Small-plot field experiments were established in the first decade of October at the Plant Breeding Station of Sládkovičovo-Nový dvor with winter wheat (Triticum aestivum L.), variety Astella. There was investigated an effect of topdressing with nitrogen on the yield of winter wheat grain and its quality characteristics in the experiment. Nitrogenous fertilizers were applied at the growth phase of the 6th leaf (Zadoks = 29). Soil of the experimental stand was analysed for inorganic nitrogen content (Nan) down to the depth of 0.6 m of soil profile. Productive nitrogen fertilizing rate was computed to ensure Nan content in soil on the level of 120 and140 kg N/ha, respectively. Three various forms of fertilizers were examined, urea solution, ammonium nitrate with dolomite, and DAM-390. Different weather conditions statistically highly, significantly influenced grain yield in respective experimental years. Topdressing with nitrogen caused a statistically highly significant increase of grain yield in all fertilized variants ranging from +0.35 to +0.82 t/ha according to respective treatments. Average grain yield in unfertilised control variant represented 7.23 t/ha. Nitrogen nutrition showed a positive effect on the main macroelements offtake (N, P, K, Ca, Mg, S) by winter wheat grain in all fertilized variants. Nitrogen fertilizing to the level of 140 kg/ha N in soil positively influenced formation of wet gluten and crude protein with highest increment in variant 5 (solution of urea) representing +12.8 and +10.7%, respectively in comparison to control unfertilised variant as well as to variant 2 (solution of urea and fertilizing on the level of120 kg N/ha) where increments represented +8.8 and 9.7%, respectively. Thousand-kernel weight, volume weight and portion of the first class grain were not markedly influenced by nitrogen fertilizing.

Wheat streak mosaic virus is the most damaging disease in winter wheat in the western Great Plains. The wheat curl mite is the vector of this virus and utilizes volunteer wheat as a “green bridge” to over-summer and re-infest fall planted winter wheat. This study demonstrates the effect of tillage and glyphosate control of volunteer wheat on mite movement and subsequent virus infection. Small mite populations (1 to 2 mites per tiller) caused high infection rates in winter wheat. Both tillage and glyphosate were effective at reducing mite populations on volunteer wheat, but tillage resulted in more rapid reduction of mite populations. If volunteer wheat is to be controlled close to planting time, tillage is the best choice for rapid control of mite populations when warm dry weather conditions exist.

Influence of organic, integrated and conventional systems on NPK and protein concentration in grain of winter wheat and spring barley was the aim of the research. Nitrogen and protein content in grain of winter wheat and spring barley in the organic system was smaller by 10-15 percent than those in conventional and integrated systems. Protein concentration in winter wheat grain from the organic system did not meet the trade standard (minimum 11.5 percent). All systems did not differentiate phosphorus concentration in grain of both cereals. Grain of winter wheat from the organic system contained about 10 percent more potassium than the grain from two other systems

A field research was carried out in the years 1994-99 at a farm Bezek near Chelm, a part of Agricultural University in Lublin. The influence of three tillage methods: conventional, minimum tillage and zero tillage on the air dry weight of roots (from 0-30 cm soil layer) and postharvest residues of winter wheat cultivated in crop rotation horse bean-winter wheat-spring barley was estimated in the field experiment on the rendzina soil. The experimental plot area was 66 square m (to harvest 40 square m). The spring barley cultivar Rudzik drilled in number 5 mln grain per hectare. The stubble and bedding weight after harvest was estimated on every plot in two randomly selected places on 400 square cm area. The root mass was determined after harvest by means of a steel cylinder of 400 square cm down to 30 cm, dividing them into the following layers: 0-10 cm, 10-20 cm, 20-30 cm. The roots were rinsed with running water with about 1 mm diameter mesh sieve, then they were dried and weighed. It was stated that before harvest winter wheat accumulated significantly higher air dry matter of roots in 0-10 cm surface layer on rendzina soil than the deeper layers (10-20 cm and 20-30 cm). In 1995 winter wheat producted bigger root mass as against the others years of investigation. Tillage systems do not differentiate the air-dry mass of roots and stubble and bedding of winter wheat. A tendency to a bigger mass of stubble and bedding of winter wheat was found for conventional tillage and not minimum tillage. Conventional tillage in comparison to minimum tillage increased the mass of winter wheat postharvest residues

A field research was carried out in the years 1994-1999 at a farm Bezek near Chełm, a part of Agricultural University in Lublin. The influence of three tillage methods: conventional, minimum tillage and zero tillage on the air dry weight of roots (from 0–30 cm soil layer) and postharvest residues of winter wheat cultivated in crop rotation horse bean-winter wheat-spring barley was estimated in the field experiment on the rendzina soil. The experimental plot area was 66 m2 (to harvest 40 m2). The spring barley cultivar Rudzik drilled in number 5 mln grain per hectare. The stubble and bedding weight after harvest was estimated on every plot in two randomly selected places on 400 cm2 area. The root mass was determined after harvest by means of a steel cylinder of 400 cm2 down to 30 cm, dividing them into the following layers: 0–10 cm, 10–20 cm, 20–30 cm. The roots were rinsed with running water with about 1 mm diameter mesh sieve, then they were dried and weighed. It was stated that before harvest winter wheat accumulated significantly higher air dry matter of roots in 0–10 cm surface layer on rendzina soil than the deeper layers (10–20 cm and 20–30 cm). In 1995 winter wheat producted bigger root mass as against the others years of investigation. Tillage systems do not differentiate the air-dry mass of roots and stubble and bedding of winter wheat. A tendency to a bigger mass of stubble and bedding of winter wheat was found for conventional tillage and not minimum tillage. Conventional tillage in comparison to minimum tillage increased the mass of winter wheat post harvest residues.

A field research was carried out in the years 1994-1999 at a farm Bezek near Chełm, a part of Agricultural University in Lublin. The influence of three tillage methods: conventional, minimum tillage and zero tillage on the air dry weight of roots (from 0–30 cm soil layer) and postharvest residues of winter wheat cultivated in crop rotation horse bean-winter wheat-spring barley was estimated in the field experiment on the rendzina soil. The experimental plot area was 66 m2 (to harvest 40 m2). The spring barley cultivar Rudzik drilled in number 5 mln grain per hectare. The stubble and bedding weight after harvest was estimated on every plot in two randomly selected places on 400 cm2 area. The root mass was determined after harvest by means of a steel cylinder of 400 cm2 down to 30 cm, dividing them into the following layers: 0–10 cm, 10–20 cm, 20–30 cm. The roots were rinsed with running water with about 1 mm diameter mesh sieve, then they were dried and weighed. It was stated that before harvest winter wheat accumulated significantly higher air dry matter of roots in 0–10 cm surface layer on rendzina soil than the deeper layers (10–20 cm and 20–30 cm). In 1995 winter wheat producted bigger root mass as against the others years of investigation. Tillage systems do not differentiate the air-dry mass of roots and stubble and bedding of winter wheat. A tendency to a bigger mass of stubble and bedding of winter wheat was found for conventional tillage and not minimum tillage. Conventional tillage in comparison to minimum tillage increased the mass of winter wheat post harvest residues.

Two field experiments in southern Australia investigated a farming system of over-cropping wheat (Triticum aestivum L.) into established lucerne (Medicago sativa subsp. L.) varieties of different winter activity ratings. The study was completed at Roseworthy, South Australia, and Katanning, Western Australia, between August 2000 and May 2003 in seasons receiving below average and average rainfall. Comparative lucerne persistence and biomass, wheat biomass, grain yield and protein contents, and soil water contents were measured. Wheat grain yield was reduced by 13–63% by over-cropping lucerne compared with wheat monoculture. Winter-dormant lucerne (winter activity Classes 0.5 and 2) reduced the yield penalty compared with winter-active varieties (Classes 6 and 10) in 2 of the 4 evaluations. The positive response to applying N at sowing in the second year of over-cropping wheat at Katanning was greatest in the most winter-dormant lucerne treatment (winter activity 0.5). Soil water contents were similar under the lucerne/wheat over-cropping and lucerne monoculture treatments irrespective of lucerne winter activity. Deficits of up to 43 mm at Roseworthy and 88 mm at Katanning were measured in the 0–200-cm soil profile at the start of the third summer of the study. The study shows that it can be more efficient in terms of land area to over-crop wheat into lucerne than to grow monocultures on separate parcels of land akin to phase farming. The improved productivity of over-cropping is associated with the separation of growth patterns of winter wheat and summer-active lucerne. This farming system offers great potential for improving sustainability and productivity in southern Australian cropping rotations.

In the years of 1998–2003 a field experiment was performed. The aim of this experiment was to determine the influence of different levels of nitrogen (0, 80, 120, 160 kg ha-1) on the grain yield and the technological parameters quality of two winter wheat cultivars (Begra, Korweta). On the basis of the results it was found out that winter wheat – cultivar Korweta was characterized by a higher grain yield in comparison to cultivar Begra. Begra was characterized by more profitable values of technological parameters (sedimentation ratio, bread volume, falling number and gluten weakening) in relation to cultivar Korweta. After the use of nitrogen in the dose of 120 kg ha-1 average essential increase of grain yield of winter wheat was found. Diverse fertilization with nitrogen, in all practical doses, determined the average protein content in grain in the studied cultivars of winter wheat. Values of the investigated technological parameters of winter wheat cultivars showed height tendencies in all ranges of nitrogen doses. It was shown that the optimum nitrogen doses having influence on the most important quality parameters, i.e. gluten content, sedimentation ratio and bread volume, are as follows: 160 kg N ha-1, 80 kg N ha-1 and 120 kg N ha-1.

In the years of 1998-2003 a field experiment was performed. The aim of this experiment was to determine the influence of different levels of nitrogen (0, 80, 120, 160 kg/ha) on the grain yield and the technological parameters quality of two winter wheat cultivars (Begra, Korweta). On the basis of the results it was found out that winter wheat - cultivar Korweta was characterized by a higher grain yield in comparison to cultivar Begra. Begra was characterized by more profitable values of technological parameters (sedimentation ratio, bread volume, falling number and gluten weakening) in relation to cultivar Korweta. After the use of nitrogen in the dose of 120 kg/ha average essential increase of grain yield of winter wheat was found. Diverse fertilization with nitrogen, in all practical doses, determined the average protein content in grain in the studied cultivars of winter wheat. Values of the investigated technological parameters of winter wheat cultivars showed height tendencies in all ranges of nitrogen doses. It was shown that the optimum nitrogen doses having influence on the most important quality parameters, i.e. gluten content, sedimentation ratio and bread volume, are as follows: 160 kg N/ha, 80 kg N/ha and 120 kg N/ha

A genetic algorithm is used in a decision support system to select the combinations of chemicals and the timing of successive treatments for the optimal control of fungal diseases in winter wheat crops, using a simulation model to predict the performance of different treatments. The search space is large and discrete, making the use of conventional optimisation methods impractical. Furthermore, the user requirements specify that the method must supply lists of near-optimal solutions, which fits with the use of populations of solutions in the genetic algorithm. Substantial improvements in the performance of the algorithm were obtained by tuning the fitness, selection, reproduction and replacement methods for the optimisation of short-term and long-term decisions. These also ensured rapid convergence in the former and prevented premature convergence in the latter.