Irrigated Varieties Research Articles

EFFECTS OF TECHNOLOGICAL METHODS OF GROWING DRIP-IRRIGATED WATERMELON FOR SEEDS ON SEED YIELD AND QUALITY

Purpose: To investigate the influence of drip irrigation of watermelon seed plants grown by different technological methods on the seed productivity, yield and sowing qualities. Methods: Field - determination of yield, biometric records and measurements; Laboratory - analyses of seed quality; Mathematical and statistical - ANOVA and statistical processing of data. Results. The optimal time for sowing seeds in drip-irrigated watermelon seed plantations was determined: the beginning of the second 10 days of May. When seeds were sown within the third 10 days of April or May, the yield of watermelon seeds was decreased by 37.8–51.6 kg/ha (16.7–18.5%, first period) and 61.5–69.0 kg/ha (24.3–27.2%, third period). Improved water supply of plants during the growing period due to drip irrigation contributed to an increase in the fruit yield and seed productivity. It was proven that the maximum yields of fruits (41.6 t/ha) and seeds (278.9 kg/ha) were harvested with a 1.4 x 0.35 m sowing scheme, plant density of 20,300 plats/ha, second sowing timeframe, and drip irrigation. The gain in the seed yield compared to the control (10,200 plants/ha) was 29.8 kg/ha (12.0%). It was found that, when watermelon seed plants were drip-irrigated, the yield of seeds was increased by 43.5–73.6 kg/ha (32.8–41.6%) compared to no irrigation variants. When seed plants were sown within the second timeframe according to a 1.4 × 1.05 m sowing scheme, with a smaller number of plants per hectare, the yield of seeds was reduced by 9.2–22.3 kg/ha (9.1%). The highest yield of certified seeds from fruits (91.9–93.8%) was harvested when seeds were sown within in the second timeframe according to any sowing schemes. Discussion. Our obtained are consistent with similar developments of domestic and foreign researchers. The high efficiency of growing watermelon seed plants under drip irrigation was demonstrated. Conclusions. The agrotechnical methods of watermelon seed plant growing, which determine the formation of fruits, their seed productivity, seed yield and quality, were studied. The optimal period for sowing seeds in drip-irrigated seed plantations (second 10 days of May, 1.4 × 0.35 m sowing scheme, and plant density of 20,300 plants/ha) was determined.

Effect of fertilizer application methods and drip irrigation on the productivity of columnar apple plants on sod-podzolic soil

The field agrochemical experiment conducted in 2021–2023 was designed to study the influence of drip irrigation and two methods of mineral fertilizer application on the components of productivity of columnar apple plants when grown on cultivated loamy textured sod-podzolic soil in the conditions of Moscow Oblast. Drip irrigation, solid fertilizer application, and fertigation were found to have different eff ects on plant productivity indicators. Th e eff ects largely depend on the cultivar and weather conditions. Drip irrigation in conjunction with solid fertilizers increased plant productivity to the greatest extent. Thus, the ‘Ostankino’ cultivar yielded by up to 2.16 kg/tree more, i. e. the productivity rose by 27.1 % compared to the controls. In the ‘President’ cultivar, yield per tree increased by up to 2.18 kg/tree (by 35.4 % compared to the controls). The irrigated and fertilized variants of the experiment were distinguished by higher vegetation productivity values for the ‘President’ cultivar plants. For this cultivar, the highest total growth rate was in the fertigation-drip irrigation variant with an increase of up to 459.2 cm/tree in 2022. Th e average growth over two years was 16.5% higher than in the control group. In the ‘Ostankino’ cultivar, the total length value of shoot growth during irrigation and solid fertilizer application decreased compared to the control group by up to 245.2 cm/tree. On average, over two years it decreased by 15.7 % compared to the controls. In the fertigation-drip irrigation variant, there was a decrease in the ammonia nitrogen content in the soil compared to the other variants. As a result, the total mineral nitrogen content in the soil layer to a depth of 60 cm was minimal. Th e highest value of ammonium content and total nitrogen in the rhizosphere were observed in the variant with drip irrigation and solid fertilizer application.

ӘРТҮРЛІ ТӘСІЛДЕРМЕН СУҒАРУ КЕЗІНДЕГІ БҰРЫШ ЖӘНЕ БАКЛАЖАН ДАҚЫЛДАРЫНЫҢ СУДЫ ПАЙДАЛАНУ КОЭФФИЦИЕНТІН ЗЕРТТЕУ

The scientific article presents the results of a study of the coefficient of water use of pepper and eggplant crops when watering in various ways. Water agriculture consumes a large amount of water. In order to save water supplied to agricultural crops, effective irrigation methods are used. The water use of crops varies and depends on various indicators. Pepper and eggplant cultures obtained as a result of research work are among the most commonly grown crops. In recent years, these crops have been drip-watered in an open field and greenhouse. In the research work, pepper and eggplant cultures were grown through seedlings in an open field, they were systematized and watered drip. Before determining the water use coefficient of vegetable crops, their total water use and average daily water use are determined. Total water use and average daily water use of pepper and eggplant crops were low in the drip irrigation variant. It was found that the height of vegetable crops in the drip irrigation variant was higher than +4+5 cm. In the variant of systematic irrigation, the coefficient of water use of vegetable crops was 40 m3/c in the corner, in the variant of drip irrigation-21 m3/c, in the variant of drip irrigation, this indicator was below 20.8 m3/c in the corner, in the variant of drip irrigation-11.2 m3/с. In the drip irrigation variant, the water use coefficient of crops was lower than 9.8-19 m3/c (47-52%).

Impact of increasing vegetation coverage on gaining and losing streams in an arid endorheic river watershed

AbstractTo improve the ecology in northern China, the Chinese government has launched a series of revegetation projects. However, the impact of increasing vegetation coverage on gaining and losing streams remains largely unexplored, particularly in arid endorheic watersheds with frequent exchanges of water and other materials between surface water and groundwater. To address this, we modified the vegetation growth module of the soil and water assessment tool (SWAT) to simulate the vegetation coverage change proposed for the middle and lower reaches of the Bayin River. We then coupled the modified SWAT to a modular finite‐difference groundwater flow model to simulate the surface and subsurface water exchange. Hydrological, meteorological, and hydrogeological observation data were then used to build and calibrate the coupled model for the period 2001–2019. We set two vegetation coverage scenarios (non‐revegetation and vegetation) and two irrigation variants (non‐irrigation and irrigation) to investigate the impact of changes in vegetation coverage and the related irrigation variant on gaining and losing streams. The results showed that the vegetated land area and annual leaf area index both increased significantly between 2019 and 2001. The groundwater discharge to the gaining streams was more strongly affected by revegetation and related irrigation than the groundwater recharge from the losing streams. Irrigation related to revegetation emphasizes the effect of revegetation on streamflow. We suggest that in arid endorheic river basins, because of the related irrigation, revegetation has a substantial impact on groundwater level and streamflow, which is mainly composed of baseflow. Therefore, the irrigation efficiency of newly planted vegetation must be improved to stabilize the groundwater level and related ecological conditions.

Quantification of water fluxes and soil water balance in agricultural fields under different tillage and irrigation systems using water stable isotopes

Sustainable agriculture should be based on management practices that improve resource usage efficiency and minimize harmful impacts on the environment while maintaining and stabilizing crop production. Both tillage and irrigation can have an influence on water resource usage and thus on hydrological processes within agroecosystems. However, it remains difficult to directly assess the effect of practices on water fluxes. Therefore, the objective of the study was to use oxygen and hydrogen isotopes (δ18O, δ2H) in the pore water of soil profiles as well as moisture contents for quantifying the soil water balance and fluxes. Covering all combinations, water content and isotope analysis in soil profiles were performed for 16 plots planted with winter wheat and managed with different tillage (conventional tillage (CT), reduced tillage (RT), minimal tillage (MT), and no-tillage (NT)) and irrigation systems (hose reel boom irrigation with nozzles (BI), sprinkler irrigation (SI), drip irrigation (DI) and no irrigation (NI)). The results indicated that the more intense the tillage, the lower the water content. Among the irrigation systems, DI had the highest average water content. Tracing the isotope minimum of winter precipitation in pore water of soil profiles showed deeper percolation of water in the CT plots, which indicates higher water flow velocity for CT compared to other tillage variants. Considering both water content and water flow velocities resulted in average water fluxes ranging from 23 to 46 mm for six months (end of November to May). For the same time period, between 80% and 91% of the water contributed to evapotranspiration. The resulting evapotranspiration within tillage and irrigation variants decreased in the order CT>RT>MT>NT and SI>BI>DI>NI. Thus, the method revealed that the lower water content in CT fields is a consequence of both deeper water infiltration and higher evapotranspiration. Moreover, irrigation water contributed mostly to evapotranspiration, and drip irrigation showed the lowest evapotranspiration among irrigation systems. This study demonstrated that water stable isotopes can be used as indicators and are a promising method to quantify average water fluxes in agricultural fields with great potential for evaluating management practices.

Scientific-based regime of irrigation of raspberry with dripping irrigation under the conditions of the Central Non-Black Earth Region

Raspberries are among the important berry crops, the production volumes of which are increasing every year. To obtain high-quality planting material, high and stable yields in unstable weather conditions, it is necessary to develop resource-saving technologies, which include drip irrigation. The purpose of the research is to develop a science-based irrigation regime for drip irrigation of raspberries in the conditions of the Central region of the Non-Chernozem zone of Russia. A two-factor field experiment was established in the fall of 2019. The first factor is the drip irrigation regime (maintaining the moisture content of the root layer of the soil in the ranges of 60…80, 70…90 and 80…100% of the lowest moisture capacity), the second factor is the variety (Nagrada and Solnyshko). Drip irrigation of raspberries can significantly save irrigation water. In the variant of drip irrigation with maintaining moisture in the root layer in the range of 80…100% of the lowest moisture capacity, the savings in irrigation water compared to traditional irrigation methods averaged 65%, and in the variant of 60-80% of the lowest moisture capacity - 78%. At the same time, with the use of local irrigation, an optimal water-air regime of the soil is created. For the irrigated variants of the experiment, the main share in the total water consumption is precipitation (from 71 to 81%), and the irrigation rate - from 15 to 22%. In the variants with maintaining humidity above 70% of the lowest moisture capacity, the diameter of the stem of seedlings is 20-40% larger than in the control, the height of seedlings is 40-50%, and the yield is 2 times, which makes it possible to recommend them as optimal.

Modelling 2050 Water Retention Scenarios for Irrigated and Non-Irrigated Crops for Adaptation to Climate Change Using the SWAT Model: The Case of the Bystra Catchment, Poland

The paper presents the estimated changes in the soil water content, the total runoff, the sediment yield and the actual evapotranspiration for the small Bystra catchment in the east of Poland. The findings are based on the results of three simulations covering the years of 2041–2050. The simulations were based on a calibrated and validated SWAT model (2010–2017). The first variant covers just the climate change and the existing structure of soil cultivation for the three regional climate models supported by the EC-EARTH global climate model in the emission scenarios RCP4.5 and RCP8.5. Variants two and three are based on the first variant in terms of the changing climate. The second variant, however, involves placing a pond in each farm in the catchment, while the third variant involves designing huge reservoirs as a result of land consolidation. Variants two and three occur in five adaptation scenarios each. The first adaptation scenario (V2.1 and V3.1) involves only increasing the number of ponds on the farm or increasing the number of reservoirs for non-irrigated arable land crops, i.e., WWHT (winter cereals), BARL (spring cereals), CANP (rapeseed) and CRDY (other crops). The second adaptation scenario (V2.2 and V3.2) involves growing vegetables without irrigation (instead of cereals). The third adaptation scenario (V2.3 and V3.3) involves growing vegetables with irrigation (instead of cereals). The fourth adaptation scenario (V2.4 and V3.4) involves partial cultivation of vegetables and cereals. The fifth adaptation scenario (V2.5 and V3.5) involves partial cultivation of orchards and cereals. The adaptation scenarios of the irrigation of vegetables from deep water-bearing layers (second variant) or reservoirs (third variant) contribute to the increase in water content in the soil, especially in summer, in comparison with the adaptation scenarios for vegetable cultivation without irrigation. What is more, the actual evapotranspiration was higher in the adaptation scenarios involving irrigation than in scenarios without irrigation. It is known that the changes in water content in soil and the intensification of water erosion are gravely affected by modifications in crops and soil cultivation. A change from cereal cultivation to irrigated vegetable cultivation or orchards increased the water content in the soil in most climatic projections. However, the increase in the number of ponds in the second variant had little impact on the soil water content, actual evapotranspiration and overall runoff, while the erosion loss decreased. With the lower precipitation levels in the years 2041–2050 relative to 2010–2017, as presented in the emissive scenario RCP 4.5, the soil water content decreases by up to 14% for most variants. Total runoff for most variants will also be lower by 4–35%. The percentage change in sediment yield will fluctuate between −86% and 116%. On the other hand, the actual evapotranspiration for most variants will be higher. With higher precipitation levels in the years 2041–2050 relative to 2010–2017, as presented in the emissive scenario RCP 8.5, the soil water content changes slightly from −7% to +3%. Total runoff for most variants will also be higher by as much as 43%. Sediment yield for most scenarios may increase by 226%. The actual evapotranspiration for most variants will also be higher. Irrigation variants tend to increase soil available water while increasing evapotranspiration and total outflow in the catchment as compared to non-irrigated LULC. The largest increase in the soil water content is observed in most irrigation variants for RCP 4.5 (annual average 316–319 mm) (V2.3-V2.5, V3.2, and V3.3) and RCP 8.5 (annual average 326–327 mm) (V2.3-V2.5 and V3.3) as compared to V1 (BaU) (315 mm–RCP 4.5 and 324 mm–RCP 8.5) for the years 2041–2050. On the other hand, the lowest increase in soil water content is observed in the V3.5 variant, with an annual average of 292 mm for RCP 4.5 and an annual average of 311 mm for RCP 8.5. Thus, for future climate change scenarios, irrigation with water reservoirs (ponds and storage reservoirs) should be considered. The study proves the rationale behind building ponds in small catchments in order to increase water resources in a landscape and also to counteract adverse effects of climate changes, i.e., sediment outflow and surface water erosion.

Водопотребление малины при капельном орошении в условиях Центрального Нечерноземья

To obtain high-quality planting material, high and stable raspberry yields in unstable weather conditions, it is necessary to develop resource-saving technologies that are currently not available for the Central Non-Сhernozem region of the European part of Russia. The purpose of the study is to identify the features of raspberry water consumption under various drip irrigation regimes in the conditions of the Central Non-Chernozem region of Russia. Field studies were carried out on the basis of the laboratory of fruit growing «Michurinskiy Sad» of the Russian State Agrarian University – Moscow Agricultural Academy named after C.A. Timiryazev. A two-factor fi eld experiment was laid down in the fall of 2019. Drip irrigation of raspberries can signifi cantly save irrigation water in comparison with other irrigation methods (furrows, sprinkling, etc.). The conducted studies showed that in the variant of the experiment with maintaining soil moisture in the range of 80-100% of the lowest moisture capacity, the saving of irrigation water compared to furrow irrigation was on average 65%, and in the variant of 60-80% of the lowest moisture capacity – 78%. In addition, the use of local irrigation contributes to the creation of an optimal water-air regime of the soil. The highest total water consumption is characterized by the variant of the experiment with maintaining moisture in the root layer of the soil in the range of 80-100% of the lowest moisture capacity (on average 4342 m3/ha), and the smallest – 60-80% of the lowest moisture capacity (on average 4026 m3/ha). The study of the contribution of the main elements of the water balance to water consumption showed that for the irrigated variants of the experiment, precipitation has a signifi cant share (from 71 to 81%), and the contribution of the irrigation rate to the total water consumption is from 15 to 22%.

ЖАМБЫЛ ОБЛЫСЫ ЖАҒДАЙЛАРЫНДАҒЫ КӨКӨНІС ДАҚЫЛДАРЫНЫҢ СУ ПАЙДАЛАНУ ЖИЫНТЫҒЫН ЗЕРТТЕУ

The scientific article presents the results of a study of the water-use aggregate of crops during irrigation of vegetable crops by various irrigation methods on loamy gray soils of the Zhambyl region. Vegetable crops were watered systematically and drip. For irrigation, a drip irrigation system was used, which has a high water-saving capacity and does not require high funds. The daily and total water use of vegetable crops during the growing season are determined. As a result of the study, it was found that the daily set of water consumption of vegetable crops showed a low indicator in the drip irrigation variant. The total water use of vegetable crops showed high indicators in the variant of systematic irrigation and amounted to 4151m3/ha, and in the variant of drip irrigation 2333m3/ha, that is-1818m3/ha. The total water use of vegetable crops for months showed low rates in the drip irrigation option. The average daily water use of vegetable crops in the drip irrigation variant in June and July was 22-24m3/ha, and in systematic irrigation in these months was 33-43m3/ha. Low average daily water use of crops was observed in the drip irrigation variant in August and was equal to 18m3/ha. The main revenue part of the water balance of vegetable crops was irrigation work. It was found that the total water use of vegetable crops in the variant of systematic irrigation showed a high rate of 44%.

Study of Photosynthetic Gas Exchange Parameters and Relative Water Content of Flag Leaf in Soft Wheat Genotypes Under Different Water Supply Conditions

The results of the study of the relative water content (RWC) and photosynthetic gas exchange parameters of the flag leaves in 21 soft wheat genotypes under rainfed conditions of Mountain Shirvan have been presented in the paper. The research was performed with drought-exposed and irrigated variants during the grain filling phase. RWC of the flag leaves of Vostorg, Murov 2, Tale 38, and Gyrmyzy gul 1 genotypes was higher both under drought and irrigated conditions. There was a positive correlation between RWC and earing time, and a negative correlation between RWC and plant height. The average difference in RWC between irrigated and drought-exposed variants for all genotypes was 10.1%. In 12thIWWYT no. 9 and 12thIWWYT no. 20 lines, this difference was high (26.5 and 19.6%), while in Gyzyl bughda, Murov 2, and Ferrigineum 2/19 genotypes, it was low (3.5, 3.6, and 2.9%). The highest values of the rate of photosynthesis were observed in the drought-exposed genotypes Sheki 1, Aran, Tale 38, and Zirva 85 (14.2, 14.8, 14.1, and 14.3 µmol CO2m−2 s−1), and in the irrigated genotypes Aran, Vostorg, and 12thIWWYT no. 9 (24.9, 23.4, and 24.0 µmol CO2 m−2s−1). Stomatal conductance (0.115, 0.120, 0.130, 0.164 mol H2O m−2 s−1), the concentration of CO2 in intercellular spaces (146.3, 156, 5, 181.7, and 213.7 µmol CO2mol−1) and the transpiration rate (3.32, 3.58, 4.13 and 4.44 mmol H2O m−2s−1) were higher in the Sheki 1, Aran, Tale 38, and Zirva 85 varieties, which manifest higher photosynthetic rate under drought conditions than other genotypes. A significant positive correlation of RWC with the rate of photosynthesis, the stomatal conductance, the concentration of CO2in intercellular spaces, and the rate of transpiration was found under drought stress conditions.

Methodology of recycling of drainage and waste water in Kazakhstan

The article discusses the issues of reuse of drainage and waste water in the middle reaches of the Syrdarya River. According to the results of the research, it was revealed that the salt balance of the soils of cotton and corn fields in the aeration zone (0-2 m) has different indicators. In the irrigation variant with drainage water up to 6.0 g/l, the soil was saturated by the end of the growing season with salts in the amount of 26.4 t/ha under cotton crops and 63.8 t/ha under corn, when irrigated with river water, a favorable salt regime was observed, i.e., salts were removed to the underlying horizons or drainage from the upper layer in the amount of 81.3 t/ha under cotton and 42.6 t/ha under corn. For desalination of drainage and waste water, crushed natural saline plants (Glycyrrhiza glabra, Alhagi, and others) and a 20 % concentration of glauconite clay or phosphogypsum, which are diluted with drainage and waste water, are used in the complex. The resulting reclamation complex allows reducing the mineralization of drainage and waste water to standard indicators.

The Effects of Irrigation, Topping, and Interrow Spacing on the Yield and Quality of Hemp (Cannabis sativa L.) Fibers in Temperate Climatic Conditions

The study was aimed at determining the most suitable irrigation schedule program for hemp grown for fibers by using evaporation from the free water surface (Eo), measured by a Class A pan and related crop plant coefficient (Kc). The experiment, carried out in Vojvodina, a northern part of the Republic of Serbia, included three irrigation regimes: I1, I2, and I3 corresponding, respectively, to daily evaporation from an open water surface (Eo), two interrow spacings: RS1 (12.5 cm) and RS2 (25 cm), and topped (T) and not topped (NT) variants. The Kc values used for the calculation of daily evapotranspiration (ETd) were 0.42 for April and May and 1.00 (I1), 0.80 (I2), and 0.60 (I3) from June to the harvest. In addition, the nonirrigated (Io) control variant was also included in the trial. The dioecious fiber hemp variety Marina was used for the trials. Irrigation was carried out by a drip irrigation system and was scheduled based on the water budget method. It started when readily available water (RAW) in the soil layer of 0.4 m was completely depleted by the plants. In the first year of the study, irrigation did not influence the yield of hemp fiber, but in the second one, the best result was achieved for the irrigation variant I1. Interrow spacing did not have a statistically significant effect on both the hemp fiber yield and the quality. The topping of plants significantly decreased the yield of hemp, and it is not recommended when the hemp is cultivated for fibers. The quality of the hemp fibers was not influenced by irrigation, inter-row spacing, and topping. The rate of hemp evapotranspiration was in an interval of 312 mm (ETa) to 520 mm (ETm). The highest values of IWUE and ETWUE in both years and the bark yield in the first year were detected for the I3 irrigation variant, which suggested that the crop plant coefficient (Kc) of 0.6 could be recommended for the correction of Eo values in the calculation of the daily evapotranspiration of hemp (ETd) from June to August. The yield response factor (Ky) with values of 0.22 and 0.60 for the total growing season reveals that, in rainy years, hemp for fiber production could be grown without irrigation in the temperate climate of the Vojvodina region. However, such years are rare. Without doubt, irrigation of fiber hemp is recommended in the mentioned region in order to obtain high yields of good quality product.

The effect of drip irrigation on the formation of the root system of raspberry seedlings in the conditions of the Non-black soil zone of Russia

Relevance. Currently, there is an acute problem of meeting the growing demand for berry and fruit products. One of the ways to intensify agricultural production in the field of horticulture and crop production is to increase the efficiency of environmental management through the use of resource-saving technologies. One of these technologies is drip irrigation, which improves the quality of crop production.Materials and methods. Field studies were carried out on the territory of the educational and experimental farm of the laboratory "Michurinsky Garden" of the Russian State Agrarian University – Moscow Timiryazev Agricultural Academy. The experiment was established in the fall of 2018 and is a two-factor study of various levels of moisture on the growth and development of raspberry seedlings. The first factor included options for maintaining soil moisture in the range: 1) control (without irrigation); 2) not less than 60% of the lowest moisture capacity; 3) not less than 70% of the lowest moisture capacity; 4) not less than 80% of the lowest moisture capacity. The second factor was the raspberry varieties Solnyshko and Nagrada.Results. Constructed moisture contours according to the study options showed that drip irrigation contributes to the optimum moisture concentration in the soil for seedlings. The most developed root system in comparison with the control was obtained on irrigated variants with maintaining a moisture content of at least 70 and 80% of the lowest moisture capacity. Here, the maximum values of the volume of the root system, the number of roots, and the average length of the root were obtained. It was revealed that in variants with irrigation, the root system of seedlings spreads in the upper layer (mainly 5-15 cm).

INFLUENCE OF TECHNOLOGICAL FACTORS ON COTTON YIELD

In the field experiment, three different thicknesses of cotton bushes (80; 100 and 120 thousand per hectare, as well as 7.2; 9.0 and 10.8 plants per 1 pogonometer, respectively), two different irrigations relative to the limited field moisture capacity of the soil (ChDNS) regime (70-70-60 and 75-75-60%, as well as the irrigation regime 2-3-0 and 2-4-0, respectively) and the ratio of the two norms of fertilizer (NPK) (1: 0.7: 0, 5 and 1: 1: 0.5) were studied. The annual norm of fertilizers was: N200 P140 and K100 and N200 R200 and K100 kg..It was taken into account that the yield of cotton grown under conditions where the irrigation regime was 70-70-60% relative to the soil ChDNS (limited field moisture capacity) was higher in the years of experiments than the yield in the 75-75-60% regime irrigated variants.In the 70-70-60% irrigation regime, the average yield was 35.7-40.9 ts / ha, depending on the thickness of the bush and the ratio of fertilizers, while in the 75-75-60% irrigation regime the yield was 33.2-36.4 on average. ts / ha.The micronair index of fiber in cotton harvested from experimental variants was 4.3-4.5, and the micronair index of cotton fiber harvested from 70-70-60% of irrigated variants was slightly higher than the 75-75-60% irrigation regime.

Chlorophyll Fluorescence Kinetics May Be Useful to Identify Early Drought and Irrigation Effects on Photosynthetic Apparatus in Field-Grown Wheat

To assess the reliability and sensitivity of non-invasive optical methods to detect the early effects of water deficit in the field, we analyzed the time-series of non-invasive measurements obtained in a dry season in a representative collection of wheat genotypes grown in small-plot field trials, in non-irrigated and irrigated variants. Despite a progressive water deficit and significant yield loss, the measurements indicated very minor changes in chlorophyll content or canopy cover. This corresponded well to the insignificant differences in spectral reflectance normalized difference vegetation index (NDVI) values. On the other hand, we identified the significant and rapid response of fast fluorescence kinetics data following the onset of irrigation. Analysis of parameters showed the main effects of drought were associated with changes in the amplitude of the I–P phase of the OJIP transient, indicating changes at the level of photosystem I and beyond. Statistical analyses identified the integrative parameter performance index PItot as the most sensitive parameter, which well-reflects the differences in responses of the genotypes to water deficit. Our results suggest that focusing on photosynthetic functions detected by the rapid chlorophyll fluorescence records can provide more accurate information on the drought stress level, compared to the structural data obtained by absorbance or reflectance measurements.

FORMATION OF PLUM SEEDLINGS UNDER DRIP IRRIGATION IN CENTRAL NON-BLACK SOIL REGION OF RUSSIA

The article presents the results of studying formation of plum seedlings under drip irrigation in conditions of the Central Non-Black Soil Region of Russia. Field research was carried out on the territory of the training and experimental farming, fruit-growing laboratory “Michurinsky Garden” of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy. The factors studied were soil irrigation regimes (60-80, 70-90, 80-100% of the lowest moisture capacity) and plum varieties (“Utro” and “Mashenka”). The results of the experiment showed that plum seedlings grown under conditions of insufficient and uneven moistening were characterized by the lowest biometric indices. The most severe lack of soil moisture was observed during intensive growth (May - early June). Insufficient and uneven moistening with intervals of reduced moistening leads to several growth waves in plants. In the seedlings grown under drip irrigation the second and third waves of growth were not observed. In irrigation variants, the root system of seedlings was mainly located in the upper arable layer of the soil which was best supplied with nutrients, had the lowest density and favorable air regime. Location of root system along the drip line and at the depth of 30 cm facilitated transferring seedlings to nurseries and ensured less damage to them during transplantation.

Efficiency of Cultivating Corn for Grain under Irrigation in the Prialeyskaya Steppe

To assess the effectiveness of irrigation when cultivating corn for grain in the conditions of the arid Prialeyskaya steppe of the Altai Territory, an irrigation regime was developed to maintain pre-irrigation moisture at 60 and 70 % minimum moisture-holding capacity in the soil layer – 0.5 m. Water with irrigation was used mineralization of 0.3 g/l, it lacked toxic salts. In 2015, the irrigation norm with an irrigation regime of 60 % minimum moisture-holding capacity was 2650 m3/ha, with a regime of 70 % minimum moisture-holding capacity – 2850 m3/ha. In 2016, irrigation norms for irrigation regimes were 60 and 70 % minimum moisture-holding capacity of 2250 and 2450 m3/ha, respectively. In 2017, at the 60 % minimum moisture-holding capacity option, 7 irrigations were carried out, the irrigation rate was 2700 m3/ha. On the irrigation variant of 70 % of the minimum moisture-holding capacity, 8 irrigations were carried out, the irrigation rate was 2900 m3/ha. The highest yield of corn grain was obtained while maintaining a humidity level of at least 70 % minimum moisture-holding capacity. The maximum yield in 2015 was 6.7 t/ha, in the control – 3.8 t/ha. The yield increases on this option were significant in comparison not only with the control without irrigation, but also in comparison with the 60 % minimum moisture-holding capacity. To identify the economic efficiency of cultivating corn with irrigation, the costs of irrigation and the cost of the resulting crop were considered. The highest net income and profitability were obtained in 2016 with an irrigation regime of 70 % minimum moisture-holding capacity. Net income was 63.31 thousand rubles/ha, profitability level 370.45 %. In all years of research, the economic indicators for irrigation options were significantly superior to those for the non-irrigation option.

Effects of Irrigation and Fertigation on Yield and Quality Parameters of 'Gala' and 'Fuji' Apple

The climate change and growing production of crops increase the demand for the water and the efficient use of water in agriculture becomes more critical. This experiment presents the results of research in the orchard with different irrigation programs and fertigation on yield and quality parameters of the ’Gala‘ and ’Fuji‘ apple tree. Three irrigation programs were applied IR + F – full irrigation with fertigation; IR – full irrigation without fertigation; NON‑IR – non‑irrigation, only natural precipitations. There were no differences observed among these three irrigation programs for tree diameter, sugar content, starch content and fruits firmness (P < 0.05). Significant deficit of water was in program IR and NON‑IR, at the length of annual growth, where the reduction was from from 680 mm to 440 mm at the ‘GALA’ variety. Statistically important differences between the irrigation variants were found out at the variety ‘Fuji’, in parametres yield, fruit weight and fruit diameter. Between programs IR + F and NON‑IR was the difference of fruit weight 25.6 g (14.3 %) and of fruit diameter 4.5 mm (5.8 %).

Effect of Drip Irrigation and Complementary Nutrition with Nitrogen on Potato Quality and Yield

A small-plot field experiment started in 2016 studied effect of drip irrigation on potato tuber yield and starch levels in the tubers. Two potato varieties with different vegetation periods (Monika, Jolana) were exposed to four drip irrigation intensity levels. They were non-irrigated controls and irrigated tubers with 60 %, 65 % and 70 % usable soil water capacity levels. The other studied parameter was represented by the effect of nitrogen fertilisation with the nitrogen nutrient added to the irrigation water (fertigation) in the course of the vegetation period in contrast to one-off application of the whole nitrogen dose before the potato planting. All irrigated variants in comparison to the non‑irrigated controls showed 30–60 % yield increase. The effect of fertigation on yields was statistically insignificant. Starch levels in the tubers were mostly affected by the variety. The irrigated variants in comparison to the non-irrigated controls showed higher starch levels in the harvested tubers but the differences were statistically insignificant.

Differential distribution patterns in cerebellar irrigation. A study with autopsy material

Aim: The aim of this investigation was characterize morphologically the cerebellar artery and its branches in a specimen of autopsy material.
 Methods: This descriptive cross-sectional study evaluated the anatomical characteristics of the cerebellar arteries and their branches in 93 brain stem and cerebellum blocks obtained from fresh cadavers. The specimens were perfused bilaterally channeling the proximal segments of the internal carotid and vertebral arteries with a semi-synthetic resin (Palatal GP40L 85%; styrene 15%) impregnated with mineral red dye. We evaluated the distribution patterns of the cerebellar artery and its branches.
 Results: The calibers of the superior cerebellar artery (SCA), anterior inferior cerebellar artery (AICA) and posterior inferior cerebellar artery (PICA) were 1.46 ± 0.2 mm, 1.02 ± 0.35 mm and 1.45 ± 0.37 mm, respectively. Agenesis of the SCA was observed in six specimens (3.2%), AICA in 30 (16.1%), and PICA in 14 (7.5%) specimens. Usual irrigation was observed in 44 (47.3%) cerebellar blocks, whereas 49 (52.7%) specimens showed irrigation variants, 23 (46.9%) of which appeared bilaterally. The dominant distribution of the cerebellar arteries corresponded to SCA in 9 (12.5%) cases, AICA in 46 (63.9%) and PICA in 7 (9.7%) specimens; shared dominance was found in 10 (13.9%) specimens.
 Conclusion: The high variability of the cerebellar arteries observed in the present study is consistent with previous reports. The diverse anatomic expressions of the cerebellar arteries were typified in relation to their dominance and territories irrigated, useful for the diagnosis and clinical-surgical management of the cerebellum blood supply.