Winter Wheat Grain Yield Research Articles

Reduced 15N Losses by Winter and Spring Night-Warming Are Related to Root Distribution of Winter Wheat

To develop efficient N management strategies for high wheat NUE and minimizing the environmental impact of N losses under asymmetric warming, 15N micro-plot experiments were conducted to investigate the effects of night-warming during winter (warming by 1.47–1.56°C from tillering to jointing), spring (warming by 1.68–1.82°C from jointing to booting), and winter + spring (warming by 1.53–1.64°C from tillering to booting) on root growth and distribution of winter wheat, the fates of 15N-labeled fertilizer, and their relationships in 2015–2017. The results showed that night-warming increased the recovery of basal 15N and top-dressed 15N, while reduced the residual and loss of basal 15N and top-dressed 15N. The losses decreases of top-dressed 15N were higher than those of basal 15N, indicating that night-warming reduced losses of fertilizer 15N mainly by reducing losses of top–dressed 15N. Moreover, pre-anthesis root dry matter accumulation rate in 0–60 cm soil layer were promoted, resulted in improved root biomass and root/shoot ratio, which favored increasing recovery of fertilizer 15N and reducing losses of fertilizer 15N. Furthermore, residual fertilizer 15N content in 0–100 cm soil layer was reduced, which was associated with improved root weight density in 0–60 cm soil layer, resulted in reduced leaching losses of fertilizer 15N. The path analysis showed that root dry matter distribution in 0–20 cm soil layer was the most important in contributing to reducing losses of total fertilizer 15N compared with other soil layers. Two years data showed that winter and spring night-warming gave better root growth and distribution in 0–20 cm soil layer, resulted in reduced the losses of fertilizer 15N and improved the recovery of fertilizer 15N, while maximizing grain yield of winter wheat, and winter + spring night-warming resulted in higher advantages than winter night-warming and spring night-warming.

Contrasting Impacts of Long-Term Application of Biofertilizers and Organic Manure on Grain Yield of Winter Wheat in North China Plain

The effects of long-term incorporation of organic manure and biofertilizers have been investigated on winter wheat in the North China Plain (NCP). The five-year field experiment (2013–2018) has illustrated the responses of grain yield and yield components. Seven fertilization approaches, included pig farm-yard-manure and biofertilizers amendments combined with five NPK% drop levels of chemical fertilizer ratio + organic fertilizer + biofertilizer (0, C+O+B) 25%, CL4; 50%, CL3; 75%, CL1; and 100%, CL0), without fertilizer as control (CK), in NCP during the years 2013–2018. Results showed that the grain yields of CL1 and CL2 were equivalent to CL0 in all growing seasons except 2014/2015. The grain yields of CL4 were 29.9% to 46.6% lower than that of CL0 during 2014/2015, 2016/2017, and 2017/2018. The valuable spike-number, grain number per-spike, and 1000-grain weight showed significant variations among different growing periods. Regression analysis of grain yield and yield components indicated that number grains per-spike showed significant increase in seed yield formation. The 1000-grain weight was the major parameter that influenced yield of moderate and low yielding periods, respectively. The results revealed that application of 30 m3 ha−1 pig farm-yard-manure and 20 kg ha−1 biofertilizers has reduced at least 50% of the NPK fertilization without dropping grain yields in the North China Plain.

Genetic gains in grain yield and physiological traits of winter wheat in Hebei Province of China, from 1964 to 2007

Understanding the key characteristics associated with genetic progress is essential to future wheat breeding strategies. Our objectives were to investigate the genetic progress in grain yield (GY) and key characteristics in wheat (Triticum aestivumL.) cultivars released from 1964 to 2007 in Hebei province, China. Field experiments including 9 milestone cultivars were conducted during three growing seasons (2010–2011, 2011–2012, and 2012–2013) at Shijiazhuang of Hebei. Grain yield is significantly increased by the linear rate of 47.4 kg ha−1 yr−1 or 0.717% (R 2 = 0.909, P < 0.001) and mainly attributed to the increase of harvest index (HI) (r = 0.927, P < 0.01), kernels per spike (Skernel) (r = 0.919, P < 0.01) and thousand kernel weight (TKW) (r = 0.869, P < 0.01). Aboveground biomass (AGBM) has also important contribution to genetic gain in yield before 1997 (r = 0.838, P < 0.05). Although there is decline tendency in spikes m−2 due to decreased maximum tiller numbers (Mtiller) and increased percentage of ear-bearing tiller (ET%) after 70 s, changes of spikes m−2 have no significant effect on yield improvement. Grain yield has positive correlation with kernels m-2 (r = 0.767, P < 0.05) in spite of slower increasing rate of kernels m−2 after 1970s. Genetic gain of GY has close relation with decreased plant height (PH) (r = −0.811, P < 0.01), and PH of stone cultivars after 1970s were 70–80 cm which was optimum for grain yield. Days to heading (DH), days to anthesis (DA) and days to maturity (DM) of stone cultivars have no significant correlation with genetic gain. The significant HI increase mainly results from a significant increase in TKW (r = 0.811, P < 0.01) and Skernel (r = 0.919, P < 0.01). The increased TKW is positively associated with the maximum filling rate (Rmax) (r = 0.720, p < 0.05), average filling rate (Ra) (r = 0.836, p < 0.01), water-soluble carbohydrate (WSC) at anthesis in stem (WSC0) (r = 0.820, p < 0.05), Stem WSC 10 d after anthesis (WSC10) (r = 0.861, p < 0.01) and chlorophyll content (Chl) (r = 0.783, p < 0.05). Thus the physiological traits of Chl of flag leaf, stem WSC and high filling rate can be used to select criterions for further improving yield potential.

Effects of delayed irrigation during the jointing stage on the photosynthetic characteristics and yield of winter wheat under different planting patterns

To study the water-saving and high-yielding planting pattern in the North China Plain (NCP), a conventional planting pattern (C) and wide-precision planting pattern (W) were adopted during the 2015–2016 and 2016–2017 winter wheat growing seasons. For each planting pattern, the plants were provided with 60 mm irrigation either during the jointing stage or 10 days after the jointing stage. During both growing seasons, the chlorophyll content index (CCI) in the flag leaves, maximum photochemical efficiency (Fv/Fm), photosynthetic rate (Pn), transpiration rate (Tr), and grain yield (GY) of winter wheat were measured. The results showed that at the heading and flowering stages, W significantly increased the CCI and Fv/Fm in flag leaves. In both growing seasons, the highest value for both CCI and Fv/Fm was observed during the filling stage in W treatment with 60 mm irrigation 10 days after the jointing stage (WI2). The trend for Pn was consistent with the change in Tr, and both reached the maximum value at the flowering stage. At the filling stage, the leaf water use efficiency (WUEL) in WI2 reached the maximum value. Delayed irrigation at the jointing stage significantly increased the number of spikes as well as the kernel numbers per spike in W; as a result, the winter wheat grain yield was significantly increased in WI2. The results indicate that the use of W in combination with 60 mm irrigation 10 days after the jointing stage is an optimal method for winter wheat production in NCP.

The Stimulatory Effects of Nanochitin Whisker on Carbon and Nitrogen Metabolism and on the Enhancement of Grain Yield and Crude Protein of Winter Wheat.

Nanochitin whisker (NC) with a cationic nature could enhance plant photosynthesis, grain yield, and quality of wheat, but have not been systematically studied. This study was designed to investigate the stimulatory effects of NC on dry matter (DM) and nitrogen (N) accumulation and translocation, and on the metabolism of carbon (C) and N in later growth stages of winter wheat to reveal the enhancement mechanism of grain yield and crude protein concentration. Different parts of NC-treated plants from pot grown experiments were collected at the pre- and post-anthesis stages. The accumulation, translocation, and contributions of DM and N from pre-anthesis vegetation organs to grains, as well as key metabolic enzyme activities, including sucrose phosphate synthase (SPS) and phosphoenolpyruvate carboxylase (PEPC), were examined. The results showed that, at an application rate of 6 mg·kg−1 of NC in the soil, the accumulation of DM and N were significantly enhanced by 16.2% and 38.8% in pre-anthesis, and by 15.4% and 30.0% in post-anthesis, respectively. Translocation of N and DM in the post-anthesis periods were enhanced by 38.4% and 50.9%, respectively. NC could also stimulate enzyme activities, and increased 39.8% and 57.1% in flag leaves, and by 36.0% and 58.8% in spikes, respectively, at anthesis. SPS and PEPC increased by 28.2% and 45.1% in flag leaves, and by 42.2% and 56.5% in spikes, respectively, at 15 days after anthesis. The results indicated that the NC promoted N metabolism more than C metabolism, and resulted in the enhancement of grain yield by 27.56% and of crude protein concentration in grain by 13.26%, respectively.

Comparisons of WUE in twelve genotypes of winter wheat and the relationship between δ 13C and WUE.

Twelve winter wheat (Triticum aestivum) genotypes were examined for differences in grain yield, water use efficiency (WUE), and stable carbon isotope composition (δ13C) in flag leaves. The plants were subjected to rain-fed treatment and supplemental irrigation at the jointing and anthesis stages, during the 2015–2016 and 2016–2017 winter wheat growing seasons. The relationships between δ13C with grain yield and WUE were analyzed under two different water environments. The results indicated that there were significant differences in δ13C, grain yield, and WUE among wheat genotypes both under rain-fed and supplemental irrigation conditions. The δ13C values increased with grain-filling proceeding, the δ13C being lower under supplemental irrigation treatment than that under rain-fed treatment. The relationships between the average of δ13C with grain yield and WUE were significantly positive during three measurement periods (R2 = 0.5785 − 0.8258), whether under rain-fed or irrigation environments. This suggests that δ13C might be associated with the grain yield and WUE in winter wheat under rain-fed and supplemental irrigation conditions in the climate region of the northwest Huang-Huai-Hai Plain of China.

Effects of tillage practices on water consumption and grain yield of dryland winter wheat under different precipitation distribution in the loess plateau of China

Deep ploughing and subsoiling are important management practices used for mitigating the risk of soil compaction under long term no-tillage or reduced tillage practices. These fallow tillage methods have been widely applied in the Loess Plateau region of China to improve soil water availability and preventing soil erosion. To investigate the effect of different tillage practices for increasing the production of winter wheat (Triticum aestivum L.) and their relationship with precipitation distribution in the semiarid southeast region of the Loess Plateau, a six-year field study was conducted from 2009 to 2015, using three tillage treatments: deep ploughing (DP), subsoiling (SS), and no-tillage (NT). Our results indicated that DP and SS treatments increased soil water storage in the 0–300 cm soil layer at sowing and soil organic carbon in the 0–20 cm soil layer at maturity. In addition, DP and SS increased soil water consumption in the 0–180 cm soil layer from sowing to anthesis, and in the 120–300 cm layer from anthesis to maturity of wheat. Furthermore, the DP and SS treatments significantly increased the root length, root surface area, and the number of root tips in the 0–80 cm and aboveground dry biomass at maturity. Additionally, DP and SS treatments increased the grain yield by 31% and 26%, precipitation use efficiency by 32% and 26%, and water use efficiency by 12% and 11% respectively, as compared with those of the NT treatments. Pearson’s correlation analysis showed that soil water consumption was significantly positively correlated with precipitation from sowing to jointing and anthesis to maturity. In addition, grain yield had a significant positive correlation with precipitation during the fallow season, particularly in the SS treatment. Moreover, grain yield was significantly positively correlated with soil water consumption in the 0–180 cm soil layer from sowing to jointing, and at 60–240 cm soil depth from jointing to maturity. In conclusion, under low precipitation, DP was more favorable for winter wheat than SS, whereas, under high precipitation, SS was more beneficial than DP.

Photosynthetic characteristics and grain yield of winter wheat (Triticum aestivum L.) in response to fertilizer, precipitation, and soil water storage before sowing under the ridge and furrow system: A path analysis

The ridge and furrow (RF) system can improve the soil moisture and temperature conditions, as well as increasing the grain yield and water use efficiency. However, the combined effects of the fertilizer amount, precipitation during the growing season (PGS), and soil water storage before sowing (SWSS) on the photosynthetic characteristics and yield under this system are still unclear in winter wheat. Thus, in this study, we used path analysis to determine the effects of these three factors based on a field experiment conducted for five years in a semiarid region of Northwest China. Path analysis showed that precipitation during the sowing to filling stage (PSF) in winter wheat had the greatest influence on the photosynthesis gas exchange characteristics of flag leaves in the filling stage, followed by the fertilizer amount. And the determination coefficients of PSF on the photosynthetic rate (Pn), transpiration rate, stomatal conductance (Gs), leaf instantaneous water use efficiency (WUE) and relative chlorophyll content (SPAD value) were 0.331, 0.868, 0.864, 0.820, and 0.414, respectively. The most important factor for the grain yield was SWSS, where the coefficient of determination was 0.838, followed by the fertilizer amount and PGS, and the indirect effect of the fertilizer amount on SWSS was negative. Therefore, our results suggest that SWSS has an important effect on the grain yield in winter wheat under the RF system in semiarid regions, and thus improving the SWSS can obtain better increases in the grain yield compared with fertilizer amount.

Effect of Crop Rotation and Cereal Monoculture on the Yield and Quality of Winter Wheat Grain and on Crop Infestation with Weeds and Soil Properties

An exact experiment, established in a system of randomized blocks, was aimed at determining the effect of crop rotation and 29-year cereal monoculture on the yield and quality of winter wheat grain as well as on straw yield, crop infestation with weeds, contents of organic C and total N in the soil, and the number of earthworms in the soil. Winter wheat was sown in two systems of crop succession: (1) in crop rotation (CR), and (2) in a cereal monoculture (CM). Winter wheat cultivation in the CM system resulted in a decrease of grain yield by 32%, compared to the CR system. Its grain yield reduction in the CM system was due to a lower number of spikes m−2, lower 1000 grain weight, shorter spikes, and lower grain weight per spike, than in the CR system. Wheat grain from the CM system was characterized by a lower content of wet gluten, lesser grain uniformity and grain volume weight, and contained more total ash than the grain from the CR system. The number and air-dry weight of weeds were higher in the CM than in the CR system by 57.1% and 75%, respectively. Differences were also demonstrated in the species composition of weeds. The soil samples collected from the CM plot contained less organic C and total N than the samples derived from the CR system. Soil samples from the CM system had also a lower number of earthworms compared to the CR soil samples.

Using a Portable Active Sensor to Monitor Growth Parameters and Predict Grain Yield of Winter Wheat.

Rapid and effective acquisition of crop growth information is a crucial step of precision agriculture for making in-season management decisions. Active canopy sensor GreenSeeker (Trimble Navigation Limited, Sunnyvale, CA, USA) is a portable device commonly used for non-destructively obtaining crop growth information. This study intended to expand the applicability of GreenSeeker in monitoring growth status and predicting grain yield of winter wheat (Triticum aestivum L.). Four field experiments with multiple wheat cultivars and N treatments were conducted during 2013–2015 for obtaining canopy normalized difference vegetation index (NDVI) and ratio vegetation index (RVI) synchronized with four agronomic parameters: leaf area index (LAI), leaf dry matter (LDM), leaf nitrogen concentration (LNC), and leaf nitrogen accumulation (LNA). Duration models based on NDVI and RVI were developed to monitor these parameters, which indicated that NDVI and RVI explained 80%, 68–70%, 10–12%, and 67–73% of the variability in LAI, LDM, LNC and LNA, respectively. According to the validation results, the relative root mean square error (RRMSE) were all <0.24 and the relative error (RE) were all <23%. Considering the variation among different wheat cultivars, the newly normalized vegetation indices rNDVI (NDVI vs. the NDVI for the highest N rate) and rRVI (RVI vs. the RVI for the highest N rate) were calculated to predict the relative grain yield (RY, the yield vs. the yield for the highest N rate). rNDVI and rRVI explained 77–85% of the variability in RY, the RRMSEs were both <0.13 and the REs were both <6.3%. The result demonstrates the feasibility of monitoring growth parameters and predicting grain yield of winter wheat with portable GreenSeeker sensor.

Organic Amendments Improve Wheat Root Growth and Yield through Regulating Soil Properties

Core IdeasOrganic amendments improved soil fertility and soil structure.Root density was quadratic correlated with water stable aggregates and macroporosity.Application of wheat straw yielded the best soil environment and crop productivity.Organic amendments prevent soil degradation and sustain crop production, but their effects on root growth and its functional responses to variations in soil properties have not been fully understood. A two‐year field experiment was conducted to investigate the impacts of organic amendments on soil properties, root growth, and grain yield of winter wheat (Triticum durumDesf.) in the Guanzhong Plain (GZP), China. The five treatments were: application of mineral fertilizer alone (control, CO) and along with 20 Mg ha−1of wheat straw (MWS), wheat husk (MWH), farmyard soil (MFS), and bioorganic fertilizer (MBF). Organic amendments increased soil organic matter (SOM, 7–15%) and total soil nitrogen (TSN, 5–15%) in the 0‐ to 40‐cm depth compared to the CO treatment. Meanwhile, organic amendments improved soil structure by increasing water stable aggregates (WSA, 5–16%) and macroporosity (ε10, 27–47%). Compared to the CO treatment, organic amendments significantly increased the root length density (RLD) and root mass density (RMD) in the 20‐cm depth of soil at the flowering stage. The significantly higher RLD and RMD were also exhibited in the MWH and MFS treatments in the 20‐ to 100‐cm depth. Additionally, the responses of RLD and RMD to WSA andε10were well‐described by quadratic equations based on all treatments. Importantly, the MWS treatment had the greatest grain yield among all five treatments with better soil fertility and structure. We suggested that the MWS treatment is an effective method for improving soil properties and crop productivity in the GZP.

Evaluating Leaf Wax and Bulk Leaf Carbon Isotope Surrogates for Water Use Efficiency and Grain Yield in Winter Wheat

Bulk leaf carbon isotopic composition (δ13Cbulk) has been widely used to investigate leaf level water use efficiency (WUEl) in efforts to boost grain yield relative to crop water use. Although widely used for isotopic analyses, the bulk leaf represents a complex mixture of compounds. Single‐compound isotopic analyses carry diagnostic advantages over bulk analyses in a range of applications and may also serve as surrogates for WUEl and grain yield in crops. This study tests whether compound‐specific carbon and hydrogen isotopes of leaf wax n‐alkanes (δ13Calk and δDalk) and n‐alcohols (δ13Calc) could be used as surrogates for WUEl and grain yield using conventional δ13Cbulk as a reference. Ten winter wheat (Triticum aestivum L.) cultivars were planted under two irrigation treatments (full and deficit irrigation) at Uvalde (wet location) and Amarillo (dry location), TX, during two growing seasons. There were significant relationships between δ13Calk or δDalk and δ13Cbulk, indicating they can all serve as surrogates for WUEl in most cases. Compared with δ13Cbulk, we found stronger relationships between δ13Calk at Uvalde or δDalk under deficit irrigation at Amarillo and grain yield. The δ13Calk also had higher broad‐sense heritability than δ13Cbulk, indicating larger cultivar effects in δ13Calk than in δ13Cbulk. In contrast, the δ13Calc was not consistently related with δ13Cbulk or grain yield. Our study introduces the idea that δ13Calk and δDalk may supplement conventional δ13Cbulk with potential to assist in the breeding process when selecting for high‐WUE and high‐yielding cultivars.

In Situ Maize Residue Mulch Improves the Water Use Efficiency and Yield of the Subsequent Wheat under a Strip Inter‐Cropping System

Core Ideas Irrigation and straw mulch increased yields and WUE, compared with non‐mulch, especially in dry years. Enhanced grain yield was largely influenced by changes in WUE, soil water, SPAD and dry matter. Residue retention in the fallow period conserves soil moisture, delays senescence and improves wheat production. Seasonal drought is a limiting factor for wheat (Triticum aestivum L.) production in the southwest hill regions of China. During a 4‐yr field experiment conducted in Jianyang, Sichuan Basin, we evaluated the effects of production‐system residue retention on water use, physiological characteristics, and grain yield of winter wheat grown in a relay strip cropping system. Four treatments were used: whole‐period without mulch or irrigation (NM), no mulch plus irrigation at sowing and jointing (NMI); whole‐period mulch without irrigation (WM); and fallow‐period mulch without irrigation (FM). The results were that irrigation and straw mulch increased yields by 0 to ∼42% and water use efficiency (WUE) by 0 to ∼30%, compared with NM, especially in dry years. Improvement in grain yield under residue retention was attributed to increased spike number. Residue retention significantly improved the following crop parameters; tiller numbers, aboveground dry mass accumulation, soil moisture, root length density, and root surface area at critical growth stages, as well as inhibiting leaf chlorophyll loss after anthesis. The FM achieved greater performance on the above parameters than WM. Enhanced grain yield was largely influenced by changes in WUE, gravimetric soil water, SPAD value and dry matter accumulation. In conclusion, residue retention over the fallow period is instrumental in conserving soil moisture, delaying leaf senescence and improving wheat production. This treatment was also the most convenient for farmers.

Optimizing plant density and nitrogen application to manipulate tiller growth and increase grain yield and nitrogen-use efficiency in winter wheat.

The growth of wheat tillers and plant nitrogen-use efficiency (NUE) will gradually deteriorate in response to high plant density and over-application of N. Therefore, in this study, a 2-year field study was conducted with three levels of plant densities (75 ×104plants ha−1, D1; 300 ×104plants ha−1, D2; 525 ×104plants ha−1, D3) and three levels of N application rates (120 kg N ha−1, N1; 240 kg N ha−1, N2; 360 kg N ha−1, N3) to determine how to optimize plant density and N application to regulate tiller growth and to assess the contribution of such measures to enhancing grain yield (GY) and NUE. The results indicated that an increase in plant density significantly increased the number of superior tillers and the number of spikes per m2(SN), resulting in a higher GY and higher partial factor productivity of applied N (PFPN). However, there was no significant difference in GY and PFPN between plant densities D2 and D3. Increasing the N application rate significantly increased the vascular bundle number (NVB) and area (AVB), however, excess N application (N3) did not significantly improve these parameters. N application significantly increased GY, whereas there was a significant decrease in PFPN in response to an increase in N application rate. The two years results suggested that increasing the plant density (from 75 ×104plants ha−1to 336 ×104plants ha−1) in conjunction with the application of 290 kg N ha−1N will maximize GY, and also increase PFPN(39.7 kg kg−1), compared with the application of 360 kg N ha−1N. Therefore, an appropriate combination of increased planting density with reduced N application could regulate tiller number and favor the superior tiller group, to produce wheat populations with enhanced yield and NUE.

Determining the Optimal N Input to Improve Grain Yield and Quality in Winter Wheat With Reduced Apparent N Loss in the North China Plain.

Excessive or improper nitrogen (N) application rates negatively affect crop production and thereby environmental quality, particularly for winter wheat production in the North China Plain. Therefore, it is very important to optimize N fertilizer input to balance grain yield, environmental risk, and benefits under irrigated conditions. Three long-term stationary field experiments including five N levels, from 0 to 300 kg ha-1 [0 (N0), 90 (N90), 180 (N180), 240 (N240), and 300 (N300) kg ha-1] were carried out to investigate the effects of N regime on wheat yield, photosynthesis, and N balance at different sites. The grain yield and protein content increased quadratically with N rate, and the maximum values were 8087 kg ha-1 and 13.9% at N application rates of 250 and 337 kg N ha-1, respectively. N application increased the photosynthetic fluorescence parameters (Pn, Gs, and Tr) and N metabolism enzyme activities (NR and GS) which then increased grain yield. The leaching of soil nitrate into the deeper soil layers ( > 100 cm) increased with higher N fertilization and experimental years. The partial factor productivity (PFPN) was decreased by N because the apparent N loss increased with N application rate. In order to balance grain yield, N use efficiency (NUE), and N loss, the recommended N rate should be 120–171 kg N ha-1, and the corresponding yields and apparent N loss were 7278–7787 ka ha-1 and 22–37 kg ha-1, respectively.

Effect of complex growth regulating preparations on yield of winter wheat (Тriticum aestivum L.) grown after different precursors

This is the first time in conditions of Semisavanna of Ukraine when mutual effect of winter wheat precursors and three complex growth-regulating preparations on the growth, development and yield of winter wheat grain has been studied. It has been determined that Antistress, Mars-EL and four amino acid complex preparations can be used for winter wheat growing technology with the aim to increase its yield both during the naked fallow sowing, and after a grain precur- © Позняк В. В., 2019 sor. Greater effect is provided by preparations at winter wheat re-sowing - the yield increase made 0.32-0.81 t/ha. The less significant but stable increase in yield of 0.27-0.59 t/ha is provided by complex growth-regulating preparations during sowing wheat over wheat. Use of the studied complex preparations with a wide range of action throughout the growing season had a positive effect on indicators characterizing growth, development and formation of winter wheat yield. The most effective was the joint use of Antistress and Mars-EL preparations (0.5-0.71 t/ha increase) and all the three drugs together (Antistress + Mars-EL + amino acid complex) when additional 0.59-0.81 t/ha of grain was obtained. Thus, our research has shown that use of new promising growth-regulating agents for winter wheat growing technology makes it possible to implement its genetic potential and increase yield more efficiently, which undoubtedly is of a great importance for agricultural farms specializing in production of this crop.

Simulation of satellite reflectance data using high-frequency ground based hyperspectral canopy measurements for in-season estimation of grain yield and grain nitrogen status in winter wheat

Remote sensing allows the assessment of biomass and grain yield of cereals. An enhanced potential to detect specific traits is offered by proximal hyperspectral sensing, in contrast the potential of satellite remote sensing might still be leveraged up seen the degree of spatial and temporal resolution. Consequently, hyperspectral satellite data are still not readily available for most agricultural applications and ground truth validation done at high frequency throughout the season remains scarce. Here, we simulate multispectral satellite data through resampling ground based hyperspectral reflection (400–1000 nm). Spectral data were collected at 3 nm resolution at high temporal frequency during 5–14 growth stages over three winter wheat growing seasons for investigating the influence of year and seasonality. The field experiment comprised 24 different genotypes, which varied in morphology and phenology, grown at varying nitrogen application and additionally by varying the sowing time and fungicide intensity during the third season. Ground based reflectance data were resampled to fit the spectral resolution of the satellite sensors Landsat-8, Quickbird, RapidEye, WorldView-2 and Sentinel-2. The resulting spectral bands were used for calculating all possible normalized difference vegetation indices, which were correlated to grain yield, grain N uptake and grain N concentration. The index performance depended substantially on the growth stages and years. For grain yield, maximum linear relationships (R2) obtained from hyperspectral sensing over the season ranged from 0.65 in 2017 to 0.88 in 2015 compared to 0.40 to 0.79 for the best simulated multispectral sensor, Sentinel-2. In most cases, indices performed better for grain N uptake and less well for grain N concentration. Typically, correlations peaked at early to medium grain filling but decreased around ear emergence. Index performance from multispectral compared to hyperspectral data decreased over time during grain filling. The sensor ranking remained consistent with Sentinel-2 followed by Worldview-2 and RapidEye clearly outperforming the other sensors. Advantages are attributed to the red edge band for N-related traits and the better coverage of the NIR range between 800 and 1000 nm by the Sentinel-2. The results can possibly be extrapolated to the application of UAV and satellite sensing by elucidating optimized measurement stages and enhancing spectral properties of sensors.

The effect of agronomic measures on grain yield of winter wheat in drier conditions

The objective of this study was to evaluate the effect of a year of cultivation and three agronomic measures (pre-crop, soil tillage, application of fungicides) on the yield of winter wheat grown in the crop rotation without the livestock production. The results from the years 2011–2017, except for the year 2012, from the Žabčice Field Experimental Station (49°01'20''N, 16°37'55''E) were evaluated. The soil texture is clay loam soil and the soil type is fluvisol. In the field trial, winter wheat was grown after two pre-crops (winter wheat, pea). Two soil tillage technologies, namely the conventional tillage – CT (ploughing – at a depth of 24 cm) and the minimum tillage – MT (shallow loosening – at a depth of 15 cm) were used. Two fungicide treatments against leaf and spikelet diseases were used, and they were compared to the non-treated variants. The obtained results showed that the grain yield of winter wheat was statistically influenced not only by a year of cultivation, but also by the pre-crop, the application of fungicides, and mostly by the interaction of these factors with the soil tillage. The importance of pea as a suitable pre-crop for winter wheat was confirmed as the grain yield was higher compared to winter wheat as a pre-crop by an average of 0.49 t/ha. It was also found that the MT is a more appropriate technology than the CT, on average by 0.12 t/ha over the six years. The importance of fungicide treatment was also confirmed, where the grain yield of winter wheat was higher by 0.26 t/ha compared to the non-treated variant. The presented results brought a new knowledge for winter wheat management practice in dry conditions.

Урожайність та показники якості пшениці озимої залежно від систем основного обробітку грунту та удобрення

Досліджено вплив застосування різних систем основного обробітку ґрунту (полицева, мілка безполицева, глибока безполицева) та рівнів удобрення на урожайність та якісні показники зерна пшениці озимої. Дослідженнями встановлено, що в умовах Правобережного Лісостепу України систематичний безполицевий обробіток ґрунту підвищує урожайність та якість зерна пшениці озимої на всіх рівнях удобрення, порівняно із традиційним полицевим. Внесення органічних і мінеральних добрив на чорноземі типовому позитивно впливає на урожайність пшениці озимої, підвищуючи її порівняно з контролем на 0,28-0,84 т/га за оранки, на 0,36-1,26 т/га за глибокого безполицевого обробітку і на 0,4-1,55 т/га – за мілкого. Виявлено, що найвищу урожайність культури (4,72 т/га) отримано за мілкого плоскорізного обробітку ґрунту на фоні органо-мінерального удобрення із застосуванням гною, а за глибокого безполицевого обробітку цей показник був лише на 3 % нижчим. Загалом уміст білка та клейковини на удобрюваних варіантах відповідали нормам якості сильної, а на контролі – цінної пшениці. Найвищі якісні показники зерна пшениці озимої відмічені на варіанті з традиційним органо-мінеральним удобренням (Гній + NPK) за мілкого безполицевого обробітку: вміст білка склав 15,5 %, а вміст клейковини – 31,9 %, що відповідає І групі якості.

Вплив елементів технології вирощування на продуктивність пшениці озимої в умовах Західного Полісся України

Due to climate change, it is necessity to take into account the stressors affecting plant growth and development to ensure a high yield of winter wheat grain. The realization of the genetic potential of winter wheat productivity in critical periods can be achieved by improving the cultivation technology features used for this grain crop. The purpose of our research is to study the effect of seed treatment with the plant growth stimulator Vympel K and the spraying the plants with the growth stimulator Vempel-2 combined with microfertilizers Orakul on winter wheat productivity in Ukrainian Western Polessia. It is established that while cultivating winter wheat Astarta on typical slightly humic black soil typical, it is effective to supplement the technology with growth stimulants Vempel-K and Vympel-2 in combination with liquid microfertilizer Oracul colofermin LLC &quot;Dolyna-Tsentr&quot;. It makes possible to increase the resistance to adverse environmental factors, reduce plant death during the growing season and has a positive effect on the formation of the main indicators of winter wheat crop structure. The investigation proves that treating seeds with growth stimulator Vympel-K (0,5 kg/t) and spraying crops with growth stimulator Vympel-2 (0,5 l/ha) at the 29th and 39th stages of organogenesis ensures obtaining the grain yield at the level of 7,03 t/ha, which is 7.7% more compared to the control. The highest productivity of winter wheat Astarta (7.48 t/ha) is provided by the use of growth stimulants Vympel-K (0.5 kg/t) to treat seed and Vympel-2 (0.5 l/ha) to spray with Orakul microfertilizer at the 29th and 39th stages of organogenesis. The grain yield proved to increase by 14.5% compared to the control. The prospects for further research should focus on the studying the effects of integrated using Orakul microfertilizer and growth stimulant Pennant on the quality of winter wheat grain