Template-Type: ReDIF-Article 1.0 Author-Name: editors Title: Index of Volume 35 (1999) Journal: Plant Protection Science Pages: I-IV Volume: 35 Issue: 4 Year: 1999 File-URL: http://pps.agriculturejournals.cz/artkey/pps-199904-0001_index-of-volume-35-1999.php File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9785-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Věra Minařiková Author-Name: Ivana Polišenská Title: Analysis of populations of Pyrenophora teres on barley in the Czech Republic Abstract: One of t he diseases that have become i mportant in the Czech Republ ic recently is net blotch of ba rley caused by Pyrenophora teres (Died.) Drechs., with the imperfect stale Drechslera teres. In 1 995-1997 infected leaves of both spring and winter barley were collected in various stands and climatic regions. Al most 400 isolates of the pathogen were obtained and tested for virulence using a differential set (Cl 5791. CI 2750, CI 9819, C 8755, Stcudclli, Harbin, C 29192, CI 739, Tifang. and the suscepti ble control Beate). To assess their reaction, the laboratory method for testing leaf segments on benzimidazole was used. The most stable resistant responses, compared also with previous tests from 1991-1994, were found in Cl 739 and Tifang where the frequency of viru lent isolates did not exceed I 0% of all tested ones. These genotypes should be involved in practical breeding of barley for resistance to the pathogen. Keywords: Hordeum vulgare, net blotch, leaf segment test Journal: Plant Protection Science Pages: 115-120 Volume: 35 Issue: 4 Year: 1999 DOI: 10.17221/9777-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9777-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9777-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Jaroslav Benada Author-Name: Antonín Pospíšil Title: Antagonistic microorganisms and medium moisture as possible sources of variation in common bunt (Tilletia tritici) incidence Abstract: Antagonistic soil microorgan isms decreased the germination of Tilletia tritici teliosporcs in dependence on the concentration of three formulations (Polyversum®, Supresivit® and lbefunginused and added in or on water agar. A higher content of water in the agar also decreased the germination, and water d rops on the agar surface inhibited it entirely. The presence and concentration of antagonistic microorganisms and soil moisture can vary in the soil and it is supposed that this may cause the variation in bunt incidence in field. This variation has to be taken into consideration in particular in variety trials. Polyversum® decreased the incidence of bunt in a field trial (efficacy 60%). Keywords: Tilletia tritici, Pythium oligandrum, Trichoderma har::ianum, Bacillus subtilis, water agar assays, field trials Journal: Plant Protection Science Pages: 121-123 Volume: 35 Issue: 4 Year: 1999 DOI: 10.17221/9778-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9778-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9778-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Josef Špak Title: Plant virusees, unique and intriguing pahtogens - a textbook of plant virology: Book Review Journal: Plant Protection Science Pages: 124 Volume: 35 Issue: 4 Year: 1999 DOI: 10.17221/9779-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9779-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9779-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Josef Šedivý Title: Population changes of the potato cyst nematode (Giobodera rostochiensis) during irregular crop rota­tion Abstract: For a period of 17 years, changes in the n umber of potato cyst nematode (PCN) cysts in the soil and in their contents were studied in two fields with an irregular crop rotation and growing resistant and susceptible potato cultivars. In all years, numbers of cysts per I 00 g of soil were higher at Skorkov (S) than at Ot radovice (0). At the beginning of the experiment, the percentages of empty PCN cysts were 30 and 28%, respectively, but they increased to 92.5 and 94.6%, respectively, by the end of it. The remaining cysts contained dead eggs/larvae and empty egg cases. Thus, the number of cysts per I 00 g of soil cannot be used to estimate the degree of soil infestation with the PCN without also knowing the number of viable stages in the cysts. When the experiment started the mean number of viable eggs/larvae per cyst was 62.7 in fields and 51.3 in field 0; no viable stages of the pest were found at the end of the experiment. Parallel to the decline in the number of viable eggs/larvae per cyst, the numbers of cysts with viable contents also declined in both fields. The mean number of dead eggs/larvae per cyst showed considerable variation in the course of the experiment. In fields it varied within a range of 1 5.9-69.4 individuals per cyst. Over the years the number of empty egg cases per cyst showed an irregular increasing trend. In field S their number varied from 34.9 to 1 97.5 per cyst. In field 0 from 46.3 to 218. No unequivocal negative effect of cropping resistant potato cultivars on the number of PCN cysts in the soil has been ascertained. In most years. The cropping of resistant cultivars was followed by an increased number of empty cysts in soil samples in both experimental fields. The effect of growing resistant cultivars on the number of viable eggs/ larvae was negative in both fields, resulting in decreased mean numbers of viable individuals per cyst. The mean number of dead eggs/larvae per cyst was variable. The number of empty egg cases was usually higher after the harvest of a resistant potato cultivar. The numbers of empty cysts and those with dead contents increased distinctly after an application of pig manure prior to growing the resistant cultivar and in subsequent years. The mean number of cysts in the soil, and of viable stages in the cysts also declined after a crop of rye. Regula r cropping of resistant potato cultivars at 3-year intervals, once interrupted by growing a susceptible plant cultivar, decreased the occurrence of viable stages of the PCN below the detectable level. Keywords: potato, Globodera rostochiensis, crop rotation, resistant cultivars, population density, cyst content, Czech Republic Journal: Plant Protection Science Pages: 125-130 Volume: 35 Issue: 4 Year: 1999 DOI: 10.17221/9780-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9780-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9780-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Shoki Al-Dobai Author-Name: Ján Praslicka Title: Effectiveness of aphid parasitoids (Hymenoptera: Aphidiidae) on winter wheat in two agricultural systems Abstract: From the obtained results we can note that the parasitoids in our experiments in 1 997 and 1998 had considerable influence on decline of aphids population density, at which the percent of parasitization in milk maturity stage of wheat was from 2.7 to 35%. The culmination of parasitization was recorded in our experiments about 7-10 days after the culmination of population density of aphids. The obtained results did not confirm the definite influence of different growing systems on parasitization of aphids, because in 1997 the parasitization was very high in integrated growing system and in 1998 in ecological growing system. The influence of different growing systems on aphids parasitization appeared during a given year and within an growing system. It also appeared between different years and it was found that these differences were significant. The parasitoids found were: Aphidius ervi Haliday, A. rlwpalosiphi De Stefani-Pcrcz, A. uzbekistanicus Luzhctzki, Praon volucre (Hal iday), Ephedrus plagialor (Nees), Diaeretiefla rapae (M'lntosh). In 1997, the most abundant species were Aphidius ervi and A. rhopafosiphi and in 1998 A. ubekistanicus and Aphidius ervi. Keywords: winter wheat, cereal aphids, Aphididae, parasitoids: Aphidiidae, Aphidius Journal: Plant Protection Science Pages: 131-135 Volume: 35 Issue: 4 Year: 1999 DOI: 10.17221/9781-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9781-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9781-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Eva Žďárková Author-Name: Radek Feit Title: Biological control of stored food mites on oilsecds using the mite predator Cheyletus eruditus (Schrank) Abstract: The suppressive biological control of mites on oilseeds can be successful under the circumstances of the ratio of prey and predators being I : 20 to 1 : 50 and the original infestation not being higher than 500 specimens per 1 kg. Preventive biological control was carried out in empty oilseed stores after they were cleared. The predators which were released in the stores 2000 specimen s being evenly distributed over an area of 100 m2 were successful and suppress the population of acaroid mites. Keywords: biological control, aca rid mites, Cheyietus eruditus: oilseeds Journal: Plant Protection Science Pages: 136-138 Volume: 35 Issue: 4 Year: 1999 DOI: 10.17221/9782-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9782-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9782-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Milan Zapletal Author-Name: Dagmar Obdržálková Author-Name: Jiří Pikula Author-Name: Jiří Pikula Author-Name: Miroslava Beklová Title: Geographic distribution of the field vole (Microtus arvalis) in the Czech Republic Abstract: The ecological distribution and requirements of the field vole (Microtus arvalis) were studied, using data on its population density in individual districts of the Czech Republic from 1955 to 1990. The field vole was found to be distributed from lowlands to the sub-alpine level, i.e., from 150 to 1600 m above sea-level. It inhabits continuously and reproduces regularly in nine different biotopes of the Czech Republic. Geographic areas of regular overcrowding of field voles correspond with areas of most suitable living conditions. Of climatic conditions the field vole prefers mainly moderately wa1m climatic regions and these are inhabited by 79.52% of its population. The analysis of quantitative requirements of the field vole indicates that there is a correlation between the distribution of this species and medium values of ecological factors. High and extremely high field vole densities are regularly encountered in areas amounting to I 0 057 km2, of which the field biotopes cover 5 072 km2. Keywords: field vole, geographic distribution, ecology, Czech Republic Journal: Plant Protection Science Pages: 139-146 Volume: 35 Issue: 4 Year: 1999 DOI: 10.17221/9783-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9783-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9783-PPS Template-Type: ReDIF-Article 1.0 Author-Name: N. Rafai Author-Name: M. Lacko-Bartošová Author-Name: R. Somr Title: Weed control by flaming and hot steam in apple orchards Abstract: Field experiments to investigate the efficacy of weed control by flaming, hot-steam and mulching on the natural weed flora at different developmental stages were conducted in apple orchards in Nova Scotia, Canada. The perennial weed most resistant to flaming was Malva neglecta, with no control at a total gas dose of 320 kg/ha. The effect of flaming on annual weeds depends mainly on the developmental stage of weed species and the propane dose required for the desired control level. To control annual weeds at later developmental stages (> 6 true leaves), single flame treatment with a propane dose of 54-40 kg/ha was not sufficient. For Chenopodium album three subsequent treatments were necessary for 95% control at a total propane dose of 162 kg per ha. For the flame control of Taraxacum officinalis the developmental stage is also crucial. If flame tolerant perennial weeds occurred in the orchard, only 76% weed reduction was achieved after four treatments and a total gas dose of 320 kg/ha. In an orchard with mainly annual weeds, three treatments and 162 kg/ha of propane controlled 95% of the weeds. The hot steam technology was not effective. An exposure time of 540 s at 150°C of the steam was not sufficient to control weeds. Mulching was a good alternative to reduce herbicide use, regardless of material used: coarse bark, saw-dust, hay. Keywords: ecological farming, apple orchards, flame weeding: hot steam weeding, mulching Journal: Plant Protection Science Pages: 147-152 Volume: 35 Issue: 4 Year: 1999 File-URL: http://pps.agriculturejournals.cz/artkey/pps-199904-0009_weed-control-by-flaming-and-hot-steam-in-apple-orchards.php File-Format: text/html Handle: RePEc:caa:jnlpps:v:35:y:1999:i:4:id:9784-PPS