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Highlights • FTIR spectroscopy quantified bean and wheat root biomasses in intercrops. • Both species had more shallow roots within own rows in intercrops than in sole stands. • In intercrops both species had more roots in deeper soil within partners than own row. • Bean genotypes differed in vertical root distribution within wheat rows in intercrops. • Two bean genotypes were identified for an improved bean-wheat intercropping system. Abstract The spatial root distribution of plant species is generally altered by intra- and interspecific competition. The assessment of species specific root distribution in intercrops was limited so far because of the difficulties to identify roots on a species level. We investigated horizontal and vertical root distribution of eight winter faba bean genotypes (Vicia faba L.) and one winter wheat cultivar (Triticum aestivum L.) grown in sole stands and in 50/50 substitutive row intercrops. Root samples were taken within and between rows with a root auger down to 60 cm soil depth in May 2015 and May 2016 at a field site in central Germany. We used Fourier transform infrared (FTIR) spectroscopy for root species identification. Vertical root distribution was described by the equation y = 1 - βd according to Gale and Grigal (1987). Horizontal root distribution did not differ between bean and wheat and between sole stands and intercrops averaged across the eight bean genotypes: Bean and wheat root biomass was on average 65% lower between rows than within rows in sole stands and in intercrops. Both species proliferated into the soil space between the rows and into the intercropping partner's row to a similar extent. Bean developed 36% of its root biomass in 0–10 cm soil depth, while wheat had 51%. Bean and wheat had shallower roots within their own row in intercrops (β bean = 0.933; β wheat = 0.858) compared to their own row in sole stands (β bean = 0.945; β wheat = 0.902). In the intercrops both species occupied deeper soil layers within their partner's row (β bean = 0.947; β wheat = 0.960) compared to their own row (β bean = 0.933; β wheat = 0.858). This change in vertical root distribution was more pronounced for wheat than for bean. Bean genotypes grown in sole stands did not differ in their horizontal and vertical root distribution. However, there were significant differences between bean genotypes within wheat rows in the intercrops: bean genotype Vf6 had the largest horizontal spread but the most shallow root growth within the wheat row, while Vf5 showed the lowest horizontal spread and the highest root fractions in deep soil layers within the wheat row. The alteration of the vertical root distribution of both species in intercrops, compared to the sole crops, could lead to a better resource utilization and an intercrop advantage. [ABSTRACT FROM AUTHOR]

The spatial pattern of Fusarium-infected kernels and their mycotoxin contamination was studied in four wheat fields in Germany using geo-referenced sampling grids (12–15 × 20–30 m, 28–30 samples per field) at harvest. For each sample, frequency of Fusarium-infected kernels and spectrum of species were assessed microbiologically; mycotoxin contents were determined by HPLC-MS/MS analysis. Spatial variability of pathogens and mycotoxins was analysed using various parameters including Spatial Analysis by Distance IndicEs (sadie® ). Microdochium majus, the most frequent head blight pathogen in 1998, was less frequent in 1999 and could not be detected in kernels from two fields in 2004. Fusarium avenaceum, F. graminearum and F. poae were the most frequent Fusarium species, with 7–8 species per field. The frequency of Fusarium-infected kernels was 3–15% and the incidence of species showed considerable within-field variability. Spatial patterns varied among Fusarium species as well as from field to field. Although pathogens and mycotoxin were often distributed randomly in the field, F. avenaceum, F. graminearum, F. poae, F. sporotrichioides, F. tricinctum and the mycotoxin moniliformin had an aggregated pattern in at least one field. Patterns are discussed in relation to spread of Fusarium species depending on inoculum sources, spore type, kind of dispersal, availability of susceptible host tissue and micro-climate. Sampling of wheat fields for representative assessment of mycotoxins is complicated by random patterns of Fusarium-infected kernels, especially where the frequency of infection is small. [ABSTRACT FROM AUTHOR]

The aim of this work was to establish an in vitro regeneration system from anther cultures of different German varieties of spring wheat (Triticum aestivum L.). Using 'Nandu', the most widely grown spring wheat cultivar in Germany. different culture conditions were investigated with regard to their influence on anther culture response. The best results were obtained when applying a cold pretreatment to the donor spikes and using the synthetic L3 induction medium, liquid or solidified with gelrite. The highest rates obtained in these experiments with 'Nandu' were 8.6% responding anthers. 22.3% embryoid induction, 15.3% albino regeneration and 5.5% green plant regeneration (all rates related to the number of cultured anthers). Of the 'Nandu' plants analysed, 51.1% were haploid and 44.3% were diploid, probably as a consequence of spontaneous chromosome doubling. When screening a further 16 commercial German varieties of spring wheat. I0 exhibited good anther culture response and four of these ('Eta', 'Jondolar'. 'Mieka'. and 'Star') proved to be highly responsive. reaching embryoid induction rates between 4.3 and 10.3% and rates of green plant regeneration between 5.4 and 10.7%. [ABSTRACT FROM AUTHOR]

The objective of this study was to compare the yield response of several present day winter wheat cultivars of different origin with the aim of broadening breeders' information from multi-year/location tests by using an appropriate cluster procedure, Yield response of 18 cultivars was analysed using data from two series of official yield performance tests in Germany. Similarity of yield response between two cultivars is defined by a positive correlation coefficient (nearly one) for the yields over all test environments. A hierarchical agglomerative procedure was used to establish clusters of similarly responding cultivars. The smallest distances in yield response were established between closely related cultivars of equal maturity. Clusters of cultivars with distinct maturity and also the groups of East and West German cultivars tested exhibited clear differences in yield response. [ABSTRACT FROM AUTHOR]

The HMW glutenin subunit and gliadin compositions of 57 German-grown varieties of wheat were determined by 1D- and 2D-polyacrylamide gel electrophoresis, respectively. A Glu-I quality score was calculated for each variety based on previously observed associations between individual HMW glutenin subunits and SDS-sedimentation volume. The results indicated that approximately 30 % of the variation in bread-making quality of the varieties was accounted for by variation in the Glu-1 quality score, and that this proportion was raised to 54 % if the presence or absence of chromosome 1BL.1RS was taken into account. It was also shown that allelic variation at tile Gli-1 and Gli-2 loci had a relatively minor effect on quality; indeed, the only significant effect was associated with variation at Gli-B1, and the influence of this locus was principally due to the detrimental effect of 1BL.1RS. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of the substitution of plowing with harrowing-twice in a 3-yr crop rotation-on persistence and distribution of a persistent herbicide such as trifluralin(a,a,a-tri(luoro-1,6-dinitro-N,N-dipropyl-p-toluid ine) to rate these two tillage systems for their environmental impact (e.g., regardingpotential ground water contamination with pesticides). Therefore, studies have been performed in Germany at two sites, a clayey silt in Reinshof and a loamy sand in Eickhorsc The herbicide was applied to oilseed rape (Brassica napus L. var. napes ), followed in consecutive years by applications to wheat (Triticum aestivam L.) or to wheat followed by rye (Secale cereale L.). The disappearance time of 50% of theinitial concentration (DT-50 value) decreased from >300 d after preplant incorporation of trifluralin to < 150 d after pre-emergence treatment, losses being greater due to volatilization resulting from the lack of soil incorporation. No influence of different tillage systemson trifluralin persistence could be observed. Distribution of the herbicide in the top 30 cm of the soils, however, was significantly influenced by the soil cultivation systems. Reduced tillage (harrowing) in two consecutive years resulted in trinuralin concentrations in thesoil layers LO to 20 cm and 20 to 30 cm under the limit of determination (0.005 mg kg-1). In contrast, plowing led to trinuralin residues of up to 0.019 mg kg-1 in these soil layers. Although no trifluralin residues could be found in the 30- to 45-cm and 45- to 60-cm soil layers under either soil cultivation system, our results imply an increased risk of ground water contamination after plowing. [ABSTRACT FROM AUTHOR]