Yield Of Spring Barley Research Articles

Simulated Regional Yields of Spring Barley in the United Kingdom under Projected Climate Change

This paper assessed the effect of projected climate change on the grain yield of barley in fourteen administrative regions in the United Kingdom (UK). Climate data for the 2030s, 2040s and 2050s for the high emission scenario (HES), medium emissions scenario (MES) and low emissions scenario (LES) were obtained from the UK Climate Projections 2009 (UKCP09) using the Weather Generator. Simulations were performed using the AquaCrop model and statistics of simulated future yields and baseline yields were compared. The results show that climate change could be beneficial to UK barley production. For all emissions scenarios and regions, differences between the simulated average future yields (2030s–2050s) and the observed yields in the baseline period (1961–1990) ranged from 1.4 to 4 tons·ha−1. The largest increase in yields and yield variability occurred under the HES in the 2050s. Absolute increases in yields over baseline yields were substantially greater in the western half of the UK than in the eastern regions but marginally from south to north. These increases notwithstanding, yield reductions were observed for some individual years due to saturated soil conditions (most common in Wales, Northern Ireland and South-West Scotland). These suggest risks of yield penalties in any growing season in the future, a situation that should be considered for planning adaptation and risk management.

Spring Barley Yield Parameters after Lignite, Sodium Humate and Nitrogen Utilization

Abstract The existence of a small number of publications dealing with the impact of solid sodium humate and lignite on the quantity and quality of grown crops was the reason for establishing the field experiment. The objective of this experiment was to detect the impact of solid lignite and solid sodium humate on the quantity and quality of spring barley yield. These substances were applied into the soil either independently or along with nitrogen fertiliser. The next objective was to determine the impact of foliar application of sodium humate water solution applied either independently or along with nitrogen fertiliser on the quality and quantity of spring barley yield. The achieved results showed that the autumn application of solid lignite and the presowing application of solid sodium humate into the soil tended to decrease the yield of both grain and straw of spring barley, crude protein content in grain, proportion of the first-class grains and volume weight of grain, whereas the impact of humate was more negative. Lignite and sodium humate in the solid form should be used along with nitrogen fertiliser. The application of sodium humate in liquid form during the growth season of barley tended to increase the yield of both grain and straw. The joint application of nitrogen and liquid sodium humate during the growth season of barley increased the grain yield of barley significantly. A lower dose of nitrogen, applied during the growth season of barley (growth season BBCH 23), increased the grain yield of barley considerably more than a higher N dose, applied into the soil before barley sowing.

Meat and bone meal as fertilizer for spring barley

The aim of this study was to determine whether meat and bone meal (MBM) can be used as NP fertilizer for spring barley grown for fodder. A two-factorial field experiment was conducted in Poland. Experimental factor I was MBM dose (0, 1.0, 1.5, 2.0, 2.5 t/ha/year) which was compared to the mineral fertilization (NPK), factor II was the year of the study (two consecutive years). MBM used in doses higher than 1.0 t/ha had a more beneficial influence on the grain yield of spring barley and grain plumpness than mineral fertilizers. The positive yield-forming effect of MBM doses 2.0 t/ha and 2.5 t/ha was statistically significant. The nitrogen (N) content of grain was similar in treatments with MBM and mineral fertilization. The two highest MBM doses contributed to a significant decrease in the phosphorus (P) content of grain, particularly in the second year of the study, in comparison with the remaining MBM doses and mineral fertilizers. Grain yield and N content were also affected by the year of the study, due to weather conditions and the residual effect of MBM. The optimal MBM dose was 1.5 t/ha, which allowed to produce 5.1 t/ha of the plumpest grain whose N and P content was consistent with the feeding standards for livestock.

Original Article. Studies on trinexapac-ethyl dose reduction by combined application with adjuvants in spring barley

Abstract Trinexapac-ethyl is a popular plant growth regulator used in various crops, mostly due to its unique anti-lodging properties. Recently it has been found that this substance is also active in stress protection, which may increase its importance in the coming years. This paper presents a new approach to its application. Trinexapac-ethyl belongs to the cyclohexanedione class of herbicide chemistry, thus it is structurally similar to common graminicides frequently used with adjuvants. This study examines the effects of the application of trinexapac-ethyl with adjuvants. Field trials were conducted in the Institute of Plant Protection in Poznań (Poland), in 2014 and 2015. Trinexapac-ethyl was applied at recommended (0.4l・ha-1) and reduced doses (0.2l・ha-1) with organosilicone surfactant, ammonium sulphate and citric acid on spring barley. Stem shortening, yield components and grain quality were examined. The results of the study confirmed the possibility of dose reduction of trinexapac-ethyl by way of combined application with citric acid that reduced the pH of spray liquid or with ammonium sulphate without affecting its effectiveness. The greatest stem height reduction was observed after the application of a full dose of trinaxapac ethyl and its reduced dose in the mixture with citric acid or ammonium sulphate. Depending on the year of study, the effectiveness of the substances on stem reduction ranged from 5.6 to 16.5%. The tested mixtures did not have any significant impact on the number of grains per ear or the yield of spring barley. Trinexapac-ethyl and its mixtures with adjuvants did not influence the crude protein and starch in spring barley grains.

Soil carbon and nitrogen and barley yield responses to repeated additions of compost and slurry

SUMMARYThe yields of spring barley during a medium-term (7 years) compost and slurry addition experiment and the soil carbon (C) and nitrogen (N) contents, bacterial community structure, soil microbial biomass and soil respiration rates have been determined to assess the effects of repeated, and in some cases very large, organic amendments on soil and crop parameters. For compost, total additions were equivalent to up to 119 t C/ha and 1·7 t N/ha and for slurry they were 25 t C/ha and 0·35 t N/ha over 7 years, which represented very large additions compared to control soil C and N contents (69 t C/ha and 0·3 t N/ha in the 0–30 cm soil depth). There was an initial positive response to compost and slurry addition on barley yield, but over the experiment the yield differential between the amounts of compost addition declined, indicating that repeated addition of compost at a lower rate over several years had the same cumulative effect as a large single compost application. By the end of the experiment it was clear that the addition of compost and slurry increased soil C and N contents, especially towards the top of the soil profile, as well as soil respiration rates. However, the increases in soil C and N contents were not proportional to the amount of C and N added, suggesting either that: (i) a portion of the added C and N was more vulnerable to loss; (ii) that its addition rendered another C or N pool in the soil more susceptible to loss; or (iii) that the C inputs from additional crop productivity did not increase in line with the organic amendments. Soil microbial biomass was depressed at the highest rate of organic amendment, and whilst this may have been due to genuine toxic or inhibitory effects of large amounts of compost, it could also be due to the inaccuracy of the substrate-induced respiration approach used for determining soil biomass when there is a large supply of organic matter. At the highest compost addition, the bacterial community structure was significantly altered, suggesting that the amendments significantly altered soil community dynamics.

Biological activity of soil contaminated with cobalt, tin, and molybdenum

In this age of intensive industrialization and urbanization, mankind’s highest concern should be to analyze the effect of all metals accumulating in the environment, both those considered toxic and trace elements. With this aim in mind, a unique study was conducted to determine the potentially negative impact of Sn2+, Co2+, and Mo5+ in optimal and increased doses on soil biological properties. These metals were applied in the form of aqueous solutions of Sn2+ (SnCl2.2H2O), Co2+ (CoCl2 · 6H2O), and Mo5+ (MoCl5), each in the doses of 0, 25, 50, 100, 200, 400, and 800 mg kg−1 soil DM. The activity of dehydrogenases, urease, acid phosphatase, alkaline phosphatase, arylsulfatase, and catalase and the counts of twelve microorganism groups were determined on the 25th and 50th day of experiment duration. Moreover, to present the studied problem comprehensively, changes in the biochemical activity and yield of spring barley were shown using soil and plant resistance indices—RS. The study shows that Sn2+, Co2+, and Mo5+ disturb the state of soil homeostasis. Co2+ and Mo5+ proved the greatest soil biological activity inhibitors. The residence of these metals in soil, particularly Co2+, also generated a drastic decrease in the value of spring barley resistance. Only Sn2+ did not disrupt its yielding. The studied enzymes can be arranged as follows for their sensitivity to Sn2+, Co2+, Mo5+: Deh > Ure > Aryl > Pal > Pac > Cat. Dehydrogenases and urease may be reliable soil health indicators.

Initial Effects of Differently Treated Biogas Residues from Municipal and Industrial Wastes on Spring Barley Yield Formation.

Soil application of biogas residues (BGRs) is important for closing nutrient cycles. This study examined the efficiency and impact on yields and yield formation of solid-liquid separated residues from biodegradable municipal and industrial wastes (bio-waste) in comparison to complete BGRs, nitrification inhibitor, agricultural BGRs, mineral fertilizer and unfertilized plots as control. The experiment was set up as a randomized block design on silt loam Cambisol. Biogas residues from four biogas plants were evaluated. Plants per m², ears per plant, grains per ear and thousand grain weight (TGW) were measured at harvest. Fertilization with BGRs resulted in similar biomass yields compared with mineral fertilizer. Mineral fertilizer (71 dt/ha) and plots fertilized with liquid fraction (59–62 dt/ha) indicated a trend to higher yields than solid fraction or complete BGR due to its high ammonia content. Liquid fractions and fraction with nitrification inhibitor induced fewer plants per m² than corresponding solid and complete variants due to a potential phytotoxicity of high NH4-N concentration during germination. However, barley on plots fertilized with liquid fraction compensated the disadvantages at the beginning during the vegetation period and induced higher grain yields than solid fraction. This was attributable to a higher number of ears per plant and grains per ear. In conclusion, BGRs from biodegradable municipal and industrial wastes can be used for soil fertilization and replace considerable amounts of mineral fertilizer. Our study showed that direct application of the liquid fraction of BGR is the most suitable strategy to achieve highest grain yields. Nevertheless potential phytotoxicity of the high NH4-N concentration in the liquid fraction should be considered.

Determinants of spring barley yield in a high-yield potential environment

SUMMARYThe literature suggests that grain number largely determines and as such limits yield in barley. Many of the reported studies were conducted in relatively low-yielding environments and it is unclear if grain number is also a limiting factor in high-yield potential climates. Nor is it known with certainty what physiological or morphological traits must be targeted in order to increase grain number. A detailed programme of assessments was carried out on replicated field plots of a two-row spring barley variety (Hordeum vulgare L. cvar Quench) at three sites (Carlow, Wexford and Cork) in Ireland from 2011 to 2013. Plots were managed for high yield potential as per current best farm practice. Destructive sampling and in-field assessments were carried out at approximately weekly intervals from emergence onwards to gather growth, development and yield component data. Across nine site/seasons, grand means of 8·52 t/ha for yield, 18 419 for grain number/m2 and 46·41 mg for mean grain weight were achieved. Grain number/m2 accounted for most of the variation in yield and ear number/m2 accounted for most of the variation in grain number/m2. Early-season maximum shoot number/m2 had little influence on harvest ear number/m2. The period over which final ear number was determined was more flexible than the literature suggests, where the phases of tiller production and senescence varied considerably. Significant post-anthesis re-tillering occurred following the initial phase of shoot mortality at two out of nine site/seasons, but this appeared to contribute little to yield. Yield was positively associated with the proportion of shoots surviving from an early season maximum to a mid-season minimum (R2 = 0·62). Shoot size and weight at the beginning of stem extension had the largest influence on shoot survival, indicating that crop condition and hence growth and development pre-stem extension may be more important for shoot survival than growth and development during the stem extension period. Achieving high shoot numbers of adequate size and weight at the beginning of stem extension may be an appropriate target for establishing a high-yield potential crop.

The yield of spring barley in the brown soils of the Nizhnee Povolzh'e region

The results of small (20-22 cm) and relatively deep main processing of the soil (27-30 cm) and variable rate application depth of arable horizon of doses of mineral nutrition (N and P2O5) on yield of spring barley. It is established that ploughing soil up to 30 cm (pillars of Cibima) with in-corporation at the same depth easy phosphorus-rhenium increases the biological activity of the soil microflora involved in the proposal of cellulose substrates is a means of increasing the fertility of light chestnut soil, which is especially important for rainfed conditions. The average crop capacity in the shallow plowing is 2 t/ha and was lower at 15% compared to Varian, where he held a deep subsurface tillage. By years of research sum-total biological activity in the deep subsurface treat-ment amounted to 930 mg of amino acids per gram of leaf, which is higher by 26% the variant with shallow plowing. Compared to shallow ploughing (option 1) at subsurface relatively deep processing of crude soil (option 2) there is greater accumulation of productive moisture in a meter layer. In the period of tillering of plants at average moisture reserves in option 2 is higher by 16% than in option 1 and constitute a 147 mm. In phase trubavina-earing and full maturity of the spring-barley the difference between the productive moisture content increases to between 20 and 33% in the direction of no-till deep processing. Relatively high soil moisture (a consequence of the method of tillage) contributed to a more rapid transition of phosphates in the horizon of 25-30 cm and nitrate in the layer 10-15 cm in available forms of nutrients for soil microorganisms. It is revealed that the application rate of nitrogen and phosphorus should be linked with the main processing of the soil, and the peculiarities of development of the root system of cultivated crops.

Вклад факторов интенсификации земледелия и условий вегетации в формирование урожайности культур полевого севооборота

Представлены данные о вкладе в формирование урожайности ярового ячменя, картофеля и ярового рапса факторов интенсификации земледелия — минеральных, органоминерального удобрений, интегрированной системы защиты растений. Исследования проводили на землях Меньковского филиала Агрофизического института в полевом стационарном зерно-травяно-пропашном семипольном севообороте, размещённом в пространстве и во времени. Система защиты растений состояла из обязательного протравливания. Обрабатывали фунгицидами, гербицидами и инсектицидами при превышении экономического порога вредоносности. В опыте использовали комплексное органоминеральное удобрение на основе куриного помета, полученное методом термической сушки. Вклад факторов оценивали как отдельно по каждой из систем защиты растений по независимым факторам, так и в целом по уровню агрофона (суммарное действие минерального и органоминерального удобрения). Объединение минеральной и органоминеральной систем удобрения в единый фактор «агрофон» позволило выявить роль системы защиты растений в изменении урожайности ярового ячменя по годам. Анализ показал, что определяющим зерновую продуктивность для скороспелого сорта показателем является уровень агрофона, условия вегетации определяли 15 % вариации признака, чуть меньшим был эффект от взаимодействия названных признаков. Показана изменчивость этих приемов интенсификации под воздействием неконтролируемых факторов (условия вегетации). Установлено, что приоритетность факторов, определяющих урожайность, различна для основных культур полевого севооборота. Определяющим зерновую продуктивность ярового ячменя показателем является уровень агрофона. Урожайность картофеля в значительной степени зависит от неконтролируемых факторов условий вегетации. Анализ показал первичность мероприятий по защите посадок картофеля перед созданием высоких уровней минерального питания. Урожайность рапса определяется совокупным действием интегрированной системы защиты растений и удобрений.

Stratification of climate projections for efficient estimation of uncertainty and variation using weather-driven models

The range of uncertainties inherent in climate models can only be portrayed by provision of multiple climate projections. Unfortunately, such provision poses a challenge to model-based impact studies, since driving the relevant impact models using weather data from large numbers of climate projections may not be computationally feasible. Hence, it is important to investigate how to draw sub-samples of climate projections in a manner that reduces the subsequent computational burden. We describe a stratification-based protocol for sub-sampling climate projections to drive crop models with strata based on changes in mean temperature and changes in relative mean rainfall. As an example of the protocol's utility, simulated weather for each selected climate projection was used to drive 3 contrasting process-based models of plant-environment interactions to predict yields of spring barley, managed grassland, and short-rotation coppice. Many of the questions about potential impact that we wish to answer are related to variation in predicted yields. Variance components analyses of predicted yields for each of 2 time periods (2040s and 2080s) indicated that, after allowing for variability between grid squares, between 16 and 61% of the remaining variance in annual yields was uncertainty due to climate projections, the corresponding range for mean yields over 9 yr being from 63 to 93%. We found that our stratification procedure enhanced the precision in the estimate of the variance component due to climate projection, enabling reductions of up to 20% in the number of climate projections required to achieve equivalent precision compared to simple random sampling.

Using basalt flour and brown algae to improve biological properties of soil contaminated with cadmium

Zaborowska M., Kucharski J., Wyszkowska J. (2015): Using basalt flour and brown algae to improve biological properties of soil contaminated with cadmium. Soil & Water Res., 10: 181–188. In order to achieve homeostasis of soil, the potential of alleviating substances (two innovative: basalt flour and brown algae extract against two classic compounds: barley straw and compost) were analyzed in soil contaminated with cadmium. The studies thus determined the activity of urease, number of ammonification bacteria, nitrogen-immobilizing bacteria, Arthrobacter sp., Azotobacter sp., and spring barley yield. The analyzed parameters were presented as the following indices: RS – resistance of soil; EF – fertilization effect of an alleviating substance; and R:S – rhizosphere effect. Cadmium was applied as CdCl2∙2.5H2O at the following doses: 0, 4, 40, 80, 120, 160, and 200 mg Cd2+/kg of soil. Straw increased the values of most examined parameters, mainly at lower doses of cadmium. Among the cultivated plants, resistance was most stimulated by compost. Basalt flour and brown algae extract did not play a major role in the recovery of contaminated soil. Ammonification bacteria were the least sensitive to stress associated with the deposition of cadmium in soil, whereas Azotobacter sp. was the most sensitive. Urease was found to be a reliable indicator of soil condition.

Экологическая пластичность сортов ярового ячменя в условиях Республики Татарстан

The article presents the results of studies, evaluating the plasticity of spring barley varieties in the Republic of Tatarstan. The groups of varieties, differing in yield and resistance to stress, were distinguished. The features, that allow to predict the yield of spring barley, were highlighted in the paper.

Effect of Copper, Zinc and Boron on Green Leaf Retention and Grain Yield of Winter and Spring Cereals

Crop nutrition has a significant effect on disease incidence, resistance or tolerance of various crops. There is currently a lack of reliable recent UK-based research about the effect of copper, zinc and boron on disease incidence, green leaf area (GLA), green leaf retention (GLR) and grain yield of winter wheat, spring wheat and spring barley. Data analysis showed that these trace elements had positive effects on GLR. These positive effects may have been due to the role of copper, zinc and boron in the production of defence related compounds (phenolics and lignin), which may have reduced the disease incidence resulting in prolonged GLR. Grain yield was significantly enhanced by the application of these trace elements on the crop grown on high pH calcareous soil, which can be partly attributed to enhanced GLR. Also trace elements have a positive role in reproductive growth, flowering and male fertility. On average, zinc was found to be the most consistent trace element in terms of enhancing GLR and grain yield. Across all trials, it was noted that for every 10% increase in GLA from trace elements, grain yields increased by 4.2% in 2012-2013, by 4.4% in 2013-2014 in winter wheat and by 3.9% in spring wheat in 2014. These are remarkably consistent and indicate that increasing GLA by 10% by early dough stage was associated with a yield improvement of about 4%. These trace elements also had a positive effect on grain protein content (GPC). This research concluded that the trace elements had positive effects in enhancing GLA and yield. It can be speculated that with the use of these trace elements, there may be more scope for using less robust or reduced rates of fungicides to control foliar diseases, which may help to maximize farm profits.

Quantifying biological nitrogen fixation of different catch crops, and residual effects of roots and tops on nitrogen uptake in barley using in-situ 15N labelling

Contributions of legume-based catch crops (LBCCs) to succeeding cereals may be significant. We quantified biological N fixation (BNF) and residual N effects of contrasting CC tops and roots. BNF of three LBCCs (red clover, winter vetch, perennial ryegrass-red clover mixture) was quantified in microplots by 15N labelling. Their residual effects on spring barley were tested against two non-LBCCs (perennial ryegrass, fodder radish) after spring incorporation of CC tops or roots in monoliths. Total N accumulated in LBCCs was 153–226 kg N ha−1, of which 62–66 % was derived from BNF in tops and 31–46 % in macro-roots (0–18 cm soil). Macro-roots represented 31–50 % of total plant N. LBCCs showed similar capacity for soil N extraction as non-LBCCs. After incorporation of LBCC residues, the dry matter and N yields of spring barley were comparable to the effect of 50 kg N fertilisation ha−1, whereas no extra N uptake was derived from non-LBCCs. The 15N-based N fertiliser values of LBCC tops were 34–47 % against 26–29 % for non-LBCCs. LBCC roots contributed substantial amounts of N to the system, a source that is usually underestimated. N immobilisation after incorporation of non-LBCCs may hamper the growth of following main crops especially after removing tops.

Remediation of soil contaminated with cadmium.

The search for the best solutions to restore soil balance is essential for attaining a stable and sustainable agricultural development worldwide. This research, which makes a contribution to these investigations, focuses on four substances (two innovative ones: basalt flour, brown algal extract, and two classic soil improvers: finely ground barley straw and compost) which can potentially alleviate the inhibitory effect of Cd2+ on the soil environment. The following were analyzed: the activity of acid phosphatase and alkaline phosphatase, counts of Pseudomonas sp., cellulolytic bacteria, copiotrophic bacteria and copiotrophic spore-forming bacteria, and the yield of spring barley. Cadmium (Cd2+) was applied as CdCl2 · 2.5H2O in the following doses: 0, 4, 40, 80, 120, 160, and 200 mg Cd2+ kg-1 of soil. For a more complete assessment of the soil, its biochemical properties and the counts of microorganisms were scrutinized with the following indices: RS – soil resistance, R:S – rhizosphere effect and EF – fertilization effect of the contamination alleviating substances. It was found that alkaline phosphatase is more sensitive to cadmium contamination of the soil than acid phosphatase. Cadmium did not exert any inhibitory effect on the number of microorganisms present or the yield of spring barley. Cellulolytic bacteria were the least sensitive to stress associated with the accumulation of high cadmium doses in the soil, whereas copiotrophic bacteria were the most sensitive microorganisms to the above stressor. The ability of cadmium-polluted soil to restore homeostasis depended on the type of a soil improver and the level of soil contamination. Negative consequences of cadmium pollution were effectively mitigated by straw, but less so by brown algal extract and basalt flour.

Influence of Sowing, Nitrogen Nutrition and Weather Conditions on Stand Structure and Yield of Spring Barley

The processes of stand structure and yield formation of spring barley were studied under different weather conditions and crop management. The multifactorial small-plot trials focused on the combined effect of variety, sowing density and nitrogen nutrition were carried out in two years with contrast weather conditions for yield formation (2011 and 2013). Evaluation of the above-ground biomass and the segmentation of tillers into three groups was conducted in four growth stages (BBCH 25, 31, 39 and 75). The performed analyses confirmed that for effective use of inputs and high yield, it is important to create a sufficient number of strong tillers at the beginning of vegetation. In year with low proportion of strong tillers at the end of tillering (2013), the differentiation of tillers is delayed and their productivity decreases. In this year therefore, yield formation is shifted from the number of spikes to the number of grains in a spike. The comparison of barley genotypes revealed that high yield plasticity can be obtained especially in the variety Bojos, which is able to compensate effectively the changes in spike number by increased grain number in a spike. This variety is also able to create a high proportion of strong tillers even under unfavourable conditions. This knowledge could help to improve the breeding and management strategy in spring barley for the expected weather conditions in the near future, especially higher temperatures in early spring.

Properties of Luvisol and spring barley yield as affected by peas as a catch crop

The share of cereals in the total area of agricultural crops is currently too high, which leads to deterioration of soil properties and makes it difficult to obtain high yields. The objective of this research was to determine the effect of field pea grown as a catch crop on soil properties and yielding capacity of spring barley cultivated after the catch crop, in a cereal crop rotation. Three treatments of catch crop management were studied: A – catch crop ploughed in in the autumn, B – catch crop left as mulch for the winter, C – control (without a catch crop). Experiments were carried out on a Luvisol (LV) in a randomized block design. The catch crop biomass ploughed in significantly improved moisture and reduced compaction of the topsoil before sowing spring barley. Use of field pea as a catch crop increased enzymatic activity and mineral nitrogen content in the soil before sowing and during tillering of barley. The effect of mulch was stronger than that obtained in the treatment with biomass ploughed in in the autumn. Catch crop significantly improved the yield of spring barley, which was mainly due to increasing the number of spikes and grains per spike in barley grown after the catch crop ploughed in, and due to increasing the number of grains per spike in the treatments with mulch. Physical and biological properties of soil in cereal crop rotations may be substantially improved by catch crop, especially used as mulch. Catch crop influence on spring barley yield was independent of its management method.

Effects of Depth Phases of the Clonroche Soil Series and Farming Skill on Spring Barley Yields

This study was carried out in the south-east of Ireland (Co. Wexford) over a four-year period (1984-7) to determine the factors responsible for the variation in yield of spring barley obtained by growers whose farms were situated on the Clonroche Soils Series. The results show that the level of management skills had a significant effect (P<0.00l Jon yield variance in all four years. The mean difference in yield over the four-year period between the most skilled growers (Class 1) and the least skilled growers (Class 3) was 1.13 t/ha. Soil depth differences within the Clonroche Series gave significant difference (P<0.001) in yield only in 1984. when the soil moisture stress was sufficiently great to expose the difference in moisture-holding capacities of the three depth phases within the Series. Key Index Words: Clonroche Soils Series, yields, management skills.

Wpływ łącznego stosowania etefonu z adiuwantami i nawozami azotowymi na wzrost i plonowanie jęczmienia jarego

Summary The field experiments with spring barley cultivar KWS Olof were conducted in 2013–2014. The tested products (Cerone 480 SL), adjuvants (Slippa, Atpolan 80 EC) and fertilizers (ammonium sulfate, urea) and some of their mixtures were applied on spring barley at the stage of BBCH 35. The higher effectiveness of shortening stems of spring barley was obtained after the use of Cerone 480 SL at the dose of 0.75 l/ha as compared to the control. The reduction of spring barley stem length was dependent of spray liquid compounds and it was 9.7–13.0% (2013) and 2.6–11.0% (2014) in the years of investigation, respectively. The addition of adjuvants Slippa or ammonium sulfate to the spray liquid containing ethephon improved efficacy of grown retardants. The method of application of ethephon did not have any influence on yield of spring barley and some parameters of yield component. However the usage of full or reduced doses of ethephon caused a non-significant decrease the thousand grain weight compared to the untreated plots. In both years of the study no phytotoxicity effect of the examined mixture was observed on spring barley cultivar KWS Olof.