Moisture Deficit Conditions Research Articles

Comprehensive evaluation of spring barley mutants according to their yield components

Background. The need to increase the genetic diversity of barley (Hordeum vulgare L.) is determined by its value and cultivation scope, which is especially important in the context of the changing climate.Material and methods. The study was carried out in 2021 and 2022 at the experimental site of the Lake Kuchak biostation located in Nizhnetavdinsky District, Tyumen Province (57°20ʼ57.3”N, 66°03ʼ21.8”E). Mutant forms were obtained by treating seeds of accessions ʻZernogradsky 813ʼ, Dz02-129 and C.I. 10995 with solutions of the chemical mutagen phosphemide at concentrations of 0.002% (2·10–3 М) and 0.01% (1·10–2 М). The mutants of the fifth (M5) and sixth (M6) generations were evaluated for a set of traits valuable for breeding in comparison with the original forms and reference cultivars ʻAchaʼ and ʻAbalakʼ. The main productivity characters were analyzed in the laboratory, and breeding indices were calculated (ear potential index, Canadian index, ear linear density index, Mexican index, plant productivity index, and Finnish-Scandinavian index).Results and conclusion. Most of the studied mutants under moisture deficit and elevated temperature conditions were superior to the original forms in their productivity characters. Mutant plant samples with stable manifestation of those traits, irrespective of the growing season conditions, were selected. Assessment of the genotype–environment interaction using breeding indices made it possible to identify promising mutants for inclusion in breeding programs. Correlation analysis helped to identify indices closely related to grain yield: Canadian index (r = 0.85), Mexican index (r = 0.76), and plant productivity index (r = 0.70). They can be recommended for selection of stress-resistant barley forms.

Arbuscular Mycorrhizal (AM) Fungi Symbiosis in Sustainable Production of Sorghum (Sorghum bicolor L. Moench) Under Drought Stress: An Emerging Biofertilizer in Dryland Areas

Sorghum (Sorghum bicolor L. Moench) is an important cereal crop grown in arid and semiarid regions where water and other resources are limited. Changes in temperature and rainfall patterns have resulted in frequent droughts, which caused significant yield loss in sorghum. In recent years, there has been an increasing interest in sorghum cultivation due to its resilience to climate change and potential source of food and income. The symbiotic interaction of sorghum with Arbuscular Mycorrhizal fungi (AMF) has been found to induce several physiological and molecular changes that improve the ability of sorghum to withstand drought stress. This symbiotic relationship enhances water and nutrient uptake, osmotic adjustment, activation of stress‐responsive genes, stomatal regulation, and antioxidant defense, leading to improved drought tolerance in sorghum. Agricultural practices such as reduced tillage, cover cropping, intercropping, crop rotation, and the use of organic amendments promote the diversity and effectiveness of AM fungal symbiosis. Such agricultural practices create more favorable conditions for AM fungal establishment and growth while reducing dependence on synthetic fertilizers. In this review, we highlight AM fungal symbiosis on sorghum growth, physiology, and molecular mechanisms underlying the beneficial effects of AM fungal symbiosis under moisture deficit conditions. Overall, the present review elucidates sorghum production and breeding success in Ethiopia, the symbiotic mechanisms between plants and AM fungi, the prospects of biofertilizers in sustainable agriculture, the potential of AM fungal symbiosis as a sustainable approach to improve sorghum production and its synergistic effect with other crop management practices.

Enhancing water stress tolerance of bread wheat during seed germination and seedling emergence: caffeine-induced modulation of antioxidative defense mechanisms.

Better crop stand establishment, a function of rapid and uniform seedling emergence, depends on the activities of germination-related enzymes, which is problematic when there is insufficient soil moisture. Different ways are in practice for counteracting this problem, including seed priming with different chemicals, which are considered helpful in obtaining better crop stand establishment to some extent through improved seed germination and seedling emergence. In this growth room experiment, caffeine was used as a seed priming agent to improve germination under moisture scarcity. Polyethylene glycol-8000 (18%) was added to Hoagland's nutrient solution to create drought stress (-0.65 MPa). The experiment was arranged in a completely randomized design (CRD), having four replications of each treatment. A newly developed wheat genotype SB-1 was used for the experimentation. Different doses of caffeine, i.e., 4 ppm, 8 ppm, 12 ppm, and 16 ppm, including no soaking and water soaking, were used as seed priming treatments. Water deficit caused oxidative stress and adversely affected the seed germination, seedling vigor, activities of germination enzymes, photosynthetic pigments, and antioxidative defense mechanism in roots and shoots of seedlings. Caffeine seed priming ameliorated the negative effects of water deficit on seed germination and seedling vigor, which was attributed to the reduction in lipid peroxidation and improvement in the activities of germination-related enzymes like glucosidase, amylase, and protease. Conclusively, seed priming with 12 ppm caffeine outperformed the other treatments and hence is recommended for better crop stand establishment under conditions of soil moisture deficit.

USE OF PLANT GROWTH PROMOTING RHIZOBACTERIA CONTAINING ACC- DEAMINASE ACTIVITY FOR IMPROVING GROUNDNUT YIELD IN RAINFED AREA

Groundnut (Arachis hypogea) is amongst the most valuable leguminous cash crops grown in rainfed areas. The role of plant growth promoting rhizobacteria (PGPR) containing ACC-deaminase is considered vital promoting plant roots under moisture deficit conditions. Under these circumstances a research experiment was conducted at the farm area of Soil and Water Conservation Research Institute, Chakwal in association with PMAS Arid Agriculture University Rawalpindi for 3 years consecutively during 2015-2017. The main objective of the experiment was to exploit and evaluate the impact of PGPR deaminase activity on yield of groundnut crop. The four treatments included farmer practice (no compost & inoculums), with inoculums, with compost and compost + inoculums in 4 replications under RCBD. The improvement recorded in the pod yield of groundnut was 12 %, in the number of pods plant-1 by 20 % and the shelling percentage by 2 % by application of the treatment inoculum + compost. Conclusively, it was ascertained that PGPR containing ACC-deaminase application is an effective approach to enhance groundnut crop production and soil characteristics of degraded soils under rainfed scenario.

ВПЛИВ ОБРОБКИ НАСІННЯ МЕТАБОЛІЧНО АКТИВНИМИ РЕЧОВИНАМИ НА ФОРМУВАННЯ КСЕРОМОРФНОЇ СТРУКТУРИ ЛИСТКІВ ТА ВОДНИЙ ПОТЕНЦІАЛ ПАГОНІВ ПРОРОСТКІВ ПШЕНИЦІ М’ЯКОЇ (TRITICUM AESTIVUM L.) ЗА УМОВ ВОДНОГО ДЕФІЦИТУ

The article offers a comparative analysis of how metabolically active substances, individually and in combinations, affect the development of xeromorphic leaf structures and the water potential of shoots in common wheat (Triticum aestivum L.) seedlings when subjected to water deficit conditions simulated using PEG 6000.The study involved the use of 10 options for seed treatment : control (untreated seed + distilled water); PEG 6000 solution (12 %); solution of vitamin E (10-8M) – E; ubiquinone-10 solution (10-8M) – Q; methionine solution (0,001 %) – M; solution of paraoxybenzoic acid (POBА) (0,001 %) – P; MgSO4 solution (0,001 %) – Mg; combinations: vitamin E (10-8M) + ubiquinone-10 (10-8M) – EQ; vitamin E (10-8M) + methionine (0,001 %) + POBА (0,001 %) – EMP; vitamin E (10-8M) + methionine (0,001 %) + POBА (0,001 %) + MgSO4 (0,001 %) – EMPMg. Experimental water deficit is simulated with a 12% solution of PEG 6000.
 It was observed that treating T. aestivum wheat seeds with solutions of paraoxybenzoic acid, ubiquinone-10, and magnesium sulfate under conditions of water deficit resulted in a 17.7 %, 16.5 %, and 16.2 % increase in the assimilation surface area of seedlings, respectively, compared to those subjected to water deficit conditions simulated using PEG 6000. Furthermore, the treatment of T. aestivum wheat seeds with solutions of ubiquinone-10, methionine, and the combination of vitamin E + ubiquinone-10 stimulated chlorophyll synthesis in wheat leaves, resulting in a 14.4 %, 11.3 %, and 15.4 % increase, respectively, compared to the group of plants whose seeds were germinated under conditions of slow water supply, resulting in a smaller leaf surface area, which is indicative of a xeromorphic leaf structure.
 Treating the seeds with these specific solutions enhances photosynthetic productivity in conditions of moisture deficit by reinforcing the xeromorphic structure of the leaves. This underscores the high adaptability of wheat from the Provintsialka variety to drought conditions. 
 It was determined that pre-treating seeds with a combination of vitamin E, methionine, paraoxybenzoic acid (POBA), and magnesium sulfate (MgSO4) resulted in a 1.1 % increase in water accumulation in the shoots, in comparison to the measurements obtained from seedlings whose seeds were exposed to water deficit conditions simulated using PEG 6000. 
 Consequently, the application of metabolically active substances in seed treatment proves to be effective in enhancing the drought resistance of soft wheat T. aestivum. This approach can be incorporated as an integral component of the technology for cultivating grain crops under conditions of water deficit.

Effects of bacterization on the development of Zea mays during droughts in the conditions of a vegetation experiment

Sustainable agriculture is a concept developed in the late 20th century to promote the production of crops using the biological capabilities of cultivated organisms while minimizing the human impact on agrocenoses. In recent years, the discovery of new types of bacteria that positively impact plant growth has opened up opportunities for the development of effective microbiological preparations and they offer promising prospects for adaptive crop production, enabling farmers to adjust to changing environmental conditions while reducing reliance on anthropogenic inputs. Corn, as the third most important grain crop after wheat and rice, is sensitive to a lack of moisture. Therefore, understanding the mechanisms of adaptation and resistance of this plant to drought remains an urgent task. The aim of the work was to determine the effect of bacterization of Zea mays ("Early gourmet 121") seeds by strains of rhizobacteria on the development of corn under conditions of artificial drought in a vegetation experiment. Strains of bacteria with known properties useful for plant growth and development were used – Bacillus cereus, Pseudomonas putida, Azospirillum brasilense and Azotobacter chroococcum. The study investigated the indicators of seedlings and the content of mono-, oligo-, and soluble sugars in the leaves and the activity of polyphenol oxidase in the roots. The results showed that bacterization of seeds with suspensions of P. putida led to an increase in the length of roots in plants grown under moisture deficit conditions and significantly affected the above-ground parts. Positive effects on the mass of the above-ground parts were observed when seeds were bacterized with suspensions of P. putida, A. chroococcum and a mixture of bacterial suspensions and grown under sufficient irrigation. A similar positive effect occurred when seeds were bacterized only with a mixture of suspensions of the tested bacteria under drought conditions. Bacterization of corn seeds with P. putida or A. brasilense resulted in increased root mass and sugar accumulation in leaves when growing seedlings under conditions of moisture deficit. Additionally, inoculation of P. putida or A. chroococcum seeds increased the activity of polyphenol oxidase enzyme in seedling roots. While the bacteria showed a positive impact on corn development under some conditions, this effect was not observed when there was sufficient moisture. Therefore, we believe that a more promising approach for developing biological preparations based on beneficial microorganisms is to explore combinations of multiple soil bacteria strains. By identifying a mix of bacteria that can effectively stimulate plant growth in both stressed and favourable conditions, we can maximize the potential benefits for crop production. Such combinations of bacteria may enhance plant growth and yield not only during drought stress but also under optimal conditions, providing a more robust and reliable solution for crop management.

ВПЛИВ СИСТЕМИ УДОБРЕННЯ НА ПРОДУКТИВНІСТЬ ТРИТИКАЛЕ ОЗИМОГО (TRITICOSECALE WITT.) В УМОВАХ ОСУШУВАНОГО ДЕРНОВО-ПІДЗОЛИСТОГО ҐРУНТУ ПОЛІССЯ

Topicality. Currently, the search for ways to improve the efficiency of triticale production on drained soils under conditions of climate change is a necessary and urgent task, since there is no scientific research to improve the technology of growing this agricultural crop under such conditions. Issues. In the Polissia of Ukraine, triticale can solve the problem of increasing grain production, considering the high adaptive properties to growing conditions and the genetic potential of yield and product quality. Aim. To study the formation peculiarities of winter triticale grain yield and quality at different levels of organomineral fertilization, and determine the most economically justified fertilizer system on drained sod-podzolic soil in conditions of moisture deficit. Methods. Stationary experiment was established; the grain quality was determined with laboratory research method, and experimental data were processed using the Microsoft Office Excel computer program. Results. Research conducted in 2016–2020 found that during the triticale grain formation and filling, the productive moisture reserves of drained sod-podzolic soil in the 0–100 cm layer decreased to a critical level of 60–80 mm (130–200 mm was accounted for by the period of growth resumption). Under conditions of low soil moisture, when using biological fertilizer system (pea-oat mix by-product), grain yield was 2.62 t/ha, and the increase compared to the absolute control was to 14.9 %. On the background of predecessor by-products, when mineral fertilizers were applied in the recommended rate for the zone (N60P60K60), grain yield increased to 3.65 t/ha. The high yield of triticale grain (4.14 t/ha) was established when using increased (intensive) rate of mineral fertilizer N90P90K90 with separate nitrogen application in three stages (N30 – at sowing, N30 – stem elongation, N30 – grain formation) combined with by-products. It was noted that indicators of winter triticale grain quality depended on the fertilizer system. Thousand grain weight was 46.5–50.2 g, the maximum val-ues were in the high agronomic background. Grain volume weight was within 674–682 g/l, the difference between the variants was insignificant. Grain protein content on fertilized backgrounds was 11.8–12.7 %, when the rate was increased to N90P90K90 – 13.1 %, which is 1.2 % more than on the control variant. Conclusions. It was determined that the highest level of profitability of winter triticale cultivation was 144 % when by-products were used in the biological fertilization system. The N90P90K90 fertilizer system combined with by-products produced the highest grain yield (4.14 t/ha) and protein content (13.1 %), but profitability of triticale cultivation decreased to 77 %. Studies have shown that mineral fertilizers increase the yield and improve the grain quality while reducing the profitability of growing the crop. Keywords: triticale, fertilizer system, improved land, moisture supply, productivity, grain quality, cost-effectiveness.

Rice Straw Vermicompost Enriched With Cellulolytic Microbes Ameliorate the Negative Effect of Drought in Wheat Through Modulating the Morpho-Physiological Attributes

Wheat growth and productivity are unfavorably pretentious by a lack of sufficient water (drought or water deficit) worldwide. Drought stress significantly affects all the morpho-physiological and biochemical characteristics and the agronomical yield of wheat. Different management approaches have been adopted to cope with the negative effects of water deficit. Soil-applied vermicompost is helpful in improving the growth and developmental processes of wheat under water deficit conditions. Therefore, a trial was carried out to optimize the best amount of vermicompost and to assess its role in ameliorating the negative effects of drought for sustainable crop production. The treatments consisted of 1) two contrasting wheat cultivars Faisalabad-08 (drought-tolerant) and Galaxy-13 (drought-sensitive), 2) drought with three levels [D0 = 70% of field capacity (no drought), D1 = 45% of field capacity (mild drought), and D2 = 30% of field capacity (severe drought)] and 3) cellulolytic microbe-enriched vermicompost prepared from rice straw with four levels (VT0 = Control, VT1 = 4 t ha−1, VT2 = 6 t ha−1 , and VT3 = 8 t ha−1). Data on various morphological, physiological, and biochemical parameters were recorded from sowing to crop harvesting. In this study, it was demonstrated that all these parameters were negatively affected by moisture deficit conditions. The application of vermi-fertilizer significantly increased (p < 0.05) the aforementioned parameters of wheat in both the absence and presence of drought. Under severe drought, VT2 treatment increased the seedling length by 14.02–26.14%, fresh weight by 15.16–22.91%, and dry weight by 0.37–28.20% in both cultivars compared with control. In addition, VT2 treatment reduced the leaf water potential by 6.36 and 3.36%, leaf osmotic potential by 1.74 and 1.68%, and increased the turgor potential by 4.83 and 3.36%, and photosynthetic rate by 18.59 and 26.42% in Faislabad-08 and Galaxy-13, respectively, over control. We concluded that the application of vermicompost is a valuable approach to alleviate the adverse impacts of water stress on wheat.

Application of herbicides in agrocenoses of spring barley with oversowing of perennial grasses

The North-West region of the Russian Federation is characterized by high weed infestation and large yield losses of spring barley. At the same time, the use of herbicides in agrocenoses of spring barley with perennial grasses oversowing has its own characteristics. The aim of the study was to determine the effectiveness of herbicides Agritox, VK and Bazagran, VR against weeds in the agrocenosis of spring barley and their effect on the growth of perennial grasses during current and next years. The studies were carried out at the agroecological station of the Menkovsky branch of the Agrophysical Research Institute, located in the Leningrad region, during 2012–2019. The studies have shown significant differences in the effectiveness of herbicides Agritox, VK and Bazagran, VR in relation to weed species common in agrocenoses of spring barley with oversowing of perennial grasses in the North-West of Russia. The herbicide Agritoks, VK turned out to be less effective against stickwort and common nipplewort, and Bazagran, VR — against white goosefoot, field pansy, common fumitory and hemp-nettle. Under conditions of moisture deficit and high average daily temperatures, the herbicide Agritox, VC induced a phytotoxic effect on red clover plants, which was reflected in the accumulation of the vegetative mass of perennial grasses both in the year of growth under the cover of barley and in next years as a targeted use during hay production.

Soil moisture-based winter–spring drought variability over West Karbi Anglong region, Assam, Northeast India using tree-rings of Pinus kesiya

Drought is increasingly becoming more frequent and intense over Northeast India (NEI). To understand the drought variability over the region, we developed a 151-year (1868–2018 CE) long tree-ring width chronology of Pinus kesiya from Assam, NEI. The correlation analyses of tree-ring width chronology with temperature, rainfall, normalized difference vegetation index (NDVI) and soil moisture were conducted. The tree-ring chronology showed significant positive correlation with previous October through current year March rainfall and negative correlation with mean temperature of March–June. Similarly, we observed positive correlation with NDVI and soil moisture for April–May and January–April, respectively. Soil-moisture being the most significant variable for winter-spring (January to April), was reconstructed since 1868. This reconstruction accounted for 23.3% of the variance of the observed soil moisture in the calibration period of 1982–2018 CE. The years of soil moisture deficit (drought) and wet soil moisture conditions were identified based on the percentile distribution. The major droughts and famines that occurred in India during the late 19th and early 20th century were observed in the reconstruction. This study adds additional input towards agricultural planning and management in NEI.

Exploring how functional traits modulate species distributions along topographic gradients in Baxian Mountain, North China

The associations between functional traits and species distributions across environments have attracted increasing interest from ecologists and can enhance knowledge about how plants respond to the environments. Here, we applied a hierarchical generalized linear model to quantifying the role of functional traits in plant occurrence across topographic gradients. Functional trait data, including specific leaf area, maximum height, seed mass and stem wood density, together with elevation, aspect and slope, were used in the model. In our results, species responses to elevation and aspect were modulated by maximum height and seed mass. Generally, shorter tree species showed positive responses to incremental elevation, while this trend became negative as the maximum height exceeded 22 m. Most trees with heavy seeds (> 1 mg) preferred more southerly aspects where the soil was drier, and those light-seed trees were opposite. In this study, the roles of maximum height and seed mass in determining species distribution along elevation and aspect gradients were highlighted where plants are confronted with low-temperature and soil moisture deficit conditions. This work contributes to the understanding of how traits may be associated with species occurrence along mesoscale environmental gradients.

Automation of soil moisture sensor-based basin irrigation system

Irrigation is one of the largest consumers of fresh water in the agricultural sector. Surface irrigation is one the most widely adopted method of irrigation due to its simplicity and low energy requirement. Although, it is mostly associated with poor irrigation application efficiency mainly due to deep percolation and uneven distribution of irrigation water. A study was conducted in closed-end level basin layout in loamy soil to establish and test an Internet of Things (IoT) based system through a wireless connection between the automatic check gate and soil moisture sensors which can be operated remotely based on real-time soil moisture status. An attempt had been made to identify the suitable location of the sensor in the basin layout for improving irrigation application efficiency. An aluminium automatic-check gate fitted in an iron frame was placed in the concrete water supply channel to control the water flow. Three capacitance-based soil moisture sensors were placed at 25%, 50% and 75% of field length (i.e., 15 m, 30 m and 45 m) at 37.5, 15 cm and 7.5 cm depth, respectively. A wireless communication network was established between capacitance-based soil moisture sensors and an automatic check gate through the LoRa module and GSM module. The software used for automatic control of the check gate in this study was Croplytics® by Agsmartic. The system was tested for nine irrigation events under bare soil conditions. Three different operational schedules based on different soil moisture sensor placement had been tested under 40%, 30% and 20% soil moisture deficit conditions. The results suggested that the best location of sensors for closing the system would be at 37.5 cm depth placed at 25% length from the inlet in higher soil moisture deficit condition and at 7.5 cm depth placed at 75% length in low moisture deficit condition. Overall, the irrigation application efficiency was improved up to 86.6% with automation.

Influence of physicochemical factors on water exchange in cotton leaves under the moisture deficit conditions

Presowing treatment of cotton seeds with a physical factor (low-frequency electromagnetic field - LF EMF) and a chemical compound (glycyrrhizic acid - GzA) and sowing them under conditions of optimal and limited water supply showed that different varieties of cotton, depending on their biological peculiarities and the method of seed treatment, had different parameters of water exchange in plants. The experiments were carried out in laboratory, greenhouse, lysimetric and field conditions, the indicators of the electrical resistance of leaf tissues (ERLT) of cotton plants depended on the conditions of water supply. According to this indicator, the varieties Ishonch, Gulbahor-2 and Navbahor-2 showed greater resistance to soil moisture deficiency, in comparison with the variety Tashkent-6. The plant varieties from seeds, treated with LF EMF and GzA, to a greater or lesser extent, are in the range with the lowest ERLT values, in comparison with the varieties from untreated seeds.

Surprising Drought Tolerance of Fir (Abies) Species between Past Climatic Adaptation and Future Projections Reveals New Chances for Adaptive Forest Management

Research Highlights: Data of advanced-age provenance tests were reanalyzed applying a new approach, to directly estimate the growth of populations at their original sites under individually generated future climates. The results revealed the high resilience potential of fir species. Background and Objectives: The growth and survival of silver fir under future climatic scenarios are insufficiently investigated at the xeric limits. The selective signature of past climate determining the current and projected growth was investigated to analyze the prospects of adaptive silviculture and assisted transfer of silver fir populations, and the introduction of non-autochthonous species. Materials and Methods: Hargreaves’ climatic moisture deficit was selected to model height responses of adult populations. Climatic transfer distance was used to assess the relative drought stress of populations at the test site, relating these to the past conditions to which the populations had adapted. ClimateEU and ClimateWNA pathway RCP8.5 data served to determine individually past, current, and future moisture deficit conditions. Besides silver fir, other fir species from South Europe and the American Northwest were also tested. Results: Drought tolerance profiles explained the responses of transferred provenances and predicted their future performance and survival. Silver fir displayed significant within-species differentiation regarding drought stress response. Applying the assumed drought tolerance limit of 100 mm relative moisture deficit, most of the tested silver fir populations seem to survive their projected climate at their origin until the end of the century. Survival is likely also for transferred Balkan fir species and for grand fir populations, but not for the Mediterranean species. Conclusions: The projections are less dramatic than provided by usual inventory assessments, considering also the resilience of populations. The method fills the existing gap between experimentally determined adaptive response and the predictions needed for management decisions. It also underscores the unique potential of provenance tests.

Multi-year white spruce drought legacies in southern Saskatchewan

In many regions across western Canada’s boreal forest, drought impacts on long-term white spruce (Picea glauca (Moench) Voss) radial growth are poorly understood. This is also the case for white spruce shelterbelt trees south of their natural range in agricultural regions of the Canadian Prairies. Understanding how white spruce has responded to drought in the past will be vital for management purposes for those who rely on shelterbelts and will help develop a better understanding of how white spruce in the Canadian Boreal Forest will be impacted by climate change. Using tree-rings, we tested how radial growth responds to different drought magnitudes, time-steps, and timing in southern Saskatchewan during and after droughts. White spruce radial growth is statistically associated to 3-month June-August and July-September Standardized Precipitation-Evapotranspiration Index (SPEI) values. Drought severity has a greater impact on radial growth compared to timing and time-step during the drought year and the five years after. Three-month, extreme droughts from July-September appear to have the greatest overall negative impact on white spruce growth in southern Saskatchewan. Our results indicate that white spruce has a complex multi-year response to varying drought conditions in southern Saskatchewan although the physiological mechanisms behind radial growth changes are yet unknown. This research augments our current understanding of white spruce’s drought-growth relationship and provides new information useful for understanding how the shelterbelts in southern Saskatchewan and the Canadian Boreal Forest may respond to different characteristics of moisture deficit conditions in the future where longer and more pronounced droughts are projected to occur.

Effect of microbial inoculants on growth and yield of chilli (Capsicum annum L.) under moisture deficit conditions

A pot experiment entitled “Effect of microbial inoculants on growth and yield of chilli (Capsicum annum L.) under moisture deficit conditions.” was carried out in the Division of Basic Sciences & Humanities Faculty of Horticulture SKUAST-K to evaluate the role of individual and combined applications of different microbial strains like AM fungus, PSB, KSB and ZnSB in chilli under moisture deficit conditions (MDC) (60% FC). The results of the study revealed that growth and yield parameters of chilli showed a significant reduction under MDC (T1) as compared to control (T0) (100% FC). Inoculation with different microbial strains significantly improved all the examined parameters in chilli as compared to control as well as MDC. Among the different microbial strains used in the experiment, the combined application of AM, PSB, KSB and ZnSB (T6) proved to be the best in terms of significantly enhancing most of the studied parameters of chilli as compared to control or MDC. Among the parameters that enhanced due to combined inoculation of microbial strains plant height, root biomass, total plant dry weight, total leaf area, number of fruits, fruit weight and yield showed a respective increase of 18.8, 69.6, 77.3, 34.0, 67.0, 48.2, 82.91, as compared to T1.

Радиальный прирост сосны обыкновенной (Pinus sylvestris L.) при ингибировании

Predicting tree growth processes is important due to the exceptional ecosystem role of forests, which carry out global climate regulation by sequestrating carbon, conserving drinking water, and providing habitat for living organisms. Trees are known to respond to any fluctuations in the environment. The research purpose is to identify weather and climatic factors that significantly affect the inhibition of growth of Scots pine (Pinus sylvestris L.) in conditions of constant moisture deficit. The studies were carried out in the eastern part of the Bryansk region within the territory the Bryansk administrative district, in the educational and experimental forestry of the Bryansk State Engineering and Technological University and the Styazhnovskoye forest district. Methods of dendrochronology were used to assess the response of 93 pine trees to fluctuations in the external environment by changing the width of annual rings (available anatomical feature of a tree) using indices of radial growth. An original approach was proposed to analyze the reasons for a sharp decline in the annual radial growth under the influence of temperature and precipitation. The years with abnormally low increments (1963, 1972, 1985, 2002 and 2010) were identified against the background of the weather-climatic situation for 5 years before and after the fall in growth. Similar dynamics of absolute values of radial increments and their indices was established, which is caused by fluctuations of natural factors, manifestation of hereditary traits, etc. Significant differences were revealed between the growth rates at average multiyear values of January, May and August air temperatures with growth rates in the years of abnormally low radial growth, which are observed in pine against the background of colder January and warmer May and August of the current year, as well as under the condition of warmer January of the previous year. At the same time, no significant role of precipitation was detected. The obtained data, expanding the idea of the features of growth processes and formation of annual increments in diameter of Scots pine in the conditions of changing climate at the turn of the 20th–21st centuries, allowed us to suggest a possible manifestation of physiological features of the species, the homeostasis optimum zone of which is located in the conditions of colder boreal climate. This information expands our understanding of the features of growth processes and formation of annual increments in diameter of Scots pine in changing climatic conditions.

Potato variety resources for starch production in the Chelyabinsk region

A collection of 146 varieties of potatoes were studied in 2015 to 2018 to determine the varieties that provide the highest yield of starch per unit area in the Chelyabinsk region. It was found that the total yield of starch depends more on the yield of potatoes than on the starch content in tubers. Productivity increases and the starch content in tubers decreases under favorable conditions. In conditions of moisture deficit, on the contrary, an increase in starchiness of tubers was noted, and their productivity was significantly reduced. Seven varieties with a high yield of starch per unit area (t/ha) identified were Il’inskiy (6.87), Belosnezhka (6.75), Terra-1 (6.66), Bashkirskiy (6.12), Vemer (6.04), Valeriy (6.02) and Svitanok kiyevskiy (6.01). The varieties which increased the starch collection from 5.00 to 5.98 t/ha were Spiridon, Dunyasha, Artom, Yagodnyy 19, Okolitsa, Slavyanka, Panyanka, Kamenskiy, Yermak, Zhuravinka, Strumok, Sinetsvet, Nikulinskiy, Otrada, Zorachka, Kolobok, Zhigulevskiy, Oredezhskiy, Sentyabr’, Simfoniya, Osen’, Zekura, Nikitinskiy ranniy, Briz, Galaktika, Nayada, Spiridon, Dunyasha, Artom, Yagodnyy 19, Okolitsa, Slavyanka, Panyanka, Kamenskiy, Yermak, Zhuravinka, Strumok, Sinetsvet, Nikulinskiy, Otrada, Zorachka, Kolobok, Zhigulevskiy, Oredezhskiy, Sentyabr’, Simfoniya, Osen’, Zekura, Nikitinskiy ranniy, Briz, Galaktika, Nayada as well as samples of the Chelyabinsk selection viz. 05.60.24, 2097/16 (Sharap), 05.62.13, 06-547.8 and 06-1547-11. To increase starch production in Chelyabinsk region, it is necessary to use potato varieties zoned in the Ural region viz. Nayada, Bashkirskiy, Kamenskiy, Nikulinskiy, Oredezhskiy, Svitanok kiyevskiy and Spiridon. For inclusion in the Register of selection achievements approved for use in the Ural region, the following varieties of Chelyabinsk selection were found promising: 2097/16 (Sharap), 05.60.24, 05.62.13, 06-547.8, 06-1547-11, Gubernator and 06.18.7, as well as varieties of other selection: Terra-1, Valeriy, Yagodnyy 19, Artom, Dunyasha, Okolitsa, Panyanka and Strumok. The varieties with a low starch content in tubers which are suitable for dietary nutrition were Zhukovskiy ranniy (11.9 %), Karatop (12.2 %), Impala (12.3 %), Skarlett (12.5 %), Obelisk (13.0 %), Vesna (13.1 %), Nikita (13.4 %), Resurs (13.4 %) and Gubernator (12.9 %).

Effect of the next-generation stimulants on the yielding capacity of winter wheat in moisture deficit conditions

In the conditions of the Stavropol Krai arid region the single nutrient fertilizer treatment of winter wheat does not always justify the costs expended due to the moisture deficit during the growing season. In this regard, one of current promising areas is the additional combined use of chemical fertilizers, growth-stimulating agents and micronutrients intended for seed and vegetative plant treatment. In 2018–2020 a research was conducted into the effect of the VL 77 growth stimulants and the Orakul Semena, Orakul Multikompleks, and Orakul Sera Activ micronutrient complexes at different growth and development stages during winter wheat cultivation in the volatile weather conditions of the Stavropol Krai arid region. The research establishes the effectiveness of the combined use of the next-generation stimulants during winter wheat cultivation on chestnut soils in the conditions of the Stavropol Krai arid region. The highest yield of the Idilliya winter wheat variety (4.68 t/ha) was achieved by initially dressing the seeds with the VL 77 growth stimulants combined with the Orakul Semena micronutrient complex and treating the seeds with the VL 77 growth stimulants in combination with the Orakul Multikompleks micronutrient complex during the spring growth resumption period. The second treatment of vegetative plants during the flag leaf stage stimulated their growth, but moisture deficit reduced the yields by 2.3%. Still, the yields obtained exceeded the test yields by 4.3%. On average, during the three years of research the growth stimulant and micronutrient complex treatment boosted the yielding capacity in moisture deficit conditions by 4.6–5.1%. The cost effectiveness concurrently increased from 66.0% to 89.0%.

ОЦЕНКА БИОЛОГИЧЕСКОЙ АКТИВНОСТИ РИЗОСФЕРЫ SORGHUM BICOLOR (L.) MOENCH ПОД ВЛИЯНИЕМ МИКРОБНЫХ ПРЕПАРАТОВ В УСЛОВИЯХ ПРЯМОГО ПОСЕВА В СТЕПНОЙ ЗОНЕ КРЫМА

In steppe plants regularly lack of moisture and it affects the biochemical functions of their development. The aim of this research was to study the enzymatic activity of the Sorghum bicolor (L.) Moench rhizosphere grown by no-till technology under the influence of introduced microorganisms under conditions of moisture deficit. The growing season of Sorghum bicolor during the research period (2018–2020) was characterized by high temperature and arid conditions. The lack of precipitation reached 68.5 % in comparison with the average long-term indicators. It was revealed that the influence of the weather conditions of the year and the complex of microbial preparations (CMP) on the changes in the enzymatic activity of the S. bicolor rhizosphere was at the level of p≤0.05. IIBS (integral indicator of biological state) was calculated based on the level of activity of various enzymes in the soil. The value of IIBS with CMP is close to 80 %. It shows that no-till farming using CMP contributes to physiological stability of the rhizosphere. At the same time, the IBPS annually decreased by 61.1–92.8 % in the control variant without pre-sowing treatment of seeds with CMP, which indicates a slowdown of biological processes. The results of the studies proved that the adaptation of sorghum plants to the effects of abiotic environmental conditions is carried out by regulating the enzymatic activity of the rhizosphere by introducing microorganisms. Consequently, the use of microbial preparations is advisable for the cultivation of S. bicolor by no-till technology in steppe zone of Crimea.