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Hop downy mildew (Pseudoperonospora humuli) and hop powdery mildew (Podosphaera macularis) are the most important pathogens of hop (Humulus lupulus). The early detection and identification of these pathogens are often made difficult by symptomless or combined infection with another pathogens. Molecular analysis of internal transcribed spacer (ITS) regions of rDNA is a novel and very effective method of species determination. Therefore, specific PCR assays were developed to detect the pathogens Pseudoperonospora humuli and Podosphaera macularis in naturally infected hop plants. The specific PCR primer combinations P1 + P2 and S1 + S2 amplified specific fragments from Pseudoperonospora humuli and Podosphaera macularis, respectively, and did not cross-react with hop DNA nor with DNA from other fungi. PCR primer combinations R1 + R2 and R3 + R4 could be used in multiplex PCR detection of Pseudoperonospora humuli, Podosphaera macularis, Verticillium albo-atrum and Fusarium sambucinum. Phylogenetic relationships were inferred for 42 species of the Erysiphales from nuclear rDNA (ITS1, 5.8S, ITS2). The molecular characterisation and phylogenetic analyses confirmed the species identification of hop powdery mildew. The PCR assays used in this study proved to be accurate and sensitive for detection, identification, classification and disease-monitoring of the major hop pathogens.

A study was conducted to determine the relationship between abdominal fat and the intake of methionine deficient diet in broilers. In this study, 66 male broilers at the age of 35 days were used. They were divided into two groups (control, n = 13, and methionine deficient group, n = 53) and all birds were housed in individual pens. During the experiment, normal and deficient diet contained 0.55% and 0.25% methionine, respectively. Control group was fed normal diet for 19 days. Treatment group received methionine deficient diet for 4 days and normal diet for 15 days. Body weight and feed intake were recorded daily. High (HG) and low (LG) groups were theoretically created according to the rates of decreases in individual feed intake. Percent decrease in feed intake of HG and LG groups was 29.4 ± 2.0 and -1.3 ± 1.7, respectively. Abdominal fat in HG and LG groups amounted to 1.62 ± 0.1 and 1.73 ± 0.2%, respectively. The feed conversion ratio of HG and LG groups was 3.1 ± 0.1 and 3.4 ± 0.2, respectively. There was a negative correlation (-0.45 in HG and -0.43 in LG) between the percent decrease in feed intake and abdominal fat.

The set of 102 samples of agricultural soils was taken for the study of the load of agricultural soils with polychlorinated dibenzo-p-dioxins and dibenzofuranes (PCDDs/Fs). The background value of PCDDs/Fs in agricultural soils of theCzech Republicwas determined. The soils with different sources of the load of PCDDs/Fs were compared. It was concluded that fluvisols in fluvial zones and soils with long-term sludge application are soils with the highest contents of PCDDs/Fs. The soils affected by imission outputs show a lower intensity of the load with PCDDs/Fs that is characterised by higher content of toxic congeners.

Retailers are the strong group both in South Bohemia and in Upper Austria. The development of this sphere is one of the development programmes priorities of both regions. South Bohemia and Upper Austria, especially Muhlviertel region, are areas with a similar economic structure, which is an excellent presupposition for mutual cooperation. An advantage will be the improvement of marketing activity and information transfer. A better technical equipment and its full exploitation will be possible. The problems, however, which could arise from cooperation with foreign partners, should not be underestimated. Not only the language barrier is concerned but also different techniques, methods and expectations that might be caused by different customs and interests of the partners. An important aid to the entrepreneurs, either concerning consultant service, establishing contacts or further education, are economic chambers and other institutions concerned with retail business development.

Knowledge Economy is an education related to the declaration and contents of the Lisbon Strategy - The Perfect Europe and a follow up strategy of the competitiveness of member states of the EU by the year 2010. The term knowledge economy can be defined as "an education about problems of upbringing and educating students, a professional education of managers and population, an education about strategies of being competitive as well as an education about reality and contents of innovating an information society". The application of the Knowledge Economy in the content of education into research and workplace consulting enriches economic theories as well as gradation of agrarian economic in the field of competitiveness and information technology. The Knowledge Economy means a world repute and maximalisation of international relations and at the same time a vision of catching up with the leaders of world economies. Present educational systems, a general and specific education of new member states, is short-sightedly oriented at regional and local education with the effort to educate "an euroengineer, an eurodoctor, etc.", into the expansion of new faculties and their entitling as "European studies, integration studies, some subjects are also innovatived with a modified agrarian and business union politics", which I myself consider to be an "educational lag behind" which is the antithesis to the attributes of catching up with the more developed.

The effects of soil conditioners TerraCottem, Frisol, Bio-algeen and fertilisers Silvamix Forte and Cererit on the survival rate and growth of European ash seedlings until the stage called established plantation were observed on two experimental plots with different anthropogenic substrates. Eight-year experiments showed that under the given conditions the tested agents fulfilled the declared effects only partially. The application of TerraCottem was statistically insignificant both in the survival rate and in the growth. In the applied dose, Frisol manifested itself as an agent that may cause problems with the survival of plants, but at the same time also as a preparation improving the overall growth of young plants statistically significantly. Its effective dosage largely depends on the soil character. Bio-algeen had a very good effect on the survival rate of plants, but it did not surpass the control plants in the initial growth of plants. Silvamix Forte did not cause the mortality of seedlings and influenced the growth of plants statistically significantly for 1-3 years. In the applied dose, Cererit caused a high mortality of seedlings. The application of soil conditioners and Silvamix Forte did not markedly accelerate the growth and development until the stage of the established plantation. Until that time, the costs of the application of conditioners were higher by 4-13% as compared with the costs in the control plants.

The aim of the study was to investigate acute toxicity of clove oil for common carp and, using values of haematological and biochemical profiles of blood and histological tissue examinations, to assess the effects of the fish exposure to that anaesthetic. Acute toxicity values of clove oil for carp were found 10 minLC50 74.3 mg/l; 10minLC0.1 51.6 mg/l; 10minLC99.9 110.1 mg/l; 96hLC50 18.10 mg/l; 96hLC0.1 15.45 mg/l; and 96hLC99.9 19.80 mg/l. The fish were divided into four groups for haematological and biochemical examinations of blood and histological examinations of tissues. The groups were Control I (before the anaesthetic administration), Experiment I (immediately after 10 min anaesthesia at the concentration of 30 mg/l), Experiment II (24 hrs after 10 min anaesthesia) and Control II (controls examined in parallel with Experiment II). A total of 40 carp were examined. Clove oil anaesthesia had not effect on the haematological profile. The 10-min exposure to clove oil at a concentration of 30 mg/l caused a significant (P < 0.01) increase in the concentration of glucose (GLU) and inorganic phosphate (PHOS) immediately after anaesthesia. Clove oil anaesthesia had not effect on other biochemical indices. Histological examination showed capillary ectasia of gill filaments immediately after clove oil anaesthesia. Twenty-four hours after anaesthesia, no ectasia was observed. No histopathological changes were demonstrated in other tissues following anaesthesia. Results of the examinations suggest that the use of clove oil at a concentration of 30 mg/l does not cause irreversible damage in carp.

Host range and growth of two Ditylenchus dipsaci (Stem and Bulb Nematode) populations on onion, garlic, leek, spinach and chicory were compared. Inoculation was conducted by placing a droplet of 1.5% CMC suspension containing nematodes between the first leaves. The life cycle of the parasite was completed in variants of the original host plants, i.e. salad chicory was infected with the chicory population, and garlic and onion with the garlic population. Survival of the nematodes on garlic and spinach inoculated with the chicory population, and on chicory inoculated with the garlic population was determined. Nematodes of the chicory population did not survive on onion and leek, nor did the garlic population survive on spinach and leek. Nematode infection did not affect the dry weight of aboveground parts of plants, although a reduction would probably occur if the experiments had lasted longer. Symptoms of the infections were apparent in chicory inoculated with the chicory population. Nematodes in the substrate in which the plants were grown were found only in those variants with plants in which the life cycle was completed.

Two ruminally cannulated Jersey cows were used to determine in situ ruminal degradability and intestinal digestibility of raw (E0) soybeans and soybeans extruded at 145°C (E145), 155°C (E155) and 165°C (E165). The degradation of dry matter (DM) and crude protein (CP) was estimated using nylon bags suspended in rumen for 2, 4, 8, 12, 16, 24 and 48 h calculating the effective ruminal degradabilities (ERD) for an assumed outflow rate of 0.06/h. Four extra sample bags were incubated for 12 h to determine CP digestibility using the mobile nylon bag method. Cows were fed a ration of 30% concentrate and 70% meadow hay. Soybean extrusion at all temperatures decreased the effective protein degradability significantly (P < 0.05). Soybean processing at the highest heat input (E165) decreased ERD (44.0%) in the rumen significantly while the values for E145 and E155 were similar, 50.8 and 50.3% respectively. Soybean extrusion at all tested temperatures was followed by a significant (P < 0.05) reduction in the proportion of the rapidly degraded DM and CP fractions a, and both the increased proportions and reduced breakdown rate (c) of the fraction b. The intestinal protein digestibility values of the rumen-undegraded protein of extruded soybean were somewhat higher, however the observed differences between treatments were not significant (P < 0.05). Estimated intestinal digestibilities were 87.2, 89.7, 92.0 and 92.6% for E0, E145, E155 and E165, respectively.

Field experiments were carried out to study effects of zinc application on quality traits of barley in 1994-1996. The treatments were applied as 0 and 23 kg/ha of zinc sulphate and incorporated into soil before sowing. The experimental design was split plot with four replications. Barley genotypes responded differently to zinc application in relation to thousand grains weight, protein content and starch content. A significant increase was determined for thousand grain weight in cultivars Tokak 157/37 and Cumhuriyet 50, for protein content in Orza, Bülbül 89 and Anadolu 86, for starch content in Karatay 94 and Cumhuriyet 50, while a significant decrease has been found for thousand grain weight in Karatay 94 and Obruk 86 and for protein content in Karatay 94, Cumhuriyet 50 and Tarm 92. When feeding and malting quality are considered together, Karatay 94 and Cumhuriyet 50 are the most suitable cultivars for growing in zinc-applied soils of semi arid areas.

This study deals with effects of pressing of ensiled sugar-beet pulp and of application of a chemical preservative on the quality of fermentation process. The experimental silages had a better sensory evaluation than the control ones. In silages treated chemically with a mixture of acids, statistically significantly (P < 0.01) higher dry matter content, lowest pH value, the value of lactic acid and the lowest content of all acids in dry matter were found after 180 days of storage from the beginning of the experiment. The statistically significantly (P < 0.01) highest lactic acid content (43.39 ± 1.25 g/kg DM) was determined in the control pressed silage. The highest LA/VFA ratio (1.40 ± 0.18) was calculated for non-pressed experimental silage (D - 3 l/t of KEM). As compared with untreated control the highest percentage (P < 0.01) of lactic acid and of all fermentation acids was found out in silage D treated with 3 l/t of KEM (58.18 ± 0.47 g/kg DM). Undesirable butyric and propionic acids were not found in chemically treated silage samples (C, D, E, F). However, the highest (P < 0.01) contents of butyric acid (26.37 ± 0.91 g/DM) and propionic acid (4.58 ± 0.78 g/DM) were measured in untreated non-pressed silage samples (B). The highest (P < 0.01) contents of acetic acid and ethanol were found in control silage samples. The quality of these silages was evaluated as very low.

After the accession to the EU, there is a necessity to develop the land market in Slovakia. The achievement of the following conditions is necessary: settlement of estates in lands and unification of the law of real property in the areas of ownership, utilization, change of the land type, soil conservation, land use planning and building multiple-function agriculture with the legislation of the market economy countries as well as its harmonization with the EU legal regulations. It is also necessary to develop an official network to follow transactions on the land market, a regular update of data and their evaluation.

In this paper we have evaluated the health condition of Prunus persica (L.) Batsch and Prunus armenia-ca L. for the occurrence of the parasitic microscopic fungus Cytospora cincta Sacc. Apricot trees in 5 localities with 10 sites and peach trees in 5 localities with 8 sites were evaluated. We identified symptoms of the disease in host plants, conditions for isolation and cultivation of the fungus and the growth rate of the mycelium hyphae on various substrates. The damage degree was evaluated in 330 trees in four localities while most trees were characterised by degree 1-3. We have derived conclusions for protective measures to prevent further spreading of the infection.

This paper deals with the meat industry in the Czech Republic, the equipment which is used for meat cutting and processing for sale and for production of smoked goods. It determines individual categories of this equipment according to the use and describes materials used for manufacturing of clothing of butchers and also the complementary tools improving labour safety during technology operations. Next it presents materials used for making metal tools and describes the situation in the market of butcher´s equipment in the Czech Republic.

Rare forest tree species that are necessary for the domestic processing industry, especially for the furniture industry, currently occur as scattered trees in many forest stands in theCzechRepublic. For their harvest and supply to the processing industry it is necessary to measure their dimensions and growing stock. Logging technologies are proposed that will enable to harvest and transport this scattered wood mass to buyers. These technologies and used conveyances must not cause any damage either to forest soil or to adjacent stands and they should be economic, i.e. increased costs of processing must be covered by selling price.

The contents of eight biogenic amines (tryptamine, phenylethylamine, histamine, tyramine, putrescine, cadaverine, spermidine and spermine) were determined in samples of processed cheese, either pasteurised (P) or sterilised (S), and consequently stored for either 22 or 57 weeks at the temperatures of 8°C and 22°C, respectively. Tyramine was quantitatively the most important biogenic amine (1.3-29.3 mg/kg); the highest level (P < 0.05) was found in P cheese stored for 22 weeks after processing at 8°C (P1). Regardless of tyramine, and with the exception of putrescine in S cheese stored for 57 weeks (2.2 mg/kg), the content of no biogenic amine exceeded 2 mg/kgin any tested sample. Significantly higher (by five to six orders of magnitude; P < 0.05) counts of total aerobic and facultative anaerobic microorganisms in P1 sample in comparison with all other samples were indicative of the cover leakage. No lactic acid bacteria were detected in any sample, the counts of coliforms and total anaerobes, respectively, were negligible and did not differ (P> 0.05) between samples. No sample of the tested long-term stored processed cheese was considered unsafe from the toxicological viewpoint.

The prevalence of thermophilic Campylobacter spp. was evaluated in the caecum and on carcasses of pigs at slaughter and in the facilities of slaughterhouses in the period of 2001- 2003. During that timeframe, prevalence of Campylobacter spp. in both the pigs and the environment of slaughterhouses decreased. In 2001, Campylobacter spp. were detected in 34% of 316 samples; in 2002 there were 27% of positive findings out of the 624 samples; and in 2003, Campylobacter spp. were detected in 16% out of 300 samples. Campylobacter spp. were mostly found primarily in the caecum (292 isolates) and in smears collected from carcasses (21 isolates), while Campylobacter spp. were isolated only sporadically from the work surfaces of equipment in slaughterhouses. The majority of isolates were identified as C. coli. In 2001, 16 out of 109 strains of Campylobacter spp. were identified as C. jejuni; in 2002, 8 out of 167 strains were C. jejuni; and in 2003, none of 47 isolates was identified as C. jejuni.

Probiotics have been used with increasing frequency in nutrition and for prophylactic purposes during the last years. In the present study we investigated the effect of Lactobacillus fermentum AD1 - canine isolate on selected intestinal microbial groups, weight gain, organic acids, haematology, glutathione peroxidase and phagocytosis of leucocytes in 2-days-old Japanese quail (Coturnix coturnix japonica). The results demonstrated that the 4-day application of this strain significantly increased the population of lactic acid bacteria - lactobacilli and enterococci in faeces (P < 0.01 and/or P < 0.001) and caecum of quail (P < 0.001) and significantly decreased the counts of E. coli in faeces (P < 0.05). The daily weight gain was increased by 14%. Although intestinal pH of both groups of birds was similar, the concentration of lactic acid was significantly increased in the experimental group (P < 0.05). The concentration of other organic acids (acetic, acetoacetic, formic, succinic, valeric, propionic, butyric) as well as blood glutathione peroxidase was not influenced. The index of phagocytic activity of leucocytes was significantly improved (P < 0.01).

Eight varieties of spring barley (Hordeum vulgaris Lin.) were artificially inoculated with a Fusarium culmorum (W.G. Smith) Saccardo - isolate and naturally infected in the middle of the flowering period, and 2 d later treated with the fungicides azoxystrobin or tebuconazol at a dose of 1 l/ha in 250 l of water. In both control and treated samples of grain the content of deoxynivalenol (DON), the main trichothecene mycotoxin produced by F. culmorum, was determined by gas chromatography (GC-ECD). The treatment with either fungicide resulted in elevated levels of DON, an effect that was more pronounced with azoxystrobin.

The influence of supplementation of a lecithin emulsifier (0.1%) to the feed mixture for piglets after weaning was studied. 16 piglets in the control group (C - without lecithin) and 16 piglets in an experimental (E) group were monitored in three replications in a 28-day experimental period. We observed higher digestibility of monitored nutrients in the experimental group (crude fat: C = 66.28 ± 12.11, E = 69.75 ± 9.85%, crude protein: C = 78.72 ± 5.47, E = 82.17 ± 2.23%, crude fibre: C = 56.70 ± 12.85, E = 59.10 ± 12.04%, nitrogen free extract: C = 86.67 ± 3.32, E = 87.75 ± 3.00%, ash: C = 63.63 ± 11.59, E = 65.73 ± 10.35%). Statistically insignificantly higher daily average gain (C = 374.1 ± 107.0, E = 399.1 ± 104.7 g) of experimental groups and a lower feed conversion ratio (C = 2.285 ± 0.416, E = 1.768 ± 0.048 kg/kg) were found out. It was also confirmed in an additional field experiment (C = 279, E = 312 piglets from birth to 71 days of age) where average daily gain weight was 270 g in control and 290 g in experimental group. The influence of lecithin on the occurrence of haemolytic strains of Escherichia coli was not proved. This experiment confirmed a positive effect of the lecithin emulsifier supplement on the efficiency of piglets.

Differences in reactions to infection and different development of Plum pox virus (PPV) symptoms were observed in leaves and fruits of one hundred sixty-five apricot and seventy-nine peach cultivars and hybrids. A very broad spectrum of reactions from high susceptibility to high resistance and immunity was proved in apricot cultivars and hybrids and the results were published (Polák et al. 1997). A much narrower spectrum of reactions was proved in peach cultivars. Relative concentrations of PPV by ELISA in flowers, intensity of virus symptoms in leaves and fruits of peach cultivars were evaluated. The relative concentration of PPV coat protein (PPV-CP) in flowers was found to be positively correlated with the intensity of leaf and fruit symptoms in most cultivars. On the basis of obtained results cultivars of peaches were divided into four groups and classified as medium resistant, tolerant, medium susceptible and susceptible to PPV. None of the investigated cultivars was immune, highly resistant or resistant to PPV. Eighteen peach cultivars were classified to be medium resistant to PPV. Nine peach cultivars were characterized as tolerant to PPV, with high relative concentration of PPV-CP protein in flowers and mild symptoms in leaves and fruits. Twenty-seven peach cultivars were characterized as medium susceptible to PPV. Twenty-five peach cultivars were rated as susceptible to PPV. It is recommended to grow medium resistant peach cultivars in the areas where PPV is widely distributed.

The work objective is to differentiate rural land of Slovakia with aspect to the possibility of effective rye growing. The differentiation is based on pedo-climatic and production economic parameters. At soil categorization, correlation relationships between the site properties (soil and climatic conditions) and crop biological and agro-technological requirements were considered. Rye requirements were included into yield databases using the software filters in the way that the given site property excluded or limited rye growing, what was reflected in predicted production. The prediction was subsequently interpolated into four suitability categories: soils not suitable for rye growing, less suitable soils, suitable soils and very suitable soils. The database was formed and each of the Bonited Soil-Ecological Units (BSEU) was added in it as well as particular category of suitability for rye growing. By mediation of the Geographic Information System on BSEU distribution in Slovakia, the map of categories of soil suitability for rye growing was also generated. In Slovakia, there is 21% of farmland very suitable for rye growing, 23% suitable, 24% less suitable and 32% non-suitable soils for rye growing according to our calculation. In the paper, these categories are characterized in details and specified from the view of geographic, soil, climatic, productivity, economic and energetic parameters.

Irrigation with saline waters is an agricultural practice that becomes increasingly common as competition for fresh water increases. In this study, three strawberry cultivars (Fragaria × ananassa Duch.) were tested for their salt tolerance. For this purpose, five salinity levels in water with electrical conductivities (EC_i) of 1.1, 1.6, 2.1, 2.5, 2.9 dS/m and river water as control (0.5 dS/m) were used in a randomised design with four replications. Percent leaf damage at two dates and accumulation of salts in soil were determined for each cultivar. Considering the results, Maraline is the most tolerant to salinity. Severe effects of salt on Muir and Tudla growth were observed even at EC_i 1.1 dS/m. The higher the level of EC_i of irrigation water, the higher the soil EC_e produced. In general, the highest soil EC_e's were produced by Muir followed by Tudla experiment.

The area of vineyards has increased to 19 261.5 hectares and the number of wine producers to 18.292 by 1 May 2004. This branch needs a long-term study that will lead to the establishment of the new politics for viniculture and wine-growing, related to the needs of the region. The trends are compared to the main European producer - France, and another country from the so called "New World"- the South African Republic. The researches are focused on the consumption of wine by population, share in the gross national product, employment in this branch, areas of vineyards, and number of wine-growers.

The study deals with the problems of territorial marginality in Slovakia. It illustrates the content structure of regional marginality, its factor satiation, as well as its spatial (territorial) localization. The historical-spatial context of marginal territories in Slovakia and their position in the transformation period are pointed out. The stress is laid on social-spatial marginality of the regions, representing its central component. The study suggests the possibilities of solving the problems of marginal regions, their developmental disposabilities, as well as the necessity of application of certain demarginalization activities, as a component part of modernization processes and their dynamization in the respective territories. The existing contradictions between the intentions of the regional policy of the Slovak Republic and the actual situation in solving the problems of marginal regions have been pointed out as well.

New possibilities of oak mildew (Microsphaera alphitoides) control were tested and compared with present methods. The results of three-year experiments in 6 localities (Cikar, Budkov, Planá nad Lužnicí, Vědomice, Voznice, Zadní Bor) clearly showed that the sulphur-based fungicides registered for the control of oak mildew (Sulikol K, Sulka) had a relatively good and stable effectiveness, and that two other newly tested preparations (Systhane 12 EC, Amistar) were even more effective when the percentage of infested plants did not exceed 2% (Systhane 12 EC) or 5% (Amistar) in any experimental locality. Their registration should be extended in this way. The biopreparations with fungicidal or fungistatic effects such as Supresivit, Polyversum and Ibefungin, known and used in forestry, showed that it was not possible to use them for oak mildew control, similar results were received in tentative testing of another preparation (PFR). Testing of preparations Bion 50 WG and Neem Triact 90 EC gave interesting and promising results. Besides their sufficient effectiveness in the control of oak infestation by the mildew, our experiments also indicated their generally positive influence on the health of plants; this could compensate their economic disadvantage compared to classical fungicides.

The spreading of bulldozer-formed windrows represents a second stage of the site restoration with bulldozers utilization in the Ore Mts. In the first period, bulldozers were used to create windrows for mechanized reforestation of immission-declined stands, causing profound devastation of forest sites, because removed surface humus was the only source of nutrients and environment for tree species roots. Preparatory stands have been established, and have to undergo re-construction in the coming years. Nowadays, the windrows are spread by the bulldozers again, covering 1/3 f the whole area between windrows by the rest of holorganic matter. This substratum is impoverished by the extensive mineralization and connected nutrient (especially N) losses, representing differently suitable space for tree rooting. Presented paper documents the effects of fertilization by different types of the SILVAMIX fertilizer on the growth and prosperity of new spruce plantations. Effects of fertilization are visible very soon and they are significantly beneficial for the new forest plantations.

Haemolytic products arising in chronic hemophthalmos cause cellular infiltration, necrosis of the vitreous structure, and fibrous membrane formation. In this process, retinal pigment epithelium plays an important role for its antioxidant properties and the capability to phagocyte the decay products.

A total of 245 isolates of Actinobacillus pleuropneumoniae included in this study were isolated from lung tissues of pigs which died of porcine pleuropneumonia. The isolates were obtained from 52 swine herds in the Czech Republic over the period 2003-2004. All the serotypes were serotyped by the coagglutination test. All isolates with cross-reactivity between serotypes 9 and 11 or 1, 9, and 11 in the coagglutination test were further serotyped by the quantitative coagglutination test. The results of serotyping showed that serotype 9 was dominant (46.5%) followed by serotypes 2 (18.5%), and 11 (14.2%). Two-way cross-reaction between serotypes 9 and 11 was found for 7.5% of the isolates. The serotypes 4, 5, 7, and 12 were found infrequently (2.4%). The isolates that could not be serotyped (11%) were classified by PCR typing system based on the apx and omlA genes into the serotype groups 1, 9, 11 (7.5%); 2, 8 (2.3%), and 7, 13 (1.1%).

Population studies and tests on the relationship between density and damage were conducted in 1999 to 2001 to determine the pest status of Empoasca dolichi on groundnut (Arachis hypogaea L.) in the Zaria area of northern Nigeria. Analyses showed that Empoasca numbers varied significantly from one year to another, and within each year the numbers of leafhoppers observed at the different growth stages of the plant were significantly different (P = 0.01). There was an inverse and highly significant relationship between the mean kernel yield and the Empoasca damage at the different growth stages of the plant. When natural population densities were plotted against economic injury level (EIL), the densities did not reach the EIL throughout the groundnut growing seasons. The insect was thus not an economic pest on groundnut in Zaria during the period of the study.