EJPAU, 2004, Volume 7, Issue 2
Agronomy

There were tested water extracts from selected Geraniaceae plants. It was observed that the plant extracts investigated inhibit feeding and development of Colorado potato beetle. The greatest antifeedant activity towards Colorado potato beetles and their larvae was noted for Pelargonium x hortorum Bailey and Geranium sanquineum L. extracts. The Pelargonium x hortorum Bailey extract added to food showed unfavourable effect on the development of female reproductive organs and significantly inhibited the number of eggs laid, however it showed effective neither towards the period of winter diapause nor towards spring emergence of beetles. The highest effectiveness under field conditions was recorded for extract from Erodium cicutarium L.

The authors calculated the total sum of microelements in plants and determined the percentage share of specific elements in this sum according to the ANE method. Then, both the changes of the microelements share in the sum and the changes of absolute microelement concentrations in plant tissues depending on soil pH were investigated. The sample collections of four plant species from the Silesia region, Poland, constituted the research material (156 samples in total). It was found that, in general, the Mn share in the sum decreased and the Fe share increased with increasing pH level. Moreover, the change of micronutrient weight-concentrations in plant tissues, which was caused by the pH changes, did not correspond with the change of the micronutrient relationship in the total sum. This result suggests that the assessment of micronutrient status in plants is not a reliable enough method when basing solely on the absolute weight-concentration in plant tissues.

The aim of the study was to determine the effect of Reglone Turbo 200 SL (diquat) as a desiccant applied to ‘Sonet’ narrow-leaved lupin on protein, amino acid, soluble carbohydrates and hemicellulose content in seeds. Reglone Turbo 200 SL was used at the dose of 2.0 lˇha^-1 on day 35 after lupin flowering. The diverse weather conditions significantly influenced the accumulation of some amino acids (threonine, proline, cysteine, glycine, tyrosine, leucine, histidine and lysine), content of soluble sugars and hemicellulose in the seeds tested. The desiccant applied to plants resulted in drought effect and hence an increase in soluble sugars content, particularly cyclitols (D-pinitol, D-chiro-inositol, myo-inositol). A similar effect was observed for hemicellulose. The desiccant applied did not modify the profile, content of amino acids and protein in the seeds tested.

The aim of the present work was to determine the variability and genetic determination of β-glucan content in the wort of spring barley as well as other significant traits, such as: yield, 1000 kernel weight, earliness, plant height and resistance to lodging and powdery mildew. Also the phenotype correlations between the analysed traits were examined. The objects of the investigation were spring barley strains of F₆ – F₇ generation evaluated in 2000-2002 in three locations. With the exception of 1000 kernel weight, genotypes were differentiated in relation to all the traits investigated. Nearing and high values CV(p) and CV(g) suggest that the variability of the barley examined forms with regard to this trait results from both genetic and environmental determinations. The barley strains examined could be a starting point for the cultivation of spring barley oriented both at decreased and increased β-glucan content while a high coefficient o

Over 2001-2003 there was researched an effect of various tillage methods on the reduction of weed infestation of a long-term fallow. The number of germinating weeds was analysed; the weeds had been obtained from a few-time-mixed soil samples collected from the top soil layers under the conditions of direct sowing, traditional ploughing, multistage ploughing and ploughing with a skim coulter. The results were compared with the abundance of weeds per 1 m² under field conditions. The log-linear analysis showed a considerable effect of weather conditions (years) on the abundance of germinating weeds in 0-5, 5-10, 10-15, 15-20, 20-25 cm layers. Multistage ploughing and ploughing with a skim coulter significantly decreased the number of germinating weeds in the top soil layers, as compared with the traditional plough and direct sowing. After two years of varied tillage methods considerably lower weed abundance was recorded for all the tillage variants, as compared with the results obta

The aim of the present research was to evaluate the yielding of perennial ryegrass (Lolium perenne L.), 'Stadion' lawn cultivar grown for seed, depending on the sowing method, date and row spacing. The research was carried out at the Experiment Station for Cultivar Testing at Chrzšstowo, in the vicinity of Bydgoszcz. The experiment was carried out over 1998-2002 in three series; each of them included the sowing year and two years of full use for farming purposes. The experimental factors included: I - sowing method/date: autumn pure stand, spring pure stand, undersown perennial ryegrass in spring barley cultivated for green matter and undersown perennial ryegrass in spring barley grown for grain, II - row spacing: 12 cm - narrow, 24 cm - average wide, 36 cm - wide and 48 cm - very wide. In the first year of full use for farming purposes, the seed yields were lowest when ryegrass was sown in autumn. Furthermore the yield of perennial ryegrass sown in spring in pure stand was significantly lower than that of undersown perennial ryegrass in barley in both its growing variants. The seed yield in the second year was significantly higher for sowing together with a cover crop, as compared with the yields obtained for autumn sowing. The application of varied row spacing showed a significant effect on the seed yield neither in the first nor in the second year of full use for farming purposes.