Fulltext search in archive

It was showed that gums induced by Fusarium oxysporum f.sp. tulipae in tulip bulbs applied to mineral Czapek-Dox Broth with Bacto Agar (CzDA) medium, containing sucrose substantially stimulated abundant growth of mycelium and sporulation of the pathogen. Addition of arabinose, xylose and their mixture, sugars occurring in tulip gum polysaccharide, to CzDA medium caused that mycelium was very sparse and sporulation was only slightly stimulated by arabinose. Mycelium growth on mineral CzDA medium without sucrose, was poor and sparse but addition of gum to the medium caused formation of abundant mycelium and increased sporulation of the pathogen. It is possible that polysaccharide of tulip gum may act mainly as elicitor and partially as substrate in regulation of mycelium growth and sporulation of Fusarium oxysporum f.sp. tulipae.

During trials (1998-2001) in the strawberry's plantation of the cv. Marmolade we monitored the appearance of the most important fungal diseases, their biology and possibilities of integrated control. Monitoring the biology of the determined fungi we established the way of overwintering, appearance of fruiting bodies and discharging of spores as well as beginning of primary infection and first symptoms of the following fungi: Mycosphaerella fragariae, Diplocarpon earliana, Gnomonia comari, Phomopsis obscurans on leaves and Botrytis cinerea on fruits. While checking the efficacy of fungicides, those most effecting to leaf diseases were Folicur Multi and Quadris, and on B. cinerea Switch and Teldor. Testing the resistance on botryticides the fungus B. cinerea showed low level of resistance to anilinopyrimidines and phenilsulfamides and high level to dicarboximides.

Field experiments were conducted in the maize-growing region on heavy gleic fluvisol from 1974 to 2000. Three variants of straw management (straw harvested, incorporated into soil and burned), two variants of soil tillage (conventional plough tillage to 0.22 m, shallow disc tillage to 0.12-0.15 m) and three variants of fertilization (30, 60 and 90 kg N.ha^-1) were studied. After conventional tillage, the highest yield was obtained in the variant with burned straw (5.50 t.ha^-1), followed by the variant with straw incorporated into soil (5.40 t.ha^-1) and the lowest after harvested straw (5.01 t.ha^-1). At shallow tillage, lower yields were assessed in all variants of straw management in comparison with conventional tillage (after straw burning 5.07 t.ha^-1, incorporation into soil 4.66 t.ha^-1 and harvest 4.54 t.ha^-1). The ranking of variants was identical to that in inversion tillage; however, the yield increased more after straw burning in comparison with its incorporation into soil. Yields increased regularly along with increasing rates of nitrogen. If long-term effects of straw incorporation on yields and yield trends were evaluated (in comparison with straw harvest), statistically significant decrease in yields was assessed after shallow in contrast with increase in yields after deeper straw incorporation.

An experiment with five different tillage systems and their influence on physical properties of a silty loam soil (Albic Luvisol) was carried in northwest Slavonia in the period of 1997-2000. The compared tillage systems were: 1. conventional tillage (CT), 2. reduced tillage (RT), 3. conservation tillage I (CP), 4. conservation tillage II (CM), 5. no-tillage system (NT). The crop rotation was soybean (Glycine max L.) - winter wheat (Triticum aestivum L.) - soybean - winter wheat. Differences between tillage systems in bulk density, total porosity, and water holding capacity and air capacity were not significant in winter wheat seasons. In soybean seasons, significant differences between some tillage systems were recorded in bulk density, total porosity, air capacity and soil moisture. The deterioration trend of physical properties was generally increasing in the order CM, CT, CP, NT and RT. The highest yield of soybean in the first experimental year was achieved under CT system and the lowest under CP system. In all other experimental years, the highest yield of winter wheat and soybean was achieved under CM system, while the lowest under RT system.

Aiming at determination differences in leaf and root potassium concentration of diverse sugar beet genotypes as well as its effect on sugar beet root quality and yield. Investigations comprising 15 sugar beet genotypes (five multigerm lines, five hybrids and five monogerm lines) were carried out on two soil types (Calcic luvisol: L-1 and L-3 and Calcic gleysol: L-2 and L-4) during two growing seasons. Root yield of the investigated genotypes on Calcic luvisol (50 t/ha) was higher, than on Calcic gleysol (34 t/ha). In general, multigerm lines were known for the highest leaf potassium concentration (2.75%), lowest root one (3.78 mmol/100 g root), highest sugar content (13.8%) and best root extractable sugar (1.5%). Monogerm lines had the lowest leaf potassium concentration (2.51%), highest root one (4.24 mmol/100 g root), lowest sugar content (12.9%), and the poorest extractable sugar (10.7%). Root yield of the investigated hybrids (48 t/ha) was higher by 16% compared to multigerm lines yield (42 t/ha) and as much as 35% higher compared to monogerm lines (36 t/ha). Sugar beet root potassium was in significantly negative correlation with sugar content at three localities (L-1: r = -0.485**, L-2: r = -0.096, L-3: r = -0.687**, L-4: r = -0.337**) whereas at all four localities it was in negative correlation with extractable sugar (L-1: r = -0.634**, L-2: r = -0.407**, L-3: r = -0.930**, L-4: r = -0.749**). Potassium concentration in sugar beet leaf was in significant positive correlation with sugar content at three localities (L-1: r = 0.382**, L-2: r = 0.231, L-3: r = 0.717**, L-4: r = 0.516**).

Substitution lines with the chromosome 3B of the Czech alternative cultivar Česká Přesívka (CP) in the genetic background of the wheat cultivars Zdar, Vala, Košutka, Jara and Sandra, differing in their requirements of vernalisation and photoperiod, were compared with the original cultivars under short and long photoperiod, to evaluate the effects of genes, located on the chromosome 3B of CP, on earliness and the response to photoperiod and vernalisation. The results suggest that these genes have only a small effect upon the vernalisation requirement, but are more related to the response to photoperiod. However, the genes on the substituted chromosome appear to influence the earliness per se and very likely interact also with the photoperiodic response.

In three investigated stands the highest increment (8.8 m3/ha per year, i.e. 1.5% of the actual stand volume, measured at the end of the control period) was reached by Jawornik I stand in the initial period of the growing up stage, and Tworylczyk stand in the advanced growing up stage (7.4 m3/ha per year, i.e. 1.2% of the actual stand volume). Jawornik II stand, in the optimum stage, the aging phase, had the lowest increment (3.9 m3/ha per year, i.e. 0.7% of the actual stand volume). The process of a natural volume loss was the most intensive in Tworylczyk stand (7.6 m3/ha per year), a little less intensive in Jawornik II stand (7.1 m3/ha per year), and the least intensive in Jawornik I stand (5.8 m3/ ha per year). The analysis of tree loss, recruitment, and increment, and the relations between these processes, can form the basis for a conclusion that stable stands developed in the Carpathian primeval beech forests in the years 1988-1998. Such steady processes can be used for the development of a stable, multifunctional model of the forest managed by the selection system, or the Swiss irregular shelterwood system in the Carpathian beech stands of a similar structure.

This contribution deals with the differentiation of agricultural enterprises, with focus on the declining enterprises as the most troublesome. In 2000, these businesses generated about 47% of the total loss in agriculture. In this respect, the methodological procedure was also used for the purpose of tipping out the highly unprofitable enterprises. The economic and financial analysis is focused on evaluation of the achieved results expressed in basic economic indicators. The analysis refers to the cause of agricultural enterprises decline. The different dynamics of restructuring process of agricultural production confirm the marked difference of results characteristic for declining enterprises with growing year-on-year loss, increasing costs, decrease of own capital, high indebtness and dependence on the foreign sources.

Arabidopsis is universally resistant as a species to many crop pathogens, including examples from other crucifers suchas Albugo candida and Hyaloperonospora parasitica from Brassica oleracea. This species level trait could potentiallyprovide a source of durable disease resistance in crops if examples can be found which are amenable to molecular geneticcharacterization. Our research has developed from the observation that null mutation in Arabidopsis of a defense regulatorygene EDS1 (enhanced disease susceptibility) is susceptible to isolates of A. candida and H. parasitica from brassica.EDS1 is required by a major structural class of R-genes to confer resistance in Arabidopsis. We have therefore focusedon identifying R-genes in Arabidopsis that are responsible for conferring resistance to brassica pathogens.

Inula viscosa is a perennial plant native to the Mediterranean Basin. Extracts made from the shoots of this plant exhibited a strong fungicidal activity in vitro and in vivo. TLC analyses revealed at least 7 fungicidal compounds. Most are lipophilic. When such extracts were sprayed on the leaf surface of crop plants they effectively controlled downy mildew in grape, cucumber and tobacco; late blight in potato and tomato; gray mold in cucumber and tomato; and, powdery mildew in cucurbits and cereals. Field experiments conducted with grape vine and potato resulted in effective control of Plasmopara viticola and Phytophthora infestans, respectively. The data suggest that Inula viscosa is a useful source of herbal fungicidal preparations for agricultural use.

The fertilising experiment was set up in 1968 on the mountain meadow (720 m a.s.l.) in Czarny Potok near Krynica (20°8' E, 49°4' N). The experiment was conducted on the acid Cambi soil and comprised objects fertilised with two nitrogen forms and two doses against the background of PK fertilisation, the untreated object, and plots with unilateral P and N fertilisation. The paper concerns 30 years of investigations (1968-1997) of the effect of different NPK fertilisation on the dynamic of yields and the meadow sward quality against a background of the same treatments. The dynamic of the botanical composition was presented as well as the dynamic of the grassland yield potential with systematic mineral fertilisation and liming. The application of nitrogen fertilisation with the rate of 90 N.ha^-1 + PK under mountain conditions and systematic liming of the meadow enables to maintain or increase production over the long period, to decrease the production risk and to prevent degradation of the environment and natural resources.

Present study focuses on making best possible use of male gametophytic generation in carnation breeding program. Exploration of pollen population revealed the existence of variability in terms of pollen morphology and histochemical content among as well as within varieties and species of Dianthus caryophyllus and D. chinensis sufficient to make selection. Pollen grain size and histochemical content were found to be associated with germination capacity and pollen tube growth rate. In addition, pollen germination capacity and elongation of pollen tube in response to presence of culture filtrate from F. oxysporum. f.sp. dianthi causal organism of fusarium wilt in carnation was found to be governed by pollen grain size and histochemical content of pollen grains. Entire result suggests the possibility of selecting the desired pollen grains from a pollen population and possibility of attempting selective pollination in carnation breeding program.

This four years experimentation work was aimed at research on using various waste organic materials and especially timber bark in cultivation substrates as a substitute of peat. Sixty-four special isolated cultivation beds were established for this purpose, each of 4.8 m³ volume, in which 11 variants of substrates consisting of different proportions of different components in several replications were tested. Standard substrates Horticultural substrate B and RKS I. were used as controls. Another variant was used as a control for growing tests of plants in containers. All tested substrates were enriched with hydroabsorbent TerraCottem. In some variants reserve fertilisers with slow release of nutrients (Silvamix Forte) were applied. For cultivation testing of studied substrates four ornamental tree species (Alnus glutinosa, Fraxinus excelsior, Salix alba, Salix matsudana) were chosen. The best evaluated variants were the ones containing 50 and 75% of bark in combination with sand. The worst was the variant composed of chips and sawdust. Thanks to the use of hydroabsorbents, even the variant containing 100% of sand appeared to be very good. The tested trees had different reactions to the different types of substrates depending on their species requirements. The limiting growth factor for Alnus was the content of water in the substrate. Similarly, the content of available nutrients in the substrate was essential for Fraxinus. The hardwood cuttings of Salix not only rooted into the substrate in a few weeks, but also formed aboveground parts of the required sizes. Obtained data on growth parameters differed according to the diversity of requirements of the different studied species.

Superoxide dismutase (SOD) isoenzymes of the rumen bacterium Streptococcus bovis 4/1 were studied. Native PAGE showed a single band of Mn-SOD, unaffected by 10 mM cyanide or 5 mM hydrogen peroxide under both aerobic and anaerobic growth conditions. When the metals were removed from the growth medium by Chelex 100, the addition of manganese increased enzymatic activity, while addition of iron inhibited SOD activity. Changes in Mn-SOD and glutathione peroxidase (GSHPx) activities evoked by paraquat and increased values of TBARS indicated that these enzymes were not able to sufficiently prevent oxidative stress at given paraquat concentrations.

The mycoflora was investigated under the conditions of climax spruce stands in the Krkonoše Mountains in relation to wood decomposition. The areas under observation have been affected more or less by air pollution since the eighties. The average mass of deadwood found on the plots is 124 m³ per ha - the mass of fallen trunks is about 32 m3 per ha, mean value from total average. About 128 species of macrofungi were identified that besides others included 43 species of wood-decaying fungi. Also 54 mycorrhizal species were identified. Among the mycorrhizal fungi about 10 species were dominant, such as Laccaria laccata (Scop.: Fr.) Cooke, Lactarius helvus Fr., Lactarius mitissimus Fr., Lactarius rufus (Scop.) Fr., Russula emetica (Schaeff.: Fr.) Pers. and Russula ochroleuca Pers. etc. Concerning the volume of decomposed wood on monitored plots in climax spruce stands, the prevalent wood-decaying fungi are brown rot fungi. The proportion of brown rot fungi in wood decomposition is 60-95% of deadwood mass on the plots of climax spruce stands. A dominant species is Fomitopsis pinicola (Sw.: Fr.) P. Karst. causing the brown rot. Concerning the group of white rot fungi, the most important is Stereum sanguinolentum (Alb. & Schw.: Fr.) Fr., participating by 17% in wood decomposition on plots damaged by deer.

Physical, chemical and microbiological properties of soils were studied in black walnut (Juglans nigra L.) stands and compared with those in stands of natural species composition, in mixed stands of black walnut with linden and in pure oak stands. The objectives were to consider a possibility of black walnut planting at floodplain sites in the alluvial area of Southern Moravia. The first results did not show any worsening of soil properties and soil production potential. A positive amelioration effect of soil- improving species was proved in black walnut stands.

The article summarises the main results of the analysis of the perception of selected meat products in theCzechRepublic (i.e. the following types of salami: Gothai, Famer´s, Tourist, Poličan, chicken ham salami, Hunter´s, pork ham salami and turkey roll). Two factors have been defined on the basis of a composition approach, which influence the evaluation of meat products by Czech consumers during their purchase. The first factor was the perceived quality of the product and the second one was the healthiness factor. It has been found out that the perceived quality of the product has a decisive influence on forming of the preferences of Czech consumers in all analysed meat products. This finding has resulted from both direct and indirect acquisition of preference data. The healthiness factor is also important even though it has a relatively higher importance mainly in the meat products made from poultry and lean parts of other slaughter animals. Further, the analysis has confirmed the hypotheses of the influence of the consumers´ perception on forming their preferences.

The foreign agri-food trade has showed an unsuitable development for the Slovak Republic during the 1999-2001s. The negative balance for the competitive commodities is increasing. These are the commodities for the production of which the SR has suitable natural conditions. The contribution deals with the selected competitive commodities in the kilogram prices. The study shows the decreasing tendency of kilogram prices in import and the increasing tendency in export. Higher export price is the consequence of the higher value added and thus also higher revenues.

Isolates of Fusarium oxysporum f.sp. ciceri from chickpea (Cicer arietnum L.) can be characterized as races and wilt and yellowing pathotypes by pathogenicity tests on varieties of differentials chickpea. This study shows that, DNA bands generated by RAPD-PCR can be used to assign Fusarium oxysporum f.sp. ciceri isolates to pathotype and pathogenic race.

The main objective of this study was to determinate the occurrence and intensity of attack by the more important fungal diseases on soybean in Eastern Croatia. Four-year investigation (1998-2001) was undertaken on 10 domestic soybean cultivars with different level of disease resistance. The investigation was set in two planting date (optimal and delayed) on experimental fields of the Agricultural Institute Osijek. Following more important diseases were established: Downy mildew, Pod and stem blight and Stem canker. Significant differences in disease incidence were caused by genetic diversity of tested materials as well as different climatic conditions among growing seasons. According to planting date, significantly higher incidence of Downy mildew and Pod and stem blight was in optimal planting date.

Nowadays manufacturers are facing rapid and fundamental changes in the ways business is done. Producers are looking for simulation systems increasing throughput and profit, reducing cycle time, improving due-date performance, reducing WIP, providing plant-wide synchronization, etc. Planning and scheduling of coffee production is important for the manufacturer to synchronize production capacity and material inputs to meet the delivery date promised to the customer. A simulation model of coffee production was compiled. It includes roasting, grinding and packaging processes. Using this model the basic features of the coffee production system are obtained. An optimization module of the simulation SW is used for improving the current structure of the production system. Gantt charts and reports are applied for scheduling. Capacity planning problems related to coffee production are discussed.

The conception of these investigations is based on the premise that a way should be found to eliminate, or at least mitigate, the harmful effect of excessive soil acidity without resorting to the massive and costly measures of liming. The main issue addressed in this study is how to increase crop yield by increasing nutrient availability rather than how to neutralize the soil. This as well as our earlier investigations, conducted on pseudogley of mesoelevations, indicate that this can be achieved by the application of special natural amendments (SNA) based on zeolite tuff, under the name Agrarvital (AV), in which clinoptilolite prevails while the remaining part is a mixture of soft lithothamnian limestone and dolomite (SLL+D). These amendments enhance ion exchange in the soil and their activation at a considerably lower pH than it is the case after liming. Fertilizing value of Agrarvital (AV) and lime materials (LM) was evaluated according to the yields achieved and some yield components of the crops grown. The results point to the good fertilizing effect of AV upon yields of winter wheat, maize, soybean and winter barley, equal to or better than the effect of conventional LM applied at several times higher rates.

A method of growth analysis was used to evaluate the yield results in experiments conducted during years 1999-2001 on School co-operative farm in Žabčice. In sequential terms of sampling from two potato varieties with different duration of growing season, the effect of leaf area index (L, LAI), on yield of tubers in soils contaminated by cadmium, arsine and beryllium, was evaluated. From a growers view the phytotoxic influence on development of assimilatory apparatus and yields during the growth of a very-early variety Rosara and a medium-early Korela were evaluated. These varieties were grown under field conditions in soils contaminated by graded levels of cadmium, arsenic and beryllium. The yields of tubers were positively influenced by duration of growing season and increased of leaf area index during three experimental years. On the contrary, graded levels of heavy metals had negative influence on both chosen varieties. The highest phytotoxic influence was recorded of arsine and the lowest of cadmium. Significant influence of arsenic and beryllium on size of leaf area index in the highest applied variants was found. The influence of experimental years on tuber yields was also statistically significant.

The influence of long-term regular mineral fertilization on the soil environment considering the total sulphur and the sulphur balance in the habitat of the permanent mountain meadow was investigated. The experimental field (set up in 1968) is situated at Czarny Potok (20°8' E, 49°4' N) in the central part of the Polish Carpathian. With completed annual NPK fertilisation 1.8 kg S/ha was introduced into the soil. The highest sulphur amount was found in the 0-10 cm horizon and this value slightly exceeded the content considered as natural. The sulphur content in the sward from Czarny Potok was lower than the mean sulphur content calculated in Poland for grasses (0.21% S). In the case of full NPK fertilisation the amount of removed sulphur ranged from 11.4 to 14.0 kg S/ha. The mean sulphur leaching into the soil profile from surface of 1 ha can be estimated from 1.1 to 3.7 kg S/ha.

Changes in fruit weight, firmness and soluble solids content during the ripening period of Karešova cv. Including relationships between these characteristics were studied in 1998-2001. These years differed from each other in the amount and distribution of rainfall and in the course of temperatures. The length of ripening period fluctuated from 14 to 21 days. An increase in average fruit weight during the ripening period was 0.1 g per day. The actual increase in fruit weight was in a close correlation with the amount of rainfall in a few previous days. After heavy rainfalls, above 40 mm, fruit weight increased by nearly 1 g within in a few days. In the course of the ripening period fruit firmness decreased from about 2.5 N at the beginning of the period to about 1.5 N at its end. This decrease seems to be mainly the function of time during ripening. However, a low correlation between the amount of rainfall in the previous days and the decrease in firmness was also found. This correlation could be connected with negative regression of fruit firmness on the weight of the fruit. In the more rainy years 1998 and 1999 these decreases in firmness were more significant than in the other two years. Soluble solids content (SSC) increased from about 12% Brix at the beginning of the period to about 16% at its end. There were also found positive correlations between the weight of fruits and SSC. Taking into account contributions of all studied factors and their changes a conclusion was drawn that Karešova cv. should be harvested within one week from the beginning of its ripening period.

This experiment was conducted to evaluate the effect of vitamin C (L-ascorbic acid) and chromium (chromium picolinate, Cr Pic) on egg production, some egg characteristics, and digestibility of nutrients in laying hens (Hy-Line) reared under a low ambient temperature (6.2°C). Two hundred and ten laying hens (32 week-old) were divided into seven groups, 30 hens per group. The treatment groups were designed in a 2 × 3 factorial arrangement using two levels of vitamin C (125 and 250 mg/kg of diet) and three levels of chromium picolinate (200, 400, or 800 µg/kg of diet), and control group was fed basal diet. The highest values of performance were obtained if 250 mg/kg vitamin C was supplemented with either 400 or 800 µg Cr per kg of diet. An interaction between vitamin C and chromium for egg production (P = 0.05) and feed efficiency (P = 0.02) was detected. Similarly, egg weight, specific gravity, egg shell thickness, egg shell weight and Haugh unit improved with diet containing 250 mg vitamin C and either 400 or 800 µg Cr per kg of diet (P £ 0.05). Digestibility of dry matter (DM), ash, organic matter (OM), crude protein (CP), and ether extract (EE) were higher with higher dietary vitamin C (P £ 0.05) and also with higher Cr (P £ 0.05). There were no interactions between vitamin C and chromium detected for any parameters measured for egg quality in terms of egg weight, specific gravidity, egg shell thickness, egg shell weight and Haugh unit and digestibility of nutrients (P ³ 0.28). Data obtained in the present study shows that a combination of 250 mg vitamin C and 400 µg chromium per kg of diet gave the best results in laying hens reared under a low ambient temperature and a conclusion is suggested that such a diet can be considered as a protective management practice in poultry to alleviate, at least in part, the depressive effect of cold stress on poultry performance.

Height and diameter growth and volume production of 22 different clones of poplars were evaluated in Sliepkovce populetum at the age of 12 years. The populetum is situated on medium-heavy and medium humic uninundated alluvia of the Laborec river; typologically, the group of forest types is Ulmeto-Fraxinetum populeum. The results of evaluation documented that among the poplars under study the clones Gigant, OP-229 and BL achieved the best growth and maximum volume production while their mean height amounted to 22.9-23.8 m, mean diameter to 31.9-33.2 cm and average annual volume increment was 25.1-28.3 m³ per 1 ha. The growth of P. Rochester 20/66 poplar was considerably much slower: its mean height amounted to 17.3 m, mean diameter to 18.7 cm and average annual volume increment was 6.3 m³ per 1 ha. It will be necessary to carry out further studies to obtain more detailed values for these clones.

Price fluctuations make agriculture a risky business. High price fluctuation of agricultural commodities may have through its income effect a very unfavourable impact on the economic situation of agricultural subjects. In finding corresponding instruments of agricultural policy to stabilize prices and incomes, it is necessary to distinguish between various types of price changes. However, important question for conception of adequate price policy is how to protect against high price fluctuations and not to restrain function of price as a signal about market situation. Application of partial equilibrium analysis to evaluate impact of price stabilization policies is an adequate method, especially if price changes in the market do not cause significant price fluctuation in other markets. Using this methodological approach is possible to prove that price stabilization brings for common net benefit consumers and producers. However in practical application some additional aspects must be taken into account if dealing with stabilization of agricultural products prices.