriction. It is concluded that algal hydrogel improves vine crop productivity under deficit irrigation conditions.

Drip irrigation and mulching are often used to alleviate the problem of poor water management in many crops; however, these technologies have not yet been tested for applying water at critical stages of guava orchard growth in subtropical humid Tarai regions of India to improve the yield and quality. A field experiment was conducted over 2020 and 2021 which included three irrigation strategies: severe deficit irrigation (DI50), moderate deficit irrigation (DI75), and full irrigation (FI100), as well as four mulching methods: silver-black mulch (MSB), black mulch (MB), organic mulch (MOM), and a control without mulch (MWM). The results showed that both the relative leaf water content (RLWC) and the proline content exhibited an increasing trend with a decrease in the irrigation regime, resulting in a 123% increase in the proline content under DI50 conditions compared with FI100, while greater plant growth was recorded in fully irrigated plants and using silver-black mulch. Leaf nutrient analysis showed that FI100 and MOM produced significantly higher concentrations of all nutrients. However, moderate deficit irrigation (DI75) along with silver-black mulch (MSB) produced higher numbers of fruits per plant, higher average fruit weights, higher fruit yields, and maximum ascorbic acid contents. The irrigation water productivity (IWP) decreased with an increase in the irrigation regime; from severe water deficit to full irrigation, resulting in a 33.79% improvement in IWP under DI50 conditions as compared with FI100. Regression analysis outperforms principal component regression analysis for fruit yield prediction, with adjusted R2 = 89.80%, RMSE = 1.91, MAE = 1.52, and MAPE = 3.83. The most important traits affecting the fruit yield of guava, based on stepwise regression, were leaf proline, leaf Cu, fruit weight, and IWP.

The combined effects of deficit irrigation and crop load level on sweet cherry (Prunus avium L.) physiological and agronomic response were evaluated during the 2019 season in a commercial orchard located in southeastern Spain. Two irrigation treatments were imposed: (i) control treatment (CTL) irrigated above crop water requirements at 110% of crop evapotranspiration (ETC) and (ii) a deficit irrigation treatment (DI) irrigated at 70% ETC. Within each irrigation treatment, crop load was adjusted to three levels: 100% (natural crop load—high), 66% (medium crop load), and 33% (low crop load). The water relations results were more affected by the irrigation strategies applied than by the crop load management. The deficit irrigation strategy applied reduced soil water availability for DI trees, which led to a continuous decrease in their gas exchange and stem water potential. At harvest, the fruit water potential and osmotic potential of cherries from the DI treatment resulted in significantly lower values than those measured in cherries from CTL trees. On the other hand, both the irrigation strategies imposed and the crop load management used impacted fruit quality. Trees with the lowest level of crop load had fruits of greater size, regardless of the irrigation treatment assayed, and in the DI treatment, cherries from the trees with the lowest crop load were darker and more acidic than those from the trees with the highest crop load. Our results emphasize the different effects that rainfall before harvest has on mature cherries. Thus, cracked cherries at harvest represented 27.1% of the total yield of CTL trees while they were 8.3% of the total yield in DI trees. Cherries from CTL trees also showed a greater cracking index than those from DI trees. Moreover, a linear relationship between crop load and fruit cracked at harvest was observed, particularly for the CTL treatment; thus, the lower the crop load, the greater the proportion of cracked cherries.

Deficit irrigation (DI) was acknowledged as an effective technique to improve water use efficiency (WUE) without significant yield reduction. In this study, a 3-year field experiment was conducted in Northeast China during 2017–2019 to investigate the combined effects of 3-week DI from 3-leaf stage and N fertilization on maize seedling growth and determine the resulting impacts on silking growth and yield formation, N use efficiency (NUE) and WUE. Results showed that seedling-stage DI decreased leaf area and photosynthesis, thus significantly limited shoot and root dry biomass for maize seedling, compared to well-watered (WW) plants. In 2017 and 2019, seedling-stage DI positively improved seedling growth with higher root: shoot ratio and enhanced drought tolerance, under higher initial soil water contents (SWC) with sufficient precipitation before DI. The DI-primed plants showed similar or better performances on reproductive growth, grain yield, WUE and NUE compared to WW plants, even experiencing heavy rainfall or drought stresses around the silking stage. However, the contrasting results were observed in 2018 with negative DI effects on seedling and silking growth and final yield, probably due to less rainfall and lower SWC before DI. In all 3 years, N fertilization had significant compensatory effects on limited seedling growth under DI, and its effect was much less in 2018 than other years due to adverse early climate. The principal component and correlation analysis revealed maize silking growth, grain yield, NUE and WUE were strongly related to the seedling growth as affected by water and N managements under various climatic conditions. In conclusion, a short-term and moderate DI regime—adopted at the seedling stage under higher initial SWC and coupled with an appropriate N fertilization—is beneficial to control redundant vegetative growth while optimizing root development, therefore effectively improving drought tolerance for maize plants and achieving higher grain yield, WUE and NUE. Deficit irrigation (DI) was acknowledged as an effective technique to improve water use efficiency (WUE) without significant yield reduction. In this study, a 3-year field experiment was conducted in Northeast China during 2017–2019 to investigate the combined effects of 3-week DI from 3-leaf stage and N fertilization on maize seedling growth and determine the resulting impacts on silking growth and yield formation, N use efficiency (NUE) and WUE. Results showed that seedling-stage DI decreased leaf area and photosynthesis, thus significantly limited shoot and root dry biomass for maize seedling, compared to well-watered (WW) plants. In 2017 and 2019, seedling-stage DI positively improved seedling growth with higher root: shoot ratio and enhanced drought tolerance, under higher initial soil water contents (SWC) with sufficient precipitation before DI. The DI-primed plants showed similar or better performances on reproductive growth, grain yield, WUE and NUE compared to WW plants, even experiencing heavy rainfall or drought stresses around the silking stage. However, the contrasting results were observed in 2018 with negative DI effects on seedling and silking growth and final yield, probably due to less rainfall and lower SWC before DI. In all 3 years, N fertilization had significant compensatory effects on limited seedling growth under DI, and its effect was much less in 2018 than other years due to adverse early climate. The principal component and correlation analysis revealed maize silking growth, grain yield, NUE and WUE were strongly related to the seedling growth as affected by water and N managements under various climatic conditions. In conclusion, a short-term and moderate DI regime—adopted at the seedling stage under higher initial SWC and coupled with an appropriate N fertilization—is beneficial to control redundant vegetative growth while optimizing root development, therefore effectively improving drought tolerance for maize plants and achieving higher grain yield, WUE and NUE.

The present study aims to determine the combined effect of cropping system and irrigation regime on the chemical composition and bioactive properties of lemon balm aerial parts. For this purpose, lemon balm plants were grown under two farming systems (conventional farming vs organic farming) and two irrigation levels (full irrigation vs deficit irrigation) and harvested twice throughout the growing period. The collected aerial parts were subjected to three different methods of extractions, namely infusion, maceration and ultrasound-assisted extraction and the obtained extracts were evaluated in terms of chemical profile and bioactivities. Five organic acids with varied composition among the tested treatments were identified in all the tested samples for both harvests, namely, citric, malic, oxalic, shikimic and quinic acid. Regarding phenolic compounds composition, the most abundant ones were rosmarinic acid, lithospermic acid A isomer I and hydroxylsalvianolic E, especially for the maceration and infusion extraction methods. Full irrigation resulted in lower EC50 values than deficit irrigation only in the treatments of the second harvest, while variable cytotoxic and anti-inflammatory effects were recorded in both harvests. Finally, in most cases the lemon balm extracts has similar or better activity than the positive controls, while the antifungal activity of lemon balm extracts was stronger than the antibacterial effects. In conclusion, the results of the present study showed that the implemented agronomic practices, as well as the extraction protocol may significantly affect the chemical profile and bioactivities of lemon balm extracts, suggesting that both the farming system and the irrigation schedule may improve the quality of the extracts depending on the implemented extraction protocol.

Crop production has a correlation with the applied water in moderate semi-arid conditions. Due to temperature and rainfall changes enhancing water productivity in crop production are needed for a limited resource conditions. In this study, maize (Zea mays L.) yields measured in fields during 11 years from 2005-2006 to 2015-2016 were compared with those simulated by the Agro-ecological Zone method under moderate semi-arid environment located at the north west of Iran with a soil texture of loamy-clay. Different research scenarios involving actual evapotranspirationc (ETa) to potential (ETm) value (ETa/ETm= 100%, 90%, 80%, 70%, 60%, 50% and 40%) under different water application efficiencies (Ea) of 40%, 50%, 60%, 70%, 80%, 90% and 100% were considered in the present study. Research scenarios affected yield and water productivity of maize. To produce potential yield of maize of 10084 kg ha-1 under water application efficiency of 100, 90, 80, 70, 60, 50 and 40%, irrigation water requirements were respectively 4683, 5203, 5854, 6690, 7805, 9366, 11708 m3 ha-1 and water productivity were respectively 2.15, 1.94, 1.72, 1.51, 1.29, 1.08, 0.86 kg m-3. Results confirmed that water productivity of maize was from 1.22 to 1.52 kg m-3 with an average of 1.38 kg m-3 during 11 years under water application efficiency of 68%. Because measured yield ranged from 3800 to 6971 kg ha-1 with an average of 5345 kg ha-1 and water applied was from 3125 to 4584 and averaged 3836 m3 ha-1. It is suggested that limited irrigation could be applied to enhance water productivity in maize production under such moderate semi-arid environment.

Increasing population and challenges among the sectors due to the climate change and incorrect water policy has increased the pressure on water resources. This situation being as a global crisis particularly in respect to the food security has accelerated productive utilization of water supplies. The aim of the current study with 2-year experiments was to identify the effect of different irrigation interval and irrigation regimes on the yield and yield components of dry bean having greater than 50% of total world legumes production. In that experiment, two different irrigation interval, 7 and 14-day, and three different irrigation levels, (I100, I75 and I50, were studied. In results, the maximum yield was obtained from 7-day irrigation interval, and 28% yield reduction was detected at 14-day irrigation interval. In examine the irrigation levels, the highest yield was found at full irrigation (I100), and increasing water stress caused significant yield reductions e.g. 21% and 49% for I75 and I50, respectively. The evapotranspiration and total applied water as an average of 2013-2014 were calculated as 533 mm, and 450 mm, respectively. In assessment of the both the combine year results, the ky value was determined as 1.59, and this finding shows that dry bean crop is sensitive to the water stress condition.

A non-destructive fluorescence method combined with chemometric algorithms has been developed for discriminating between olive oils. The excitation-emission matrices (EEMs) of two olive oil varieties (Arbosana and Oliana) from two crop seasons, which had undergone two different irrigation treatments (control irrigation strategy and regulated deficit irrigation (RDI)), were recorded. EEMs were analysed using parallel factor analysis (PARAFAC), followed by linear discriminant analysis (LDA) incorporating three PARAFAC components. This analysis was able to discriminate between olive oils according to crop season (100% of predictions in the validation set were correct) and variety (100% of predictions were correct). Moreover, good discrimination (80% of correct predictions) was also achieved when examining olive oils belonging to the same variety but submitted to two different irrigation treatments. Further, the olive oil quality parameters obtained using conventional methods were compared with those obtained using unfolded partial least squares (U-PLS). Good correlation coefficients were obtained for Rancimat hours (r = 0.87), K270 (r = 0.75) and total polyphenol content (r = 0.94).

The postharvest life of table grape is restricted by quality deterioration from harvest to retail, mainly due to water loss, accelerated berry softening, pathogen attract and senescence. Preharvest cultivation practices, as well as postharvest treatments, are effective on postharvest life of the grape. Remarkable part of the grapevines experience seasonal or long term drought stress across the world. Therefore, the present study was conducted to reveal the quality response of stem detached berries of ‘Alphonse Lavallee’ table grapes during cold storage as influenced by preharvest sustained deficit irrigation (DI) and postharvest UV‑C irradiation as non-chemical disinfection method. The soilless grown experimental grapevines in protected cultivation were divided into two lines as full irrigation (maintaining the substrate water holding capacity at 100%) and DI (fifty percent of FI) sustained during the vegetation in glasshouse. The representative berries from each irrigation practices were stored with or without UV‑C postharvest irradiation at 1 ± 0.5 °C, 80–90% RH during 21 d. Berry visual quality did not change up to the 14th d of storage across the grapes, while the berries underwent noticeable decreases in visual quality after the 14th d, except for FI plus UV‑C treatments. UV‑C helped to maintain the moisture content and skin rupture force of the stemless berries during the storage. Color, SSC, acidity and pH values of the stored berries did not display considerable response to UV‑C. In certain cases, antioxidant and total phenol were considerably higher in the must of the berries subjected to UV‑C. Overall, postharvest UV‑C irradiation retained the loss in physical and biochemical properties of minimally processed table grape and thus it would be recommadable for both DI and FI grapes.

This study was conducted in the Aegean region conditions of Turkey in 2020. It was carried out on May-505, a local cotton variety. The study examined the variation of seed yield, water use efficiency (WUE), and irrigation water use efficiency (IWUE) of cotton with different irrigation programs and water levels. The field trial, which was designed as two factors and three replications, was designed according to the randomized complete block trial design. Four different irrigation levels (IL) (100%, 67%, 33%, and 0%) and two different irrigation scheduling approaches (gravimetric and pan evaporation) were investigated in the study. Seasonal water use values in treatments varied between 215 (0%) and 746 (100% - Pan evaporation approach) mm during the production period. The average yield values obtained with irrigation levels, which have essential effects on cotton seed yield, are listed as follows; 2057 kg ha-1 (IL-0%), 3471 kg ha-1 (IL-33%), 3771 kg ha-1 (IL-67%), and 5083 kg ha-1 (IL-100%). It was determined pan evaporation applications performed higher yields than gravimetric applications. WUE values were between 0.63 – 1.04 kg m-3. The gravimetric method’s yield response factor (ky) was 0.73, and the pan evaporation method’s yield response factor (ky) was 0.89. These results show that cotton is tolerant of water stress. In conclusion, although the pan evaporation approach with 100% treatment is suggested for cotton production in the parts of the Aegean region within the semi-arid climate zone, while water resources are sufficient. When the results are evaluated in terms of seed cotton yield for a deficit irrigation strategy, IL-67% treatment with a gravimetric approach can be used.

Adoption of water-saving cultivation strategy for cereal crops benefits development of the sustainable agriculture worldwide. In this study, the effects of water supply on agronomic traits, ABA contents, drought response-associated physiological parameters, and expression patterns of the ABA receptor family genes during late stage were investigated. Under normal irrigation condition (NI, with irrigations performed prior to seed sowing, and at stages of jointing and flowering), the wheat cultivars, namely, the drought tolerant Cangmai 14 and the sensitive Jimai 325, displayed comparable agronomic traits (i.e. yields, yield components, and water use efficiencies), ABA contents, and the physiological traits associated with drought stress (i.e., proline and soluble sugar contents, and photosynthetic parameters). Under deficit irrigation (DI, without irrigation at flowering stage compared with NI), Cangmai 14 was much better on the agronomic traits, ABA contents, and the drought response-associated traits at late stage than Jimai 325. These results suggested that the improvement of drought response-associated traits contributed to the enhanced yield formation capacity of the drought-tolerant cultivars. Expression analysis on ABA receptor genes (i.e., PYL family ones) involving ABA signal perception indicated that TaPYL3, TaPYL5 and TaPYL8, three of the PYL family members, modified expression in the tested cultivars upon modified water supply copnditions, with more transcripts detected under DI than NI. Moreover, the expression levels of these genes were all shown to be higher in Cangmai 14 under DI than in Jimai 325. Transgene analysis on TaPYL3 validated that this gene exerted positive roles in modulating biomass production and photosynthetic function of plants under drought treatment. These results suggested the essential function of the ABA signaling genes in modulating plant drought response, whose enhanced transcription efficiencies positively impact on the drought response-associated physiological process, biomass production, and the yield formation capacity of wheat plants treated with DI through possibly an ABA-dependent pathway.

Phosphorus (P) acts as one of the essential macronutrients and plays critical roles in regulating growth, development, and yield formation capacity of the crop plants. Elucidating the physiological and molecular processes underlying plant P deprivation responses benefit the crop cultivation with high P use efficiency (PUE). In this study, we investigated the P-associated and agronomic traits as well as the transcriptome profile under contrasting inorganic phosphorus (Pi) levels combined with deficit irrigation, using two wheat cultivars contrasted by PUE (i.e., high PUE Shixin 828 and P deprivation sensitive Jimai 518). The deficient-P (DP) treatment decreased P accumulative amounts, photosynthetic function, and biomass in plants at various growth stages and reduced yields with respect to sufficient-P (SP) condition. Although the two cultivars were comparable on growth and P-associated traits as well as yields under SP, Shixin 828 displayed better growth traits, more P accumulation, and higher yields than Jimai 518 under DP, suggesting that the high PUE cultivars with enhanced P uptake positively affects photosynthetic function, biomass production, and productivity of plants under P deprivation conditions. A large quantity of genes with differential expression patterns, including 2948 upregulated and 1844 downregulated, were identified based on RNA-seq analysis in the Shixin 828 plants treated with P deprivation. These DE genes were shown to be associated with biological process (i.e., metabolic process and cellular process etc.), cellular components (cell body and organelle etc.), and molecular function (binding and catalytic activity), and phytohormone signaling pathways. Transgene analysis on TaZFP1, a gene in ZFP transcription factor family that exhibited upregulated expression in P-deprived plants, validated its role in enhancing P accumulation and P starvation adaptation of plants. Our results suggested that plant P deprivation response is underlying modulation of various physiological processes via modifying gene transcription at global level. RNA-seq sequencing combined with physiological and transgene analyses dissected the molecular processes related to P-associated and agronomic traits in wheat cultivated under Pi deprivation condition.

Yield and quality attributes of table grapes are directly depending on water availability. Therefore water is critical factor for the sustainability in the Mediterranean zone. Climate change and water scarcity cause serious problems in these areas. Different strategies that save water in semi-arid regions have gradually gained importance and deficit irrigation treatments have emerged in order to maintain yield and quality in modern viticulture. In this context, the effects of deficit irrigation practices on physiological reactions, vine growth, yield and quality attributes in field grown cv. Fantasy Seedless table grape were examined during 2016 and 2017 seasons in this paper. Three treatments were applied: Ir 100 (control) irrigated to the field capacity, Ir 65 and Ir 35 irrigated of 65% and 35% of Ir 100 treatment, respectively. Significant effects on physiological responses, vine growth, yield and quality attributes were observed depending on soil water content and vine water potential. For all treatments, significant correlation was determined between g(s) and psi(md). As the water stress level increased, stomatal conductivity decreased in both two years. In 2016, the higher yield was obtained from Ir 100, while in 2017 it was obtained from both Ir 100 and Ir 65. There was a significant correlation between psi(md) and pruning wood weight (PWW). Moreover, vine vigor, ravaz index (IR) and PWW reduced much more under Ir 35 (18.6%, 19.7%, 22.6% respectively). Ir 100 had 5.1% and 7.9% higher (significantly) berry weight values than Ir 65 and Ir 35 in 2017. Whereas, there was no significant difference in 2016. On the other hand, Ir 65 had 15% higher WUE and 25% lower ET than Ir 100 while Ir 35 had 50% higher WUE and 47% lower ET than Ir 100. Consequently, to avoid severe reduction in yield, vine performance and quality attributes in this cultivar, we suggested optimization of yield and quality balance considering physiological responses and ET. Therefore Ir 65 treatment displayed more tolerant in comparison to Ir 35., Republic of Turkey, Ministry of Agriculture and Forestry, This study is a part of General Directorate of Agricultural Research and Policies (GDAR) project of the corresponding author. It was supported by the Republic of Turkey, Ministry of Agriculture and Forestry.

To assess and investigate the effects of application of superabsorbent polymer (SAP) and salicylic acid (SA) on performance of drought-affected sesame (Sesamum indicum L.), soil characteristics, and water productivity of irrigation (WPi). A randomized complete block design with split-strip plot arrangement and three replications in two successive cropping years was arranged. Two levels of irrigation consisting of supplying 50% and 100% of the sesame water requirement (deficit irrigation, DI and full irrigation, FI, respectively) were allocated to the main plots, and application of SAP (80 kg ha−1) was allocated to the subplots. Foliar application of SA (1 mM) and control was allocated to the strip plots. The results showed that the highest seed yield (SY) was obtained from DI, along with SAP and SA application. Under drought stress (DI), separate and simultaneous applications of SAP and SA increased WPi by 42% (SAP), 36% (SA), and 43% (SAP + SA), respectively, compared with control. The highest WPi was achieved through DI plus SAP application, which was 60% more than combination treatment of FI plus no-application of SAP. The results of principal component analysis (PCA) indicated that SY, seed weight per plant (SW), crop growth rate (CGR), and WPi were the effective variables of the first principal component (PC) and explained 67% of the total variance of the data. The nutritional management was effective in reducing drought stresses; moreover, the highest SY and biological yield (BY), CGR, the total amount of soil nitrogen (Soil N), and WPi were obtained in the simultaneous application of SAP and SA.

This study aimed to determine the discriminatory power of textural features to differentiate the sorghum grains subjected to normal, mild deficit, and severe deficit irrigation. The studies were carried out with the use of image processing, discrimination analysis, analysis of variance and cluster analysis using the selected texture parameters calculate for images from individual color channels L, a, b, R, G, B, U, V, S, X, Y and Z. The results indicated that different levels of irrigation can discriminate the sorghum grain with an accuracy of up to about 100%. Most of the genotypes for each level of irrigation were different in the terms of values of textural features and formed separate homogeneous groups. Drought is one of the limiting factors contributing to a decrease in sorghum grain productivity and nutritional quality, especially when it is cultivated in a marginal area. Therefore, low-quality grains produced under water stress should be recognized before they enter into the food and feed chain. The application of image analysis based on textures of sorghum grain images proved to be useful for the discrimination of sorghum grains subjected to drought stress. The applied procedure provided the fast, objective results that may be applied in practice for screening distinguishing the sorghum grains with different irrigation levels.

The granting of permits for the use of water resources has been legislated to ensure adequate access to water for all user sectors. However, this management instrument may not effectively perform quantitative control over the granting process, and permits for flows greater than the water availability may be granted and thus are not always representative of the actual abstractions. Therefore, the present study aimed to develop a methodology to optimize the use of water in shared management schemes under conflict conditions. The proposal is based on the initial evaluation of water availability conditions within a legal plan, in which the flows that consider all uses are associated with the annual run-of-river water availability, and, subsequently, for the segments where the demands are higher than the availability, on the analysis of water availability condition in an operational plan. At the operational level, the demands are characterized by the permitted flows that consider all uses except those corresponding to irrigation activities, which are estimated based on the flows required by the equivalent hectares. In this plan, the availability is considered on a monthly run-of-river basis and with the presence of flow-regulation reservoirs. For the application of the proposed methodology, the Rio Branco basin in western Bahia State is considered. The results indicated that management bodies require extensive knowledge of the actual abstractions corresponding to the permits granted, the potentialities of considering the minimum monthly run-of-river water availability and potential water availability of the basin under regulated-flow conditions, changes in cropping calendars and the use of deficit irrigation under conditions with conflicts over water use.

This study was carried out with the aim of determining the appropriate plant (Kc) and Pan (Kp) coefficients for Class A Pan by using the irrigation program that was monitored by soil moisture in th...

Plants are subjected to low use efficiency of water and nutrients in marginal lands such as calcareous soils. Moreover, plant wastes are not utilized optimally by the farmers. Hence, field trials w...

This study was carried out in a private farm located in Gharbiya Governorate, the Nile Delta, Egypt. The study aimed to assess how far the alternative furrow application and deficit irrigation may improve irrigation indices and water productivity of Soybean. Two techniques of alternation were applied. The first is Standing Alternate furrow Irrigation (SAI), the second is Reciprocal Alternate furrow Irrigation (RAI). The two techniques were compared with Conventional furrow Irrigation (CI), at which, all furrows are conventionally irrigated per each irrigation (Control). Results revealed that irrigation requirements under both of (SAI) and (RAI) techniques s are significantly less than that with (CI). Surface runoff increased as the level of application increased. The significant difference was found only between (RAI) with the level of 50 % Etc. and the treatment of (CI) with the level of 100% Etc. The highest value of (Ea) was achieved with (RAI) and 75% ETc irrigation level while the lowest value was found with (CI) and 100% ETc irrigation level. The lowest values of actual ET were found (RAI) and 50% ETc irrigation level. Also, results indicated that produced yield of soybean varied significantly (P

Aim: To study the effect of deficit irrigation on yield and water productivity of sunflower in East and South eastern coastal plains of Odisha. Methodology: The present study on water productivity was undertaken using hybrid sunflower (Swathi: NSFH-145) with application of deficit irrigation having Management Allowable Deficit level of 20%, 40%, 60% and one farmers’ practice of 70% MAD level of irrigation. Growth attributes like leaf area Index, plant height, and head diameter were recorded at 20, 45, 65 and 80 days after sowing. Yield attributes like 1000 seed weight (test weight), above ground biomass and grain yield, were recorded after threshing. Results: The growth, yield and water productivity of sunflower were significantly influenced by different irrigation levels. Irrigation scheduling at 20% MAD level showed the highest grain yield, while the lowest yield was obtained from the farmers’ practice. Irrigation at 60% MAD level showed the highest water productivity when compared with farmer’s practice as it produced the highest yield per unit quantity of water application of 0.85 kg m-3 and also produced the highest average benefit to cost ratio of 2.08. Interpretation: Taking the yield, water productivity and benefit-cost ratio into account, irrigation at 60% MAD level was found to be the best. However, irrigation at 50% to 60% MAD level may be suggested for growing sunflower under water scarce conditions in sandy loam soil for increasing water productivity.

Elucidating physiological mechanisms underlying the plant N uptake benefits breeding of high N use efficiency (NUE) crop cultivars. In this study, we investigated the growth and N uptake-associated processes in wheat under N deprivation and deficit irrigation, using two contrasting NUE cultivars. Compared with sufficient-N (SN), deficient-N (DN) treatment reduced plant biomass, N accumulation, and yields in two cultivars (high NUE Shinong 086 and N deprivation-sensitive Jimai 585), suggesting that N deprivation negatively regulates plant growth and N uptake. Shinong 086 was better on growth and N uptake-associated traits than Jimai 585 due to the improved root biomass across soil profile, which was consistent with the decrease of available N contents in soil layers. These results suggested that the improved root system architecture (RAS) enhances plant acquirement for soil N under N- and water-deprivation condition, contributing to the plant N uptake and yield formation capacities. Transcriptome investigation revealed that numerous genes were differentially expressed (DE) in the N-deprived Shinong 086 plants, which involve the regulation of complicate biochemical pathways. These results suggested that the modified RAS and N uptake in high NUE plants are accomplished underlying the regulation of numerous DE genes. TaWRKY20, a gene in ZFP transcription factor family, was functionally characterized for the role in mediating plant N uptake. Overexpression of it conferred plants improved growth and N uptake under DN due to its regulation on TaNRT2.1 and TaNRT2.2, two nitrate transporter genes. Our investigation provides insights in high NUE mechanisms in wheat under N deprivation.

Drought tolerance of Brassica crops can be genetically improved by establishing plant ideotypes with improved yield responses associated with agronomic traits and biochemical markers. The objective of this study was to compare 20 Brassica oleracea L. accessions grown under two different water treatments (100% and 35% reintegration of evapotranspiration by irrigation) to select potential tolerant genotypes for organic cultivation based on several agronomic and biochemical parameters measured in response to drought stress. Significant differences were registered for the genotype and the irrigation regime and for their interaction (p < 0.0001 ***). A principal component analysis was performed to summarize the correlations among the analyzed phytochemicals and the stressed and not stressed genotypes and highlighted the importance of the antioxidant compounds as stress biomarkers. The present results showed that drought significantly reduces growth parameters and increases the amount of ascorbic acid and polyphenols compared to the irrigated control. Additionally, the results show that antioxidant metabolism increased by drought in some genotypes while others maintained a good biomass production by increasing the value of growth parameters considered. Based on the average sum of ranks (ASR) of morpho-physiological and biochemical parameters, the genotypes CR, CC, and BH were determined to be the most drought tolerant, whereas CI5, BU, and CV1 were determined to be the most susceptible. Due to the potential of these genotypes, further molecular and cellular research will be carried out to identify the genetic marker associated with the water stress response.

Sustainable field crop management has been considered to reach the food security issue due to global warming and water scarcity. The effect of deficit irrigation and nitrogen rates on quinoa yield is a challenging issue in those areas. In this regard, the interaction effects of different N rates (0, 125, 250, and 375 kg N ha−1) and irrigation regimes [full irrigation (FI) and deficit irrigation at 0.75 FI and 0.5 FI] on quinoa yield and water and nitrogen efficiencies were evaluated with a two-year field experiment. Increasing nitrogen fertilizer application levels from 250 to 375 kg N ha−1 under FI and deficit irrigation did not cause a significant difference in seed yield and the total dry matter of quinoa. Furthermore, 20% and 34% reductions were observed for nitrogen use efficiency (NUE) and nitrogen yield efficiency with the application of 375 kg N ha−1 compared with that obtained in 250 kg N ha−1 nitrogen fertilizer, respectively. Therefore, a Nitrogen application rate of 250 kg ha−1 and applying 0.75 FI is suggested as the optimum rate to reach the highest seed water use efficiency (0.7 kg m−3) and NUE (0.28 kg m−3) to gain 4.12 Mg ha−1 quinoa seed yield. Under non–limited water resource conditions, an FI and N application rate of 375 kg ha−1 could be used for higher seed yield; however, under water-deficit regimes, an N application rate of 250 kg ha−1 could be adequate. However, questions about which environmental factors impressively restricted the quinoa growth for optimizing the potential yield need further investigation.

Water deficit during the growing season is a major factor limiting vegetable production. Therefore, saving water used for vegetable production by applying regulated deficit irrigation (RDI) can be a strategy to reduce water supply. The effects of different RDI levels from irrigation systems on vegetable yields, yield components, water use, and water use efficiency (WUE) of maize, lettuce, and garland chrysanthemum were investigated in a pot experiment. Plants were subjected to four irrigation levels, as follows: full irrigation as a control (RDI-100), 70% of full irrigation (RDI-70), 50% of full irrigation (RDI-50), and 30% of full irrigation (RDI-30). The WUE values of maize and lettuce were significantly higher with RDI-30 than other treatments, yet a significant reduction of WUE in garland chrysanthemum was detected compared to other treatments. There were significant correlations of WUEi with WUEyield and WUEbiomass in maize plants, indicating that WUEi can be a useful nondestructive estimator of yields and biomass contents in maize. Moreover, a significant correlation between WUEi and WUEyield in lettuce plants was observed. This index was correlated with economic production, and can be used to assess fresh weights and as an index of the irrigated water content. These results for evaluating water deficits in plants used nondestructive measurements that are applicable to large-scale water management of vegetable plants, thereby enabling scarce water resources to be conserved.

Sustainability of quality fruit production in Indian jujube is adversely affected by improper irrigation and nutrient management. A field study comprising of four irrigation levels (drip irrigation at 0.8, 0.6 and 0.4 of pan evaporation (E0) and surface irrigation at 1.0 IW/CPE with 50 mm depth) and three nutrient levels (100% RDF, 75% RDF+25% RDF as vermicompost and 50% RDF+50% RDF as vermicompost) was conducted during 2018-19 (11 months) on jujube plant. Results showed that tallest tree (3.72 m), greatest tree circumference (0.32 m), maximum fruits tree-1 (563), highest fruit weight (15.5 g) and fruit yield tree-1 (8.42 kg) were recorded with drip irrigation at 0.8 E0 with 100% RDF. Minimum growth, yield components and yield were found with drip irrigation at 0.4 E0 with 50% RDF+50% RDF as vermicompost. Seasonal ETa was 373.6, 409.4 and 446.4 mm for drip irrigation at 0.4, 0.6 and 0.8 E0, respectively and 694 mm for surface irrigation. Maximum CWUE of 18.87 g tree-1 mm-1 was obtained with drip irrigation at 0.8 E0 with 100% RDF. About 55.7-75.5% water was saved by drip irrigations which could bring an additional area of 55.5-85.8% under drip irrigated jujube. Highest predicted yield of 9.02 kg tree-1 was accomplished with 278 mm irrigation water. This model approach could serve as a good guideline to yield potential decision in relation to limited irrigation water for jujube growers in the Indo-Gangetic plains or similar agro-climatic regions.

In this study, photosynthesis and assimilate translocation and their contribution to improving grain yield and harvest index (HI) of triticale under different N sources and irrigation regimes in an...

Salinity, water scarcity, and nitrogen (N) deficiency are the main limiting factors for plant production. However, over-irrigation and excessive N utilization can also limit the growth and biomass yield of leafy vegetables. The aim of this study is to investigate the growth regulation of spinach (Spinacia oleracea L.) under different levels of irrigation water salinity, water utilization, and nitrogen supply. Combinations of five salinity levels (1, 4, 7, 9, and 11 dS m−1) with three levels of water consumption including deficit irrigation (W–), full irrigation (W0) and over-irrigation (W+), and four levels of N supply (0, 50, 75, and 100% of N requirement) were examined under controlled greenhouse conditions. The least plant biomass, evapotranspiration (ET), and nitrogen use efficiency (NUE) were observed when high-saline water was applied in combination of water and N deficiency. However, the osmotic/drought effect is a short-term effect of salinity that can be further exacerbated by the condition W–. With increasing the fertilizer rate up to 150 mg N kg−1 soil, the plant growth traits increased significantly for all salinity levels; however, an excessive N utilization caused no significant increase. Water stress caused a morphological adaptation in the plant by reducing leaf area and ET, resulting in improved water use efficiency (WUE). With increasing salinity, WUE increased then decreased significantly. In other words, both the relative ET and relative yield were reduced with increasing salinity; however, at intermediate salinity levels (4 and 7 dS m–1), further decline in the former than in the latter resulted in higher WUE values. The stepwise regression analysis showed that the plant yield was affected mostly by WUE, ET, and leaves number (R2 = 0.983***). The findings of this study revealed that the reduced leaf area was the main growth regulation in the spinach plant under stress conditions, which ultimately could enhance WUE.

SECAMENTO PARCIAL DA ZONA RADICULAR NA BANANEIRA ‘GRAND NAINE’ NO SEMIÁRIDO DO NORTE DE MINAS GERAIS EUGÊNIO FERREIRA COELHO1; DIONEI LIMA SANTOS2; ARIANE CASTRICINI3; JOSÉ CARLOS LOPES DE LIMA4; JOÃO BATISTA RIBEIRO DA SILVA REIS3 1Embrapa Mandioca e Fruticultura, Rua Embrapa s/n, Caixa Postal 007, CEP 44380-000, Cruz das Almas, BA, Brasil, eugenio.coelho@embrapa.br . 2Instituto Federal de Educação, Ciência e Tecnologia do Pará, Campus Conceição do Araguaia, Avenida Couto Magalhães, Nº 1649, Setor Universitário, 68540-000, Conceição do Araguaia, PA, Brasil, dionei.santos@ifpa.edu.br. 3Empresa de Pesquisa Agropecuária de Minas Gerais, Rod. MGT 122, km 155, CEP: 39525-000 – Nova Porteirinha, MG, Brasil, castriciniariane08@gmail.com, jbrsreis@epamig.br. 4Mestrando do Programa de Pós-Graduação em Engenharia Agrícola da Universidade Federal do Recôncavo da Bahia, Campus Cruz das Almas, CEP 44380-000, Cruz das Almas, BA, Brasil, josecarlosdude@hotmail.com. 1 RESUMO A irrigação com déficit que permite a redução de até 50% do dispêndio de água é uma alternativa cuja viabilidade deve ser uma meta de alcance nas pesquisas. Portanto, este trabalho objetivou definir a viabilidade do uso do método do secamento parcial da zona radicular para a bananeira cultivar ‘Grand Naine’ nas condições edafoclimáticas do Norte de Minas Gerais. O estudo avaliou três frequências de alternância do lado irrigado da fileira de plantas somadas à condição de irrigação de um só lado, todos com redução de 50% da lâmina de irrigação calculada e com ambos os lados da fileira de plantas irrigados com 100% da lâmina calculada. Foram avaliados os indicadores de manejo de água do solo e a condutância estomática das folhas dos tratamentos, além das variáveis de produção e de qualidade de frutos. Os resultados indicaram a viabilidade do uso do secamento parcial da zona radicular para a bananeira cultivar ‘Grand Naine’ com redução da lâmina de irrigação de 50% e frequência de alternância do lado irrigado da fileira de plantas de 7 e 14 dias. A qualidade pós-colheita dos frutos não foi influenciada pelos estresses hídricos temporários do solo resultantes dos tratamentos. Palavras-chave: Musa spp., déficit hídrico, manejo da irrigação. COELHO, E. F.; SANTOS, D. L.; CASTRICINI, A.; DE LIMA, J. C. L.; REIS, J. B. R. DA S. PARTIAL ROOT-ZONE DRYING FOR BANANA ‘GRAND NAINE’ IN THE SEMI-ARID OF THE NORTHERN OF MINAS GERAIS 2 ABSTRACT The deficit irrigation allows the reduction of about 50% of the water use and is an alternative whose feasibility should be a goal for research. Thus, this work aimed to define the feasibility of using of the partial root-zone drying for banana cv Grand Naine under the edaphoclimatic conditions of the Northern of Minas Gerais. The study evaluated three frequencies of irrigated-side shifting of plant row, added up to one-sided irrigation condition, all sides with reduction of 50% of the irrigation blade calculated and with both sides of the plants row irrigated with 100% of the irrigation blade calculated. Soil and water management indicators and leaf stomatal conductance of the treatments were evaluated and variables of production and post-harvest fruit quality, as well. Results indicated the feasibility of the use of partial root-zone drying for banana cv grand Naine with 50% reduction of irrigation blade and frequencies of 7 and 14 days for irrigated-side shifting of plant row. The post-harvest fruit quality was not influenced by the transient water stress provided by treatments. Keywords: Musa spp., water deficit, irrigation management.