Root diseases of lucerne (Medicago sativa L.) play a significant role in reducing the persistence and productivity of stands; however, the potential of using biological control in lucerne crops has not yet been investigated. Our objectives were to determine the effect of biological crop protection on (i) lucerne plant density and root traits development and (ii) lucerne forage yield and nutritive value in a two-year field experiment. The lucerne stand was managed under three treatments of disease control: an untreated control and spraying with either Albit (hydrolysate of microorganisms containing microelements and poly-beta-hydroxy butyric acid) or Polyversum (mycoparasitic Pythium oligandrum) under five-cut utilization. Application of Albit resulted in a negative yield response, associated with a reduction of root branching, and it also reduced crude protein and increased crude fibre and water-soluble carbohydrates in the second cut of the first year of the experiment. Polyversum increased the percentage of infected plants relative to the control in the last year of the experiment. The study highlights that biological control of lucerne under field conditions may not always be beneficial because of the complex interactions between plant, biological preparation, and environment.

The spectra of non-structural phenolics in herbage were used to study genetic affinity in polyploid complex of Dactylis L., next in complex of octoploid brome species, and in red fescue cultivar collection. The diploid (2n = 14) subspecies of Dactylis revealed distinct differences from the tetraploid (2n = 28) ones as a clearly specialized group. In the genus Bromus the affinity bounds of the species inside the section (e.g. Ceratochloa) were not very tight in comparison to those between the species from various sections. Also remarkable differences in affinity bonds among red fescue cultivars were determined. Although the conclusions are only based on the results from one year and two sites, they bring significant information on exploitation of phenolic compounds. They demonstrate that phenolic profiles could be used in chemical taxonomy of grasses also at low taxonomic levels as a useful marker. As they are environmentally not as stable as the markers of primary metabolism, plant material for analyses should be standardized as to growing condition, growth stages of plants etc.

A calibration equation for NIRSystems 6500 instrument was derived at VSTE Jevíèko using the measurement of broad collection of Czech samples of winter rape, allowing sufficiently accurate prediction of content of dry matter (DM), crude protein (XP), crude fat (XL), glucosinolates (GSL), oleic and linoleic acids in an extremely short time. The prediction accuracy was verified on a validation file (n = 60). The coefficients of determinance (R 2 ) were 0.83 for XP, 0.71 for XL, and 0.84 for GSL. The prediction accuracy according to the VSTE equation was compared to the prediction accuracy according to the VDLUFA calibration equation (Kassel, FRG) used in EU near infrared spectroscopy network. It was stated that the former was not distinctly worse. Non-destructive NIR-analysis of the whole seed also allows sowing selected seeds in the year of harvest and thus accelerates the breeding cycle.

Based on NIRS (near infrared reflectance spectroscopy) measurements carried out in a collection of 262 samples of winter oilseed rape with a different content of fatty acids (FA) in oil, calibration equations for the laboratory instrument Foss-NIRSystem 6500 were developed. Calibration was focused on the possibility of screening seed samples of different composition of oleic acid (C18:1), linoleic acid (C18:2) and linolenic acid (C18:3) using NIRS analysis. The reference method was gas chromatography (GC). The content of FA in segregating F₂ generations after crossing between lines with different contents of FA and lines with standard content of FA in oil ranged from 32.3 to 82.0% for C18:1, 10.2–26.8% for C18:2 and 3.3–11.8% for C18:3. The verification of a validation equation in 50 randomly selected samples of F₂ generation in the year 2006 proved high correlation coefficients (r) between NIRS analysis and GC values, r = 0.86 for C18:1, r = 0.82 for C18:2 and r = 0.85 for C18:3. Non-destructive NIRS analysis enables rapid and reliable selection of materials with different composition of FA in the seed of oilseed rape (lines with desirable high content of C18:1 and low content of C18:3).  

No abstract