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A downy mildew disease was observed on leaves of Dianthus chinensis L. cv. Scarlet in Brno in June 2011. Characteristics of visual symptoms and microscopic features are described. The morphology of the fungus was typical of Peronospora dianthicola, conforming to the published description by Francis (1983). P. dianthicola causing leaf spots on Dianthus has been recorded for the first time in the Czech Republic.

The antimicrobial activity of six plant extracts from Ocimum basilicum (Sweat Basil), Azadirachta indica (Neem), Eucalyptus chamadulonsis (Eucalyptus), Datura stramonium (Jimsonweed), Nerium oleander (Oleander), and Allium sativum (Garlic) was tested for controlling Alternaria solani in vitro and in vivo. In in vitro study the leaf extracts of D. stramonium, A. indica, and A. sativum at 5% concentration caused the highest reduction of mycelial growth of A. solani (44.4, 43.3 and 42.2%, respectively), while O. basilicum at 1% and 5% concentration and N. oleander at 5% concentration caused the lowest inhibition of mycelial growth of the pathogen. In greenhouse experiments the highest reduction of disease severity was achieved by the extracts of A. sativum at 5% concentration and D. stramonium at 1% and 5% concentration. The greatest reduction of disease severity was achieved by A. sativum at 5% concentration and the smallest reduction was obtained when tomato plants were treated with O. basilicum at 1% and 5% concentration (46.1 and 45.2 %, respectively). D. stramonium and A. sativum at 5% concentration increased the fruit yield by 76.2% and 66.7% compared to the infected control. All treatments with plant extracts significantly reduced the early blight disease as well as increased the yield of tomato compared to the infected control under field conditions.

Ten-year results of the practical immunity investigation of apricot cv. Harlayne are presented. Two-year-old trees of cv. Harlayne were inoculated by chip-budding with six different strains and isolates of Plum pox virus (PPV). PPV inoculated trees grew in the field and were evaluated from 2001 to 2011. No PPV symptoms appeared in the leaves of cv. Harlayne within ten years (2002-2011), and within eight years (2004-2011) in the fruits and stones. None of the six isolates of three different PPV strains was detected in the leaves and fruits by ELISA. Suckers of the rootstock Prunus myrobalana developed around cv. Harlayne trees in 2005-2011 were symptomless and ELISA was negative within seven years. New trees of cv. Harlayne obtained from tested trees by budding on PPV susceptible apricot rootstock MVA-2 in 2007 were PPV free from 2008 through 2011. The presence of PPV was proved by ELISA neither in leaves of cv. Harlayne nor in rootstock MVA-2.

Sugarcane plant samples affected by the disease pokkah boeng were collected from the major sugarcane producing areas in Iran. Fifty isolates of Fusarium verticillioides were recovered from diseased sugarcanes. Results of pathogenicity tests revealed that all isolates were pathogenic to sugarcane. Four hundred and eighty-five nitrate non-utilising mutants were generated from F. verticillioides isolates. Media used for nit mutant generation included potato dextrose agar, minimal medium and Czapeck agar amended with 1.8%, 2%, 2.5%, and 3% potassium chlorate. Nit mutants were divided into three phenotypic (nit1, nit3, and nitM) classes based on their growth on different nitrogen sources in the culture media. Among the isolates tested, 280, 115 and 90 nit1, nit3, and nit M were generated, respectively. Nit mutants were used to force the heterokaryon formation to determine the distribution of VCGs and their relation to pathogenicity and geographic origin. Forty-eight VCGs of F. verticillioides were isolated from sugarcane. Forty-six of the VCGs were represented by a single isolate, whereas the remaining two comprised two isolates. None of the VCGs was common.

The biological efficacy of some biorational and conventional insecticides against different stages of Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) was evaluated under laboratory and semi-field conditions. Seven different commercial products were tested, including the biorational insecticides: Spinosad, Mectin, Fitoverm, Match, Neemix in addition to two conventional insecticides: Actara and Actellic. Data indicated that all tested insecticides showed low toxic effects to L. decemlineata eggs, but most hatching neonates died shortly after hatching. All tested insecticides at their field rates showed high toxicity to larvae of L. decemlineata. The highest mortality was obtained in earlier instars, as compared to older ones, and mortality increased with the time of exposure. Moreover, the lower concentrations (up to 25% of the field rate) of Actara, Mectin, Spinosad, and Fitoverm showed high efficacy against L. decemlineata third instar larvae. Also, Actara caused the highest mortality in L. decemlineata adults, followed by Spinosad, Mectin, and Fitoverm as compared to Actellic, Match, and Neemix. In pupal bioassay, Fitoverm caused the greatest reduction in L. decemlineata adult emergence followed by Mectin, Actara, Actellic and Spinosad. In translocation bioassays, Actara caused the highest mortality in L. decemlineata 3^rd instar larvae or adults followed by Spinosad and Mectin. The residual activity of tested insecticides against third instar larvae was also evaluated. Actara, Spinosad, and Mectin were more persistent under field conditions, consequently the mortality rates after 30 days of application were 46.67%, 44.44%, and 35.56%, respectively.

Choke of grasses caused by Epichloë typhina occurred in 2008 and 2009 in more than 25% of grass seed stands of timothy (Phleum pratense and P. nodosum); a lower incidence was reported in orchard grass (Dactylis glomerata). A decline in disease incidence in 2010 was caused partly by a reduction in the total area of grasses grown for seed production and partly by a decrease of older grass seed stands. The incidence of choke in timothy varieties Odenwälder and Pampas was very high; they differed statistically from the other 24 grown cultivars. No difference was found among 21 varieties of orchard grass. The highest incidence of choke was observed in varieties Comer and Dolina (timothy) and Amera (orchard grass). The incidence of choke in cultivated varieties of Phleum spp. and D. glomerata was affected by stand age (the incidence of the disease in timothy was recorded in 13% of stands in the first cropping year and in 50% of stands in the fifth cropping year). Choke disease occurred in all regions where the species were grown for seed.

Sheath rot of rice and leaf blight of wheat caused by Pseudomonas syringae pv. syringae are the important bacterial pathogens of rice and wheat in Iran. The randomly amplified polymorphic DNA (RAPD) method was used to investigate the genetic diversity of 60 strains of P. s. pv. syringae obtained from rice and wheat in different growth stages. Cluster analysis by UPGMA method showed that strains were grouped into two clusters. The AMOVA analysis indicated that about 18% of the total genetic variation existed between two populations of rice and wheat, which showed the lack of host specialization in P. s. pv. syringae strains among rice and wheat. We confirmed that high genetic heterogeneity existed in the P. s. pv. syringae strains which are detectable by RAPD analysis, and that molecular and statistical analysis of RAPD fragments can be used both to distinguish between strains and to determine relatedness between them.

The attacks of adult Apate monachus (Fabricius) on pomegranate (Punica granatum L.) and carob (Ceratonia siliqua L.) trees in a plant nursery in southern Italy was described. The adult beetles produce circular holes and large sinuous tunnels on young trees that can involve the trunk and branches. The same plant can be affected by large numbers of such access holes. The adults appear during late June and reach a peak during the first three weeks of July. Given the increase in the spread of cultivation of these trees and, therefore, in the rate of spread of this pest species, further damage to crops is expected.

The literature linking Bt maize versus non-Bt maize and the changes in the fungal microflora spectrum and in the mycotoxins content have been summarised. The European corn borer reportedly promotes the infection of maize by Fusarium spp. Stalk and ear rots caused by Fusarium spp. are often related to mycotoxin accumulation in maize kernels. As a result, food and animal feed from maize are more severely contaminated with Fusarium mycotoxins: e.g. fumonisins (FUM), deoxynivalenol (DON), and zearalenone (ZEA). Mycotoxins in field maize lead annually economic losses of hundreds of millions of dollars in all regions of the world. The insecticidal proteins in genetically modified hybrid Bt maize reduce insect damage caused by certain Lepidopteran larvae, which in turn can reduce the infection of the grain by the mycotoxigenic fungi. Where such insect damage is a major factor in mycotoxin contamination, Bt maize can lower mycotoxin levels in many cases. The protection of maize plants against insect damage (European corn borer) through the use of Bt technology seems to be one of the ways to reduce the contamination of maize by Fusarium species and mycotoxins.

The reaction of five apple cultivars to olive wilt caused byVerticillium dahliae Kleb was evaluated. Five apple cultivars (Royal Gala, Delicious Anabri, Double Red, Golden Delicious, Granny Smith) and one olive cultivar (Nabali Mohassan) were inoculated with V. dahliae and grown under partially controlled greenhouse conditions. Typical symptoms of the disease were developed on the inoculated olive seedlings. However, all tested apple cultivars did not show the typical symptoms of Verticillium wilt except cv. Delicious Anbari, which showed 8.31% disease severity. The average percentage of disease severity was 61.2% in Nabali Mohassan. The pathogen was positively re-isolated from the inoculated seedlings of cvs Nabali Mohassan and Delicious Anbari after 12 months from the inoculation date. Results indicate that an apple plantation to replace dead or severely diseased olive trees infested with Verticillium wilt is an appropriate low-cost and environmentally sound IPM alternative approach to control Verticillium wilt.

Chemical seed protectants are used to reduce the adverse effects of seedling fungal pathogens or insect attack on legume pastures and crops. Chickpea seeds are also frequently treated with Mesorhizobium sp. Cicer inoculant to promote effective symbiotic nitrogen fixation (SNF), which seems to be a cost effective measure. The population of viable Mesorhizobium sp. Cicer on seeds of chickpea declined with time of storage (4°C) in pesticide treated and untreated chickpea seeds in vitro. A significant reduction in chickpea rhizobia was observed in seed treatment with Captan followed by Endosulfan and Chlorpyrifos. In a field experiment during the winter season 2006-2008, no difference in the emergence count of chickpea plants was observed. Treatments inoculated with Mesorhizobium sp. Cicer alone or along with Captan, Chlorpyrifos or Endosulfan showed improved plant growth and symbiotic parameters (plant height, nodulation, leghaemoglobin content, and nitrogen content) in comparison with the uninoculated control treatment. Significantly higher grain yield (9.6%) was observed in the treatment inoculated with Mesorhizobium sp. Cicer alone as compared to the uninoculated control. A non-significant difference in grain yield among treatments where Mesorhizobium sp. Cicer along with a mixture of fungicide and insecticides was applied was observed in contrast to the Mesorhizobium sp. Cicer treatment. In conclusion, the recommended rates of fungicide and insecticides as seed treatment were not detrimental to chickpea-Mesorhizobium sp. Cicer symbiosis, hence they can be safely used to obtain higher productivity.

32 experimental plots were sown at Borovce (district Trnava) in Slovakia during 2008 with 8 maize hybrids, including coleopteran-protected MON 88017, the lepidopteran-protected MON 89034, the stacked product, MON 89034 × MON 88017, that same hybrids isoline that did not have the Bt trait or traits, and 4 commercial hybrids. Part of the fourth repetition was unexpectedly infested and damaged with the Western corn rootworm (WCR). High numbers of the WCR adults were found in the damaged plots on July 8. Adult WCR abundance remained concentrated in this area until August 12-19. The beetles apparently began to disperse during August 19-September 2, and after September 2. The trap captures increased in the uninfested areas up to September 16, no significant difference having been found in the adult WCR captures between the infested and uninfested plots, including the plots with MON 88017. Bt-maize hybrids containing MON 88017 strongly influenced the level of the WCR damage as assessed by lodging of the maize plants, and they also influenced the numbers of the WCR adults before maize flowering. We found that intensive movement of the WCR adults from the place of their origin started later in the vegetation season.

Ornamental nurseries, garden centres, public gardens and urban greenery in the Czech Republic were surveyed in 2006-2009 for the presence of Phytophthora spp. and the diseases they cause on ericaceous plants. Diseased plants such as Rhododendron spp., Pieris floribunda, Vaccinium sp., and Azalea sp. showed various symptoms including leaf spot, shoot blight, twig lesions or stem, root and collar rot. Nearly 140 Phytophthora isolates were collected from symptomatic plants in different areas of the country. Of the Phytophthora spp. on ericaceous plants or in their surroundings, P. plurivora appeared to be the most common species. Herein, we focus on the most frequently occurring species, P. plurivora, and describe its morpho-physiological and pathogenicity features and confirm its identity based on ITS sequences of rDNA. In addition, we give a list of other Phytophthora spp. including P. cactorum, P. cambivora, P. cinnamomi, P. citrophthora, P. megasperma, P. multivora, P. ramorum, and P. gonapodyides that we identified on the basis of their cultural and morphological characteristics and DNA sequences. We also discuss their importance in cultivated and natural ecosystems.

Field efficacy of seven geographical isolates of Helicoverpa armigera nucleopolyhedrovirus (HaNPV) along with an insecticide control was evaluated against H. armigera on cotton and chickpea in the Coimbatore district of Tamil Nadu, India. Among the HaNPV isolates, CBE I (Coimbatore) and NEG (Negamum) applied at 3.0 × 10¹² POB/ha to cotton and 1.5 × 10¹² POB/ha to chickpea with an adjuvant, crude sugar, significantly reduced the H. armigera larval population and increased the yield. CBE I and NEG recorded the highest yield of 2038 kg/ha and 2033 kg/ha, which was on a par with endosulfan (2026.7 kg/ha) with cost/benefit ratios of 1:2.32, 1:2.48, and 1:1.12, respectively, on cotton. In chickpea grain yields of 980, 983, and 973.3 kg/ha and cost/benefit ratios of 1:1.36, 1:1.48 and 1:0.87, respectively, in CBE I, NEG and endosulfan treated plots were obtained. The isolate RAJ (Rajasthan) recorded the lowest yield comparable to that of the untreated control in both crops.

The susceptibility to five new insecticide mixtures: chlorosan, feroban, cygron, engeo, and kingbo was studied in the 2^nd and 4^th instar larvae of the cotton leafworm Spodoptera littoralis (Boisd.). The efficiency and residual effects of these compounds against S. littoralis under field conditions were also investigated. Obtained results revealed that feroban was the most effective compared with the other toxicants, while engeo was the least toxic insecticide in both instars after 2 and 5 days from treatment. Data also indicated that feroban had the longest half-life (Lt₅₀) while engeo recorded the shortest one. Biochemical analysis showed that the tested compounds caused pronounced changes in acetyl cholinesterase and phenol oxidase.

The Fusarium species associated with maize are widely distributed in Malaysia. Eight Fusarium species were obtained in this country. A series of field samplings was conducted from 2006 to 2008, when 167 Fusarium isolates were obtained from maize plants in seven locations throughout Malaysia. The determination was based on micro- and macromorphological features (growth rates, colony features, mode of production of microconidia, macroconidia, conidiophores, and chlamydospores). F. proliferatum (29.9% isolates), F. semitectum (22.2% isolates), F. verticillioides (13.7% isolates), and F. subglutinans (12.6% isolates) were found out most frequently. F. equiseti, F. pseudograminearum, F. oxysporum, and F. solani were also isolated. This is the first report on the occurrence of F. equiseti, F. pseudograminearum, and F. subglutinans associated with maize plants in Malaysia.

Sorghum anthracnose is a disease of worldwide importance and host-plant resistance is the most practical method of disease management. In this study, 154 sorghum accessions from the Botswana collection maintained by the United States National Plant Germplasm System were inoculated with Colletotrichum sublineolum and evaluated for disease resistance at the Tropical Agriculture Research Station in Isabela, Puerto Rico during 2007 and 2008. A resistant response was observed for 69 accessions in 2007 and for 48 accessions in 2008 with no acervuli development observed on inoculated leaves. The low frequency of resistant germplasm is expected from a region of low annual rainfall. However, disease severity was low for the susceptible accessions with a mean severity of 11% for the 85 susceptible accessions observed in 2007 and 17% for the 106 susceptible accessions identified in 2008. The highest frequency of resistant accessions was observed for the Ngamiland district with 58% of the accessions rated as resistant, whereas the frequency of resistant accessions ranged from 22% to 36% for the other districts. The lowest mean disease severity was also observed for the susceptible accessions from the Ngamiland district with the highest mean disease severity observed for susceptible accessions from the Kgatleng district. The resistant accessions identified in this study would be useful for the development of disease resistant varieties and the results indicated an ecogeographic association with disease resistance.

In November 2009 the gall midge species Horidiplosis ficifolii Harris 2003 was detected in the Czech Republic on leaves of an ornamental fig Ficus microcarpa. The insect is native to South East Asia, where it lives on the genus Ficus. No information is currently available on the prevalence of the pest in the countries of its origin. Imported Ficus plants from China into the Netherlands are sometimes heavily infested with the gall midge. In Europe it is also known from Denmark and the United Kingdom. As Horidiplosis ficifolii is a tropical species, no environmental and social damage is expected.

A downy mildew was observed on Buddleja × weyeriana Weyer ex Rehd. (B. davidii × globosa) cv. Sungold in a nursery in the northern part of the Czech Republic in July 2008. This downy mildew disease of Buddleja (Butterfly Bush) had been unknown in the country so far. Characteristics of visual symptoms and microscopic features are described. The morphology of the fungus was typical for Peronospora hariotii, conforming to the published description by GÄUMANN (1919). The sexual stage was not found. This is the first report of Peronospora hariotii causing leaf spot disease on Buddleja in the Czech Republic.

Bifenazate, a new selective carbazate acaricide, seems to be a very good substitute for propargite to control spider mites (Tetranychus urticae Koch) on hops in the Czech Republic. To investigate the phenomenon of T. urticae resistance to this compound, 20 samples of field populations were taken in several Czech and Moravian hop-growing regions in 2006 and 2007 and subjected to laboratory tests in a Potter tower. Low values of C100 M (100% mortality) in comparison with the supposed registered concentration reveal that bifenazate may become a useful acaricide within the anti-resistant strategy against T. urticae not only in Czech but also in all European hop-growing regions.

Forty plant parasitic nematode species were identified in soil of fruit orchards in the southeastern and southwestern areas of the Danubian Lowlands and East Slovak Lowland, characterised by light sandy soil of riverine origin, locally combined with drift sand landscape. They were Ditylenchus dipsaci, Helicotylenchus canadensis, H. digonicus, H. dihystera, H. multicinctus, Rotylenchus agnetis, R. fallorobustus, R. goodeyi, Rotylenchulus borealis, Pratylenchus crenatus, P. penetrans, P. pratensis, P. thornei, Zygotylenchus guevarai, Pratylenchoides laticauda, Meloidogyne hapla, Bitylenchus dubius, Tylenchorhynchus cylindricus, Merlinius nanus, Macroposthonia antipolitana, M. rustica, M. xenoplax, Paratylenchus bukowinensis, P. elachistus, P. nanus, P. projectus, Longidorus elongatus, L. euonymus, L. juvenilis, unidentified Longidorus sp., Xiphinema diversicaudatum, X. italiae, X. pachtaicum, X. taylori, X. vuittenezi, Trichodorus primitivus, T. sparsus, T. viruliferus, Paratrichodorus macrostylus and P. pachydermus. Many of the observed species are phytopathologically important parasites of fruit trees and some are also vectors of plant viruses. The frequency of occurrence, dominance and abundance of individual species were determined.

The continued use of waste water for irrigation of agricultural fields in Egypt may lead to accumulation of heavy metals in soils and adverse effects on soil-living communities. We investigated responses of oribatid communities to heavy metal contamination in mango plantations irrigated by the Ismailia canal in the Suez region. Mean concentrations of heavy metals determined in irrigation water were considerably above the recommended levels. Concentrations of metals in agricultural soil were however below the permissible levels. A comparison with concentrations of a typical uncontaminated soil in this area revealed that the Ismailia water canal used for irrigation of agricultural land has elevated levels of heavy metals. The results of our ecological survey showed that the abundance and structure of the soil oribatid communities were not influenced by levels of heavy metals in the soil. We also showed that the diversity index can be a valuable tool for assessing the possible impact of pollutants on different species of oribatid mites. The oribatid species appeared to be accumulating different amounts of heavy metals when characterised by their bioconcentration factors. Most species were poor zinc accumulators. The accumulation of heavy metals in the body of oribatids was not strictly determined by their body size or by the trophic level. In conclusion, our study showed that mango plantations impacted by waste water from the Ismailia canal are accumulating heavy metals in their soils above the background concentrations, but ecological effects on soil-living communities are not apparent yet.

Twenty fungal species were isolated from sclerotia of ergot (Claviceps purpurea) originating from rye. In in vitro tests with the anamorphic stage of ergot (known as Sphacelia segetum) high mycoparasitic activity was exhibited only by two of them - Clonostachys rosea and Trichoderma harzianum, moderate mycoparasitic activity was detected in Ulocladium sp., Clonostachys catenulata, Trichoderma hamatum, and Trichothecium roseum. In in vitro tests of mycoparasitic activity with sclerotia of the fungus Sclerotinia sclerotiorum their rapid and total destruction was brought about only by the fungi Clonostachys rosea and Trichoderma harzianum. The viability of overwintering ergot sclerotia in the soil was influenced by their placement, age, depth of placement and treatment with a conidial suspension of the fungus Clonostachys rosea. The highest viability values were reported in fresh one-year-old sclerotia. In two-year-old sclerotia their viability was reduced and their sensitivity to microbial activity was higher. The sclerotia aged 3 years or more did not germinate and were all microbiologically degraded in the soil. More than 80% of degradation of sclerotia which were 1 to 2 years old was caused by the fungus Clonostachys rosea. The degradation of sclerotia aged 3 to 4 years was brought about by bacteria, soil edafauna (mites, nematodes) and fungi of the genera Trichoderma, Fusarium, Clonostachys, etc.

The interaction between Plasmodiophora brassicae and its host Brassica rapa is investigated by two strategies. (1) IAA-conjugate hydrolases: Root hypertrophy in club root disease is dependent on increased auxin levels and these could result from auxin-conjugate hydrolysis. So far we isolated 5 different cDNA fragments out of various tissues which revealed high identity to IAR3/ILL5, ILL2, ILL3, ILL6 and ILR1 genes from Arabidopsis by comparison with database entries. (2) Random priming: Using this method, we have so far obtained 26 clones from clubroot tissue, from which several sequences may be components of plant signal transduction chains, metabolic pathways and transcriptional regulation.

The effects of droplet spectra, spray volume, and the addition of an adjuvant to the spray solution against Phytophthora infestans were evaluated using contact fungicides, mixtures of contact and systemic fungicides, and a contact fungicide + an adjuvant. Six droplet spectra, ranging from VMD = 183 µm to VMD = 939 µm, were used. The spray volumes were 300, 450 and 600 l/ha for the contact fungicides, and 300 l/ha was used for the mix of contact with systemic fungicides. No significant differences in efficiency were observed between different droplet spectra when used for the mix of contact with systemic fungicide treatments. However, the efficiency of treatments with a contact fungicide significantly increased with smaller droplet spectra. The larger droplet spectra required larger spray volumes for greater efficiency. The addition of the adjuvant (pinolene, 96%) to the spray solution of the contact fungicide caused the efficiency to be similar for all droplet spectra. The effect of droplet spectra is more pronounced in contact compounds. The translocation of the systemic compounds and the ability of the surfactant to improve the coverage with contact compounds may be the main mechanisms that counteract the effects of larger droplet spectra and lower leaf coverage.

Resistance to powdery mildew (Blumeria graminis (DC.) E. O. Speer f.sp. tritici Em. Marchal) in Aegilops crassa Boiss., Ae. ventricosa Tausch, Ae. biuncialis Vis., Ae. triuncialis L. and Ae. cylindrica Host was tested at the stage of primary leaves in the years 2000 and 2001. All plants of Ae. ventricosa, Ae. biuncialis and sample No. 9 of Ae. cylindrica repeatedly showed a susceptible reaction after being inoculated by all powdery mildew isolates used. In contrast, plants of Ae. crassa, sample No. 8 of Ae. cylindrica and all samples (No. 13, 21, 22, 24 and 26) of Ae. triuncialis were resistant to all isolates. Samples No. 5, 6, 7, 19 and 23 of Ae. cylindrica contained resistant and susceptible plants in both years. Virulence to these samples ranged from 3% to 18%. Cluster analysis using DNA microsatellite markers showed that the accessions are arranged in groups based on taxonomic relationship but not on basis of resistance. Plants susceptible to powdery mildew at the juvenile stage showed satisfactory adult plant resistance.