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The water deficit resulting from climate variations limits the profitability and sustainability of sugarcane fields, making water supply through irrigation necessary to sustain the potential production of sugarcane. However, the water used for irrigation purposes must be properly managed, ensuring the conservation of water resources and the reduction of costs with the use of inputs and energy. Pulsed drip irrigation aims to support irrigation management, improving the efficient use of water and mitigating the deleterious effects of water deficit. This study aims to evaluate the growth, productivity, and industrial yield of sugarcane cultivated under continuous and pulsed drip irrigation. A field experiment was conducted at the Experimental Sugarcane Station of Carpina, in Carpina in the State of Pernambuco, Northeast Brazil, from December 2020 to December 2021. The experimental arrangement was randomized blocks in a 2 x 5 factorial design, with two types of irrigation application (pulsed and continuous) and five irrigation levels (40, 60, 80, 100, and 120% of crop evapotranspiration – ETc), with four replications. Pulsed drip irrigation increased the yield of stalks (9%) and sugar (21%) in the sugarcane crop and ethanol (17%) derived from sugar in the juice. Pulsed drip irrigation, when compared to continuous irrigation, improved the performance of sugarcane, providing a reduction in water consumption and increasing growth, stalk yield, sugar and predicted ethanol yield. Thus, based on this study, pulse irrigation is an efficient approach to irrigation management, contributing to the stability of sugarcane production while conserving water relative to continuous irrigation. [ABSTRACT FROM AUTHOR]

AbstractForage legumes face simultaneous abiotic and biotic stresses, causing substantial yield losses. This study explores the combined impacts of drought and Phoma medicaginis infection on the growth and photosynthetic activity of Medicago truncatula contrasting lines TN6.18 and F83005.5. The tolerant TN6.18 line exhibits superior tolerance to combined drought and P. medicaginis infection, manifesting in minimal leaf area reduction, the highest number of healthy leaves, increased carotenoids content, a consistently high and stable photosynthesis rate, and enhanced performance of photosystems PSI and PSII. On the contrary, the sensitive F83005.5 line shows pronounced leaf chlorosis, particularly under drought stress, and decreased pigment levels under the combination of drought and P. medicaginis infection stresses (combined stress). Moreover, the drought-stressed F83005.5, experiences reduced hydration and photosynthetic performance, linked to diminished gas exchange and chlorophyll fluorescence parameters. Chlorophyll fluorescence revealed more severe PSI impairment than PSII under combined stress. In conclusion, understanding the Pm8 infection-drought interaction enhances insights into M. truncatula resistance mechanisms to the combination of these stresses. [ABSTRACT FROM AUTHOR]

Anticipating future impacts of climate warming and aridification on drylands requires understanding how coexisting woody plant species respond to climate variability. However, we lack knowledge of the growth resilience capacity of Mediterranean shrubs. Do coexisting trees and shrubs differ in their response to climate? Do coexisting shrub species have comparable post‐drought growth resilience?This study was conducted in two Mediterranean shrublands with sparse trees in semi‐arid north‐eastern Spain. We selected sites situated in formerly agricultural or grassland areas in two regions subjected to semi‐arid Mediterranean climate conditions. We sampled six shrubs' species (Juniperus phoenicea, Juniperus oxycedrus, Pistacia lentiscus, Pistacia terebinthus, Rhamnus lycioides and Rhamnus alaternus) and one tree species (Pinus halepensis) to measure their radial growth and to reconstruct their past growth patterns using dendrochronology. We quantified climate–growth relationships of trees and shrubs, as well as the growth resilience capacity after drought events of the six shrubs.Growth patterns differed between species but a prevalent trade‐off between growth and longevity was found. Growth responses to climate were comparable between species but differed between sites. Most species responded positively to precipitation and negatively to temperature. The most negative correlations of growth with drought severity were found at the driest Valcuerna site. Shrubs differed in their resilience capacity. Across sites, species were more resistant and resilient in Alcubierre, the wettest site. The shrubs P. terebinthus and R. lycioides were more resistant and resilient than the rest of species, which required longer growth recovery times and accumulated stronger growth reductions, particularly J. phoenicea.Synthesis. These results highlight the importance of drought as a driver of growth in Mediterranean scrublands. Growth resilience strategies differed between species with junipers being less resilient to drought than other coexisting shrubs. Further research should investigate how this difference in post‐drought resilience is related to functional traits, particularly those related with plant water‐use strategies. [ABSTRACT FROM AUTHOR]

The impacts of climate change are reaching unprecedented levels, heightening the risk of species loss and ecosystem service degradation. Wetlands, highly threatened ecosystems, serve vital ecological functions by capturing carbon, filtering water, and harbouring diverse wildlife. Coastal wetlands encounter many challenges, such as increased drought periods and escalating salinity levels, severely impacting plant biodiversity. Assessing how plants respond to various environmental stress factors is imperative for devising successful conservation strategies. In the present study, we examined three representative grass species found in various habitats within the Albufera Natural Park, close to the city of Valencia on the Spanish Mediterranean coast: Imperata cylindrica, Phragmites australis, and Saccharum ravennae. High salinity and water stress conditions were induced by subjecting the plants to irrigation with solutions containing 200, 400, 600, and 800 mM NaCl or withholding irrigation altogether to mimic coastal flooding and drought scenarios. The treatments were maintained until noticeable wilting of the plants occurred, at which point a range of stress biomarkers were determined, including photosynthetic pigments, ions, osmolytes, oxidative stress markers, and antioxidant metabolites, as well as antioxidant enzyme activities. Saccharum ravennae displayed the highest sensitivity to salt stress, whereas I. cylindrica appeared to be the most tolerant. The primary salinity tolerance mechanism observed in I. cylindrica and P. australis was a blockage of ion transport from the root zone to the aerial part, together with the salt-induced accumulation of proline and soluble sugars to high concentrations in the former. No significant effects of the water deficit treatment on the growth or biochemical parameters were observed for any of the analysed species. These findings offer valuable information for the effective management and conservation of coastal wetlands facing the challenges posed by climate change. [ABSTRACT FROM AUTHOR]

As one of the most important food crops, the potato is widely planted in the oasis agricultural region of Northwest China. To ascertain the impact of regulated deficit irrigation (RDI) on various facets including dry matter accumulation, tuber yield, quality and water use efficiency (WUE) of potato plants, a two-growth season field experiment under mulched drip irrigation was conducted in the desert oasis region of Northwest China. Water deficits, applied at the seedling, tuber formation, tuber expansion and starch accumulation stages, encompassed two distinctive levels: mild (55–65% of field capacity, FC) and moderate (45–55% FC) deficit, with full irrigation (65–75% FC) throughout the growing season as the control (CK). The results showed that water deficit significantly reduced (p < 0.05) above-ground dry matter, water consumption and tuber yield compared to CK, and the reduction increased with the increasing water deficit. A mild water deficit at the tuber formation stage, without significantly reducing (p > 0.05) yield, could significantly increase WUE and irrigation water use efficiency (IWUE), with two-year average increases of 25.55% and 32.33%, respectively, compared to CK. Water deficit at the tuber formation stage increased starch content, whereas water deficit at tuber expansion stage significantly reduced starch, protein and reducing sugar content. Additionally, a comprehensive evaluation showed that a mild water deficit at the tuber formation stage is the optimal RDI strategy for potato production, providing a good balance between yield, quality and WUE. The results of this study can provide theoretical support for efficient and sustainable potato production in the desert oasis regions of Northwest China. [ABSTRACT FROM AUTHOR]

Seed germination and seedling development are the most susceptible stages to water deficit in the plant's life cycle. Silicon (Si) treatment was reported as a mitigator of water deficit stress effects for the growth and productivity of many crops. In this context, this study aims to explore the stimulatory effect of exogenous silicon (1.5 mM CaSiO3) application on germination and seedling growth of two chickpeas (Cicer arietinum L.) varieties, Zahor (ZA) and Farihane (FA), under two levels of water deficit, mild (-0.45 MPa) and severe stress (-0.75 MPa), induced using polyethylene glycol (PEG6000) for 8 days. Several germination traits, seedling growth attributes, and embryo reserve mobilization were assessed, as well as the molecules involved in osmoregulation and antioxidant defense systems. The results showed that both stress levels significantly (p < 0.001) reduced seed germination and seedling growth and induced oxidative stress in the studied chickpea varieties. Meanwhile, under severe stress, the Si treatment significantly (p < 0.001) improved the final germination percentage by 92.8% and 45.6%, the fresh weight by 13.5% and 54.16%, the shoot length by 47.8% and 82.14%, and the root length by 48.7% and 95.38% in ZA and FA varieties, respectively. Exogenous Si supply significantly (p < 0.05) counteracted the negative impact of the water deficit on seed germination by improving the reserve mobilization process. Si significantly (p < 0.05) mitigated water deficit-mediated oxidative stress by reducing electrolyte leakage, malondialdehyde, and hydrogen peroxide contents and by enhancing proline accumulation and enzymatic (superoxide dismutase and peroxidase) and non-enzymatic (total polyphenols and flavonoids) antioxidant activities. These findings suggested that Si might confer an improved tolerance of chickpea to the water deficit during germination and seedling growth. [ABSTRACT FROM AUTHOR]

Coffee is one of Brazil's main commodities. Among the goals of crop improvement, the search for drought-tolerant materials has stood out, mainly due to the water scarcity of the producing regions. The knowledge of genetic diversity and the morphophysiological analysis of plants allow the identification of genotypes with potential use in genetic improvement. Thus, this study aimed to evaluate the diversity, by morphophysiological characteristics, in 173 genotypes of Coffea canephora, from populations of contrasting crosses regarding the drought tolerance of the breeding program of Incaper, and to identify the relative importance of traits, subsidizing the selection for drought tolerance, based on the factor analysis index (FAI). The experiment was conducted in three evaluation periods, under field conditions without irrigation at the Incaper Experimental Farm of Marilândia, in the state of Espírito Santo. There was great variability between and within populations, which was affected by the evaluation season. Based on the traits of greater relative importance identified in this work (LL, LW, SLA, LAR, LT, TLA, PBL, CHL, NO3−, TSP, PRO, A, and iWUE), the FAI identified the genotypes 76 × 48 − 1, 76 × 48 − 10, 76 × 48 − 16, 76 × 48 − 76, 76 × 48 − 77, 76 × 48 − 83, 76 × 48 − 90, 76 × 48 − 128, 76 × 04 − 1, and 76 × 04 − 32 as more promising, from the ideotype of lower LL, LW, SLA, and LAR, and higher LT, TLA, PBL, CHL, NO3−, TSP, PRO, A, and iWUE. [ABSTRACT FROM AUTHOR]

Common beans (Phaseolus vulgaris L.), besides being an important source of nutrients such as iron, magnesium, and protein, are crucial for food security, especially in developing countries. Common bean cultivation areas commonly face production challenges due to drought occurrences, mainly during the reproductive period. Dry spells last approximately 20 days, enough time to compromise production. Hence, it is crucial to understand the genetic and molecular mechanisms that confer drought tolerance to improve common bean cultivars' adaptation to drought. Sixty six RNASeq libraries, generated from tolerant and sensitive cultivars in drought time sourced from the R5 phenological stage at 0 to 20 days of water deficit were sequenced, generated over 1.5 billion reads, that aligned to 62,524 transcripts originating from a reference transcriptome, as well as 6673 transcripts obtained via de novo assembly. Differentially expressed transcripts were functionally annotated, revealing a variety of genes associated with molecular functions such as oxidoreductase and transferase activity, as well as biological processes related to stress response and signaling. The presence of regulatory genes involved in signaling cascades and transcriptional control was also highlighted, for example, LEA proteins and dehydrins associated with dehydration protection, and transcription factors such as WRKY, MYB, and NAC, which modulate plant response to water deficit. Additionally, genes related to membrane and protein protection, as well as water and ion uptake and transport, were identified, including aquaporins, RING-type E3 ubiquitin transferases, antioxidant enzymes such as GSTs and CYPs, and thioredoxins. This study highlights the complexity of plant response to water scarcity, focusing on the functional diversity of the genes involved and their participation in the biological processes essential for plant adaptation to water stress. The identification of regulatory and cell protection genes offers promising prospects for genetic improvement aiming at the production of common bean varieties more resistant to drought. These findings have the potential to drive sustainable agriculture, providing valuable insights to ensure food security in a context of climate change. [ABSTRACT FROM AUTHOR]

Introduction: Hairy vetch a plant that can be used in different ways, such as fodder, silage, grazing, and green manure and its seeds can be used to feed poultry. Like other legume family plants, vetch can improve and strengthen the soil and fix nitrogen. Iron (Fe) is an essential micronutrient to virtually all forms of life. Although Fe is the second most abundant metal element in earth's crust its low solubility and high fixation in soil reduce its bioavailability to the plant roots. Fe plays a major role in redox reactions in metabolic processes such as photosynthesis, respiration, and nitrogen assimilation besides being involved in the biosynthesis of chlorophyll and hormones, Drought stress is the most common environmental stress that reduces crop production, and low soil moisture leads to the lack of low consumption elements, especially iron and zinc elements in plants, So With the aim of investigating the effect of foliar application of different sources of iron fertilizer on fodder characteristics of vetch, this research was conducted. Materials and methods: The research was conducted in the agricultural research farm of the Agricultural Jihad Organization in Baneh city in Kurdistan province, at 2021 crop season. The experimental design was implemented as a split plot where different levels of irrigation include no irrigation (rainfed conditions), one irrigation and two irrigations in the main plots, and foliar spraying of different sources of iron fertilizer including, control (spraying solution with water), iron chelate (Fe-EDTA), iron nanochelate (Khizra) and nonchelated source of iron sulfate were placed in sub-plots in three replicates. In the study chlorophyll index, plant height, fresh forage yield, dry fodder yield, Fodder protein percentage, digestibility percentage, ADF, NDF, soluble carbohydrates, crude fiber and ash percent of fodder were measured. Results and discussion: The results showed that the main effect of irrigation and foliar spraying on all investigated traits was significant. Results revealed that the interaction effect of irrigation with iron fertilizer foliar application on chlorophyll index, plant height, digestibility percentage, cell wall NDF, fiber percentage, and ash percentage was a significant, In our study dry conditions, compared to the treatment of two times of irrigation, decreased the wet fodder yield and dry fodder yield and the protein content of fodder by 71.65, 50.16, and 58.58%, respectively, and increased the insoluble fibers in the acidic cell (ADF) by 48.15%. Also, under iron nano chelate treatment of fresh and dry fodder yield, the protein content of the fodder and the content of soluble carbohydrates increased by 84.35, 40.19, 22.90 and 64.08, respectively, and the insoluble fibers in the neutral cell wall (NDF) decreased by 11.60%. Among the interaction treatments of irrigation with the iron foliar application, the highest chlorophyll content (133.45 and 131.04 mg/g fresh weight respectively), plant height (23.81 and 23.43 cm respectively), fodder digestibility percentage (72 42.42 and 77.10% respectively), fiber percentage (37.75 and 40.98 respectively) and fodder ash percentage (19.37 and 21.01% respectively) And the lowest NDF of the cell wall (21.78 and 26.93% respectively) was recorded in the treatment of iron chelate (Fe-EDTA) and iron nano chelate with two times of irrigation. The results of the interaction treatments also showed that iron chelate (Fe-EDTA) under the one-time irrigation treatment could significantly increase the leaf chlorophyll content, the percentage of forage digestibility and the percentage of forage fiber compared to the control treatment. Conclusion: It can be concluded that foliar application of iron fertilizer from sources of iron chelate (Fe-EDTA) and nano-iron chelate (Khizra) with two times of irrigation to achieve the maximum quantitative and qualitative characteristics of the fodder of the cluster flower is recommended, therefore it can be stated that supplementary irrigation and foliar application of iron fertilizer can be a solution to improve the quantitative and qualitative characteristics of fodder in vetch. [ABSTRACT FROM AUTHOR]

Nowadays, as the pressure of drought on water resources increases, new approaches regarding paddy rice irrigation, which has the highest water consumption rate, need to be taken into consideration.One of these approaches is the drip irrigation method, which saves significant amount of water in paddy rice irrigation. In this study, 4 different irrigation programs (25%, 50%, 75% and 100%) in drip irrigation method and ponding methodfor paddy rice in Edirne were examined in TAGEM-SUET. As a result of the study, the evapotranspiration of paddy rice during the production season was calculated as 692.83 mm, the amount of irrigation water was calculated as 162-648 mm in drip irrigation. In the model, it was measured that the optimum drip irrigation program would not cause a decrease in efficiency despite saving 38% of water compared to the ponding method. It is thought that TAGEM-Suet can be a good tool for irrigation planning and management of paddy rice, depending on climatic conditions.

Water deficit (drought) is an important environmental factor affecting physiological processes in plants. The present work focuses on the study of changes in physiological responses of juvenile plants (plants in the vegetative phase of growth BBCH 14-16) of selected sorghum genotypes Dokok, 30485, Barnard Red and Ruzrok to water deficit and after rehydration. Water deficit affected the observed physiological parameters - gas exchange and chlorophyll fluorescence. Genotypic differences were also confirmed, with Dokok appearing to be the more sensitive genotype and Ruzrok and Barnard Red appearing to be tolerant. Following rehydration, these parameters increased but did not reach the levels of the control plants. A significant decrease in photosynthetic rate (Pn), transpiration (E) and fluorescence compared to the control was found in the water-deficient variant twice for 10 days and 6 days between rehydration periods. Only in the variant where water deficit (14 days) was followed by irrigation (10 days) transpiration increased in genotype 30485. Chlorophyll fluorescence (Fv/Fm) also decreased significantly in this cultivar. The results suggest that a rehydration period of 14 days is insufficient to restore the photosynthetic functions of stressed sorghum plants.

The improvement of water consumption efficiency is very significant, especially in arid and semi-arid regions. In this research, the effects of three hydrogel rates (0, 10, and 50 Mg ha-1) and three irrigation regimes (50%, 70%, and 100% of water requirement) on growth, yield, and oil production of Thymus daenensis were studied in a lysimetric experiment. The process of hydrogel synthesis was performed with sodium alginate as the main bone of the polymer and acrylic acid and acrylamide as monomers with the rapeseed meal biochar was made at 300 ºC. The results showed that the essential oil content produced by the plant was impressed by the hydrogel application. The essential oil content increased with an increase in water deficit, but the essential oil yield decreased in the lysimeters with water deficit compared to the ones without water stress. Besides, the application of 50 Mg ha-1 hydrogel caused a 17% increase in the dry matter and a 12% increase in the plant's height. According to the results of this experiment, the application of hydrogel caused the improvement in most characteristics of the Thymus daenensis in water stress conditions.

Abstract Background Fructans are water-soluble carbohydrates that accumulate in wheat and are thought to contribute to a pool of stored carbon reserves used in grain filling and tolerance to abiotic stress. Results In this study, transgenic wheat plants were engineered to overexpress a fusion of two fructan biosynthesis pathway genes, wheat sucrose: sucrose 1-fructosyltransferase (Ta1SST) and wheat sucrose: fructan 6-fructosyltransferase (Ta6SFT), regulated by a wheat ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (TaRbcS) gene promoter. We have shown that T4 generation transgene-homozygous single-copy events accumulated more fructan polymers in leaf, stem and grain when compared in the same tissues from transgene null lines. Under water-deficit (WD) conditions, transgenic wheat plants showed an increased accumulation of fructan polymers with a high degree of polymerisation (DP) when compared to non-transgenic plants. In wheat grain of a transgenic event, increased deposition of particular fructan polymers such as, DP4 was observed. Conclusions This study demonstrated that the tissue-regulated expression of a gene fusion between Ta1SST and Ta6SFT resulted in modified fructan accumulation in transgenic wheat plants and was influenced by water-deficit stress conditions.

Abstract Drought and Pierce’s disease are common throughout many grapevine-growing regions such as Mexico and the United States. Yet, how ongoing water deficits affect infections of Xylella fastidiosa, the causal agent of Pierce’s disease, is poorly understood. Symptoms were observed to be significantly more severe in water-stressed plants one month after X. fastidiosa inoculation, and, in one experiment, titers were significantly lower in water-stressed than well-watered grapevines. Host chemistry examinations revealed overall amino acid and phenolic levels did not statistically differ due to water deficits, but sugar levels were significantly greater in water stressed than well-watered plants. Results highlight the need to especially manage Pierce’s disease spread in grapevines experiencing drought.

Abstract Drought has a significant impact on rice yield by restricting the crop's ability to grow and develop. Producing rice cultivars adapted to water deficit conditions is still the main interest of rice breeders and geneticists. To address this challenge, a set of 413 highly diverse rice populations were evaluated under normal and water deficit conditions for two growing seasons of 2021 and 2022. High genetic variation was found among genotypes for all studied traits. The heritability estimates ranged from 0.82 (panicle length) to 0.95 (plant height). Sterility percentage (SET%) was the most trait affected by water deficit in two growing seasons. 22 Rice genotypes were classified as drought tolerant in both years. Genome-wide association mapping was performed for all traits in the two growing seasons under both conditions using a total of 700,000 SNPs. The GWAS results revealed important and major SNPs associated with all traits. 26 Significant SNPs with stable allele effects were found to be associated with yield traits under water deficit conditions in both years. The results of this study provided rice genotypes that can be adapted under water deficit conditions and important stable SNP markers that can be used for marker-assisted selection after validation in different genetic backgrounds.

Water deficiency has been recognized as a major abiotic stress that causes losses in maize crops around the world. The maize crop is very important due to the range of products that are derived from this plant. A potential way to reduce the damages caused by water deficiency in maize crops is through the association with plant growth-promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF). To define the mechanisms developed by associative PGPB and AMF in maize that are involved in protection against moderate drought (MD), this study evaluated the biometrical, anatomical, biochemical, and physiological parameters of maize grown under MD and inoculated with different PGPB (Azospirillum brasilense strain Ab-V5 and Bacillus sp. strain ZK) and with AMF. The relative water content did not change in the treatments. The association with ZK increased the shoot:total ratio, total dry weight, maximum quantum yield of photosystem II, vascular cylinder thickness, and vascular cylinder area. The Ab-V5 inoculation led to an increment in root dry weight, the area of metaxylem vessel elements, and nitrate reductase activity. The AMF association did not lead to changes in the measured parameters. The results indicate that the association with PGPB is a relevant alternative to contribute to reducing losses in maize crops under drought. However, AMF is not indicated for this crop under drought. [ABSTRACT FROM AUTHOR]

Water scarcity is a significant constraint on agricultural practices, particularly in Colombia, where numerous palm cultivators rely on rainfed systems for their plantations. Identifying drought-tolerant cultivars becomes pivotal to mitigating the detrimental impacts of water stress on growth and productivity. This study scrutinizes the variability in drought responses of growth, physiological, and biochemical variables integral to selecting drought-tolerant oil palm cultivars in the nursery. A comprehensive dataset was compiled by subjecting seedlings of eleven cultivars to four soil water potentials (−0.05 MPa, −0.5 MPa, −1 MPa, and −2 MPa) over 60 days. This dataset encompasses growth attributes, photosynthetic parameters like maximum quantum yield and electron transfer rate, gas exchange (photosynthesis, transpiration, and water use efficiency), levels of osmolytes (proline and sugars), abscisic acid (ABA) content, as well as antioxidant-related enzymes, including peroxidase, catalase, ascorbate peroxidase, glutathione reductase, and superoxide dismutase. Principal Component Analysis (PCA) elucidated two principal components that account for approximately 65% of the cumulative variance. Noteworthy enzyme activity was detected for glutathione reductase and ascorbate peroxidase. When juxtaposed with the other evaluated cultivars, one of the cultivars (IRHO 7001) exhibited the most robust response to water deficit. The six characteristics evaluated (photosynthesis, predawn water potential, proline, transpiration, catalase activity, sugars) were determined to be the most discriminant when selecting palm oil cultivars with tolerance to water deficit. [ABSTRACT FROM AUTHOR]

Raphanus sativus L. is a potential source of raw material for biodiesel fuel due to the high oil content in its grains. In Brazil, this species is cultivated in the low rainfall off-season, which limits the productivity of the crop. The present study investigated the effects of water restriction on the physiological and biochemical responses, production components, and oil quality of R. sativus at different development stages. The treatments consisted of 100% water replacement (control), 66%, and 33% of field capacity during the phenological stages of vegetative growth, flowering, and grain filling. We evaluated characteristics of water relations, gas exchange, chlorophyll a fluorescence, chloroplast pigment, proline, and sugar content. The production components and chemical properties of the oil were also determined at the end of the harvest cycle. Drought tolerance of R. sativus was found to be mediated primarily during the vegetative growth stage by changes in photosynthetic metabolism, stability of photochemical efficiency, increased proline concentrations, and maintenance of tissue hydration. Grain filling was most sensitive to water limitation and showed a reduction in yield and oil content. However, the chemical composition of the oil was not altered by the water deficit. Our data suggest that R. sativus is a drought-tolerant species. [ABSTRACT FROM AUTHOR]

This study investigated the impact of stress modifiers in intercropping systems on seed yield and yield components, physiological traits, and antioxidant activity of safflower (Carthamus tinctorius L.) and chickpea (Cicer arietinum L.) under rainfed (water deficit) conditions. The experimental design included three stressmodulator levels [control, 1 mM salicylic acid (SA), and 10 mM selenium (Se)] and five planting patterns [intercropping one row of safflower and two rows of chickpeas (1S:2C), two rows of safflower and four rows of chickpeas (2S:4C), and three rows of safflower and five rows of chickpeas (3S:5C), and sole cropping of safflower (Ss) and chickpea (Cs)]. The results revealed that Ss treated with Se produced the highest safflower biological yield (4,905.50 kg ha-1) and seed yield (1,259.50 kg ha-1), while Cs produced the highest chickpea biological yield (2,799.67 kg ha-1) and seed yield (852.44 kg ha-1), followed by Cs treated with SA (2,419.25 kg ha-1 and 764.83 kg ha-1, respectively). Conversely, the 3S:5C intercropping ratio (IR) with Se application recorded the highest safflower oil content (32.08%), while Ss treated with Se produced the highest oil yield (358.62 kg ha-1). The 2S:4C configuration with Se application produced the highest unsaturated fatty acid (oleic and linoleic acids) concentrations in safflower, while 2S:4C and 3S:5C treated with Se produced the highest chlorophyll a and chlorophyll b contents in safflower and chickpea. Furthermore, 1S:2C and 2S:4C treated with SA or Se produced the highest proline and total soluble sugars in safflower and chickpea. The SA and Se treatments in the intercropping systems increased catalase, ascorbate peroxidase, and superoxide dismutase activities compared to the respective control plants (sole cropping) and enhanced oil contents, fatty acid composition, physiological traits, and antioxidant properties. These results underscore the potential of intercropping systems coupled with stress modulator treatments as a sustainable approach for safflower and chickpea cultivation under rainfed conditions. [ABSTRACT FROM AUTHOR]

Irrigation scheduling, coupled with the use of biofertilizers, constitutes an effective management strategy to overcome soil drought. This study aimed to assess the individual and combined effects of three selected biofertilizers—(R) Bacillus sp. and Bacillus subtilis, (M) native arbuscular mycorrhizal fungi, and (C) compost—on Triticum durum L. The agro-physiological and biochemical traits, along with the soil properties, were evaluated under two different water regimes, 100% crop evapotranspiration (ETc) for the well-watered regime and 30% ETc for the drought-stressed regime under field conditions, using a drip irrigation system. Drought stress (DS) led to significant reductions in the biomass, physiological parameters, and biochemical markers. Furthermore, the application of CM and MR significantly boosted the shoot and root dry weight by 137% and 72%, respectively, under DS compared to the control. Moreover, CM and R resulted in a notable increase of 167% and 130% in the grain and straw yield, respectively, under the same conditions. The normalized difference vegetation index showed improved values in the plants inoculated with MR and CMR, respectively, under DS conditions. Additionally, the soil quality was positively influenced by the application of M and/or R and/or C biofertilizers. These findings provide valuable insights into the intricate soil–plant interactions and the beneficial effects of combined biofertilizers in enhancing wheat's resilience to drought stress. [ABSTRACT FROM AUTHOR]

Drought may considerably decrease the growth and yield of potatoes. Small tubers may have lower performance and be more sensitive to abiotic stresses than larger tubers. Since an increase in drought areas may be expected, the development of potato varieties with drought tolerance has become necessary. Two-year greenhouse experiments were conducted to test the drought tolerance of potato breeding lines (C103, C107, C20) with great osmotic stress tolerance. Minitubers with diameters of 25–35, 20–24, 15–19 and 10–14 mm were planted. Treatments were the optimal irrigated control (100%) and moderate and severe drought (60% and 20% of optimum water supply). To study the after-effects of drought, tubers from different treatments were planted separately the following year because seed tuber priming may increase drought tolerance. Seed tubers (25–35 mm), two irrigation treatments (control and severe drought), and two control cultivars were used in the second year. We observed the rate of emergence from day-after-planting (DAP) 20 to 30 and flowering from 48 to 54. NDVI measurements were performed on the DAP35-45-75. Plant height and fresh weight of aboveground biomass (AGB) were recorded on DAP76. Harvested tubers were counted, weighed, and size-categorized, and then the number and fresh tuber yield per plant (TN and TY) were calculated. Stress indices (SI) were calculated as percentages of the results of control plots to compare the responses of genotypes to drought stress. We found that each breeding line showed adequate drought tolerance, although only the C103 and C107 breeding lines were stable in in vivo conditions. SI values for tuber number/tuber yield were 103/57; 102/63; 83/52; 80/58 and 55/41 in C103, C107, C20, 'Boglárka' and 'Desiree' (the last two were control varieties), respectively. The size of the seed tuber significantly affected each character, and usually minitubers larger than 20 mm performed better than smaller ones. No significant after-effect of drought stress on the next generation was found. Although we found a positive correlation (r = 0.83) between NDVI values and yield parameters, the correlations in our study were not consistent in all genotypes and water treatments. [ABSTRACT FROM AUTHOR]

Water stress can lead to physiological and morphological damage, affecting the growth and development of popcorn. The objective of this study was to identify the yield potential of 43 popcorn lines derived from a Latin American germplasm collection, based on agronomic and physiological traits, under full irrigation (WW) and water deficit conditions (WS), aiming to select superior germplasm. The evaluated agronomic traits included the ear length and diameter, number of grains per row (NGR) and rows per ear (NRE), grain yield (GY), popping expansion (EC), volume of expanded popcorn per hectare (VP), grain length (GL), width, and thickness. The physiological traits included the chlorophyll, anthocyanin, and flavonoid content in the leaves. The genetic variability and distinct behavior among the lines for all the agronomic traits under WW and WS conditions were observed. When comparing the water conditions, line L292 had the highest mean for the GY, and line L688 had the highest mean for the EC, highlighting them as the most drought-tolerant lines. A water deficit reduced the leaf greenness but increased the anthocyanin content as an adaptive response. The GY trait showed positive correlations with the VP, NGR, and GL under both water conditions, making the latter useful for indirect selection and thus of great interest for plant breeding targeting the simultaneous improvement of these traits. [ABSTRACT FROM AUTHOR]

A positive relationship between protein concentration and yield has been documented in different combinations of genotype and environment, often under potential conditions. However, the ecophysiological bases underlying this positive relationship under heat stress (HS) and drought stress (DS) during seed filling are still lacking. Our objective was to evaluate the relationship between seed protein content and concentration with yield in field experiments exposed to HS, DS and HS × DS interaction during the seed filling. Two field experiments were conducted and assimilates accumulation, remobilization and redistribution patterns were analysed in high and low seed protein soybean genotypes. The crop was exposed to four treatments: control (ambient temperature and soil water content near field capacity), HS (episodes above 32°C, 6 h d−1) during 15 days, DS (soil water content ≤25% of field capacity) during the whole seed filling and HS × DS. Significant and positive relationships between seed protein content and concentration with yield were observed across treatments and genotypes. Under DS and HS × DS, assimilates available during the seed filling decreased, and assimilates remobilization and partition to seeds were limited, responses significantly associated with seed protein content and concentration, and yield reductions. Furthermore, we demonstrated here that the high leaf N content at the beginning of seed filling, the short early reproductive phase duration, the high source to sink ratio and the high dry matter stem remobilization capacity, as well as the low seed number and high seed weight are intrinsic characteristics of the high protein genotype that could be associated with its high seed protein content and concentration and yield under stressful conditions. This knowledge is key to develop soybean management strategies to improve seed protein level and yield under contrasting productive scenarios. [ABSTRACT FROM AUTHOR]

Background: Drought stress during flowering of maize (Zea mays L.) frequently results in decreased kernel setting, leading to grain yield depressions. Plasma membrane (PM) H+‐ATPase was identified as a key enzyme responsible for supply of assimilates to the developing maize kernels shortly after pollination. The activity of this enzyme was strongly inhibited under salt stress, pointing to an involvement in kernel abortion. Aims: This study aimed to determine whether also drought stress causes inhibition of PM H+‐ATPase in developing maize kernels shortly after pollination, leading to diminished hexose uptake and finally kernel abortion. The key questions are as follows: What are the limiting factors for grain yield production of maize plants facing drought? Are physiologically relevant parameters, quantified at flowering, reflected by yield determinants at maturity? Methods: Maize plants were cultivated using the container technique, and drought stress was imposed during 3 weeks bracketing flowering compared to well‐watered conditions throughout the entire growth period. The developing kernels were harvested 2 days after pollination, and PM vesicles were isolated and purified using two‐phase partitioning. Results: Water deficit caused a significant decrease in grain yield at maturity (−35%), which was determined by a reduced kernel number (−42%). Source limitation in the developing kernels under stress could be excluded. Acid invertase activity was unaffected by water deficit. Hexose availability was also no limiting factor for kernel setting and development. However, Vmax of in vitro hydrolytic activity of PM H+‐ATPase was significantly decreased in the developing maize kernels under drought stress and the maximal pH gradient at the PM was also significantly reduced. The observed inhibiting effects on PM H+‐ATPase were mainly of quantitative nature, as a lower number of proton pumps was present in the kernel PM. Qualitative changes of the enzyme (activation energy Ea, Michaelis constant Km) due to drought were not observed. Conclusions: The lower pH gradient probably decreased the proton‐driven transport of hexoses by carriers into the cytosol of the kernel cells, leading to kernel starvation and eventually contributing to kernel abortion. [ABSTRACT FROM AUTHOR]

The impact of water deficit severity and the specific growth stages at which water stress is applied have been found to have significant implications for both tomato yield and fruit quality. Recent findings have highlighted the influence of water deficits during the reproductive phase on tomato fruit quality. This study aimed to assess the effects of deficit irrigation on tomato fruit quality and overall plant productivity. Cherry tomatoes (Solanum lycopersicum var. cerasiforme) were grown in a greenhouse from August to November 2022. Three distinct watering regimes were implemented: Daily watering (T1), watering every 3 days (T2) and watering every 7 days (T3), starting from the flowering stage and continuing through subsequent plant development stages. The mean soil metric potentials (SMP) were -4.9, -29.7 and -52.8 kPa for T1, T2 and T3, respectively. Various traits of fruit size, fruit biomass, total soluble solids (TSS), water content, glucose content and lycopene content were measured. Additionally, the overall plant biomass and root-to-shoot ratio were evaluated. The results revealed that traits of the fruit size, such as diameter, length, volume and fresh weight, were most favorable when plants were subjected to the T2 watering regime, while higher and lower watering frequencies led to smaller fruit sizes. Interestingly, the TSS concentration had the most pronounced response to drought stress, indicating increased fruit sweetness. However, the fruit water content, glucose content and lycopene content remained unaffected by the different watering regimes. Furthermore, plants subjected to the T3 with the minimum SMP at -196.4 kPa exhibited enhanced development of the root system, prioritizing resource acquisition such as water and mineral nutrients over shoot components. In conclusion, this study provided valuable insights for agricultural practitioners, offering a range of alternatives that can inform optimal irrigation strategies that effectively enhance the quality of cherry tomato yields. [ABSTRACT FROM AUTHOR]

In agroforestry systems, such as integrated crop-livestock-forest (iCLF), the agricultural, livestock and arboreal components are explored in the same field in rotation, succession or intercropping. Our objective was to investigate if the diameter growth of eucalyptus in agroforestry systems differs from those cultivated as a planted forest, as well as to assess whether there is a difference in its growth in face of the air temperature and precipitation. The study was held at Ponta Porã, Brazil, a region of humid subtropical climate with hot summers and soil classified as Oxisol, which is fertile, deep and clayey. Dendrometer bands measured the diameter growth of eucalyptus (Eucalyptus urograndis) cultivated as a forest and in iCLF, with eucalyptus rows distance of 12.5 × 12.5 m, 12.5 m one side × 25 m another side and 25 × 25 m. The study took place from four years and nine months after transplanting till six years and seven months (22 months monitoring). On iCLF, the inter-row was explored with grain crops (soybean or corn) and pasture. Climate data of air temperature and precipitation were used to investigate their influence or not on diameter growth. Eucalyptus diameter growth is higher when cultivated in agroforestry systems and this growth is as higher as larger is the distance between eucalyptus rows. Precipitation proved to strongly and positively influence the diameter growth, especially when cultivated in agroforestry systems. On the other hand, under the conditions of this study, air temperature showed little or no correlation with eucalyptus diameter growth. [ABSTRACT FROM AUTHOR]

In the perspective of current climate variability and the impact of human activities on water overexploitation, it is essential to analyze dry and wet episodes for a better prevention and rationalization of water resources. The Mediterranean region and particularly the southern shore, is a drought sensitive area. Algeria, like most Mediterranean countries has experienced alternating dry and wet periods in recent decades. Several climatic events have had a negative impact on agriculture, industry and drinking water supply. As a result, human societies and ecosystems are under increasing threat requiring new adaptations of life and economic models to support these upheavals. The present study focuses on monitoring of the meteorological drought evolution in the Isser wadi watershed, located in the north-central part of Algeria, based on available rainfall data covering a 43-year period from 1973 to 2016. The current study has made it possible to account for the extreme variability of rainfall in this watershed. In order to do this, different indices were studied in this work, namely the normalized precipitation index SPI, the rainfall deficit index RDI, and the drought index DI. All The obtained results have highlighted the severe and sustainable character of the climatic drought observed in the Isser basin from 1973 to 2002 as well as the return to a wet phase, well pronounced in the north of the basin from 2003 to 2016. Finally, in order to better understand this work, index maps tools for decision-making have been established. [ABSTRACT FROM AUTHOR]

Scarcity and quality of irrigation water restrict sustainability of wheat production in arid and semi-arid regions. Deficit saline irrigation up to 65% of full water requirement can reduce the salt load along with water saving. Plant bioregulators (PBRs) are phytohormones that regulate physiological and biochemical reactions in plants and respond to variety of abiotic stresses. But the field scale quantification of mitigating effect of PBRs application at representative sites having multiple stresses (deficit water and salinity) is rare. Present study was carried out for two successive years from 2016–17 to 2017–18 at ICAR-Central Soil Salinity Institute (ICAR-CSSRI) research farm, Nain, Panipat, Haryana, India, to assess the effectiveness of two PBRs, i.e., salicylic acid (SA) and thiourea (TU). In a triple replicated, split–split design experiment, two PBRs applied as seed priming and foliar sprays at booting and milking (critical stages) stages in alleviation of adverse effects of deficit (60, 80 and 100% of crop evapo-transpiration) and saline (ECiw; 2, 4, 8, 12 dS m−1) irrigation on wheat variety KRL 210. The grain yield reduction under 8 and 12 dS m−1 were 7.68 and 32.93%, respectively. Higher irrigation amount using highest salinity water (100% ETc + 12 dS m−1) caused maximum reduction in grain yield. Application of SA and TU increased grain yield by 12.90 and 17.36%, respectively. Water and salinity (≥ 8 dS m−1) adversely affected the spikes and grains number (m−2), relative water content (RWC), proline, membrane injury (MI), Fv/Fm, chlorophyll content (Chl) and Na/K ratio. Positive response of PBRs increased with increasing intensity of both the stresses. At mild salinity (4 dS m−1), SA performed better than TU, but at severe salinity (12 dS m−1), TU performed better than SA. The study concluded that the application of SA and TU effectively ameliorated the salinity and drought stress in wheat. [ABSTRACT FROM AUTHOR]

Little attention is paid to the mitigating effect of different potassium (K) levels on sesame (Sesamum indicum L.) growth performance in response to drought stress (DS). A pot experiment was performed under DS conditions along with four K levels (0, 60, 120 and 180 kg ha−1, denoted as DK0, DK1, DK2 and DK3 respectively), and 120 kg ha−1 of K2O application under normal watering was set as control (CK). Results showed that the plant height, specific leaf weight, leaf water content, chlorophyll content, crop growth rate and biomass were significantly decreased by 6.9%, 15.3%, 7.3%, 17.9%, 55.6% and 34.1%, respectively, as compared to CK whereas K could alleviate the adverse effects of drought on the aforementioned parameters, and the mitigation was more prominent as K rates increased. The decrease in capsule number per plant (1.72 g) primarily accounted for yield loss (1.95 g) induced by DS. Expectedly, K supply compensated for the yield reduction to an extent and the maximum compensation was recorded under DK3, which increased by 50.0% as compared to DK0. Additionally, enhanced yield and yield components were positively correlated with K accumulation as it was further evidenced by significantly increased K uptake in plant tissues. For every extra 1 g of K absorbed by the plant, the yield per plant would increase by 16 g However, the K utilization efficiency showed a downward trend along with increased exogenous K supply under DS. In conclusion, K application at the rate of 120 kg ha−1 is an economical and effective approach for alleviating drought susceptibility in sesame crops. [ABSTRACT FROM AUTHOR]

Simple Summary: This research article investigates the ploidy's impact on daylilies' (Hemerocallis spp.) response to water deficit conditions. By analyzing the morphological and physiological changes in diploid and tetraploid plants under drought stress, this study aims to elucidate the adaptive mechanisms that contribute to their differential tolerance levels. The results reveal distinct responses in the chlorophyll content, flavonoid accumulation, and nitrogen balance between the two ploidy groups, highlighting the superior stress resistance of tetraploid daylilies. The conclusions emphasize the importance of considering ploidy in understanding plant responses to drought stress and suggest the potential for cultivating drought-tolerant varieties to mitigate water scarcity challenges. This study's insights hold significant value for society by informing strategies for sustainable floriculture, enhancing greenery resilience to climate change, and promoting water-efficient plant breeding practices. This study aimed to understand the differences in the performance of diploid and tetraploid daylily cultivars under water deficit conditions, which are essential indicators of drought tolerance. This research revealed that tetraploid daylilies performed better than diploid varieties in arid conditions due to their enhanced adaptability and resilience to water deficit conditions. The analysis of the results highlighted the need to clarify the specific physiological and molecular mechanisms underlying the enhanced drought tolerance observed in tetraploid plants compared to diploids. This research offers valuable knowledge for improving crop resilience and sustainable floricultural practices in changing environmental conditions. The morphological and physiological parameters were analyzed in 19 diploid and 21 tetraploid daylily cultivars under controlled water deficit conditions, and three drought resistance groups were formed based on the clustering of these parameters. In a high drought resistance cluster, 93.3% tetraploid cultivars were exhibited. This study demonstrates the significance of ploidy in shaping plant responses to drought stress. It emphasizes the importance of studying plant responses to water deficit in landscape horticulture to develop drought-tolerant plants and ensure aspects of climate change. [ABSTRACT FROM AUTHOR]

Ascorbic Acid (AsA) is a water-soluble antioxidant that makes plants resistant to environmental stresses by neutralizing free radicals. However, it is unknown to what extent this antioxidant may help Improve Irrigation Water Use Efficiency (IWUE) and reduce the adverse effects of water deficit on mung bean growth and yield. In an attempt to clarify whether exogenous application of this antioxidant could alleviate the adverse effects of water deficit on mung bean plants, two seasons (2019 and 2020) of field experiments were conducted using twelve combinations of three AsA levels (distilled water as a control and 10 and 20 mM of AsA) and four irrigation water amounts (25, 50, 75, and 100% of the plant water requirement). Based on the results, the maximum IWUE was obtained with W50AsA50 in the two seasons. The beneficial effect of AsA application on IWUE was determined under water stress conditions (W50). High water deficit (W50) plus applying 50 mM ascorbic acid, i.e. W(50)AsA(50) treatment, improved seed yield about 43.7% as in the two seasons compared to high water deficit without ascorbic acid, i.e. W(50)AsA(0). In 2019 and 2020, water saving in W(50)AsA(20) compared to the control, was equal to 50% (2,550 and 2,500 m3 ha-1, respectively). In W(50)AsA(20) treatment, the increase of seed yield ranged between 79-107% in both seasons. Thus, the results reveal the potency of AsA to save water under low water supply and increase yield in mung bean fields. [ABSTRACT FROM AUTHOR]

Water availability is a limiting factor to plant development and productivity. Many drought‐induced physiological processes that affect patterns of growth, biomass allocation, and ultimately, yield, are also regulated by the red/far‐red photoreceptor phytochromes (PHYs). However, as the mechanisms and responses to drought stress vary among plant developmental phases, it is reasonable to conjecture that PHY‐dependent morphophysiological responses to drought may be different according to the plant growth stage. In this study, we submitted tomato phyB1 mutant plants to water deficit in two distinct growth stages, during vegetative and flower‐bearing reproductive phases, comparing the morphophysiological development, fruit yield and quality to wild‐type (WT). In general, phyB1 plants overcome growth limitations imposed by water availability limitations during vegetative phase, being taller and leafier than WT. Restrictions to growth are less acute for both genotypes when water deficit occurs during reproductive phase compared to vegetative phase. phyB1 yield is lower when water is limited during reproductive phase, but its fruits accumulate more soluble solids, associated with better quality. These results highlight that drought‐induced modulations in tomato growth and yield are dependent upon PHYB1 regulation and the developmental phase when water deficit is applied. [ABSTRACT FROM AUTHOR]

The contribution of Eucalyptus globulus plantations to timber production for pulp, paper and energy production may be hampered by climate change. It is expected that Eucalyptus productivity may be affected through drought stress and changes to both pathogen distribution/pathogenicity and host–pathogen interactions. The impact of the fungal pathogen Neofusicoccum kwambonambiense on E. globulus, causing cankers and dieback, is well known but the impact of drought on disease development is still understudied. Our aim was to study the effect of drought on N. kwambonambiense infection by inoculating E. globulus plants under well‐watered conditions or with water limitation. Non‐infected plants for both water regimes were also analysed. Morphophysiological, biochemical and hormonal parameters were assessed 65 days post‐inoculation. Inoculation under conditions of water stress decreased water potential and photosynthetic efficiency and increased abscisic acid, jasmonic acid and lipid peroxidation. Water‐stressed infected plants also showed higher fungal colonization and external lesion length in comparison with well‐watered inoculated plants. Our results indicate that drought increased E. globulus predisposition to N. kwambonambiense infection and may also have promoted a change in the lifestyle of the fungus. Identifying host–pathogen interaction responses under different stress conditions is necessary to provide knowledge for decision‐making in the management of forest systems in general and of Eucalyptus production in particular. [ABSTRACT FROM AUTHOR]

The interaction of root hemi-parasite (sandalwood) with its hosts is crucial for establishing successful plantations under abiotic stresses. In the present study, we explored the best possible host for sandalwood along with its effect on sandalwood physiology in terms of water and nutrients. Interactive effects of host species (Alternanthera sp., Azadirachta indica, Dalbergia sissoo, Melia dubia, and Aquilaria malaccensis) with sandalwood were observed under eight treatments {100% best available water (BAW); 100% BAW + nutrient medium; 50% water deficit; 50% water deficit + nutrient medium; 100% saline water (ECiw 8ds/m); 100% saline water (ECiw 8ds/m) + nutrient medium; 50% water deficit + saline water (ECiw 8ds/m); and 50% water deficit + saline water (ECiw 8ds/m) + nutrient medium}. A significant change in morpho-physiological traits of sandalwood roots was observed under different stress conditions, which were slightly improved through external supply of nutrient medium. Dalbergia sissoo (Shisham) and Melia dubia (Dek) seemed to be the best host plants providing better environment for sandalwood growth and development, i.e., higher plant height (59.7 and 53.68 cm) and collar diameter (3.24 and 3.07 mm) under stresses by maintaining water and ionic balance. Root length is an important parameter that was reduced by 27.58%, 19.22%, and 36.3% under water deficit, salinity, and combined stress of water deficit and salinity. Sandalwood grown with D. sissoo and M. dubia maintained the lowest Ψw (− 1.38 MPa) and Ψs (− 1.47 and − 1.48 MPa), respectively. In addition, sandalwood cultivated with D. sissoo and A. indica had higher accumulation of soluble proteins (0.48 and 0.42 mg/g) and soluble sugars (98.56 and 91.04 mg/g) in their roots. Results also showed that sandalwood roots had higher K+/Na+ with compatible host, i.e., with A. indica (1.85) and D. sissoo (1.83) than other studied hosts. It was also observed that sandalwood plants could not grow and survive alone under stress conditions even with application of nutrient medium. Based on the morphological traits, it was observed that sandalwood grown with hosts, Dalbergia sissoo and Melia dubia, was able to tolerate stress conditions better than other studied hosts. We can further recommend growing sandalwood with D. sissoo and M. dubia as a viable option to endure adverse environmental conditions. [ABSTRACT FROM AUTHOR]

Approaches for remote sensing can be used to estimate the influence of changes in environmental conditions on terrestrial plants, providing timely protection of their growth, development, and productivity. Different optical methods, including the informative multispectral and hyperspectral imaging of reflected light, can be used for plant remote sensing; however, multispectral and hyperspectral cameras are technically complex and have a high cost. RGB imaging based on the analysis of color images of plants is definitely simpler and more accessible, but using this tool for remote sensing plant characteristics under changeable environmental conditions requires the development of methods to increase its informativity. Our review focused on using RGB imaging for remote sensing the characteristics of terrestrial plants. In this review, we considered different color models, methods of exclusion of background in color images of plant canopies, and various color indices and their relations to characteristics of plants, using regression models, texture analysis, and machine learning for the estimation of these characteristics based on color images, and some approaches to provide transformation of simple color images to hyperspectral and multispectral images. As a whole, our review shows that RGB imaging can be an effective tool for estimating plant characteristics; however, further development of methods to analyze color images of plants is necessary. [ABSTRACT FROM AUTHOR]

The PlantEye multispectral scanner is an optoelectrical sensor automatically applied to a mechatronic platform that allows the non-destructive, accurate, and high-throughput detection of morphological and physiological plant parameters. In this study, we describe how the advanced phenotyping platform precisely assesses changes in plant architecture and growth parameters of wild rocket salad (Diplotaxis tenuifolia L. [DC.]) under drought stress conditions. Four different irrigation supply levels from moderate to severe, required to keep 100, 70, 50, and 30% of the water-holding capacity, were adopted. Growth rate and plant architecture were recorded through the digital measure of biomass, leaf area, Canopy Light Penetration Depth, five convex hull traits, plant height, Surface Angle Average, and Voxel Volume Total. Vegetation color assessments included hue, lightness, and saturation. Vegetation and senescence indices were calculated from canopy reflectance in the red (620–645 nm), green (530–540 nm), blue (peak wavelength 460–485 nm), near-infrared (820–850 nm), and 3D laser (940 nm) ranges. The temperature, relative humidity, and solar radiation of the environment were also recorded. Overall, morphological parameters, color, multispectral data, and vegetation indices provided over 7200 data points through daily scans over three weeks of cultivation. Although a general decrease in growth parameters with increasing stress severity was observed, plants were able to maintain the same morpho-physiological performances as the control during the early growth stages, keeping both 70% and 50% of the total water-holding capacity. Among indices, the Normalized Differential Vegetation Index (NDVI) contributed the most to the differentiation between different stress levels during the cultivation cycle. Across the 3 weeks of growth, statistically significant differences were observed for all traits except for the Saturation Average. Comparisons with respect to the control highlighted the strong impact of drought stress on morphological plant traits. This study provided meaningful insights into the health status of wild rocket salad under increasing drought stress. [ABSTRACT FROM AUTHOR]

Background: Fructans are water-soluble carbohydrates that accumulate in wheat and are thought to contribute to a pool of stored carbon reserves used in grain filling and tolerance to abiotic stress. Results: In this study, transgenic wheat plants were engineered to overexpress a fusion of two fructan biosynthesis pathway genes, wheat sucrose: sucrose 1-fructosyltransferase (Ta1SST) and wheat sucrose: fructan 6-fructosyltransferase (Ta6SFT), regulated by a wheat ribulose-1,5-bisphosphate carboxylase/oxygenase small subunit (TaRbcS) gene promoter. We have shown that T4 generation transgene-homozygous single-copy events accumulated more fructan polymers in leaf, stem and grain when compared in the same tissues from transgene null lines. Under water-deficit (WD) conditions, transgenic wheat plants showed an increased accumulation of fructan polymers with a high degree of polymerisation (DP) when compared to non-transgenic plants. In wheat grain of a transgenic event, increased deposition of particular fructan polymers such as, DP4 was observed. Conclusions: This study demonstrated that the tissue-regulated expression of a gene fusion between Ta1SST and Ta6SFT resulted in modified fructan accumulation in transgenic wheat plants and was influenced by water-deficit stress conditions. [ABSTRACT FROM AUTHOR]

Drought and Pierce's disease are common throughout many grapevine-growing regions such as Mexico and the United States. Yet, how ongoing water deficits affect infections of Xylella fastidiosa, the causal agent of Pierce's disease, is poorly understood. Symptoms were observed to be significantly more severe in water-stressed plants one month after X. fastidiosa inoculation, and, in one experiment, titers were significantly lower in water-stressed than well-watered grapevines. Host chemistry examinations revealed overall amino acid and phenolic levels did not statistically differ due to water deficits, but sugar levels were significantly greater in water stressed than well-watered plants. Results highlight the need to especially manage Pierce's disease spread in grapevines experiencing drought. [ABSTRACT FROM AUTHOR]

Drought has a significant impact on rice yield by restricting the crop's ability to grow and develop. Producing rice cultivars adapted to water deficit conditions is still the main interest of rice breeders and geneticists. To address this challenge, a set of 413 highly diverse rice populations were evaluated under normal and water deficit conditions for two growing seasons of 2021 and 2022. High genetic variation was found among genotypes for all studied traits. The heritability estimates ranged from 0.82 (panicle length) to 0.95 (plant height). Sterility percentage (SET%) was the most trait affected by water deficit in two growing seasons. 22 Rice genotypes were classified as drought tolerant in both years. Genome-wide association mapping was performed for all traits in the two growing seasons under both conditions using a total of 700,000 SNPs. The GWAS results revealed important and major SNPs associated with all traits. 26 Significant SNPs with stable allele effects were found to be associated with yield traits under water deficit conditions in both years. The results of this study provided rice genotypes that can be adapted under water deficit conditions and important stable SNP markers that can be used for marker-assisted selection after validation in different genetic backgrounds. [ABSTRACT FROM AUTHOR]

Barley is a staple crop of major global importance and relatively resilient to a wide range of stress factors in the field. Transgenic reporter lines to investigate physiological parameters during stress treatments remain scarce. We generated and characterized transgenic homozygous barley lines (cv. Golden Promise Fast) expressing the genetically encoded biosensor Grx1–roGFP2, which indicates the redox potential of the major antioxidant glutathione in the cytosol. Our results demonstrated functionality of the sensor in living barley plants. We determined the glutathione redox potential (E GSH) of the cytosol to be in the range of –308 mV to –320 mV. E GSH was robust against a combined NaCl (150 mM) and water deficit treatment (–0.8 MPa) but responded with oxidation to infiltration with the phytotoxic secretome of the necrotrophic fungus Botrytis cinerea. The generated reporter lines are a novel resource to study biotic and abiotic stress resilience in barley, pinpointing that even severe abiotic stress leading to a growth delay does not automatically induce cytosolic E GSH oxidation, while necrotrophic pathogens can undermine this robustness. [ABSTRACT FROM AUTHOR]

A common garden trial with 18-month-old trees from 64 half-sib families of Pinus patula was established to identify genetic variation in growth and survival in response to drought for four months (November 25, 2020 to March 25, 2021, winter). A split-plot design with two moisture levels (Irrigation S0 = 40 - 55 % and Drought S1 = 20 - 39 % volumetric moisture) was used in large plots and families in small plots. At the beginning and end of the trial, the height (HT), diameter of the base (DB), and number of whorls and branches were determined, and the absolute (AGR) and relative (RGR) growth rates in HT and DB were calculated. Differences were found between the moisture levels during growth. Survival was 71 % in S0 and 60 % in S1. In S1, AGR in HT and DB was affected by 52 and 38 %, and RGR by 46 and 32 %, respectively, with respect to S0. In S0, 31.4 % of the plants formed one whorl and 2.1 % two, in S1 only 13.4 % and 0.2 % did. Genetic control was moderate in the joint environments with h²i between 0.03 and 0.17 and h²f between 0.15 and 0.53. The performance of the families between the two humidity conditions was stable (rB from 0.71 to 1.0) in all variables, with greater genetic variation in S0 than in S1. Moderate genetic variability was observed in the growth of Pinus patula families under water restriction. [ABSTRACT FROM AUTHOR]

Drought strongly limits tomato yield, and the introgression of genes from wild tomatoes is a powerful tool to obtain drought‐tolerant progenies. The aim of this study was to select drought‐tolerant transgressive progeny obtained from interspecific crosses between drought‐susceptible tomatoes (Solanum lycopersicum) × drought‐tolerant wild species (Solanum pennellii) under in vitro and greenhouse conditions. BC1F2 populations were advanced from backcrosses between F1 × Jumbo AG‐592 (cultivar for fresh consumption) and F1 × BRS Tospodoro (cultivar for industrial processing). For this, BC1F2 seeds were germinated in vitro and evaluated for tolerance to drought. Then, eight genotypes from each BC1F2 were selected and submitted to 14 days of drought (0% of water supply) or well‐watered (100% of water supply) in greenhouse conditions and evaluated for growth, water balance and gas exchanges. Using in vitro assays with mannitol‐induced drought proved to be effective for the initial screening of drought‐tolerant BC1F2 plants, while greenhouse experiments showed that drought decreased photosynthesis in all genotypes, but almost all the BC1F2 progenies had greater photosynthetic capacity, water balance and growth than their commercial parents. As a result, we selected six progenies for fresh consumption and six progenies for industrial processing with increased drought tolerance. [ABSTRACT FROM AUTHOR]

The improvement of water consumption efficiency is very significant, especially in arid and semi-arid regions. In this research, the effects of three hydrogel rates (0, 10, and 50 Mg ha-1 ) and three irrigation regimes (50%, 70%, and 100% of water requirement) on growth, yield, and oil production of Thymus daenensis were studied in a lysimetric experiment. The process of hydrogel synthesis was performed with sodium alginate as the main bone of the polymer and acrylic acid and acrylamide as monomers with the rapeseed meal biochar was made at 300 ºC. The results showed that the essential oil content produced by the plant was impressed by the hydrogel application. The essential oil content increased with an increase in water deficit, but the essential oil yield decreased in the lysimeters with water deficit compared to the ones without water stress. Besides, the application of 50 Mg ha-1 hydrogel caused a 17% increase in the dry matter and a 12% increase in the plant's height. According to the results of this experiment, the application of hydrogel caused the improvement in most characteristics of the Thymus daenensis in water stress conditions. [ABSTRACT FROM AUTHOR]

Background: Recently, multipurpose and biomass canes have become important in breeding. However, biomass sampling is limited in early generation selection. The surrogate traits that represent biomass performance need to be established, especially using non-destructive sampling. Therefore, the objective of this study was to determine the correlation between agronomic and physiological traits and the biomass of a diverse set of sugarcane genotypes under different drought durations. Methods: The experiment was conducted under field conditions and arranged in a split plot in a randomized complete block design with four replications. The main plot was represented by three drought durations: no water stress, short-term drought and long-term drought and the subplot consisted of six sugarcane genotypes. Samples were collected at 3, 6, 8 and 12 months after transplanting to determine biomass and nondestructive agronomic and physiological traits. A simple correlation was used to determine the relationship between biomass and physiological and agronomic traits. Result: In both field capacity and long drought conditions, 3 months after transplanting, there was a positive correlation between canopy height and biomass and between green leaf number and biomass. The non-destructive leaf area index was a trait that contributed to biomass at 6 months after transplanting under non-water stress conditions. At 8 months after transplanting, a positive relationship between canopy height and biomass was found under short drought and long drought conditions and green leaf number was also related to biomass under field capacity conditions. Biomass at the harvesting stage contributed to canopy width in sugarcane under field capacity conditions. Non-destructive traits in this experiment, such as canopy height and green leaf number, could be used as indirect measurements to reflect the biomass performance under field capacity and long drought conditions at the tillering and physiological maturity phases. For the elongation phase, the non-destructive leaf area index was an altered characteristic that indirectly determined biomass. This information will be useful as an alternative measurement to indicate biomass in the breeding program for drought resistance at the early growth stage. [ABSTRACT FROM AUTHOR]

Drought stress is one of the main environmental factors that cause negative impacts on sugarcane (Saccharum spp.) crops. The identification of drought-tolerant varieties is essential to boost the sugar-energy sector in agricultural years with an incidence of drought stress. Two experiments were conducted under greenhouse conditions to evaluate the degree of drought tolerance of 13 sugarcane varieties (CTC2, CTC4, IACSP95-5000, RB825336, RB835054, RB855035, RB855156, RB855453, RB855536, RB867515, RB965902, RB966928 and SP80-1842) when exposed to restrictions of 50% (moderate water deficiency) and 25% (severe water deficiency) of the soil's water retention capacity. Twelve drought tolerance indices were calculated from the production of shoot dry matter without water restriction (YP) and under moderate or severe water deficit (YS). The RB855035, RB855453 and RB 965902 varieties have greater drought tolerance, and are the most suitable to be cultivated in regions with moderate and severe water restriction. The RB855536 and IACSP95-5000 varieties have greater susceptibility to moderate and severe water deficit. Tolerance indices MP, DI, STI, GMP, YI, k1STI, k2STI and HM were the most suitable for identifying the sugarcane varieties with greater drought tolerance and high potential for shoot dry matter production. under conditions of moderate and severe water stress. [ABSTRACT FROM AUTHOR]

With the increasing impacts of climate change, establishing more sustainable and robust plants such as desert dates (Balanites aegyptiaca) seems to be necessary. Known for its resilience in arid conditions, this tree has the potential to become a more important food source, particularly for its potential to yield edible oil. This study characterized Balanites kernel oil (BKO) as a promising oil source in arid regions, studying the influence of geographical origin and environmental factors. Moroccan and Sudanese BKO samples were analyzed and compared with Mauritanian BKO. In the fatty acid profile, unsaturated fatty acids constituted over 70% of the BKO profile, with a predominance of linoleic acid (Li), oleic acid (Ol), palmitic acid (Pa), and stearic acid (St). Consequently, the predominant triacylglycerols were PaLiLi, PaLiOl, LiLiOl, OlLiOl, and StLiOl. α-Tocopherol dominated the tocochromanol composition (324 to 607 mg/kg), followed by γ-tocopherol (120 to 226 mg/kg), constituting 90% of the total tocochromanols. The total phytosterol content in BKO ranged from 871 to 2218 mg/kg oil, with β-sitosterol dominating (58% to 74%). Principal Component Analysis revealed that the geographical origin significantly influences BKO composition, emphasizing environmental factors, particularly water deficit and/or temperatures. Notably, Moroccan BKO collected from an area characterized by high aridity and relatively low winter temperatures, showcased a unique profile in fatty acid, phytosterols, and tocochromanols. The valorization of BKO presents an opportunity for local agricultural development in arid regions and a role model for plant development and agricultural practices in other parts of the world. [ABSTRACT FROM AUTHOR]

Introduction: Lettuce production and quality could be seriously affected by the increasingly limited water resources. Methods: The effect of drought on the content of two antioxidant compounds, vitamin C and anthocyanins, in five cultivated lettuces and two wild relatives was assessed for 2 years. Results and discusion: In leaf samples, Lactuca wild species generally had a higher content of total vitamin C than the cultivated lettuces. In contrast, the commercial varieties usually contained more total anthocyanins than the wild species. Total vitamin C decreased with the drought stress in all accessions, commercial varieties, and lettuce wild relatives, with this tendency being consistent and reproducible across the 2 years. These differences were significant in the case of the green commercial varieties 'Winter Crop' (in 2020/2021) and 'Dolomiti G12' (in 2021/2022) and very significant in the red commercial variety 'Red Sails' (in 2020/2021). However, the only group in which the effect of drought was either significant or very significant in both years was the wild species, Lactuca homblei and Lactuca dregeana, and in the latter also in both tissues (leaf and stem) analyzed. Water stress resulted in an increase of the total anthocyanin content in the leaves from all the accessions, both red commercial varieties and wild relatives, in both years. The most significant enrichment and the only one being either significant or very significant in both years was observed in one of the wild relatives assayed (L. homblei). Stems (L. dregeana) contained more anthocyanins than leaves under control conditions, and it was exactly the opposite under drought. Changes in anthocyanins in the two tissues in response to drought stress were in opposite directions, increasing in leaves and decreasing in stems. This could suggest a translocation of anthocyanins as a first quick mechanism to cope with a severe lack of water. In conclusion, anthocyanins (unlike vitamin C) could play a role in the mechanisms deployed by the plant to tolerate drought stress. The wild species with a robust significant enrichment in anthocyanins as a response to drought (L. homblei) is a promising plant material to breed more resilient lettuces. [ABSTRACT FROM AUTHOR]

Pre-exposure of plants to moderate stress may create a "stress memory" that enables a fast protective response to next stress event. Protocols to differentiate the crop genotypes for such traits are essential for genetic improvement of plant stress tolerance. We hypothesized that memory due to soil moisture deficit may get reflected in leaf canopy temperature responses to fluctuating ambient temperature. We conducted a factorial completely randomized block design experiment with two treatments: well-watered (WW) and water deficit stress (WS) in three and two popular cultivars of sugarcane and sorghum, respectively, with eight replications. The 30 and 15 days old plants of sugarcane and sorghum were exposed to soil moisture deficit for 25 and 10 days, respectively, followed by their recovery. For differentiating the response of plants after stress recovery (ASR), the WW and WS plants were labelled as WWASR and WSASR, respectively. After 30 days of recovery, canopy temperature responses to ambient temperature fluctuations were monitored. Warming of the canopy was faster in WSASR as compared to WWASR plants. Further, there was a difference within the WSASR cultivars, indicating the existence of genetic variation in recalling and responding to desiccation caused by increasing ambient temperature. These indicated that water exhaustive and non-exhaustive C4 plants differ in their adaptive mechanisms associated with transpirational cooling of the plant canopy. The pixel-wise analysis of thermal images of plants provided a more effective differentiation of stress responses among sugarcane and sorghum cultivars compared to the conventional method of recording canopy temperature. The existence of cultivar differences suggests that the trait representing stress memory can be phenotyped with protocols optimized with the IR imaging system and may serve as a promising tool for phenotyping crop stress tolerance. [ABSTRACT FROM AUTHOR]

Drought is one of the most common and important factors limiting production in arid and semi-arid regions. Some organic amendments can be used to reduce the effects of drought on plants. The aim of this study was to investigate the effect of municipal waste compost and farmyard manure on the growth characteristics of basil (Ocimum basilicum L) under water deficit. A factorial experiment was conducted based on a completely randomized design with three replications in 2022 in the greenhouse of Razi University, Kermanshah. The factors included water deficit (at three levels of 50, 75 and 100 % of field capacity (FC), farmyard manure (at three levels of 15, 30 and 45 ton/ha) and municipal waste compost (at three levels of 15, 30 and 45 ton/ha). For the manure, the treatment without manure and also for the compost, the treatment without compost is considered as the control. The results showed that the interaction effect of compost and farmyard manure under water deficit on most of the growth characteristics as well as the amounts of proline, soluble sugars and plant pigments were significant (P≤0.01). The highest shoot and root dry weight (2.1 and 1.7 g, respectively), shoot height (24.1 cm), leaf area (75.5 cm2) and relative water content (29.3 %) were obtained with application of 45 tons/ha of compost, 45 tons/ha of manure and FC. Also, the highest amount of proline (9.78 μmol/g) and soluble sugars (1.06 mg/g) were found under 50% of FC, without the use of compost and manure. In general, the simultaneous use of municipal waste compost and farmyard manure is a simple, suitable and cheap strategy to reduce the effects of water deficit in basil. [ABSTRACT FROM AUTHOR]