Two field experiments investigated the applicability of two French breeding lines of winter pea for green crop as winter catch crop and for seeds as the main crop. Over the eight-year research period winter survival of pea plants accounted for an average of 51%, ranging from 0 to 92%. Minimal temperature at the ground determined winter survival most considerably, while the total freezing of plants occurred at -18^oC. Due to poor winter survival, pea grown for green crop was inferior to hairy vetch although the yield potential of both species was similar. Spring development rate and the content of total protein in the aboveground parts of pea and vetch plants were similar. Pea winter losses and a low 1000 seed weight resulted in a relatively low seed yield of 10-12 dt·ha^-1. Winter pea reproduction coefficient ranged from 8 to 12, depending on the breeding line.

The 1999-2000 experiment investigated the field weed infestation, depending on the crop species (spring barley, oat, buckwheat), and weed control methods in spring barley (post-emergence harrowing, Chwastox 540 SL, post-emergence harrowing + Chwastox 540 SL). The weed infestation depended mainly on the weather conditions, and less considerably – on the crop species. Post-emergence harrowing of spring barley during dry weather was slightly more effective than a single herbicide application. A decrease in secondary weed infestation on the plots from which buckwheat was harvested is noteworthy.

Research was conducted over 2000-2002 at the Brody Experimental Station of the Poznań Agricultural University to investigate the effect of long-term organic and mineral fertilization on the yield of spring barley in monoculture. The yield of spring barley grown in monoculture was 24% lower than that in crop rotation. The highest yield was obtained after a combined organic and mineral fertilization. The continuous cropping of spring barley led to an increased weed infestation and stem base diseases infection. Farmyard manure was the main factor which caused changes in chemical properties of soil, including soil reaction, organic C, total N, available P, K and Mg contents.

Preliminary studies were conducted on the effects of various doses of NaCl (salinity levels) added to soil on the growth kinetics of three clones of Salix viminalis L. During vegetation the plants were treated twice with the solution of sodium chloride at the following concentrations: 0 (control); 1; 1.5; 2%. Growth was measured with increases in shoot length and thickness; dry matter was also determined. The growth process was best described with quadratic function. The highest elongation growth dynamics was noted for Bjor clone at 1% salinity level. At the same salinity the greatest stem thickness increase was observed in Jorr and Tora. As far as the dry matter yield was concerned, Jorr was found to be most tolerant to saline stress, while Tora – least tolerant.

The aim of the paper was to determine quantitatively thermal requirements of winter triticale and to define probability of reaching wax maturity within assumed dates. The paper uses the 1982-1996 data on winter tritcale phenology and the 1972-2001 meteorological data from 57 stations of the Institute of Meteorology and Water Management (IMGW). The relation between the length of interphases and the average air temperature at the interphase and also the total hours of absolute sunshine was determined with the linear regression method. The thermal requirements of winter triticale at particular development stages were determined with the totals of effective temperatures. It was found that in Poland winter triticale reaches wax maturity when the totals of the temperatures counted above 3^oC from the moment of stable revival of vegetation amount to 1158^oC. The probability of reaching wax maturity by winter triticale before July 20 varies from below 10% in the north-eastern and north-western Poland to over 70% on the area of Silesian Lowlands. By July 31 triticale reaches wax maturity all across Poland at least every other year and as for the Lowland of Poland – in each 9 out of 10 years.

The present research covers the time of the second rotation: sugar beet-spring wheat-pea-winter triticale (1999-2002). The investigations were conducted on a very good rye complex soil. A reduced tillage for sugar beet and no-tillage for the other crops in crop rotation result in labor, fuel and energy consumption reduction, as compared with conventional tillage by an average of 50% and expenditure by 42%. The highest energy effectiveness in crop rotation was observed in the system in which sugar beet was cultivated in reduced tillage, and other crops in no-tillage. The effectiveness increases by 135% for conventional tillage for all the crops in rotation. The lowest effectiveness is obtained for conventional tillage with intercrop for sugar beet and pea, and conventional tillage for spring wheat and winter triticale.

The field experiment was to evaluate the phytosanitary value of a spring barley and field pea mixture as a forecrop for the cultivation of spring barley. It was shown that, as compared with the other forecrops (potato, field pea and spring barley), the experimental mixture reduced the incidence of barley leaf net blotch (Helminthosporium teres) in barley cultivated the following year, yet it stimulated plant infections by pathogens causing stem base diseases (Fusarium spp. and oth.) and by powdery mildew (Erysiphe graminis). The reduction in barley leaf net blotch (Helminthosporium teres) was most clearly seen in barley cultivated after barley. The field pea reduced infections of the stem base caused mainly by Fusarium spp. From the phytosanitary point of view, the cereal-and-legume mixture was a better forecrop for barley than barley in pure stand.

Pea cultivated in monoculture showed a higher level of root infection, as compared with crop rotation, mainly because of Fusarium oxysporum and F. solani fungi. The plant infection was stronger over flowering than over emergence. The soil fungi F. oxysporum, Trichoderma viride, Phoma ssp. and Cephalosporium asperum proved to be most susceptible to Topogard herbicide. The dose lower than the field one inhibited the mycelium growth significantly. The fungi F. avenaceum, Rhizoctonia solani and Zygorhynchus spp. were least susceptible to the herbicide.

A field experiment was conducted over 1999-2001 into the effect of varied control of rape against pests, diseases and weeds on the seed quality. Crude fat, total protein and glucosinolates contents were determined and the protein and fat yields were calculated. It was found that the absence of any pest control throughout the study period resulted in a decrease in fat content by 1.8-2.8 %, as compared to the protected rape. The other seed components analysed remained unaffected by the plant control applied. The quality of the Polish composite hybrid cultivar, Margo, was better than that of the conventional cultivar, Star, due to a significantly lower content of glucosinolates and a higher protein content.

Over 2000-2002 the effect of herbicides doses reduction on spring barley weed infestation was investigated at the Experiment Station at Mochełek in the vicinity of Bydgoszcz on the lessive soil of good rye complex. The 25-50% Aminopielik Super 464 SL and Chisel 75 WG herbicides doses reduction by 25% and 50% with adjuvants added were enough to control the infestation of spring barley and its yielding similarly to the objects where the doses recommended by the manufacturers of these preparations were applied.

Field and laboratory research were conducted to determine the potential of Mamestra dissimilis Knoch., Lepidoptera: Noctuidae to control mossy sorrel (Rumex confertus Willd.). In the natural sorrel habitat a dynamics of the plant growth and the number of Mamestra dissimilis Knoch larvae occurring on that plant over 50 days were researched. The highest number of M. dissimilis larvae was caught at the end of the first decade of June when the host plant rosette was fully developed. In the laboratory, the weight of consumed food by larvae, and larval body weight were measured at 20^oC. The relations between the weight of the mossy sorrel leaves consumed and L₄ and L₅ larvae body weight gains were significant, (r = 0.97 and r = 0.88, respectively). A very progressive feeding of L₄ larvae was noted, which was defined by first degree equation (r = 0.98). It was calculated that each day over 20 days of feeding L4 larvae consumed about 5.9 mg more leaves than L₅ larvae. For L5 larvae, the relationship was the second degree equation (r = 0.96). An estimated weight of mossy sorrel leaves consumed by M. dissimilis larvae under natural conditions was 159.3 g, which accounted for about 11% loss of the host biomass.

In 1999-2002 a strict field experiment was established in split-block design with control object at the Mochełek Experimental Station of the Faculty of Agriculture, University of Technology and Agriculture. Plants of traditional yellow lupin cultivar ‘Polo’ were sprayed with Topflor 15 SC (15% flurprimidol), which is a pirymidine growth regulator. Two dates of Topflor application, once – at the beginning of plant budding and at the beginning of flowering, twice – at the beginning of plant budding and flowering constituted the first factor. Topflor was applied at three doses – 0.15; 0.30 and 0.45 dm^3.ha^-1, which constituted the second factor. There was observed neither a significant effect of the date nor of the dose of Topflor application on yellow lupin seed yield and structural yield components. Topflor affected neither the plant height nor the straw yield. The seed structure according to their thickness as well as protein content in seeds were affected neither by the date of application nor the dose of Topflor. Only a significant increase in the value of yellow lupin harvest index and seed weight in pods developed on branches were a result of a favorable effect of Topflor.

The experiment was carried out according to additive design to study shoot and root competition between spring triticale and field bean during early stages of plant growth. It was conducted in plastic boxes 76 cm long, 15 cm wide and 15 cm deep, filled with 16 kg of aerial dry alluvial sandy loam soil, containing 15-20% of silt. The soil was classified as good rye agricultural suitability complex. Appropriate arrangement of boxes and aboveground aluminium foil partitions allowed separating four competition treatments: no competition, shoot, root and shoot +  root competition. The results of the experiment showed that at the beginning of species interaction in triticale-field bean intercrop system, root competition is more intense than shoot competition. Triticale outcompeted field bean when crops interacted with their roots, but when only shoots competed, field bean tended to be the dominant species. The study presented did not show definitely that cereal is better competitor than legume during early stages of plant growth.

The research material was made up of ‘Wanad’ spring triticale grains obtained from the experiments carried out from 1999 to 2001 at the Zawady Experimental Station of the Podlasie University in Siedlce. The aim of the present research was to define the effect of the sowing density (500 and 750 grains per square meter) and herbicides (Arelon 75 WP and Puma Super 069) on the amino acids composition and biological value of the protein (CS and EAAI). The content of exogenous and endogenous amino acids in the triticale grains and the biological value of protein (CS and EAAI) were higher for the sowing density of 750 rather than 500 grains per square meter. The herbicides applied did not show a significant effect on the content of amino acids in spring triticale kernels. The increased precipitation in 2000 enhanced the accumulation of amino acids in triticale grains.

The 1996-2003 field trial on Kwidzyń Lowland heavy alluvial soil (complex of agricultural suitability 8 and class 3b, according to the Polish Soil Sciences Society) aimed at defining the productivity of six willow clones planted from 20,000 to 60,000 plants·ha^-1 and harvested in annual cutting cycles. The yield of one-year old stems ranged from 12.51 to 21.52 t of dry matter ·ha^-1·year^-1. The highest yield of dry matter of wood was recorded for Salix viminalis 082, 19.77 t·ha^-1·year^-1 on average. Increasing planting density from 20,000 to 40,000 plants·ha^-1 resulted in a significant increase in dry matter of wood. A further increase in planting density up to 60,000 plants·ha^-1 resulted in a slight yield increase trend only. The water content in one-year willow stems over harvest ranged from 50.4 to 53.1%.

A three-year field experiment (2001-2003) evaluated the influence of different field pea cultivation intensity on the protein content and yields in pea seeds and involved low-, medium- and high-expenditure cultivation technologies. Four pea cultivars were investigated: two edible cultivars: Rola and Agra, and two fodder cultivars: Sokolik and Wiato. Although the highest protein content and yield in seeds was observed in all the pea cultivars cultivated with high-intensity technology, the effect of the technology was significantly lower as a considerably greater variation in the protein content and yield was due to variability in weather conditions over the years.

The aim of the present research was to define the accumulation of fertilization macroelements in the biomass of non-papilionaceous plants grown in stubble intercrop. The field experiments were carried out over 1996-1998 at the Research Station of the Faculty of Agriculture at Mochełek in the vicinity of Bydgoszcz, on a very good rye complex soil. The research covered five non-papilionaceous plant species: white mustard, radish, winter rape, sunflower and tansy phacelia, grown in stubble intercrop after winter wheat. Three plant fertilization variants were used: cattle slurry, wheaten straw with mineral fertilizers added and mineral fertilizers exclusively. The research showed a high potential of non-papilionaceous plants to accumulate macroelements unused by plants cultivated as a forecrop. All the plants accumulated much more nitrogen and potassium in its biomass than the amount of their intake in a form of fertilizers. The substantial part of the matter of the nutrient uptake was accumulated in the overground biomass of plants cultivated in stubble intercrop. The greatest macroelements accumulation potential was recorded for radish.