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The aim of the investigations was to determine the effect of farmyard manure or aftercrops organic fertilization and of methods of haulm destroying on plant health, yielding and tuber structure in two potato varieties. The three-factor split-plot experiments were carried out in 2000–2002 at the Plant Experimental Station in Pawłowice near Wrocław. Virus infection of potato plants increased in the successive years of reproduction. This resulted both from genetic traits of potato varieties and weather conditions that were favourable for aphid incursion onto crops. In the third year of reproduction (2002) the proportion of plants infected with viruses (PVY, PLRV and PVM) ranged from 60.6% when haulm was destroyed by chemical treatment up to 72% when haulm withered naturally. Earlier destroying of potato haulm mechanically or with Reglone reduced the incidence of infection. Genetic traits of the investigated varieties had a considerable effect on the total tuber yield, commercial tuber yield and seed potato yield as well as on percentage share of the latter two yields in the total yield. In contrast, neither earlier destroying of haulm nor a type of organic fertilization did affect tuber yield or its structure, although earlier haulm destroying resulted in the tendency to lower the total yield, and to increase the seed potato yield. Variety Balbina compared to var. Mila was characterized by considerably higher total tuber yield and commercial tuber yield, and by the greater share of the latter in the total yield. Moreover, it produced tubers of the greater average weight. In turn, the yield of seed potato produced by var. Mila, and its share in the total yield, exceeded those obtained with var. Balbina.

In the years 1997–2002 the field experiments were carried out under light soil conditions to determine nitrogen doses and their efficiency in growing of 38 potato cultivars. In these experiments 5 levels of nitrogen fertilization were applied: 0, 50, 100, 150 and 200 kg×ha-1 N, at the constant levels of phosphorus 120 kg×ha-1 P2O5 and potassium 180 kg×ha-1 K2O. For all the cultivars maximum biological nitrogen doses and recommended doses as well as their efficiency were established. The cultivars were divided into three groups, representing low, medium and high requirement for nitrogen. The established maximum biological nitrogen doses were as follows: 112 to 138 kg×ha-1, 148 to 176 kg×ha-1 and 179 to 198 kg×ha-1, respectively. The recommended N doses were lower by approx. 30–40 kg×ha-1. The maximum biological dose effected 47 to 116 kg of tubers. This yield was lower by about 10–15 kg of tubers per 1 kg of nitrogen as compared to that obtained following application of the recommended dose. Some cultivars characterized by the low requirement for nitrogen exhibited higher efficiency than cultivars of medium and high requirements.

The study was based on the results of investigations performed at the Research and Didactic Crop Irrigation Station in Samotwor near Wrocław, and on meteorological data from the neighbouring station Wrocław-Strachowice from 1974–2001. The soil of the experimental plot was light loam belonging to good rye complex (5). The experiments were performed using the method of random sub-blocks as a related system. The variables were: variety, level of nitrogen fertilisation and sprinkling irrigation. In total, 49 varieties were investigated (15 — early, 12 — medium early, 13 — medium late and 9 — late). Based on regression analysis of yielding as dependent on atmospheric precipitation in the period May-July, it was found that the highest yields of medium-late varieties can be expected in the years with 240–270 mm precipitation. With rainfall above that amount the yield of most of the varieties studied was decisively lower. Moreover, increased precipitation from May to July significantly lowered the content of starch in potato tubers. Irrigation of potatoes caused a significant increase in the yield of all the groups studied as follows: early variety by 14%, medium early by 11%, medium late by 23%, and late by 11%. Irrigation had no significant effect on starch content of the tubers in all the groups. The highest tuber yields of early varieties were obtained when the plants were fertilized with nitrogen at 80–120 kg/ha, and of the remaining varieties at 120–160 kg/ha. When the level of nitrogen fertilization increased, the starch content of tubers diminished in all the varieties.

The aim of the work was to determine the effect of sprinkling irrigation and differentiated mineral fertilisation on quantity and structure of potato tuber yielding. The object of the study was var. Karlena, which is good for consumption but especially for production of chips. The experiment was conducted in the years 1999–2001, at the Agro-Science Station in SamotwĂłr that belongs to the Agricultural University of Wrocław. The trials were performed on brown soil representing good rye complex. The soil was characterised by acidic reaction (pH 5.1–5.3), medium content of available phosphorus and magnesium, and high potassium content. The weather course in successive years of the investigation was not favourable for irrigation because, aside from dry periods, an excess of rainfalls was registered in several decades. In the 3-year the average increase in yielding due to irrigation was 19%, and it varied from 16% in 2000 to 29% in the dry year 1999. The applied doses of mineral fertilisation (233 and 280 kg/ha) caused an increase in tuber yield compared to control. The increase reached 43 to 58%, depending on the fertilisation technique. The average yields in the treatments fertilized in a row-like manner were by 1.1 t/ha higher than those obtained using traditional fertilisation (broadcast over the entire area). The agro-technical treatments used in the study resulted in similar tendencies in changes of commercial yields, the range of the changes due to irrigation being higher, and that of fertilisation smaller, than in the case of general yield. Sprinkling irrigation favourably affected both the yield structure, increasing the share of large tubers, and the number and mass of tubers from one plant.

The aim of the field trials carried out at the Plant Breeding and Acclimatization Institute in Bonin in the years 2000–2002 was to assess influence of nitrogen fertilization on tuber yield, its quality and storage stability. The highest marketable yield was obtained with varieties Wawrzyn (53.5 t×ha-1) and Wolfram (43.2 t×ha-1), and the lowest one with var. Wiking (36.8 t×ha-1). All tested potato varieties exhibited high nitrogen requirements. The optimum dose was 150 kg N×ha-1, and the fertilization efficiency fluctuated between 68 kg and 135 kg of tubers per 1 kg of nitrogen. Increase of nitrogen fertilization reduced both the development of late blight on potato foliage and incidence of common scab and rust internal spots. Higher N doses resulted in the increase of content of nitrates in tubers, particularly in varieties Wiking and Wolfram, but had not significant effects on tuber losses during storage.

Yielding of potato cultivars after applying different methods of protection against weed infestation was evaluated in a three-year field experiment conducted in the years 1995–1997. The highest effectiveness of weed control was obtained by application of Sencor 70 WP at a dose of 0.5 kg×ha-1 before potato emergence and Titus 25 DF at 50 g×ha-1 with adjuvant Atpol after plants emergence. Mechanical-chemical control compared to mechanical treatment alone resulted in a higher yield of trade fraction of tubers by 23.8–82.5 dt×ha-1, and of seed fraction by 16.5–68.2 dt×ha-1. A significant effect of potato cultivars and weather conditions during the vegetation periods on the yields of tubers was observed.

The field experiments were conducted in the years 1999–2001 to compare seven methods of weed control in potato crops. Herbicides and their mixtures applied in the experiment caused lowering of the content of air-dry matter of weeds, and increase of a trade fraction of potato tubers by 3.3 to 12.5 tons per hectare, as compared with the yield of potatoes only subjected to mechanical control of weeds.

The aim of this paper was to identify weed species occurring in potatoes in Poland in the years 1995–2002, evaluate control methods and describe herbicides that are most frequently applied. Dicotyledonous weeds were found to predominate in potato fields. Among them, fat-hen (Chenopodium album) and field pansy (Viola arvensis) were in prevalence. Weeds are controlled mainly by mechanical and mechanical-chemical methods. Herbicides are essentially applied in the pre-emergence period. Herbicides containing linuron and metribuzin are most frequently used.

The aim of the experiments was determination of sensitivity of potato cultivars registered in the years 1995–2002 to metribuzine applied after emergence in a dose of 350 g biological active substance (0.5 kg/ha) of the herbicide Sencor 70WG. The cultivars were tested in a 2–3 year cycle. The sensitivity of cultivars was determined according to the EWRC (European Weed Research Council). On the basis of cultivars’ reaction expressed in the 9 degrees scale, the cultivars were classified into 4 groups. The influence of vegetation conditions on sensitivity of cultivars and decrease of tuber yield caused by damages of potato plants were assessed.

The susceptibility level of Colorado potato beetle (CPB) larvae (Leptinotarsa decemlineata Say) to insecticides most often used in Poland was studied. Bancol 50 WP (a.i. bensultap), Decis 2.5 EC (a.i. deltamethrin), Karate 025 EC, (a.i. λ-cyhalothrin) and Fastac 100 EC (a.i. α-cypermethrin) were tested. In the laboratory tests, the standard dipping method was used as recommended by the Insecticide Resistance Action Committee (IRAC method no. 7). Bioassays of insecticide for resistance monitoring were performed in central, northern and western regions of Poland (Institute of Industrial Organic Chemistry in Warsaw, Plant Breeding and Acclimatization Institute in Bonin and Institute of Plant Protection in Poznań, respectively). The susceptibility level was expressed by percent of mortality. The susceptibility of larvae to pyrethroids was lower in some localities of the central and northern regions, and for bensultap it was locally lower in all the tested districts.

Analysis of storage losses of potato tubers was carried out on samples from field experiment performed in 1998–2000 in Parczew. Two experimental factors were studied: cultivation technology (with protection and without protection against potato late blight) and potato cultivars (Karlena, Jantar, Meduza, Panda and mixture of these cultivars). Tuber samples were taken from the field experiment (6 from each combination) and stored in a clamp during 5 months in the 1998/1999–2000/2001 seasons. The samples were placed in two spots at 1/3 and 1/2 distances from the end of clamp and in 3 layers: at the bottom, in the middle, and at the top of the pile. At the end of experiment, the following elements of storage durability were evaluated: germ weight, natural losses of tuber weight due to transpiration and respiration processes and losses due to fungal and bacterial diseases. Technology of cultivation didn’t reduce tuber losses due to germination, respiration, evaporation and rots. Variety properties determined the storage durability. Jantar and mixture of cultivars were very good for long-term storage, while cv. Karlena, Panda and Meduza were good.

Ventilation dose is the main parameter of a ventilation system in storage of potatoes. Analysis was made of main factors influencing selection of ventilation dose in two types of storage: loose and pallet box. Thermal balance, in which the produced heat is balanced by ventilation system, was calculated. Amount of ventilation dose depends on intensity of respiration of potatoes and on time of work of ventilation. The results indicate that ventilation dose for cultivars with average respiration cultivars in a loose storage should be 78 m3/t×h and 116 m3/t×h in pallet box storage. For cultivars with high intensity of respiration the ventilation dose should be about 20% higher.

Three ventilation systems were compared in loose and pallet box storages of potato. Low ventilation dose in the pile storage (25 m3/t×h) and high ventilation dose in the pallet box (120 m3/t×h) and pile storages were tested. The pallet box storage had a flow-around ventilation system. The following technical parameters were compared: average time of ventilation per day, capacity of ventilation, amount of air flowed through potatoes during the season and energy expenditures. Natural losses of the variety Triada in 3 potato storages were assessed. The highest natural losses were recorded in the pallet box storage (10.1%). In the pile storage, higher natural losses (7.7%) has been were stated at the low ventilation dose.

The aim of the work was to determine the susceptibility of Polish potato varieties included into production in 1983–2002 to mechanical damage of tubers. The tested varieties were classified, according to the 9-degree scale, on the basis of the obtained data (a laboratory grader was used). It was stated that the susceptibility of potato varieties to mechanical damage of tubers is related to their anatomical and morphological structure as well as chemical composition. Higher susceptibility to mechanical damages caused increase of diseases and storage losses.

Effectiveness of Tecto 450 FW and Fungazil 100 SL in limitation of occurrence of storage diseases was tested in the storage season 1999–2000. The seed dressers were applied on potato tubers a day after harvesting. The results showed that the tested Fungazil 100 SL reduced significantly black scurf and silver scurf during the storage season. Influence of the tested fungicides on inhibition of dry rot and gangrene was not observed.

The aim of the experiment was to determine storability of 25 new potato cultivars. The experiments were carried out in the seasons 1997/1998–2001/2002 at the Department of Potato Storage and Processing in Jadwisin. Potato tubers were always produced at the some location and were stored in a storehouse at 2°, 4°, 6°, 8°C (for table cultivars) and 2°, 4°, 6°C (for starch cultivars) at the relative air humidity above 90%. The following characters of varietal storability were assessed: physiological losses (natural and sprout losses) and infection of tubers with diseases. It was found that the cultivars were significantly differentiated in natural losses and losses caused by diseases. Losses caused by the diseases were dependent mainly on cultivar resistance.

The decreasing number of viruses’ sources and growing spatial isolation between seed plantations, resulting from the decrease of potato cultivation area, are the conducive factors. On the other hand, recent registration of numerous cultivars susceptible to viral diseases and earlier spring migration of some aphid species (the vectors) augment the danger of viral infection at early growth stages.

The influence of two methods of potato cultivation (traditional cultivation — hill planting and bed planting) on tuber infection by potato viruses was compared in the years 2000–2002. Trials were carried out in Bonin near Koszalin on a mid-early cultivar Balbina. Besides the methods of potato cultivation, three  distances of plants spacing in row (21 cm, 27 cm and 36 cm) were studied to diversity number of plants per ha. It was affirmed that there was more PLRV infection at the loose planting. The most profitable densities of planting were 63 thousand plants/ha at hill planting and 74 thousand plants/ha at bed planting. However, the investigated methods of potato cultivation and number of plants per ha have no clear influence on PVY and PVM infection like in the case of a potato leafroll virus (PLRV).

The elaboration concerns the problem of starch potato cultivars breeding in Poland. The attention was paid to some agronomical features (starch content in tubers, starch yield and correlation between starch content and other features), storage durability and quality of starch potato (size of starch grains, chemical composition, darkening of raw tubers flesh and glicoalkaloids content).

Four varieties of potato: Orlik (very early), Sumak (early), Ekra (mid-early, starchy) and Bryza (very late) were used in the experiment. The French fries were prepared from the raw material by the two-stage method. Potato strips were blanched in the following solutions: 0.4% calcium chloride and 0.4% magnesium chloride. The basic chemical composition was determined in potatoes. In French fries, the following parameters were studied: fat content, calcium and magnesium ions content — by the ASA method and the texture by the objective method. It was stated that blanching in the solutions caused a significant decrease of fat content in French fries obtained from the Bryza and Orlik varieties. Blanching of potato strips in the solutions of 0.4% calcium chloride and 0.4% magnesium chloride caused increase of Ca and Mg contents in French fries and improvement of the texture of ready products, particularly of those obtained from potatoes of early varieties. The addition of magnesium salt to blanching solution influenced the texture of French fries to higher degree than the addition of calcium salt.

The effectiveness of the chemical control of black scurf (Rhizoctonia solani) development on the potato plants and tubers was estimated in field trials. Potato seed tubers were dressed with the chemicals: Vitavax 200 FS and Monceren 250 FS 2–3 days before planting. After harvest, 10 kg samples of tubers (from each plot) were washed and visually assessed for black scurf and crop fractions. The results showed that all the tested chemicals were efficient in the black scurf control in the years 1999–2002 (statistically significant). The use of dressing caused yield increase of large tubers from 26.5% to 48.5% for the variety Bryza and from 0.5 to 12.0% for the variety Rywal.

The resistance to viruses of potato cultivars from the Polish National List for 2003 was analyzed. The Polish National List for 2003 contains 117 original potato cultivars: 83 from domestic breeding and 34 from abroad. The mean resistance to PVY of 83 Polish potato cultivars is high (7.5) when compared to that of 34 foreign ones, which are 2.1 grades lower. The level of resistance to PLRV of the Polish and the foreign cultivars is similar. The PVM resistance of the recently registered Polish cultivars is one degree higher in relation to the foreign ones.

Changes in populations of Phytophthora infestans influenced earlier appearance of the disease. The late blight monitoring system enables evaluation of reliability of the forecast part in the decision systems of potato protection against late blight and, at the same time, serves as a safeguard for practice if a new, earlier infection source appears. The first step in building of Polish late blight monitoring system, approachable in Internet, was observation carried out by workers of Plant Protection Inspectorate in Lublin voivodship as a part of Polish-Danish research project “Development of an Internet based DSS for Cereal Diseases and Potato Late Blight in Poland, 2001–2002”. The results show that it was possible to find early infections as primary attacks (spots on leaves). In most cases the attacks were initially found on susceptible varieties (74%). The growth stage at first attacks was higher than 37 (BBCH), indicating that very early attacks caused by oospores from the soil was not a widespread problem in the Lublin voivodship.

Assessment of the incidence of main fungal and bacterial diseases (late blight, early blight, black leg, soft rot and common scab) at potato crops was based on questionnaire data in cooperation of Plant Breeding and Acclimatization Institute in Radzików Department of Potato Protection and Seed Science in Bonin with Plant Health and Seed Inspection Service. Evaluation of occurrence date and frequency (% of plant infection) of the most important pathogens was based on weekly observations performed on potato crops (100 plants × 4 replications), which started just after plant emergence. Dates of first symptoms appearance and rate of disease development were recorded for early blight and late blight. Natural infections of potato tuber with soft rot and common scab were assessed on tuber samples (4 × 100 tubers) after harvesting. There were significant differences in the incidence of black leg and soft rot among voivodships and years of observations. Such differences of the incidence of early and late blight and common scab were not noted.

The aim of studies, carried out in 2001–2002, was determination of usefulness of the biopreparation Polyversum in protection of potato haulm against Phytophthora infestans (Mont.) de Bary. Before planting, tubers of six potato varieties were dressed with the biopreparation. The observations have been carried out since the time of first late blight symptoms. The experiments showed a possibility of Polyversum application in protection of potato plants against Phytophthora infestans.

The studies carried out in the years 2000–2002 comprised a precise field experiment established in Tomaszkowo in the vicinity of Olsztyn. The edible potato cultivars: Bard, Rybitwa and Wawrzyn were fertilized with different doses of nitrogen: 30, 60 and 90 kg×ha-1, respectively. The isolation of fungi from leaves, according to the methodology of Chruściak (1974), and from the haulm, by means of the commonly used phytopathologic method, was conducted in the laboratory to determine potato phyllosphere fungal community. The analysis of the fungal community of potato phyllosphere shows a large count and high species diversity of the fungi. The total number of isolates amounting to 10.429 was isolated from 39 species of fungi and yeast-like fungi. The yeast-like fungi constituted the most numerous group (50.5%). Among pathogenic fungi the most often isolated species were Alternaria alternata (10.9%) and Botrytis cinerea (8.8%), less frequent were fungi of the Fusarium genus (5.7%) and Colletotrichum coccodes (3.1%). Rhizoctonia solani sp. was not common — 48 colonies. Saprophytic fungi were represented by the genera Epicoccum (4.8%), Cladosporium (2.6%), Penicillium (2.4%), and the order Mucorales (5.0%). The results of the studies indicate that potato cultivars, doses of nitrogen fertilization and the time of experiment had a diversifying effect on the qualitative and quantitative composition of fungi colonies inhabiting the potato phyllosphere. The largest number of fungi colonized the Bard cultivar. The analysis of the average values of the period under study showed that the smallest number of colonies was obtained from the potato fertilized with the highest nitrogen dose 90 kg×ha-1. The least number of isolates was noted in the last year of the experiment which was characterized by warm and dry summer. This type of vegetation season facilitated the development of Alternaria alternata and Fusarium, whereas the number of isolates of Botrytis cinerea and Rhizoctonia solani decreased.

Path coefficient analysis based on the results for 25 lines of semi-dwarf winter wheat showed high direct effects of 1000 grain weight, ear density, number of spikelets and number of grains per spikelet on plot grain yield. Significant simple correlation between yield and a number of spikelets per ear and a number of grains per ear was found. An analysis of ear variables can be used as an indicator in a selection program. Increases in grain number were associated with increases in 1000 kernels weight that varied according to severity of dwarfism and varietals background.

Heritability and diallel analysis techniques were used to study the genetic basis of two grain quality parameters: Zeleny sedimentation value and Hagberg falling number. Heritability for sedimentation value was fairly high in 1999 (h2 = 57%) and high in 2000 (h2 = 76%). There was also significant correlation between sedimentation values obtained in 1999 and 2000 (r = 0.44). Heritability estimates for Hagberg falling number were lower (h2 = 49% in 1999 and 44% in 2000) and there was no correlation between values from the two years. Diallel analysis revealed that both characters were determined by partial dominance in 1999 and full dominance in 2000. High values of sedimentation were associated with recessive genes, whereas high Hagberg falling number was governed by dominant genes.

Diallel crosses between eight winter wheat varieties of A, B and C quality group and differing in HMW-GS composition were made. From F1 plants growing in greenhouse, F2 kernels were collected and halves of the kernels were electrophoreses with SDS-PAGE. Segregants homozygotic in all alleles encoding HMW-GS were selected. In cross combinations Zyta × Korweta, Roma × Zyta, Mobela × Begra and Roma × Mobela homozygotic segregants with high quality scores of glutenin subunits (10 and 9 score), exceeding those higher for parental varieties, were selected.

During 5 years, selection was conducted in 20 F4 populations of winter wheat, which were obtained from crosses between 13 lines tolerant to toxic concentration of aluminium and 9 cultivars with high economic value. Selection was conducted according to the classical pedigree breeding method. Single plants were chosen and increased based on their visual scoring in comparison to standard cultivars. During next years, the selected breeding lines were scored in comparative trials. From the 20 initial populations, 7 breeding lines tolerant to toxic concentration of aluminum and with high economic value were selected. These breeding lines were provided to the Gene Bank in Plant Breeding and Acclimatization Institute at RadzikĂłw as sources of tolerance to aluminium.

The aim of this study was to compare wheat F1 hybrids and their parents in terms of main parameters connected with the efficiency of haploid production by wheat × maize crosses. The material for the study covered F1 hybrids and parental genotypes of the following cross combinations: Alidos × Kobra, Alidos × Kris, Alidos × Mikon, Alidos × Elena, Batis × Charger, Batis × Kris, Kornett × Elena, Kornett × Kobra. The experiment was carried out in a complete randomised design with four replications. The number of ovaries, ovaries with embryos and developed haploid plants were observed. The hybrids Alidos × Kobra and Alidos × Kris gave a higher percent of ovaries with embryos than their parents. In Kornett × Kobra and Alidos × Kris a number of haploids per 100 cultured embryos was higher than that in parental genotypes. Our results confirmed influence of genotypes on efficiency of wheat haploidization, and showed the higher effectively of haploid production from F1 hybrids than from parental cultivars.

Trials were conducted in the experimental field of Agricultural University in Poznań in 2000–2001 and 2001–2002. Twenty-two genotypes of winter spelt were compared regarding vegetation period, plant height, number of stems and spikes, yield per spike and plant, resistance to powdery mildew and brown rust infestation. High variability of plant and spike productivity and of other morphological characters was found. The highest yields among tested genotypes were obtained with Waggershauser Hohenh. Weiβer Kolben (no. 22), Oberlaender (no. 2), Spelt inz Drogendijk (no. 4) and HTRI 9631/75 SKL (no. 16). Three genotypes: Spelt. inz Drogendijk (no. 4), Ostro (no. 8) and HTRI 16981/95 SKL (no. 21) expressed high resistance to brown rust and powdery mildew. Variety Waggershauser Hohenh. Weiβer Kolben (no. 22) showed the highest economic value among the tested spelt forms, due to the highest plant and spikes yields as well as high resistance to powdery mildew and brown rust.

The paper analyses the effect of the main agrotechnical measurements, including sowing time, sowing density and nitrogen fertilization, on grain yield, yield components (number of heads per area unit, grain yield per head, grain yield per plant, number of kernels per head, number of kernels per plant, weight of 1000 grains) and stand architecture. It was found that genetically determined yield potential of winter wheat cultivars is very big and can be utilized in agrotechnical practices provided that agrotechnical factors are adequate to cultivars requirements.

Two-factorial experiment was carried out during two growing seasons (2000–2001 and 2001–2002) in a IUNG greenhouse in Puławy. Plastic containers were used with soil from fields where potato or winter wheat were cultivated in monoculture. The following 10 winter wheat varieties: Kaja, Korweta, Kris, Mewa, Mikula, Mobela, Rysa, Soraja, Symfonia, and Zyta were chosen for yield assessment. A significant influence of forecrop on productivity of the analysed varieties was proved. Three groups of varieties were distinguished: 1) strongly reacting to bad forecrop with significant grain yield drops (25–27%) — (Mewa, Mobela, Symfonia); 2) reacting with medium grain yield drops (10–18%) — Mikula, Korweta, Kris, Soraja; 3) with insignificant reaction to cultivation after cereals (grain yield drops only 2–6%) — Kaja, Rysa, Zyta. Smaller 1000 grain weight and lower productive tillering were the main reasons of grain yield reduction, which was confirmed by the correlation coefficients. Cultivation of winter wheat after winter wheat causes lower chlorophyll concentration in leaves (lower SPAD values), which may indicate worse N nutrient status, mainly in the varieties with stronger reaction to bad forecrop.

Field studies were conducted in the years 1999–2001, to compare winter wheat cultivation profitability under different methods of plant protection. Direct surplus per one hectare, per one zloty direct costs, and per direct costs one man-hour were taken as the most important criteria. The intensity of plant protection significantly differentiated wheat yielding. Intensive protection was the most important factor for wheat yielding but the most economical was integrated plant protection system. Under integrated protection method, a little lower yield was obtained when compared with intensive one but the direct costs were also lower.

Susceptibility of winter wheat genotypes to Puccinia graminis infection was tested on experimental plots of the Plant Pathology Department, Warsaw Academy of Agriculture, in the years 2000–2002. The evaluated wheat forms originated from the Polish breeding stations. The first infections of plants were caused by eciospores from barberry bushes and the secondary ones by urediniospores formed on leaves and sheaths of wheat. Provocative conditions during the experiments secured good development of stem rust. Infection degree of comparative combination plants (wheat cv. Gama) reached the highest value. Among the 2771 tested genotypes more than 74% were severely infected by Puccinia graminis. Genotypes free of stem rust symptoms constituted 16% of all tested forms. There was also a high percentage (74%) of very susceptible materials among winter wheat lines in the registration trials. These results show at urgent necessity of taking the stem rust into consideration in breeding work on wheat.

The inheritance of resistance to tan spot in winter wheat cultivar Michigan Amber was investigated in reciprocal crosses with four susceptible cultivars Gama, Olma, Almari and Maltanka. The all hybrids of F1 generation after inoculation by P. tritici-repentis reacted as susceptible parents, and cytoplasmic effect was statistically insignificant. Trait segregation ratio 3:1 susceptible to resistant at F2 generation indicates that the resistance to tan spot in cv. Michigan Amber is determined by one recessive gene.

Grain yield, nitrogen and phosphorus accumulation and utilization efficiency varied considerably among spring wheat cultivars and strains grown in a field experiment. The majority of highest yielding strains had high harvest index (HI), nitrogen and phosphorus harvest index (NHI, PHI), also high amount of accumulated nitrogen in grain. The lines KOC 1477/98, KOC 2361/98, CJ 179/98, RAH 1796 showing high utilization efficiency of nitrogen and phosphorus were characterized also by high values of other tested traits. The HEC 1428/98, KOC 2003/98, KOC 2245/98, KOC 2249/98 and KOC 3845/98 showed high utilization efficiency for both nitrogen and phosphorus. The RAH 2070/98 and KOC 3530/97 had high utilization efficiency of nitrogen, the CJ 396/98, HEC 1957/98 –high utilization efficiency of phosphorus. The strains were characterized by average values of plant and grain dry matter, the same was nitrogen and phosphorus accumulation in grain, accumulation of these elements in plant was average or low. We conclude that there is a possibility of selection of spring wheat lines that integrate high grain yield with high mineral nutrients utilization.

Plants of 39 strains and 3 cultivars of spring wheat were grown hydroponically until shooting phase at low level of mineral elements (0.5 concentrated Hoagland medium solution), in a growth chamber. Dry matter, N and P content of plant organs, number and mass of seminal and adventitious roots, number of spikelets per spike and the main spike development stage were determined. Indices of N and P accumulation and utilization efficiency were calculated. Statistically significant differences between the wheat genotypes have been stated for all the investigated characteristics. A wide variability in dry matter of above ground part and roots, nitrogen and phosphorus contents was found among the wheat strains and cultivars. Nitrogen and phosphorus utilization efficiency showed the lowest coefficients of variability. Basing on analysis of important traits, there is a possibility of selection of spring wheat lines with high efficiency of nitrogen and phosphorus uptake and utilization together with high dry mass of plants and roots. The RAH 1796, KOC 2249/98, KOC 3845/98 examined in water culture experiment and field experiments, showed high values of these traits. The joint results of phytotron and field experiments enabled complex evaluation of wheat strains and selection of breeding material.