The results of three-year trials (1999 to 2001) conducted with six winter wheat varieties in which was investigated the effect of sites, years and varieties on the final grain yield and technological quality showed statistically significant differences (LSD, 95%) among sites in grain yield and these parameters of quality: test volume mass, wet gluten content, sedimentation test, protein content, falling number and flour water absorption capacity. As to the quality, the Žatec site showed itself as generally most suitable, and the Jaroměřice site as the least suitable one. Climate conditions showed a statistically significant effect (LSD, 95%) on grain yield and all quality parameters, beside the percentage of complete grains and swelling capacity of gluten and falling number, which were insignificant. The most favourable weather conditions, a lot of precipitation and high temperature in the course of ripening from three years were proved in the year 2000. Among the varieties were statistically significant differences (LSD, 95%) in grain yield and these parameters of quality: test volume mass, thousand grain weight, ash content, percentage of complete grains, sedimentation test, protein content, reologic properties of dough and baking tests. From the six varieties the best profits were shown from variety Sulamit (loaf volume 595 ml/100 g of flour), the worst was Semper (loaf volume 543 ml/100 g of flour) and Vlasta (loaf volume 532 ml/100 g of flour). The best grain yield was in 2001 (average of sites 8.84 t/ha) and the variety Semper had the highest grain yield of 9.17 t/ha, that is higher at 13.41% compared with Sulamit (7.94 t/ha).

In the work were presented the effects of differentiated fertilization on yields of winter wheat cultivated in short term monoculture. The field experiment was carried out on Albic Luvisols developed on loamy sand in 2000-04. Winter wheat cv. Sakwa grown in short-term monoculture and in seven-course crop rotation (potato-spring barley-alfalfa-alfalfa-spring oilseed rape-winter wheat-winter rye) under eleven levels of fertilization. There was an association between growing-season precipitation and winter wheat yield, the lowest grain yield was in 2003 with 192.8 mm precipitation. Winter wheat grown continuously gave 15.3 percent lower yields than crop rotation

This paper deals with effects of the three- and four-crop rotation on the grain yield compared with winter wheat continuous cropping. In three-crop rotation variant following crops were: maize, soybean and winter wheat. The four-crop rotation encompassed maize, winter wheat, red clover and spring barley + red clover. The winter wheat cultivar Pobeda grown under rainfed conditions on leached chernozem was studied. The analysis of variance of the winter wheat yield showed significant differences among years of investigation. The highest yield of winter wheat (4.53 t/ha) was obtained in 2001, while the lowest one (3.05 t/ha) was recorded in dry 2003. Grain yield of winter wheat in continuous cropping (3.70 t/ha) was statistically very significantly lower than yield in the three- (4.11 t/ha) and four-crop rotation (4.07 t/ha), while difference in grain yield between the three- and the four-crop rotation variants was no statistically significant.

The weed infestation was assessed in a field experiment at the Research Institute for Folder Crops Ltd., Troubsko near Brno in 2001−2004. Numbers of individual weed species were determined using a counting method on the area of 0.25 m2 in winter wheat stands within the 6-crop rotation (peas, winter wheat, spring barley, oilseed rape, winter wheat, winter wheat) in different variants of soil tillage and straw management. The highest weed infestation in all variants was found when winter wheat followed winter wheat. The highest number of weeds was assessed in the variant with stubble tillage to the depth of 0.12−0.15 m, planting with a precision drill and straw chopping. The lowest number of weeds was found in winter wheat after peas in the variant with incorporation of chopped straw using a tiller to 0.12−0.15 m and planting with a drilling combination, and in the variant where chopped straw was sprayed with the BETA-LIQ preparation, incorporation with a tiller to 0.12−0.15 m and planting with a drilling combination.

The influence of the mode of tillage on the number of winter wheat plants infected with fungi causing culm base diseases was analysed in 1999-02. Three forecrops were used for the tests: winter rape, oats and spring wheat. Seven winter wheat cultivars were sown in treatments under ploughing, simplified tillage and direct sowing. The results of long-linear analysis showed a significant interaction of the modes of tillage and years with the winter wheat cultivars. The lowest number of infected culms was in the treatment after winter rape forecrop, while in that after spring wheat the number of plants with culm base disease was the highest

In organic farming systems without livestock some problems arise concerning the nitrogen management: On the one hand, there is a lack of transportable nitrogen fertilisers, on the other hand there is a potential for high losses with the usual management. The biological N2 fixation is decreased, when clover grass is mulched. If the biomass of intercrops and clover grass gets mineralised in autumn, it can be leached in winter. In the trial referred to here, the impact of fermentation of biomass on some agricultural parameters like yield etc. are investigated within a crop-rotation of clover grass, potatoes, winter wheat, peas, winter wheat and summer wheat with undersown clover grass. Intercrops are sown after winter wheat and peas. In the control variant the coupled products (clover grass, straw and intercrops) are left on the field as mulch. In the biogas system this material is harvested for digesting. The remaining products are used as fertilisers. There are liquid products which were used to fertilise the winter wheat and solid ones, which were used for fertilizing potatoes and summer wheat. This system allows a higher efficiency of the nitrogen management: The yield and the content of raw protein in winter wheat increased. The solid material did not mineralise as fast as necessary. It would be better to add this material to the intercrops.

The main goal of study was to evaluate the effects of soil quality and the type of forecrop on the yield of cereal crops. The species responded more relevantly on the soil than on the stand in crop rotation. Various cereal crops differed with their reaction, the strongest impact was detected for winter wheat and the other species placed in ranking were winter triticale, spring wheat and spring barley. The survey confirmed a great value of oilseed rape and vegetables as a forecrop for the winter wheat, as well as legumes for the spring wheat

Two tillage systems for maize (Zea mays) after soybean (Glycine max), no-till (NT) and conventional till (CT), which consisted of double disking in the spring, were included in the experiment on two sites in Indiana, USA. Each tillage plot had three winter wheat (Triticum aestivum L.) cover crop levels: no cover crop (N), early desiccation (E), 3-4 weeks prior to planting the maize, and regular desiccation (R), within the maize planting week. Due to the mulching effect, both E and R for both tillage systems increased soil moisture, except in the case of spring drought, when E proved dominant. Soil temperature for both tillage systems showed N > E > R order. Young maize plants tended to grow taller and have greater shoot biomass in NT than in CT. Both E and R improved early maize growth. In the case of drought, the E proved significantly better for maize on both tillage treatments, due to the better soil water conservation, therefore the winter wheat cover crop should be desiccated early in given climate conditions.

The incidence of fusarium foot-rot occurrence on the winter wheat cultivars Roma and Sakwa was examined in the years 2001-03. Fungicides were applied on the growing plants during the periods of shooting and heading. The control plots were sprayed with water. The sanitary state of leaf sheaths was evaluated at heading phase (GS 55). The symptoms of fusarium foot-rot were examined at the phase of milky maturity (GS 75) and waxy maturity of grain (GS 87). The study aimed at assessing the average index of infection of the winter wheat stem base caused by the species of Fusarium genus, assessing the vulnerability of the Roma and Sakwa cultivars to these fungi and determining the effectiveness of pesticides in control of fusarium foot-rot. Fusarium foot-rot (Fusarium spp.) of winter wheat dominated on the winter wheat stem base. Most of the examined stems were severely infected. The Roma cultivar was more susceptible to infection by Fusarium fungi than the Sakwa cultivar. The effectiveness of fungicides in controlling fusarium foot-rot on the winter wheat was satisfactory, but largely depended on the cultivar and weather conditions. Mirage 450EC and Sportak Alpha 380EC fungicides were the most effective. The species F. culmorum and F. avenaceum dominated in the fungal populations colonizing the stem base of winter wheat with visible symptoms typical of fusarium foot-rot