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Oregano essential oil (EO) is known as one of the EOs with the highest biological activity on target plant species. In this study, the inhibitory effects of different doses of oregano (Origanum onites L.) EO on the germination and seedling growth of some wheat cultivars and some problem weed species in wheat fields was investigated. For this purpose, both laboratory and pot experiments were carried out. Oregano EO obtained by steam distillation method and component analysis was made via GS/MS. Germination tests and pot experiments were carried out under controlled laboratory and greenhouse conditions. In the study, five wheat varieties, four for bread and one for durum, and five different weed species were used. The effects of different doses of oregano EO on the germination rate, viable plant rate, seedling length, and biomass of test plants were analyzed. According to the results, it was observed that oregano EO showed bioactivity on all species and cultivars included in the experiment. In terms of all parameters, it was concluded that wheat varieties showed higher resistance to oregano EO than weed species. These results show that oregano EO can be used to control some weed species that are a problem in wheat. [ABSTRACT FROM AUTHOR]

Prediction models for crude protein concentration (CP) in winter wheat (Triticum aestivum L.) based on multispectral reflectance data from field trials in 2019 and 2020 in southern Sweden were developed and evaluated for independent trial sites. Reflectance data were collected using an unpiloted aerial vehicle (UAV)-borne camera with nine spectral bands having similar specification to nine bands of Sentinel-2 satellite data. Models were tested for application on near-real time Sentinel-2 imagery, on the prospect that CP prediction models can be made available in satellite-based decision support systems (DSS) for precision agriculture. Two different prediction methods were tested: linear regression and multivariate adaptive regression splines (MARS). Linear regression based on the best-performing vegetation index (the chlorophyll index) was found to be approximately as accurate as the best performing MARS model with multiple predictor variables in leave-one-trial-out cross-validation (R2 = 0.71, R2 = 0.70 and mean absolute error 0.64%, 0.60% CP respectively). Models applied on satellite data explained to a small degree between-field variations in CP (R2 = 0.36), however did not reproduce within-field variation accurately. The results of the different methods presented here show the differences between methods used and their potential for application in a DSS. [ABSTRACT FROM AUTHOR]

Ethiopia is the primary wheat producer in Sub-Saharan Africa (SSA) owing to the suitable agro-ecological conditions. Despite wheats economic potential for food security, the actual yield under smallholder farmers conditions is low due to various production constraints. Thus, the objectives of this study were to assess the present wheat production opportunities and constraints and identify farmer-preferred traits to guide variety design with stem rust-resistance and economic traits in eastern Ethiopia. Data on production constraints and trait preferences were collected using structured questionnaires involving 144 wheat-producing farmers. Wheat rust (reported by 97.3% of respondents), small land size (90.4%) and a lack of improved varieties (75.6%) were identified as the major constraints. About 41.7% of respondents in the West-Hararghe and 27.8% in the East-Hararghe zones did not use crop protection strategies to control rusts. Substantial respondent farmers used cultural practices (18.8%), rust-resistant cultivars (13.2%) or, a combination of these (10.4%) to control rust diseases. The essential farmer preferred traits in a wheat variety were rust resistance, high yield potential and good quality grain for bread making. Therefore, there is a need to breed new varieties with high grain yield and quality and durable rust resistance for sustainable wheat production in eastern Ethiopia. [ABSTRACT FROM AUTHOR]

The production and quality of wheat are affected by abiotic constraints including water stress and soil nutrient deficiencies. It is imperative to develop drought-tolerant wheat varieties with high yield potential and enhanced grain protein content for food security. Silicon (Si) is important for plant growth and development but its role in abiotic stress tolerance has been overlooked in breeding programs. Identifying the underlying functional genes controlling drought tolerance, protein content and grain yield is essential for wheat improvement, especially under drought stress. Silicon uptake is conditioned by several Si transporter genes such as Lsi1, Lsi2 and Lsi6 and aquaporins, which facilitate transport of silicon and water between cells. The objectives of this review are to examine the role of Si in improving plant nutrition and drought tolerance, and to appraise the genetic control of Si uptake and breeding methods for improving Si uptake for drought adaptation and improved grain yield and quality. The review highlights the limited progress made in breeding for drought tolerance in wheat, especially in sub-Sahara Africa where the challenge is prevalent. Limited understanding of the genetic basis for Si uptake and physiology contribute to the limited progress in its exploitation in wheat improvement programs. [ABSTRACT FROM AUTHOR]

Intercropping (IC) can reduce nitrogen fertilizer requirements, supress weeds, and improve crop yields and yield stability. Three field trials were conducted in Denmark in 2018 with intercropping and sole crops (SC) using spring wheat, barley, faba bean and field pea to compare productivity under five fertilizer levels. The trials were carried out using in a split-plot design with four. Anomalous weather during the 2018 cropping season created drought conditions and high temperatures above 31°C. No effect of fertilizer treatment was found, and total dry matter and grain yields were supressed in all systems. Wheat grain yields averaged 2.14 t ha−1 across systems, ranging from 1.58 t ha−1 as a component of the IC to 2.44 t ha−1 as SC, and barley grain yields averaged 2.35 t ha−1. Faba bean yielded 1.78 t ha−1 as SC, but failed in the IC. Pea failed in both systems. Intercropping barley with cover crops had no effect on grain yield or total dry matter. These results suggest that intercropping provided no production advantage during a drought and illuminate the need to continue conducting research and breeding on drought-resistant cultivars. [ABSTRACT FROM AUTHOR]

This study investigated the agronomic response and economic return of wheat grown in compacted and non-compacted soils to represent the conditions of non-controlled (non-CTF) and controlled traffic (CTF) systems, respectively. Yield-to-nitrogen responses were derived after application of urea, DMPP-treated urea, and UAN at rates between 0 and 300 kg ha−1 N. Soil properties were measured to guide parametrisation of APSIM, which was used to assess long-term (50 years) effects of CTF and non-CTF soil conditions on crop productivity, rainfall-use efficiency (RUE) and surface runoff. Grain yield and yield components were significantly higher in CTF compared with non-CTF. When N inputs were optimised, N use efficiency (NUE) was more than double in CTF (≈23%) compared with non-CTF (≈9%). RUE was about 15% higher in CTF, which concurrently reduced the amount of surface runoff compared with non-CTF. For years with average rainfall (240-mm in-crop), yield penalties of up 12% may be expected in non-CTF. APSIM simulations showed that increased productivity, and inter-annual yield stability, can increase gross margin of wheat by AUD30-50 ha−1 depending on in-crop rainfall and the tillage method used. In non-CTF systems, improvements in NUE and RUE are constrained by soil compaction. Enhanced efficiency fertilizers cannot compensate for other stresses caused by compaction and therefore cannot achieve the same NUE and RUE as the CTF system. Adoption of CTF in water-constrained environments improves profitability and resource-use efficiency. [ABSTRACT FROM AUTHOR]

Endophytic bacteria are those that colonise the internal tissues of plant without negative impact on plant health. This work aims to isolate the endophytic bacteria colonising Triticum vulgare and Phragmites australis and evaluate their compatibility as biostimulants to maize. Three of the six obtained isolates were selected upon their surpassing ability to stimulate the growth of maize seedlings (maximum of 18% increase in germination and 2.4-fold increase in the number of lateral roots). These isolates were molecularly identified as Klebsiella MK2R2, Bacillus B2L2 and Enterobacter E1S2. The response of maize seedlings to the combined effect of these isolates revealed that Bacillus B2L2, containing treatments, surpassed the other treatments in growth vigour parameters and upon this result these treatments were applied in a field experiment either alone or in combination with 100% N fertilisation. Maize plants, inoculated with Klebsiella MK2R2 and Bacillus B2L2 either alone or in combination with Enterobacter E1S2 in the presence of urea, surpassed significantly other treatments as the weight of ear increased almost two times and the number of grains increased 1.8 times compared to the control values. It could be concluded that the obtained strains are compatible biostimulants to maize. [ABSTRACT FROM AUTHOR]

Nordic conditions necessitate varieties adapted to marginal environments (short vegetation period, winter damages etc.) to reduce environmental influence on yield and quality. This study evaluated yield and quality variability of five spring and six winter wheat varieties grown in six locations throughout Estonia during 2011–2014. The variation of quality parameters was larger in spring wheat, according to the coefficient of variation. Average protein content for spring wheat was 13.6%, for winter wheat 13.3%. Average gluten content was 29.1% for spring wheat, 29.4% for winter wheat. Spring wheat varieties 'Manu' and 'Quarna' and winter wheat varieties 'Ada', 'Fredis', and 'Ramiro' had the highest baking quality. Protein and gluten content variation for both types of wheat depended mostly on the year. Baking strength W was higher for spring wheat. Variation of W of spring wheat depended more on genotype while variation of winter wheat more on year. The ratio of tenacity and extensibility (P/L) was similar for both wheat types; variation depended most on genotype. Average yield of winter wheat was 6.8 and spring wheat 5.3 t ha−1. 'Nemunas', 'Kallas', and 'Skagen' were high yielding among winter wheat varieties and had the best stability according to cultivar superiority index [ABSTRACT FROM AUTHOR]

Assessing the genetic variation and relationships present in crop germplasm is a pre-requisite for parental selection and breeding. The objective of this study was to determine the genetic relationships present among selected heat and drought tolerant wheat genotypes using simple sequence repeat (SSR) markers, agronomic traits and grain quality parameters to select desirable parents for breeding. Twenty-four agronomically selected wheat genotypes sourced from the International Maize and Wheat Improvement Centre (CIMMYT)'s heat and drought tolerance nursery and four local check varieties were genotyped using 12 selected polymorphic SSR markers. The test genotypes were phenotyped using yield and yield-component traits, and grain protein content (GPC) under non-stressed (NS) and drought-stressed (DS) conditions. Expected heterozygosity mean value of 0.58 indicated moderate genetic diversity for breeding. The studied wheat genotypes were delineated into six genetic groups using cluster analysis. Significant genotypic differences were observed for agronomic traits and GPC under NS and DS conditions. Genetically unrelated breeding parents including LM02, LM13, LM23, LM41, LM44, LM71, LM73 and LM75 were selected for population development and breeding for enhanced grain yield and protein content under heat and drought-stressed environments. [ABSTRACT FROM AUTHOR]

Drought is a major factor threatening crop production worldwide. Developing wheat varieties that are adapted to drought prone environments is a sustainable strategy to improve wheat production and productivity. The aim of this study was to evaluate and select bread wheat genotypes for yield and yield components, and for stability under drought stress and non-stress conditions. One hundred and twenty genotypes were evaluated at five test sites in the 2018/19 cropping season using a 10 x 12 alpha lattice design with two replicates. The level of drought stress was imposed using different sowing dates (early planting representing non-stressed, while late planting as drought stressed conditions) following the onset of the main rain at each site. Grain yield and yield components were recorded, and drought indices were calculated for each genotype. Among the drought tolerance indices, GMP, MP, HM, STI and YI were found to be the most suitable for predicting drought tolerance because they had significant and positive correlations with yield under drought stress and non-stress conditions. Rank sum analysis identified the most drought tolerant genotypes as 'YS-34', 'YS-85' and 'YS-82'. The selected wheat genotypes are useful genetic resources for future drought tolerance breeding programmes in Ethiopia or similar agro-ecologies. [ABSTRACT FROM AUTHOR]

Under drought and normal conditions, exogenous coronatine (COR), by the way of spraying, could induce the resistance of wheats (JiMai22 and LiangXing99). As a kind analogue of JA-Ile and compared to water-spraying, COR-spraying could improve water metabolism, photosynthesis, antioxidant enzymes activity and reduce the MDA and super anion contents. Moreover, though the way of JA acted with other hormones, especially the ABA, to regulate the plant growth, and then improve the drought resistance. [ABSTRACT FROM AUTHOR]

Wheat genotypes with pre- and post-anthesis drought tolerance offer enhanced yield gains under water-limited environments. This study determined pre- and post-anthesis drought responses of selected bread wheat genotypes in order to identify and select candidate genotypes for breeding. Fifteen genetically differentiated wheat genotypes were evaluated under non-stressed (NS), pre-anthesis drought stress (PrADS) and post-anthesis drought stress (PoADS) in glasshouse (GH) and field (FLD) environments. Data were collected on agronomic and physiological traits including number of days to heading (DTH), days to maturity (DTM), plant height (PH), number of spikelet per spike (NSPS), number of kernels per spike (NKPS), thousand kernel weight (TKW), grain yield (GY) and canopy temperature (CT). Analysis of variance revealed significant effects of genotypes, environments and their interactions for studied traits. Weak and positive correlations were recorded between GY with PH (r = 0.47 and 0.32), NSPS (r = 0.37 and 0.52) and TKW (r = 0.30 and r = 0.20) under PrADS and PoADS conditions, respectively. Genotypes SMY-006, SMY-008, SMY-016, SMY-042 and SMY-044 were identified with pre- and post-anthesis drought tolerance and high yield potential and suitable yield-component traits. These are useful genetic stocks for breeding or cultivation in water-limited environments to improve yield gains. [ABSTRACT FROM AUTHOR]

The selection response of wheat (Triticum aestivum L.) under water-limited condition can be enhanced through breeding novel genotypes possessing drought-adaptive and yield-related agronomic and physiological traits. The objective of this study was to evaluate terminal drought tolerance among bread wheat genotypes and select superior parents for breeding. Agronomic and physiological responses of 28 wheat lines were assessed under well-watered (WW) and terminal drought (TD) treatments using a 7 × 4 alpha-lattice design under rainout shelter (RS) and glasshouse (GH) environments. Significant (p ≤ 0.05) genotype × environment interaction effects were observed for number of days to heading (DTH), number of days to maturity (DTM), number of productive tillers per plant (TN), grain yield (GY), thousand kernel weight (TKW), stomatal conductance (SC), leaf canopy temperature (LCT) and chlorophyll content index (CCI) suggesting varied genotypic response under WW and TD treatments. Correlation analysis revealed significant associations TN and GY (r = 0.67; p ≤ 0.001), TKW and GY (r = 0.72; p ≤ 0.001), CCI and GY (r = 0.39; p ≤ 0.05) under TD treatment. Drought tolerant wheat genotypes such as LM100, LM72, LM22 and LM95 are useful for direct cultivation and for developing breeding populations with enhanced yield performance. [ABSTRACT FROM AUTHOR]

The selection of relatively high and stable yielding genotypes is key in wheat breeding programs to improve yield performance under heat and drought-stressed environments. This study determined grain yield response and stability among elite heat and drought tolerant bread wheat genotypes under simulated drought-stressed (DS) and non-stressed (NS) environments to select promising parents for breeding. Twenty-four elite bread wheat genotypes selected from the International Maize and Wheat Improvement Centre (CIMMYT) drought and heat tolerant nursery were assessed under NS and DS conditions using a 7 × 4 alpha-lattice design under rainout shelter (RS) and glasshouse (GH) environments. Grain yield data was subjected to analysis of variance (ANOVA), the additive main effect and multiplicative interaction (AMMI) and genotype and genotype-by-environment (GGE) biplot analyses. ANOVA and AMMI revealed highly significant (p ≤ 0.001) differences among test genotypes (G), environments (E) and G × E interaction effects suggesting differential responses for selection. The GGE biplot explained 83.76% of total variation and aided in selection of high-yielding and stable heat and drought tolerant wheat genotypes such as LM13, LM22, LM95 and LM100. These selections are recommended for breeding for yield gains under heat and drought-stressed environments. [ABSTRACT FROM AUTHOR]

Biofortification experiments with three winter wheat cultivars treated with sodium selenate through foliar- and soil-fertilisation were conducted at two locations in Croatia and Serbia in two consecutive years to increase the selenium (Se) concentration in bread-making wheat grain. The treatments were: (a) 5 g ha−1 Se foliar-, (b) 10 g ha−1 Se foliar- and (c) 10 g ha−1 Se in soil surface-application and they were compared with (d) control. Both Se foliar- and soil-fertilisation increased the Se concentration in grains from 2.6- to 4.6-fold. The concentration in grain was highest with Se foliar-fertilisation of 10 g ha−1 and it was increased by 29–32 µg Se kg−1 dry weight for each gram of Se applied per ha. The wheat cultivars differed in grain yield and Se uptake (g ha−1 Se). However, on average, there were no differences between wheat cultivars with respect to Se grain concentrations. Agronomic use efficiency (by grain) was significantly higher for Se foliar- (19%) than for soil-fertilisation (13%). It can be concluded that agronomic biofortification of winter wheat can be effective in increasing Se grain concentration, where the efficiency depends on the rate of Se applied, application method and local environmental conditions rather than on cultivar differences. [ABSTRACT FROM AUTHOR]

Genetic improvement of wheat for drought tolerance can be achieved by developing suitable ideotypes with enhanced yield-response associated with agronomic traits and biochemical markers. The objective of this study was to determine drought response of elite drought tolerant wheat genotypes using agronomic and biochemical traits to select promising lines for breeding. Fourteen wheat genotypes selected from the International Maize and Wheat Improvement Center's heat and drought tolerance nursery and one standard check variety were evaluated under drought-stressed (DS) and non-stressed (NS) conditions using a randomised complete block design in three replications. Significant (P < 0.05) genotype, drought condition and genotype × drought condition interaction effect were detected for the tested traits suggesting differential response of genotype for selection. Grain yield positively correlated with sucrose (r = 0.58; P < 0.05), fructose (r = 0.52; P < 0.05) and total sugar (r = 0.52; P < 0.05) contents under NS condition and with sucrose (r = 0.80; P < 0.001), total sugar (r = 0.84; P < 0.001) content, proline content (r = 0.74; P < 0.001) and number of grains per spike (r = 0.58; P < 0.05) under DS condition. Genetically unrelated wheat genotypes such as SM04, SM19, SM29, SM32, SM45 and SM97 possessing key agronomic and biochemical traits were selected for cultivar development for drought-stressed environments. [ABSTRACT FROM AUTHOR]

Nitrogen uptake being part of nitrogen use efficiency (NUE) is largely decided by root traits. Root traits variability has hardly been explored by breeders mainly because of difficulties in scoring. The hydroponic system requiring lesser space for precise phenotyping of large numbers of genotypes independently of the growing season can be a suitable alternative. However, the effectiveness of hydroponic screening methods needs to be verified under the soil condition of the field or pot. In the present study, root traits and NUE were investigated in 19 genotypes under two conditions (hydroponic and pipe filled with soil). Both environments revealed large variability for root traits and NUE under high and low N conditions establishing the absence of any direct selection for these traits in the past. Under both sets of experimentation, NUpE was largely responsible for improved nitrogen efficiency mainly because of higher root biomass. The significant association between the two screening methods i.e. hydroponic and pot filled with soil under both low and high N condition support large scale screening for root traits under hydroponic condition. [ABSTRACT FROM AUTHOR]

The nitrogen fertilisation management should focus on increasing fertilisation efficiency in favour of a more sustainable and productive agriculture. Thus, this study aimed to evaluate the effect of inoculation with Azospirillum brasilense, associated to N doses and sources, in Savannah conditions, on agronomic efficiency (AE), recovery of applied nitrogen (RAN), physiological efficiency (PE), agrophysiological efficiency (AGREC), nitrogen use efficiency (NUE), nitrogen harvest index (NHI) and wheat grain yield. The experiment was developed in a Rhodic Hapludox soil under no-tillage system. The experimental design was a randomised complete block design with four replicates arranged in a 2 × 5×2 factorial scheme: Two N sources [(urea and urea with inhibitor of the enzyme NBPT (N – (n – butyl thiophosphoric) Triamide))], five N doses applied in top-dressing (0, 50, 100, 150 and 200 kg ha−1), with and without inoculation with A. brasilense. The increase in N doses reduced the nitrogen fertilisation efficiency. No significant differences were observed among the N sources. Inoculation increased the AE of nitrogen sources and can increase RAN. The increase in N dose up to 140 kg ha−1 associated with inoculation increased wheat grain yield. [ABSTRACT FROM AUTHOR]

Water shortages is a major constraint in wheat production in South Africa. It is important therefore to assist irrigated wheat farmers to identify water stress tolerant growth stages in irrigated wheat genotypes. This study evaluated new wheat genotypes for water stress at different growth stages. An 8 (genotypes) × 2 (water treatments) × 3 (growth stages) factorial experiment was laid out in a randomised complete block design with three replicates. The results indicated that plant height was not affected (p >.05) by water stress at tillering and grain filling. Water stress imposed at the tillering stage reduced the number of fertile tillers (p <.05) in susceptible genotypes while at the flowering and grain filling stages all genotypes were tolerant (p >.05). Aboveground biomass was only affected (p <.05) by water stress imposed at the tillering stage. Water stress reduced grain yield on the genotypes where stress was imposed at the tillering stage (p <.05); whereas when stress was imposed at flowering and grain filling the grain yield was not reduced (p >.05). This study provided evidence to suggest that most genotypes were tolerant to water stress at the flowering and grain filling stages. [ABSTRACT FROM AUTHOR]

The negative impact on the environment caused by intensive agriculture has been extensively discussed for years. In particular, excessive nitrogen application has been associated with biodiversity loss. Many studies have shown the potential to reduce the use of nitrogen without any impact on crop yield. Maintaining crop yield has been the goal, whereas crop quality has not been considered. In this paper, we investigate the effect of the level of soil organic carbon (SOC) and nitrogen fertiliser application on winter wheat (Triticum aestivum) yield and its quality. We show that the absence of nitrogen fertiliser decreased both yield and quality parameters of cereal grain. Quality parameters, such as protein and gluten contents, zeleny value, falling number and hardness were strongly positively influenced by nitrogen fertiliser application. The SOC level had no significant effect on these grain quality parameters. As a result, in the absence of nitrogen fertiliser, grain was not suitable for baking bread. We recommend that in the debate on the potential to limit the use of nitrogen in agricultural production, its impact on grain quality should be taken into consideration, especially at low levels of SOC. [ABSTRACT FROM AUTHOR]

Multilocation testing remains the main tool for understanding varietal responses to the environment. Here, Latvian and Norwegian hull-less and hulled barley varieties were tested in field experiments in Latvia and Norway in order to assess the varieties adaptability across environments (sites). Two Latvian (cv Irbe and cv Kornelija) and one Norwegian hull-less barley variety (cv Pihl) were tested along with one Latvian (cv Rubiola) and one Norwegian hulled barley variety (cv Tyra) under conventional and organic management systems. The grain yield, together with physical and chemical grain parameters were compared, and variety yield and protein stability determined. Overall, grain yield of hull-less barley varieties was significantly lower than for hulled barley varieties regardless of climatic conditions and management system. However, in the organic farming systems this difference between barley types was less pronounced. The hull-less barley varieties cv Pihl and cv Irbe, along with both hulled varieties, had good yield stability across environments and were well adapted to both cropping systems. Hull-less barley varieties tended to contain more protein and β -glucans than hulled barley varieties. Despite being bred for local conditions in Norway and Latvia, our study shows that all the varieties used may be successfully transferred across countries. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine drought tolerance characteristics of dryland wheat genotypes based on leaf gas exchange and water-use efficiency in order to identify promising genotypes for drought tolerance breeding. Physiological responses of ten genetically diverse wheat genotypes were studied under non-stressed (NS) and water stressed (WS) conditions using a 2 × 10 factorial experiment replicated 3 times. A highly significant water condition × genotype interaction (P < 0.001) was observed for photosynthetic rate (A), ratio of photosynthetic rate and internal CO2 concentration (A/Ci), ratio of internal and atmospheric CO2 (Ci/Ca), intrinsic (WUEi) and instantaneous (WUEinst) water-use efficiencies suggesting genotypic variability among wheat genotypes under both test conditions. Principal component analysis (PCA) identified three principal components (PC's) under both test conditions accounting for 84% and 89% of total variation, respectively. Bi-plot analysis identified G339 and G344 as drought tolerant genotypes with higher values of A, T, gs, A/Ci, WUEi and WUEinst under WS condition. The current study detected significant genetic variation for drought tolerance among the tested wheat genotypes using physiological parameters. Genotypes G339 and G344 were identified to be drought tolerant with efficient A, T, gs, A/Ci and water-use under water stressed condition. [ABSTRACT FROM AUTHOR]

Water stress is one of the major environmental stresses that affect agricultural production worldwide, especially in arid and semi-arid regions. This research investigated the effect of water deficit, induced by PEG-6000 on wheat genotypes (GA-2002, Chakwal-97, Uqab-2000, Chakwal-50 and Wafaq-2001) grown in modified MS medium solution. Osmotic stress caused a more pronounced inhibition in leaf relative water content and leaf membrane stability more sensitive (index in Wafaq-2001 and Uqab-2000) genotypes compared with the tolerant (Chakwal-50, GA-2002 and Chakwal-97) genotypes. Upon dehydration, an incline in proline, total soluble sugar, total soluble protein, superoxide dismutase, peroxidase, catalase and malondialdehyde activity content were evident in all genotypes, especially at osmotic stress of −8 bars. The observed data showed that status of biochemical attributes and antioxidant enzymes could provide a meaningful tool for depicting drought tolerance of wheat genotypes. The present study shows that genotypic differences in drought tolerance could be likely attributed to the ability of wheat plants to induce antioxidant defense under drought conditions. In order to develop genotypes with stable, higher yields in dry farming conditions, it is necessary to characterise genetic resources based on drought adaptation, determine suitable genotypes, and then use them in breeding programmes. [ABSTRACT FROM AUTHOR]

Gene introgression in wheat is not only limited by crossability but also affected by environmental conditions, genotypic differences and necrotic genes. Hence, the present investigation was formulated to determine the influence of genotypic and environmental factors on the crossability of elite triticale and wheat genotypes, screen the effect of necrotic genes in the F1hybrids and the relative performance of hybrids towards haploid induction following theImperata cylindrica-mediated chromosome elimination approach. The dry temperate region was observed to be significantly better than sub-humid mid-hills for seed set in intergeneric crosses. Lower rate of crossability (17.49–48.33% and 14.46–36.51%) was found in triticale × wheat crosses at both locations. The hybrids having HPW236 as one of the parent revealed necrosis ranging from the lowest to highest grade. Further, negative influence of the necrotic genes on the haploid induction parameters was apparent due to significant hybrid necrosis symptoms in F1hybrids. Statistically significant variation in haploid induction parameters was also evident between and within different cross combinations, indicating that haploid induction parameters were profoundly influenced by genotypic specificity. [ABSTRACT FROM AUTHOR]

The renaissance of spelt is associated with the development of alternative farming and a trend to maintain biodiversity. The present study carried out a comparison between two methods of weeding (mechanical and chemical) as well as a cereal cultivar influence on chemical composition of spelt and wheat. The research material was taken from field experiments carried out during three years. In order to assess the chemical composition, the following cereal cultivars were used: lines of winter spelt – STH 8 and STH 11 and a winter common wheat cv. Tonacja. In all cases, the overall protein content in spelt was significantly higher than in common wheat. Spelt grain is also richer in fats than common wheat. A visible tendency to higher concentration of raw fibre was observed when mechanical weeding was applied. Also, mechanical weeding as well as the variety significantly influenced β-glucan content. The study of the impact of a weeding method and a variety does not clearly show the direction of the amino acid content changes. The research indicates that there are ample opportunities to shape the level of nutrients, which decide about spelt grain application in the food industry through agronomic factors (methods of weeding and cultivar). [ABSTRACT FROM AUTHOR]

In Indian agriculture, nitrogen (N) and phosphorus (P) fertilizers are predominantly used by the farmers, often ignoring secondary and micronutrients. Significance of boron (B) in nutrient management studies has been increasingly underlined under intensive cropping systems particularly in acid soils. In order to understand the distribution of soil native B in different fractions and their contribution to plant B uptake as influenced by nutrient management, soil samples collected after wheat (2009–2010) from a long-term experiment (LTE) continuing since 1972–1973 on Typic Paleustalf of Ranchi were subjected to sequential fractionation of soil B. Treatments included N alone, NP, NPK, 150% of recommended NPK, NPK + farmyard manure (FYM), NPK + lime, and an unfertilized-control. Five soil B fractions were determined along with hot CaCl2-extractable (available) B. Averaged across the treatments, the soil had low organic carbon (C), pH and cation exchange capacity (CEC), and high free sesquioxides. Total B content was 21.7 mg kg−1. Among different B fractions, residual B was the major contributor to total B and other fractions collectively shared 7% of total B only. Application of N alone depleted readily soluble, specifically adsorbed and organically bound B bringing the contents even below unfertilized-control. Conjoint use of lime or FYM with NPK increased significantly these fractions, whereas a decrease in oxide bound B was noticed under these treatments. Available B was positively correlated with these fractions indicating their significance in controlling B availability in the soil. The study revealed that use of lime or FYM helped modifying the distribution of soil B in different fractions by way of changing soil pH and organic C content, resulting in enrichment of plant available pool. A drastically low available B content in different treatments receiving fertilizers alone, however, suggested the necessity of B fertilization at prescribed rates for maintaining soil B fertility as also high crop yields. [ABSTRACT FROM AUTHOR]

Spring-sown crops are expected to have a higher risk of drought during summer in the next decades in Central Europe due to expected climate change. Therefore, a two-year experiment was conducted under Pannonian growing conditions in Eastern Austria to investigate the effect of autumn- and spring-sowing of facultative wheat. Autumn-sowing of facultative wheat enhanced crop development, soil coverage, crop stand height, crop growth rate, and nitrogen (N) utilization efficiency during the vegetation period compared to spring-sowing; duration of growth stages was prolonged and crops were earlier ripe. In contrast, spring-sowing resulted in higher relative growth rates, higher N concentrations of aboveground dry matter, higher relative N uptake rates, and more mineral N in the soil. At harvest, grain yield and yield components ears m−2and thousand kernel weight (TKW) were higher in autumn-sown than in spring-sown wheat, resulting thereby in an increased seed yield. Spring-sown wheat had higher N concentrations in grain and in straw. Anyhow, N yield was slightly higher with autumn-sowing due to the higher grain and straw yields. Grain and straw yield, plant stand height, ears m−2, and TKW were impaired in the second experimental year by a severe drought for both sowing dates as well as N concentrations and N yields of grain and straw, partial factor N use efficiency and N utilization efficiency. But the yield components harvest index, grains m−2, and grains ear−1were strongly impaired with spring-sowing under drought conditions. Thus, autumn-sowing of wheat resulted in higher yield stability across both years, based on these yield components highlighting possible benefits of autumn-sowing with expected summer drought under climate change. [ABSTRACT FROM AUTHOR]

There is increasing awareness of the need for efficient nutrient recycling in food production. Therefore, a pot experiment was conducted to contribute to the development of alternative compound fertilisers with balanced nutrient ratios for cereal production. We compared the (1) fertilisation effects and (2) effects on soil chemistry of four organic nitrogen (N)- and phosphorous (P)-rich waste-based products (WBPs), applied with or without potassium (K)-rich bottom wood ash (BWA). WBPs and BWA were applied at two rates (80 kg N ha−1+ 35 kg K ha−1and 160 kg N ha−1+ 70 kg K ha−1) to spring barley (Hordeum vulgare) in year one and spring wheat (Triticum aestivum) in year two, and the effects were compared with those of commercial mineral and organic compound fertilisers. The K fertilisation effects of BWA were masked by the soil's ability to provide plant-available K during both years of the experiment. Plant-available N was, therefore, the growth-limiting factor for barley in year one, when there were no differences in grain yield between treatments with and without K-rich BWA. The mineral fertiliser equivalent of WBPs was 64–118% for N uptake in barley grain, but can be expected to be lower under field conditions. During year two, wheat yield was determined by the plant availability of P and N. Meat-rich meat and bone meal caused P deficiency at the lower application rate as a result of alkaline soil conditions, whereas the P in BWA appeared to be almost as plant-available as soluble mineral P. [ABSTRACT FROM AUTHOR]

Water scarcity and nitrate contamination in groundwater are serious problems in the North China Plain (NCP). The objective of this study was to compare the effects of farmer's practice and optimal water and nitrogen management on nitrate leaching, and water and nitrogen use efficiencies (WUE, NUE) during winter wheat season in the NCP. A winter wheat experiment with four treatments (traditional irrigation plus traditional fertilizer, W1N1; traditional irrigation plus optimal fertilizer, W1N2; optimal irrigation plus traditional fertilizer, W2N1; optimal irrigation plus optimal fertilizer, W2N2) was conducted from October 1999 to June 2001 in Beijing suburban. The soil–plant system, water and solute transport model was calibrated and validated based on the data collected from the experimental field, then the model was used to simulate the water movement, nitrogen (N) transport, and crop growth process. The results showed that the simulated soil water content, nitrate concentration in the soil profile, leaf area index, crop N uptake, and grain yield were all in good agreement with the measured data. The simulated results indicated that the improved management of water and fertilizer practice could increase crop yield, and reduce water drainage, nitrate leaching, and gaseous N loss compared to farmers' practice. WUE and NUE under improved practice were 1.36 kg m−3and 34.9 kg kg−1N−1in 2000, 1.07 kg m−3and 31.5 kg kg−1N−1in 2001, respectively. Compared to farmers' practice, the optimal management practice can save water about 4–19%, water drainage decreased 50–65%, N leaching reduced over 90% and gaseous N loss decreased about 70%, at same time leading to an increase in WUE and NUE by 10.6% and 10.3% in 2000, 64.5% and 98.3% in 2001, respectively. [ABSTRACT FROM AUTHOR]

Nitrogen (N) is usually the main nutrient affecting grain yields and is, therefore, applied in large quantities to maintain optimal yields. Economically, optimal fertilization may imply higher N application than the amount of N removed in grain, thereby causing high risk for N losses. The aims of this paper were to study the fertilization practice for cereals and the relationship between N application and yield, N balance, and N use efficiency for barley and oats in three of the catchments included in the Norwegian Agricultural Monitoring Programme (JOVA). The results showed that the average amount of applied N to cereals in these three catchments was higher, and sometimes considerably so, than the recommended N application. Within the range of N application in these catchments, there was no relationship between N application and yield for oats, whereas a tendency of increased yield with increased N application was found for barley in two of the catchments. The average N surplus in cereal production was significantly higher than that expected if fertilization recommendations had been followed. The average N surplus for the different cereals varied from 36 to 60 kg N ha−1in two of the catchments and from 22 to 40 kg N ha−1in the third catchment. The average N use efficiency (calculated as N removed in grain divided by the amount of applied N) ranged from 61 to 71% for barley and from 67 to 82% for oat. The JOVA data clearly demonstrate the importance of using moderate N applications in order to reduce N surplus, and thereby reduce N losses. N application for higher yield levels than those normally obtained, results in low N use efficiency and high N surplus in most years. [ABSTRACT FROM AUTHOR]

This study examined nickel (Ni) concentrations in Swedish soils and cereal grains and how soil properties and different fertilization regimes affect Ni uptake by plants. Analysis of data from the Swedish environmental monitoring program on arable land showed that Ni concentrations in soils were significantly correlated with clay contents (R2= 0.55;p< 0.001), while the correlation with organic matter content was weak, although significant (R2= 0.02;p< 0.001). Concentrations of Ni in grains were positively correlated with the concentrations of total Ni in soil (R2= 0.13;p< 0.001), negatively correlated with soil pH values (R2= 0.14;p< 0.001), and multiple regression including Ni in soil and soil pH improved the correlation (R2= 0.34). Therefore, analysis of total Ni concentrations in soils together with pH values can provide some guidance on where low Ni concentrations in crops are most likely to occur. Data from long-term field trials showed that Ni concentrations in wheat grain did not increase significantly after long-term application of cattle manure or sewage sludge compared with mineral fertilized or unfertilized treatments. Differences detected were attributed to pH changes in soil and differences in yields. It was found that Ni in organic amendments was not easily available for crop uptake. Application of inorganic fertilizer (NPK) decreased Ni concentrations in wheat grain compared with the unfertilized treatment, probably due to dilution in high-yielding crops. Concentrations in grains were low, and mean concentrations were 0.18, 0.07, and 1.20 for winter wheat, spring barley, and oats, respectively. For barley, this implies that 77% of the samples from the monitoring program had Ni concentrations below a proposed critical concentration for optimal germination (0.09 mg kg−1). Nickel shortage can be an overlooked problem in Swedish seed production that needs further attention. [ABSTRACT FROM PUBLISHER]

Regression modelling and statistical correlations are often developed to aid reasonable predictions of metal solubility and free metal ion in terrestrial ecosystems. In the present study, we test how regression model predictions of metal solubility and free metal ion correlate with metal concentrations in plants. We previously optimised a model for the prediction of metal solubility and free metal ion concentrations in soil solution from sites collected in the Danube basin of Eastern Croatia, containing total metal concentration (concentrated HNO3), soil pH, soil organic matter (SOM) and dissolved organic carbon (DOC) as model parameters. In the present study, we report how our optimised models correlate with metal concentration in plants reported by Lončarić et al., which was based on a study from a smaller part of the same sampling area. Our default regression model and further optimised model predicted metal solubility and free metal ion concentrations. These predictions correlated well with Fe, Mn, Zn and Cd concentrations in wheat grain, but the different extraction methods and parameter optimisations affected the significance of correlations differently. Due to the low concentrations of total metal concentrations in soil and little variation in SOM, the soil pH was the only variable, in addition to the total metal controlling the metal solubility, free metal ion in soil water and also the concentrations in wheat grain. Results show that after optimisation for the few most important soil chemical variables regression models can predict metal concentrations in plants fairly well. For this particular study, optimisation for total metal,soil pH and perhaps also SOM and DOC are sufficient. [ABSTRACT FROM PUBLISHER]

Results of 240 annual N fertilizer trials in 1991–2007 in spring and winter cereals are presented. On average, spring barley and oat yields increased little beyond 120 kg N ha−1 in fertilizer. Somewhat higher figures were found for spring and winter wheat. Regression equations for yield and N uptakes in grain and straw were derived, related to N fertilizer input and the yield level in individual trials (indicator of yield expectancy). These equations accounted for 90% of the variation in yield and 80% of that in N uptake. Quadratic N responses were significant in all cases, as were interactions between N responses and yield level. They were verified with data from 27 separate trials performed in 2008–2010. The yield equations were used to calculate economically optimum N fertilizer levels with varying ratios of product price to fertilizer cost at contrasting levels of yield. The optimum N fertilizer level for barley and oats was found to increase by 8.3 kg N ha−1 per Mg increase in expected yield. The equivalent figure in wheat was 16.3 kg N ha−1. Optimum N fertilizer levels decreased by 4.1 and 6.7 kg N ha−1, for barley/oats and wheat respectively, per unit increase in the cost/price ratio. The equations for N uptake were used to calculate simple N balances between fertilizer input and removal in crop products. Large N surpluses were indicated at low levels of yield expectancy, but the surplus declined markedly with increasing yield level, despite greater N fertilizer inputs at high yield. Calculations made for national average yield levels in recent years showed N surpluses of 50–60 kg N ha−1 when only grain is removed and 25–40 kg N ha−1 when straw is removed also. Limiting N input to obtain zero balance reduces yields considerably at average levels of yield expectancy. [ABSTRACT FROM PUBLISHER]

Lodging is largely influenced by the strength of the stem, which is determined by the length of the internodes, the thickness of the stem and stem cortex and the solidity of the stem. The aim of this study was to study the effect of different N treatments and plant densities on stem strength of selected cultivars and their hybrids. Four combinations of plant density and N fertilizer were evaluated. Plant height, length and diameter of each internode, stem cortex and pith thickness, breaking weight and stem strength were measured. When plant density and N fertilizer increased, stem strength decreased, but the combined effect of these two factors was higher than when applied separately. The cultivar which performed the best in all treatments was a double haploid which expressed the solid stem trait for all internodes. Cultivars and hybrids with normal stems performed the poorest. Breaking weight was positively correlated with stem strength for all four treatments. Shorter internodes caused stronger stems. Stem cortex thickness was also positively correlated with stem strength for all the treatments. This shows that the thicker the stem cortex and the thicker the pith, the stronger the stem of the plant. [ABSTRACT FROM AUTHOR]

For studies of the effects of seedbed properties on crop emergence, experiments were carried out in shallow plastic boxes. In some experiments, it was examined whether rainfall after sowing could cause oxygen deficiency in the seedbed sufficiently severe to hamper emergence. Crops studied were barley (Hordeum vulgare L.), wheat (Triticum aestivum L.), oilseed rape (Brassica napus var. oleifera, L., Metzg.) and pea (Pisum sativum L.). For harmful oxygen deficiency to develop it appeared that rainfall would need to cause structural collapse of the surface layer followed by continuously wet weather accompanied by slow drainage and high oxygen consumption in the soil; in the experiments the latter was achieved by large amounts of easily decomposable organic matter. It was concluded that such conditions are rare in the field. Therefore, unless rainfall after sowing generates surface water for an extended period, the poor crop emergence often observed after such rainfall is nearly always caused not by oxygen deficiency, but by surface layer hardening when this layer dries. [ABSTRACT FROM PUBLISHER]

Rapid and uniform crop establishment is a prerequisite for efficient crop production and minimal environmental impact. Experiments were carried out in shallow plastic boxes placed directly on the ground in the field for studies of the effects of seedbed properties on emergence of various crops. This paper presents an analysis of the time required for germination and emergence under near-optimal seedbed conditions. The crops studied were barley, oats, wheat, pea, rape seed, white mustard, sugar beet, red clover and timothy. The time required for germination generally increased with size of the seeds, presumably because larger seeds needed more water to initiate germination. This applied both when comparing different crops and different seed sizes of the same crop. However, considerable differences occurred between seed lots of the same crop and there were greater differences between seed lots of the same crop than between the three small grain crops studied. Growth rate of the seedlings generally increased with seed size, presumably because of increased energy content in the seed. Consequently, the most rapid emergence was obtained from small seeds at shallow sowing and from large seeds at deep sowing. The crops studied had a minimum temperature for germination and seedling growth close to 0 °C. Under optimal seedbed conditions, thermal time required for 50% germination of barley was typically about 65 °C days over this base temperature and for seedling growth about 6 °C days cm-1. From 4 cm sowing depth, about 80 °C days were required for emergence but with considerable variations between seed lots. For rape seed or white mustard about 40 °C days were required for germination and about 8 °C days cm-1 for the seedling growth. [ABSTRACT FROM AUTHOR]

Winters are typically harsh in the northernmost agricultural areas of Europe, and winter rye (Secale cereale L.) and wheat (Triticum aestivum L.) are the only winter grain crops that can be grown. However, climate change is projected to result in milder winters, which may enable cultivation of winter crops to a greater extent in the future than is possible today. In this study we aimed at identifying main temperature, precipitation events and characteristics that have resulted in past poor overwintering of rye and wheat in their current production areas in Finland. Using long-term (1970-2006), multi-location datasets, we compared our findings with the projected major changes attributable to climate change. Mixed models were used to estimate mutually comparable overwintering damage to all experiments and logistic regression was used to determine whether climatic parameters are related to high levels of overwintering damage. Severity of overwintering damage, and associated yield penalties, fluctuate considerably on a year-to-year basis and no consistent reduction in variability was recorded during the study period. Particularly for wheat, severity of winter damage in any one year was associated negatively with area sown in the following year. There was no evidence of consistent genetic improvements in winter hardiness, but rye was more winter hardy than wheat. Current risks associated with rye production related to low temperatures could be alleviated in the future, although overwintering damage currently enhanced by high autumn precipitation could increase due to climate change. For wheat, fluctuating conditions hampered overwintering, which may be an even harder challenge in future when weather variation is projected to increase and extreme weather events are projected to become more common. [ABSTRACT FROM AUTHOR]

A range of locally available liming materials of different geological origin, particle size, and application rate were investigated in 15 field sites over a period of 8 years. At 5 sites, lime addition to soils caused average yield losses of 7%. Concentrations of Mn and Cu but not of boron and zinc in grains declined in limed plots. Decline in concentrations of Mn and Cu were significantly correlated with increasing soil pH-values. Crop data indicated that concentrations of Mn and Cu in grains reached low, critical levels. Yields declined at threshold values amounting to 15 mg Mn kg-1 for wheat and barley, 25 mg Mn kg-1 for rye, 30 mg Mn kg-1 for oat, and 3 mg Cu kg-1 for the four cereals. [ABSTRACT FROM AUTHOR]

The present investigation was undertaken to calculate the genetic variability and heritability of desirable physiological traits of wheat (Triticum aestivum L.). Forty-two F1 populations of Triticum aestivum L. were planted in the field and studied for variation and heritability. The variance calculated pointed out that phenotypic traits were significant (P<0.01) for such physiology traits as plant height, superoxide dismutase, catalase, peroxidase, relative water content, membrane stability index, and K+/Na+ ratio. Partitioning of the variance component estimated that the environment had its main impact on the performance of traits like plant height, catalase, and relative water content, while superoxide dismutase, peroxidase, membrane stability index, and K+/Na+ ratio were genetically influenced. Considering the wide variability and high heritability calculated, progress could be expected from selection based on catalase, membrane stability index, and K+/Na+ ratio. [ABSTRACT FROM AUTHOR]

Terrain attributes and soil properties are the major parameters to be considered for sustainable agricultural productivity and landscape management in dry farming. The objectives of this study were to predict the biomass, grain yield, and grain protein in wheat grown in hilly regions using an artificial neural network model and to identify the most important topographic attributes and soil properties affecting the variability of the wheat-yield components under rainfed conditions in the semiarid and hilly regions of western Iran. Wheat-yield data and surface-soil samples (0-30 cm depth) were collected from 1-m2 plots at 100 selected points. The sampling points were chosen in a stratified random manner on given geomorphic surfaces including summit, shoulder, backslope, footslope, and toeslope at the site. Primary and secondary terrain attributes were calculated using the digital elevation model. Selected soil physical and chemical properties were measured for the collected soil samples. Prediction of the artificial neural network models in the study area resulted in R 2 and root mean square error values of 0.95 and 0.022 for biomass, 0.93 and 0.021 for grain yield, and 0.89 and 0.063 for grain protein, respectively. The sediment-transport index was identified as the most important topographic attribute influencing the wheat biomass, while grain yield and grain protein were affected the most by the total nitrogen. Overall, our results indicated that the artificial neural network models could explain 89-95% of the total variability in wheat biomass, grain yield, and grain protein content. Also, the predictability of wheat yield and quality could be further improved by considering management practices followed during the growing season. [ABSTRACT FROM AUTHOR]

Salinity is one of the most damaging agro-environmental problems limiting plant growth and development in most parts of the world. The problem of salinity existed long before human beings and the start of agricultural practice and today it has become a very serious problem for crop production, particularly in arid and semi-arid regions, which constitute about one third of the world's land surface. The magnitude of genetic variation for salinity tolerance in spring wheat and broad-sense heritabilities has been estimated at different salinity levels. The 68 genotypes responded with different behaviors to increasing salinity levels in the growing medium. Responses of different genotypes to increased salinity levels in reduced growth were found, with those originating from Australia exhibiting a significant increase in salinity tolerance compared with others, originating from Pakistan. Plant vigor and salinity tolerance were found to have no significant correlation as measured by relative growth rates in saline environments. The relative growth rate of various accessions grouped on the basis of different geographic origin and different genes of various stresses also were not different significantly from each other, which suggests that different genes may be controlling the characteristic, from a single major dominant or from recessive genes. Estimated broad-sense heritability indicated that phenotypic variance exceeded that of genotypic by nearly two orders of magnitude. This study was to determine genetic and phenotypic relationships between plant performance in the presence of NaCl at three developmental stages in wheat. These results suggest that improvement in salinity tolerance in spring wheat is possible through selection and breeding. [ABSTRACT FROM AUTHOR]

The market for cereal cover crop straw and herbage seed straw has diminished in many seed-production areas due to there being less livestock. Seed growers therefore want to chop and return the straw both in the sowing year and in the seed-harvest years. The objectives of this research were (1) to compare decomposition rates of straw of barley and wheat cover crops and timothy (Phleum pratense L.), meadow fescue (Festuca pratensis Huds.), and red clover (Trifolium pratense L.) seed crops, (2) to study the effect on soil microbial activity of adding mineral nitrogen or fresh leaves from undersown seed crops, and (3) to evaluate the effect of straw placement/soil contact on straw-decomposition rates. Microbial activity/straw-decomposition rates were evaluated by regular measurement of CO2 production in four laboratory incubation experiments lasting for 150-161 days. Microbial activity was always enhanced by adding straw on the soil surface. Straw of barley resulted in higher CO2 production than did straw of wheat, while straw of red clover and meadow fescue resulted in higher CO2 production than with straw of timothy. Inclusion of fresh leaves of white clover and timothy increased CO2 production during the first and second half of the incubation experiments, respectively. Neither in the sowing year nor in the seed-harvest year was microbial activity stimulated by adding fertilizer nitrogen, but soil mineral nitrogen by the end of the experiments was higher after adding fertilizer or fresh leaves, and lower after adding grass seed straw. Presumably owing to higher humidity, straw decomposition in a field experiment was higher in timothy stubble than in wheat stubble and higher at 2 cm than at 10 cm above the soil surface. For practical seed production, growers are recommended to leave short stubble, to chop the straw as finely as possible, and to distribute the straw evenly on the surface in close contact with soil particles. [ABSTRACT FROM AUTHOR]

The effects of pretreatment with salicylic acid on wheat seed germination (Triticum aestivum L. cv. Roshan), lipid peroxidation, and superoxide dismutase, catalase, polyphenol oxidase, and peroxidase activity were studied under conditions of salt stress. Seeds treated with different concentrations of salicylic acid were used for measuring germination traits. Salt stress was induced by sodium chloride solution. Seeds were soaked in salicylic acid solution for 24 h, dried with sterile paper, transferred to sterile Petri dishes, and treated with 10 ml NaCl solution at different concentrations. After 1 week, the number of germinated seeds, root length, seedling length, and dry weight were recorded. Antioxidant enzyme activity and lipid peroxidation were also assayed. Salinity decreased seed germination. Thus, a high concentration of NaCl (200 mM) decreased germination by 17.6% compared with control treatment. Salicylic acid significantly increased germination in stressed and control seeds. Salicylic acid increased the level of cell division of seedlings and roots, which increased plant growth. Salt stress significantly increased the activity of the antioxidative enzymes catalase, superoxide dismutase, peroxidase, and polyphenol oxidase in wheat seedlings, and salicylic acid reduced the activity of antioxidant enzymes as stress signal molecules. Our results indicated that scavenging of reactive oxygen species was effective, especially by salicylic acid, and that membrane damage was limited. The aim of the present work was to study the character of changes in enzymatic systems induced by NaCl and salicylic acid in wheat seedlings under conditions of salt stress. In brief, salicylic acid treatment reduced the damaging action of salinity on embryo growth and accelerated a restoration of growth processes; thereupon it may be effective for the improvement of seed germination in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

A group of spring wheat cultivars originating from Sweden, Finland, Norway, Germany, and the Netherlands was analysed for powdery mildew resistance. Using functional molecular markers, two alleles of the major resistance gene Pm3 were detected among the cultivars under the study. One of the alleles, Pm3d, was detected in the resistant cultivars 'Vinjett', 'SW Estrad', and 'Zebra', and in 'Tjalve', a cultivar of earlier release susceptible to the local population of powdery mildew. The second allele of Pm3 detected in the analysed group of cultivars was the allele Pm3f, rarely used in Europe. It was identified in the resistant cultivars 'Satu', 'Helle', and in the moderatively resistant cultivar 'Mahti'. Pm3f was found to be effective against the local population of powdery mildew in Estonia, while Pm3d provided no protective effect. Besides the Pm3d allele on chromosome 1A, monosomic analysis of the cultivar 'Vinjett',which is almost immune to powdery mildew, identified two additional loci on chromosomes 5D and 7D, respectively, presumably responsible for the high resistance in this cultivar. In contrast to the earlier cultivars, six recently released cultivars ('Vinjett', 'SW Estrad', 'Zebra', 'Satu', 'Helle', 'Meri') demonstrated a high resistance to the powdery mildew fungus Blumeria graminis DC. f. sp. tritici both in the field and seedling tests, showing that the genetic basis of powdery mildew resistance in Nordic spring wheat has been improved noticeably in the last ten years. [ABSTRACT FROM AUTHOR]

Waterlogging is an important factor influencing yield and yield components in wheat. The objective of this study was to evaluate the effect of waterlogging on yield, yield components, protein and proline content, and chlorophyll a and b in wheat. In the study, seven levels of waterlogging treatment, 0, 5, 10, 15, 20, 25 and 60 days of flooding were applied. Increasing waterlogging stress decreased yield, spike number per m2, seed weight and number per spike, protein content, and chlorophyll a and b; and caused increase in proline content. Results indicated significant linear responses for yield, spike number per m2, seed weight and number per spike, protein content, chlorophyll a and b. [ABSTRACT FROM AUTHOR]

The Random Amplified Polymorphic DNA (RAPD) technique was used to study the genetic diversity and relationships within the collection of the National Plant Genetics Resources of Wheat. A total of 413 fragments were amplified with 40 random decamer primers 46.97% of which were polymorphism. The aim of the work was to elaborate a dendrogram of genetic similarity between salt tolerant and salt sensitive and to divide collection into clusters. Forty primers were applied to 16 wheat cultivars different in the place of origin and 194 polymorphism bands were generated for each cultivar. The RAPD variation observed among these cultivars was low. The wheat genotypes were clustered in to one major group (B) and two small groups (A and C). The most salt sensitive distant genotypes in to the dendrogram were SW-20, which was genetically dissimilar with the other genotypes. It has been clearly shown that most of the cultivars except SW-20 possessed narrow genetic background. The information would be useful for future genome mapping programme as well as for the application of intellectual breeder right in the worldwide. [ABSTRACT FROM AUTHOR]

In some parts of the world, the soil selenium (Se) content is too low to ensure the Se level recommended for human or animal consumption in the crops produced. In order to secure a desired concentration of Se in crops, Se has been applied as mineral fertilizer to agricultural fields. Since only a minor part of the inorganic Se applied is utilized by plants and small increases in Se concentrations in, e.g., drinking water, may be toxic, the method is somewhat controversial. As an alternative to Se-enriched mineral fertilizer, different seafood-processing wastes have been examined as a source for Se in crop production. Both in greenhouse pot experiments and field trials the Se in seafood waste was not plant-available during the first growing season. There was no significant difference between the Se concentration in wheat growing in soil without added Se and in soil receiving Se from seafood waste in amounts ranging from 0.9 to 9 g ha-1. Neither was any residual effect of Se in seafood waste seen during a second year growth period. Thus, seafood-processing waste cannot be regarded as a potential source of Se in crop production. Possible mobilization of formerly applied Se, as seafood-processing waste or Se enriched mineral fertilizer due to changes in soil redox conditions were examined in a leaching experiment. The mobility of formerly applied Se was generally very low, but the results indicated that under permanently wet soil conditions leaching of Se may occur in plant dormant periods in soils with low organic matter content and high pH. [ABSTRACT FROM AUTHOR]

The formation of yield in two different combinations: vetch with wheat or oats, and the effect of vetch on yield potential of cereals has been investigated in Estonian field experiments over three years. We found that the inclusion of vetch seed in cereal seed and increase of its seed density led to considerable decrease in the yield of the cereal component (R=0.980-0.998). The adverse effect of vetch on cereal yield led to a reduction in wheat yield by up to 1861 kg ha-1 on average for the three years, and in oats yield by up to 1413 kg ha-1. One reason for the decreases in cereal yields was the formation of smaller grains in cereals under increased vetch seed densities. As a three-year average, the wheat 1000-seed weight decreased by up to 6.3 g while the corresponding figure for oats under identical conditions was 2.5 g. The inclusion of vetch in a crop and the increase of its seed density led to a substantial increase in the protein content of cereal grains. In oats, the change in grain protein content was smaller. At the same time, the maximum protein yield per area unit in cereals was obtained from their monocultures. In a mix with vetch, the amounts of nitrogen consumed by cereals decreased and protein yield of cereals per area unit reduced at higher vetch seed densities. Vetch-cereal mixes had an advantage over cereal monocultures as far as protein yield was concerned. In vetch-wheat and vetch-oats mixes the maximum protein yield was 500 kg ha-1 and 438 kg ha-1, respectively, on average for the three years. Of the two combinations, vetch-oats mixed crop gave the highest yield of grain, whereas the higher mixed crop yield resulted from the oats component. Oats is somewhat more competitive with vetch than wheat. Vetch-wheat mixed crop gave the highest protein yield because the protein content of wheat grains was higher than oat grains. Legume-cereal mixes are particularly suited for the conditions of organic farming as they ensure a relatively good harvest and a high protein yield. [ABSTRACT FROM AUTHOR]

The objective of this study was to utilise existing databases for evaluating effects of soil and management factors on the yields of barley and wheat in Norway. In a multiple regression model, 17% and 19% of the variation of barley and wheat yield, respectively, was explained by 15 significant predictors. The highest-ranking predictors for barley yield were percent area of wheat (indicating more favourable climatic condition), irrigation, pH and silt. Other significant predictors were agricultural education, CV pH, man-hours on farm, (pH) 2 , loam, ln P-AL, ln area of farm, number of fields, (ln P-AL) 2 , (ln area) 2 and percent grass area. For wheat yield, the highest-ranking predictors were irrigation, percent winter wheat, pH and ln area of farm. Other significant predictors were CV pH, ln P-AL, (pH) 2 , loam, number of fields, (ln P-AL) 2 , man-hours per ha, percent grass area, agricultural education, other grain and (ln area) 2 . [ABSTRACT FROM AUTHOR]

Field experiments were carried out on three representative soils, to evaluate the effect of various starter fertilizers, together with different rates of band placed phosphorus (P), on nutrient uptake and yield of spring barley ( Hordeum vulgare L.) and spring wheat ( Triticum aestivum L.). The starter fertilizers were placed in the immediate vicinity of the seed, while the band placed P was placed at about 5 cm below the seeds and spaced at 25 cm between alternate seed rows. As starter fertilizer, monoammonium phosphate (MAP), calcium nitrate (CAN), ammonium nitrate (AN) and triple superphosphate (P20) were compared. In both species, effects of starter fertilizer on P uptake were most marked early in the growing season. At GS 13 application of 20 kg P ha -1 as MAP increased the P uptake by 50% in barley and by 35% in wheat, compared to no seed-placed nutrients. For grain, the increase in P content was 8% for both species. The higher P uptake at GS 13 was supported by observations of higher plant vigour in the treatments with either P20 or MAP as starter fertilizer. The use of N only as starter fertilizer did not increase the vigour of the plants. Band placement of P also gave more vigorous plants in spring barley. The grain yield increased on the silty clay loam and on the silt soil when starter fertilizer was applied, especially with the use of MAP. Smaller and non-significant yield differences were found when starter fertilizer was used on the loam soil. No delay or reduction of emergence was observed with starter fertilizer. Therefore, on soils where root growth or nutrient uptake becomes limited during the first weeks after sowing, application of starter fertilizer is recommended in Norway for both spring barley and spring wheat. Crops grown on silty soils seem to have an especially high demand for easily available P given as starter fertilizer. [ABSTRACT FROM AUTHOR]