scholarly journals Effect of some factors on the incidence of choke (Epichloë typhina) in grass seed stands in the Czech Republic

2012 ◽  
Vol 48 (No. 1) ◽  
pp. 10-16 ◽  
Author(s):  
B. Cagaš ◽  
R. Macháč

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.  

Plant Disease ◽  
1999 ◽  
Vol 83 (8) ◽  
pp. 754-758 ◽  
Author(s):  
W. F. Pfender ◽  
S. C. Alderman

A 1998 survey was conducted in the Willamette Valley of Oregon, the major U.S. production area for orchardgrass seed, to determine the extent and severity of choke disease in Dactylis glomerata. This disease is a severe constraint to orchardgrass seed production in other parts of the world, but was unknown in Oregon prior to 1997. Thirty-seven fields, representing 27 cultivars and the geographical extent of production in the Willamette Valley, were selected from a list of fields registered for certification. Choke was found in 26 (70%) of the fields, and disease incidence ranged from <0.05 to 28% tillers affected. Five of the 37 fields had only trace levels of the disease, but four of the fields, representing three counties, had incidences >10%. In a survey of 16 fields located within 3.5 km of the 1997 discovery, choke was found in 14 fields, of which three had incidences >20%. Increase in disease incidence between 1997 and 1998 ranged from 2.1- to 3.3-fold in the three fields where disease increase was measured. One year after its presence was confirmed in Oregon, choke disease of orchardgrass is well-established throughout the orchardgrass seed producing region at damaging levels and is apparently able to increase and spread under the prevailing climatic and cultural conditions.


1961 ◽  
Vol 93 (11) ◽  
pp. 1048-1049 ◽  
Author(s):  
G. E. Bucher ◽  
A. P. Arthur

The Essex skipper, Thymelicus (Adopaea) lineola (Ochs.), is said to have been introduced from Europe to the area of London, Ontario, about 1910 but attracted Iittie attention until 1955 (MacNay, 1956). Since then it has been found over most of southern Ontario (MacNay, 1959) and presently is causing damage to fields of timothy, Phleum pratense L., near Priceville, Ontario. As the larvae eat the leaves of timothy and orchard grass, Dactylis glomerata L., this species is a potential pest of forage crops.


2012 ◽  
Vol 38 (No. 1) ◽  
pp. 23-28
Author(s):  
J. Macháč ◽  
B. Cagaš ◽  
R. Macháč

The tolerance to or phytotoxicity of selected herbicides and their impact on seed yield was investigated in six grasses grown for seed: Phleum pratense cv. Sobol (a), Festuca rubra cv. T&aacute;borsk&aacute; (b), Festuca pratensis cv. Otava (c), Poa pratensis cv. Slezanka (d), Arrhenatherum elatius cv. Medi&aacute;n (e) and Dactylis glomerata cv. Zora (f). All species were tolerant to Grodyl 75 WG (amidosulfuron 75%), (a) and (f) were tolerant to Grodyl plus (amidosulfuron 15 g/kg + isoproturon 600 g/kg) which was phytotoxic to the other grass species; all species were tolerant to Stomp 330 E (pendimethalin 330 g/l); Lintur 70 WG (triasulfuron 4.1% + dicamba 65.9%) was phytotoxic only to (c) while the other species were tolerant to it.


2012 ◽  
Vol 52 (No. 4) ◽  
pp. 147-157
Author(s):  
J. Novák ◽  
M. Slodičák

European larch (Larix decidua Mill.) is one of the most important tree species in substitute stands of the Kru&scaron;n&eacute; hory Mts. (northern part of the Czech Republic). At present, young larch stands have dynamic height growth and their canopy is closing. Therefore, the proper forest treatment with respect to all functions of these stands is an urgent issue. The aim of the study is to recognise when it is possible to start with thinning and what types of thinning regimes are more suitable in larch stands with respect to their functions as substitute tree species stands. Research was conducted on experimental series Kalek established in a larch monoculture in 1999 (stand age of 12 years) at an elevation of 780 m above sea level in the category Piceeto-Fagetum oligo-mesotrophicum &ndash; Calamagrostis villosa. The presented analysis has two main parts: (a) effect of closing canopy on growth of larch &ndash; comparison of the groups of trees from border and inside rows and (b) effect of opening canopy on growth and development of young larch stands &ndash; comparison of two partial plots (500 m<sup>2</sup> each): the one without thinning and the other with thinning (negative selection mainly from above at the age of 13 years). Comparative analyses of trees from border and inside rows showed high growth dynamics of these young larch stands, and therefore the first thinning is necessary in this stage (by 15 years of age). In spite of air pollution, the growth of experimental stands is supernormal and exceeds the data from growth tables, but 60% of individuals showed some malformations, mostly one-sided or two-sided stem curvature. Five years after the first thinning we found a significantly lower h/d ratio of mean stem on the thinned plot in comparison with the plot without thinning. On the other hand, the applied thinning had no effect (five years after realisation) on the h/d ratio of dominant trees (200 thickest trees per hectare).


1977 ◽  
Vol 57 (1) ◽  
pp. 57-60 ◽  
Author(s):  
B. R. CHRISTIE

Twenty-seven topcross and nine polycross progenies of bromegrass (Bromus inermis Leyss) were evaluated for in vitro digestibility (IVD) and yield. Two groups of polycross progenies of orchard grass (Dactylis glomerata L.) were also evaluated. Bromegrass plants varied in IVD from 58 to 70%, while their topcross progenies varied from 58.2 to 64.6%. The correlation between parents and progeny was 0.55. Selection for high IVD did not result in any improvement over cv. Saratoga. One group of 10 orchard grass plants was high in IVD (62–66%), while the other was low (50–58%). The polycross progenies of these two groups were similar (68.2% vs. 68.5%). Selection for IVD was not effective in altering progeny IVD values.


1979 ◽  
Author(s):  
J. G. Kelton ◽  
P. B. Neame ◽  
I. Walker ◽  
A. G. Turpie ◽  
J. McBride ◽  
...  

Thrombotic thrombocytopenic purpura (TTP) is a rare but serious illness of unknown etiology. Treatment by plasmapheresis has been reported to be effective but the mechanism for benefit is unknown. We have investigated the effect of plasmapheresis in 2 patients with TTP by quantitating platelet associated IgG (PAIgG) levels prior to and following plasmapheresis. Both patients had very high levels of PAIgG at presentation (90 and A8 fg IgG/platelet respectively, normal 0-5). in both, the PAIgG levels progressively fell to within the normal range and the platelet count rose following plasmapheresis. One patient remained in remission with normal platelet counts and PAIgG levels. The other relapsed after plasmapheresis and the PAIgG level rose prior to the fall in platelet count. Plasmapheresis was repeated and resulted in normalization of both the platelet count and PAIgG level. It is suggested that plasmapheresis removes antiplatelet antibody or immune complexes which may be of etiological importance in this illness.


2010 ◽  
Vol 59 (2) ◽  
pp. 295-314 ◽  
Author(s):  
Imre Kádár

Egy műtrágyázási tartamkísérlet 32. évében, 2005-ben vizsgáltuk az eltérő N-, P- és K-ellátottsági szintek és kombinációik hatását a réti csenkesz (Festuca pratensis) vezérnövényű, nyolckomponensű, pillangós nélküli gyepkeverék termésére, fejlődésére és elemtartalmára. A termőhely mészlepedékes csernozjom talaja a szántott rétegben mintegy 3% humuszt, 3–5% CaCO3-ot és 20–22% agyagot tartalmazott, N és K elemekben közepesen, P és Zn elemekben gyengén ellátottnak minősült. A kísérlet 4N×4P×4K = 64 kezelést×2 ismétlést = 128 parcellát foglalt magában. A talajvíz 13–15 m mélyen helyezkedik el, a terület aszályérzékeny. A vizsgált 2005. évben azonban kielégítő mennyiségű (649 mm) csapadék hullott és annak eloszlása is kedvező volt. A gyep telepítése spenót elővetemény után 2000. szeptember 20-án történt gabona sortávra 60 kg·ha–1 vetőmaggal, amelynek 25%-át (15 kg) a réti csenkesz (Festuca pratensis); 21–21%-át (12,6 kg) a nádképű csenkesz (Festuca arundinacea) és az angol perje (Lolium perenne); 9%-át (5,4 kg) a taréjos búzafű (Agropyron cristatum), valamint 6–6%-át (3,6 kg) a vörös csenkesz (Festuca rubra), a réti komócsin (Phleum pratense), a zöld pántlikafű (Phalaris arundinacea) és a csomós ebír (Dactylis glomerata) tette ki. Főbb eredményeink: – A meghatározó N-trágyázás nyomán a szénatermés 5-szörösére emelkedett a két kaszálással a N-kontrollhoz viszonyítva. A maximális 10 t·ha–1 körüli légszáraz szénahozamokat a 300 kg N·ha–1·év–1 N-adag, valamint a 150 mg·kg–1 körüli AL-P2O5-, illetve 150 mg·kg–1 feletti AL-K2O-tartalom biztosította. Növénydiagnosztikai szempontból a nagy terméshez kötődő optimális elemtartalom 2% körüli N- és K-, illetve 0,2–0,3% P-koncentráció volt a szénában. – A két kaszálással felvett minimum (a 2 t·ha–1 körüli szénatermést adó N-kontroll) és maximum (a 10 t·ha–1 körüli szénahozamú, nitrogénnel és PK-vel jól ellátott talajok) elemmennyiségek a következőképpen alakultak: N 21–196 kg, K 39–188 kg, Ca 9–48 kg, Mg 4–22 kg, P 6–21 kg. – Az N×P és N×K kölcsönhatások kifejezettebbé váltak a 2. kaszálás idején. A P 0,18–0,55%, a NO3-N 86–1582 mg·kg–1, a Cu 4,7–7,4 mg·kg–1, a Mo 0,7–4,1 mg·kg–1 extrém értékeket jelzett az N×P kezelések függvényében. Az N×K kezelésekben a K 1,44–2,73%, a Mg 0,26–0,39%, a Na 71–2178 mg·kg–1, a Ba 4,1–9,6 mg·kg–1, a Cd 15–44 µg·kg–1 szélsőértékekkel volt jellemezhető. A Sr a 10–26 mg·kg–1 koncentrációtartományban módosult a P×K-ellátottság nyomán. Élettani, takarmányozástani szempontból az indukált kölcsönhatások nyomon követése elengedhetetlen, amennyiben olyan mérvű tápelemhiányok, illetve aránytalanságok jöhetnek létre, melyek anyagcserezavarokat okozhatnak a növényt fogyasztó állatban.


2016 ◽  
Vol 2 (91) ◽  
pp. 74-79
Author(s):  
V.H. Kurhak ◽  
M.I. Shtakal ◽  
V.M. Shtakal

There showed the productivity, chemical composition of feed and the timing of mowing of grass and variety mixes of permanent grasses on drained peat soils of Left Bank Forest-Steppe of Ukraine. The presence of early rip­ ened seeded grass provides a uniform supply use mowed mass from middle May until the end of September and the productivity of lands, which ranges from 10 to 14 t/ha of dry weight, metabolizable energy – 100.0 – 130.0 GJ and feed units 7-11 t/ha. Additional manuring of N90 on the background Р45К120 is effective at the start of second year of use. On the organization of hay conveyors of different ripening time herbages is possible to extend the optimal tim­ ing of mowing of green mass to 25-35 days. Best among the early-maturing grass crops are Dactylis glomerata va­ riety Kyivska rannia-1 with Alopecurus pratensis variety Sarnenskiy ranniy or its mixture with Bromus inermis and Festuca pratensis. With medium ripening – pure sowing eastern fescue of variety Lyudmila, Phalaris arundinacea variety Sarnenski-40, Bromus inermis variety Arsen and their compounds. High productivity of late-ripening herb­ age is provided by the inclusion in the composition of grass mixtures of Phleum pratense L. variety Vyshgorodska and Dactylis glomerata of variety Ukrainka, and Agrostis gigantea Roth variety Sarnenska piznia. It is also possible organization hay conveyors of different ripening varieties of Dactylis glomerata varieties Kyivska rannia, Muravka, Ukrainka.


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