WINTER CROWN ROT OR SNOW MOLD OF ALFALFA, CLOVERS, AND GRASSES IN ALBERTA: II. FIELD STUDIES ON HOST AND VARIETAL RESISTANCE AND OTHER FACTORS RELATED TO CONTROL

1952 ◽  
Vol 30 (5) ◽  
pp. 537-548 ◽  
Author(s):  
M. W. Cormack

Many overwintering cultivated and native plants proved susceptible to the low-temperature basidiomycete which causes winter crown rot or snow mold of forage legumes and grasses in Alberta. Tests were made by inoculation in the late fall, or by planting in infested land. In the legumes, high resistance was found only in Medicago falcata and a Siberian strain of Trifolium pratense. T. hybridum, Melilotus spp., and the commonly grown varieties of alfalfa were particularly susceptible. Bromus spp. and Agropyron spp. proved highly resistant. Resistance was moderate in Elymus spp., Poa pratensis, and Festuca elatior; and slight in F. rubra and Phleum pratense. Agrostis alba, winter wheat, and winter rye were highly susceptible. In tests on horticultural plants, rhubarb and chives appeared to be immune; raspberry, peony, and columbine were resistant; and strawberry, parsnip, iris, and tulip were highly susceptible. A wide range of native plants and weeds suffered severe damage, and only Thalictrum spp. proved highly resistant. Shrubs and trees were not attacked.Following severe damage, crop rotation proved to be essential for the control of winter crown rot. The pathogen did not persist in the soil to any extent for longer than two to three years in land which was summer-fallowed or planted to annual crops or resistant grasses. Brome and other resistant grasses proved helpful in maintaining forage stands. Fertilizer treatments did not reduce the damage. Uncut tops and debris favored spread of the disease in alfalfa stands.

1985 ◽  
Vol 65 (2) ◽  
pp. 363-368 ◽  
Author(s):  
J. A. IVANY ◽  
J. M. SADLER ◽  
E. R. KIMBALL ◽  
K. B. McRAE

Field studies on Prince Edward Island (P.E.I.) loam to fine sandy loam soils from 1977 to 1980 determined the rate of breakdown of atrazine and soil residue effects on crops grown in rotation with silage corn (Zea mays L.). The rate of breakdown was rapid during the first 30 days after application with an estimated half-life of 23 days when averaged over rates and years. Timothy (Phleum pratense L.) and red clover (Trifolium pratense L.) were most sensitive to atrazine residues; yields of red clover were reduced significantly from the 1.13-kg/ha rate and of timothy after the 2.25-kg/ha rate. Yields of winter rye (Secale cereale L.) broadcast seeded in standing corn in August and barley (Hordeum vulgare L.) seeded the next spring were not affected, or reduced only slightly, by atrazine residues from initial applications of 1.13 kg/ha but showed significant yield losses at the 2.25- and 4.50-kg/ha rates. Alfalfa (Medicago sativa L.) seeded the next spring after atrazine use was tolerant of residues showing significant yield losses only at the 4.50-kg/ha rate. In this study, atrazine applied at 1.13 kg/ha in silage corn was sufficiently broken down to permit production of all crops studied except red clover.Key words: Atrazine, residue, clover (red), timothy, alfalfa, rye (winter), barley


Author(s):  
Denes DEAK ◽  
Ioan ROTAR ◽  
Florin PACURAR ◽  
Anca BOGDAN

Seeded lawns is one of the most important links in the process of improving the forage base, ensure feed quality with high productivity. Mixtures of red clover crops (Trifolium pratense) with perennial grasses (Lolium multiflorum, Phleum pratense and Poa pratensis) has high productivity due to better utilization of ecological niches of the biotope (ROTAR I.et al.). These crops has advantages like high content of protein because of the red clover, economy-based fertilizer nitrogen from atmospheric nitrogen fixation by bacteria Rhizobium spp. located in the root of legumes. These seeded pastures get a balanced feed nutrients (proteins, carbohydrates, lipids), have a high palatability. The species Trifolium pratense has a greater capacity to restore the soil structure and also the enrichment of the macro-elements, like phosphorus and potassium (CARLIER L., et. al). Our experience took place in the village Simonesti, Cobătesti village of the Harghita county. The experimental field was located respecting the experimental technique rules in randomized blocks with a technique that includes three variants based on red clover plus a perennial grass (Lolium multiflorum, Poa pratensis and Phleum pratense). Every version was fertilized with two types of fertilizer: one liquid (gull) and one solid (stable manure) in four different doses in all three variants. The doses were: V1 = 0 gull; V2 = 5 t / ha gull; V3 = 10 t / ha gull; V4 = 20 t / ha gulle and V1 = 0 stable manure; V2 = 10 t / ha stable manure; V3 = 30 t / ha stable manure and V4 = 50 t / ha stable manure. In our studies we present the influence of fertilization with gull and stable manure on yield of green mass of all three variants. In general, both gull fertilization with manure favors grasses at the expense of installing legumes. The higher doses of fertilizer increase, the share of participant of grasses increases.


1964 ◽  
Vol 36 (1) ◽  
pp. 135-160
Author(s):  
Mikko Raatikainen ◽  
Terttu Raatikainen

Laihian pitäjässä on tutkittu 18 tilalta 49 avo-ojitettua kevätviljalohkoa. Kultakin lohkolta on tehty 2.—14.7.1961 välisenä aikana kevätviljasta neljä 0.25 m2:n suuruista näytealakuvausta eli yhteensä 196 näytealakuvausta. Näiden kevätviljalohkojen sisäisten sarkaojien pientareista on tehty sama määrä näytealakuvauksia. Näytealakuvauksia tehtäessä putkilokasvit on pyritty määrittämään lajilleen ja kunkin lajin peittävyys on arvioitu prosentteina. Pelloissa on todettu turvemaalla esiintyviksi 7, turvesavimaalla 2 ja savimaalla 21 lajia (taulukko 1). Pientareissa on todettu turvemaalla esiintyviksi 9, turvesavimaalla 6 ja savimaalla 19 lajia (taulukko 2). Esikasvi vaikuttaa kevätviljavaiheen kasvien yleisyyteen. Pelloissa on todettu kevätviljan jälkeen 7 lajin tai suvun olevan yleisemmän kuin nurmen jälkeen. Nurmen jälkeen on vastaavasti todettu 8 lajin olevan yleisemmän kuin kevätviljan jälkeen (taulukko 3). Kevätviljan jälkeen yleiset lajit ovat etupäässä yksivuotisia ja nurmen jälkeen yleiset monivuotisia. Pientareissa on todettu neljän lajin tai suvun olevan yleisemmän kevätviljan kuin nurmen jälkeen ja kuuden lajin yleisemmän nurmen kuin kevätviljan jälkeen (taulukko 4). Edellisistä lajeista kolme on yksivuotista ja yksi monivuotinen. Jälkimmäiset lajit ovat kaikki monivuotisia. Poa pratensis, Phleum pratense ja Trifolium pratense esiintyvät pientareissa etupäässä savimaalla, pelloissa turvemaalla. Pelloissa niitä viljellään etenkin turvemailla, tai niiden siemeniä joutuu sinne. Kyseessä olevat lajit eivät kuitenkaan kykene piennarkasvustoissa menestymään turvemaalla niin hyvin kuin savimaalla. Peltojen kasvillisuudesta on kuvattu kaksi kasvustoa, joista toinen esiintyy turve- ja toinen savimaalla. Samaan kasvustoon on luettu kaikki viljelykierrossa eri vuosina erotettavat osakasvustot, joita kutsutaan vuosiosakasvustoiksi. Kevätviljavaiheen vuosiosakasvustoja kuvataan taulukon 5 sarakkeissa 1 ja 3. Pientareiden kasvillisuudesta on myös kuvattu kaksi kasvustoa (taulukko 5, sarakkeet 9 ja 11), joista toinen esiintyy turve-, toinen savimaalla. Pelloissa on todettu 196 näytealalla yhteensä 78 ja pientareissa vastaavasti 112 lajia. Pientareiden lajeista on suhteellisesti suurempi osa kuin peltojen lajeista pienimmässä yleisyysluokassa. Lohkojen pelloissa ja pientareissa 1 m2:llä todetut lajimäärät ovat positiivisessa korrelaatiossa toisiinsa. 64 lajin on todettu esiintyvän sekä pelloissa että pientareissa. Näistä lajeista 52 on esiintynyt samalla lohkolla sekä pellossa että pientareissa. Näiden lajien yhtäläisyysverranteet ovat 0.3—50.0. Kevätviljapeltojen ja niiden sarkaojien pientareiden kasvustot ovat melko erilaisia. Suurimmat yhtäläisyydet ovat eräillä monivuotisilla piennarlajeilla.


1986 ◽  
Vol 66 (3) ◽  
pp. 601-608 ◽  
Author(s):  
B. E. GUDLEIFSSON ◽  
C. J. ANDREWS ◽  
H. BJORNSSON

A number of forage grass species were tested for cold hardiness and ice tolerance after growth and cold hardening under controlled conditions. Tests exposing cold-hardened plants to a single level of stress separated species into statistically similar groups but, in a number of cases, the stress was not sufficient to kill plants so the true cultivar rankings were obscured. Derivation of the 50% kill point from a wide range of levels of stress served to identify cold hardiness and ice tolerance levels of cultivars of 10 species. Ranked according to the most hardy cultivar of the species tested were: timothy (Phleum pratense L.), Kentucky bluegrass (Poa pratensis L.), meadow foxtail (Alopecurus pratensis L.), red fescue (Festuca rubra L.), meadow fescue (Festuca pratensis L.), tufted hairgrass (Deschampsia caespitosa L.), creeping foxtail (Alopecurus arundinaceus L.), berings hairgrass (Deschampsia beringensis L.), orchardgrass (Dactylis glomerata L.), reed canarygrass (Phalaris arundinaceae). LT50 values varied from −15.7 °C for timothy to −4.7 °C for reed canarygrass. Cold hardiness and ice tolerance were only loosely associated (r = 0.36). The most ice-tolerant species were berings and tufted hairgrasses and timothy with LI50 values of 50, 39 and 44 d, respectively.Key words: Acclimation, encasement, freezing, resistance


2020 ◽  
Vol 612 (1) ◽  
pp. 012045
Author(s):  
D A Postnikov

Abstract Floristic composition of terrestrial and aquatic plants in the ecotopes of surface water bodies, Blue Lakes and Lake Biserovo, was studied to assess environmental health of aquatic ecosystems in the Moscow region. The research was carried out both in the field and in the laboratory. Blue Lakes were lacking aquatic vegetation and the dominant synusia of the following plant species was found along the coastal zone: meadow clover (Trifolium pratense L.), meadow bluegrass (Poa pratensis L.), sedge coastal (Carex riparia Curt.), chamomile (Matricaria chamomilla L.), plantain (Plantago major L.), Timothy meadow (Phleum pratense L.). The vegetation cover of Lake Biserovo was patchy: submerged vegetation was most widespread, Canadian Elodea (Elodea canadensis Michx.) was the dominant species. Pure thickets of vegetation were formed only by the common American water plantain(Alisma plantago-aquatica L.), lake cattail (Schoenoplectus lacustris L.), common reed (Phragmites communis Trin.) and sedge coastal (Carex riparia Curt). It should be noted that in all the studied water bodies, the pH of the water area can be classified as very clean: Blue Lakes (7.8), samples from Lake Biserov (8.32). Water samples from Lake Biserova had the highest turbidity (11.5), which was associated with the accumulation of particles of the silt fraction of the reservoir, which began the process of eutrophication, high anthropogenic load. According to the results of a comprehensive assessment (hydrological indicators, calculation of the Mayer index) of the studied samples from the reservoirs, it was concluded that the water area of the Blue Lake had the best environmental status in the Noginsk region.


1984 ◽  
Vol 62 (11) ◽  
pp. 2193-2207 ◽  
Author(s):  
Paul F. Maycock ◽  
Malgorzata Guzikowa

A stable old field 5.4 ha in extent and undisturbed for at least 50 years is described qualitatively and in quantitative terms. Despite relative physiognomic uniformity, seven homogeneous areas were studied using presence and frequency and estimated cover in randomly distributed 1-m2 quadrats. Of the rich total flora of 118 species, 99 were found in the communities and only 61 had measurable cover. Agropyron repens, Vicia cracca, and Poa pratensis were major dominants followed by Solidago altissima, Phleum pratense, and Hieracium pratense. Although native (52%) outnumber introduced species (48%) in the field as a whole, in terms of cover, exotic plants may exceed indigenous species by at least 2:1 and perhaps as high as 4:1, depending on the designation of species of controversial origin. Solidago species seem to be the only native plants clearly capable of coping with the competition provided by exotics. Species respond to small differences in site moisture and to different stages of succession toward forest which appear to vary mainly with position in the field.


2016 ◽  
Vol 3 (3) ◽  
pp. 28-34
Author(s):  
V. Volkogon ◽  
I. Korotka

Aim. To determine physiologically expedient rates of mineral nitrogen in winter rye production on sod-podzol- ic soils based on the orientation of the processes of biological nitrogen transformation in the plants rhizosphere. Methods. Field studies, gas chromatography determination of potential nitrogen fi xation activity and potential emissions of N 2 O. Results. The results obtained have demonstrated that the rates of mineral nitrogen, not ex- ceeding 60 kg/ha, can be considered physiologically expedient for winter rye production on sod-podzolic soils. Under the application of microbial preparation Diazobakteryn, there is a higher physiological need of plants for nitrogen, which allows increasing the rates of nitrogen fertilizers up to 90 kg/ha. Conclusions. The orienta- tion of the processes of biological nitrogen transformation in the root zone of plants is a reliable indicator of determining the appropriateness of nitrogen fertilization of crops.


2010 ◽  
Vol 59 (2) ◽  
pp. 255-268
Author(s):  
István Harmati

Sekély humuszos szintű, erősen karbonátos réti talajon kialakult természetes (Achilleo-Festucetum pseudovinae) gyepen beállított tartamkísérletekben vizsgáltuk a műtrágyázás kérdéseit a gyep növényi összetételének megjavítása, termésének növelése és minősége javítása céljából. A kísérlet humuszban gazdag, nitrogénnel és káliummal igen jól ellátott, de foszforban szegény talaján az N- és P-műtrágya 2-2 adagját szólóban és kombinációikban alkalmaztuk. Az öntözetlen kísérletet 28, az öntözöttet 14 éven át folyamatosan, széleskörűen vizsgáltuk. Megállapításainkat a következőkben foglaljuk össze. – A gyep növényi összetételét a N- és a P-műtrágyák adagjaiktól és kombinációiktól függően megváltoztatták. A nitrogén a füvek, a foszfor a pillangósok versenyképességét fokozta és segítette elő növekedését. Az önmagában alkalmazott N-műtrágya a talaj nagyfokú P-szegénysége miatt nem gyakorolt pozitív hatást a gyepre. A P-műtrágya viszont kedvező változásokat okozott: a füvek fejlődésének elősegítése mellett nagymértékben növelte a pillangósok borítási értékét és tömegarányát, különösen az öntözött parcellákon. Öntözetlen viszonyok között a réti perje (Poa pratensis), a sovány csenkesz (Festuca pseudovina) és a komlós lucerna (Medicago lupulina) alkotta a gyep termésének túlnyomó részét, néhány egyéb fű- és pillangósvirágú komponens társaságában. Az öntözött kísérletben a pillangósok abszolút uralma mellett gyakran a réti perje jutott vezető szerephez. A pillangósok közül az eperhere (Trifolium fragiferum), a komlós lucerna (Medicago lupulina) és a vörös here (Trifolium pratense) váltakozva jutott uralomra. Az időjárás nagyban befolyásolta a gyep pillangós komponenseinek tömegarányát. Az NP kombinációkban a pillangósok tömegaránya erősen lecsökkent, különösen a nagyobb N-adag használata esetén. Öntözetlen területen a sovány csenkesz és a réti perje változó arányban alkotta a gyep termésének túlnyomó részét. Az öntözött parcellákon azonban a réti perje abszolút uralkodóvá vált és az egyre jobban előretörő tarackbúza (Agropyron repens) is jelentősen részt vett a termés kialakításában, elsősorban a nagyobb N-dózisú kombinációkban. A kísérlet 3. évtizedében a csapadékos években megjelent a francia perje (Arrhenatherum elatius) és a réti csenkesz (Festuca pratensis) is. – A gyep termését az önmagában alkalmazott N-műtrágya nem növelte jelentősen. Ezzel szemben a P-műtrágya nagy hatékonysággal 2–4-szeresére (3–5 t·ha–1-ra) növelte a gyep szénatermését, elsősorban a pillangósok nagyarányú térhódítása révén. 1 kg P2O5 öntözetlen körülmények között 43, míg öntözöttben 68 kg szénaterméstöbbletet eredményezett, sokévi átlagban. A 90 kg P2O5·ha–1 adag néhány év után soknak bizonyult. A legjobb eredményt a 200 kg N·ha–1 + 60 kg P2O5·ha–1 adaggal értük el, amellyel az öntözetlen területen – 28 év átlagában – 7,87, öntözötten – 14 év átlagában – 7,12 t·ha–1 szénatermést kaptunk. Az időjárás nagymértékben befolyásolta a termés mennyiségét és minőségét, legfőképpen a pillangósok tömegarányának változása révén, különösen az öntözetlen kísérletben. A három növedék tömegének aránya 7 évi átlagban, az öntözetlen kísérletben a szóló foszforkezeléseknél 48:37:15%, míg az NP kombinációknál 56:35:9% volt. Az öntözött területen ezek az arányok az előbbi sorrendben: 39:49:12, illetve 43:41:16%. A nitrogénből számított nyersfehérjehozam sokévi átlagban az öntözetlen kísérletben 428–550, míg az öntözöttben 560–760 kg·ha–1 volt. – A talaj felvehető tápanyagtartalma az évek során jelentősen megváltozott, különösen a talaj 0–10 cm-es rétegében. A P-trágyázás önmagában, de az NP kombinációiban is az adagoktól, illetve az ezek hatására kialakult termések mennyiségétől függő mértékben növelte a talaj P-tartalmát. A legjobbnak a 200 kg N·ha–1 + 60 kg P2O5·ha–1 kezelésű parcellákban bizonyult: a kísérlet 22. évében a talaj 0–10 cm-es rétegében a P-tartalom 260 mg P2O5·kg–1 lett, ami az erősen karbonátos talajok esetében igen jó P-ellátottságnak mondható. A K-ellátottság azonban az NP-kezeléseknél az optimális szint alá csökkent (172 mg K2O·kg–1) a termések nagyarányú K-kivonása következtében. Ezért néhány évi NP-trágyázás után K-pótlásra is szükség van.


Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 689
Author(s):  
Rudolf Brázdil ◽  
Kateřina Chromá ◽  
Tomáš Púčik ◽  
Zbyněk Černoch ◽  
Petr Dobrovolný ◽  
...  

In the Czech Republic, tornadoes may reach an intensity of F2 and F3 on the Fujita scale, causing “considerable” to “severe” damage. Documentary evidence is sufficient to allow the creation of a chronology of such events, from the earliest recorded occurrence in 1119 CE (Common Era) to 2019, including a total of 108 proven or probable significant tornadoes on 90 separate days. Since only 11 significant tornadoes were documented before 1800, this basic analysis centers around the 1811–2019 period, during which 97 tornadoes were recorded. Their frequency of occurrence was at its highest in the 1921–1930, 1931–1940, and 2001–2010 decades. In terms of annual variations, they took place most frequently in July, June, and August (in order of frequency), while daily variation favored the afternoon and early evening hours. Conservative estimates of human casualties mention 8 fatalities and over 95 people injured. The most frequent types of damage were related to buildings, individual trees, and forests. Tornadoes of F2–F3 intensity were particularly associated with synoptic types characterized by airflow from the western quadrant together with troughs of low pressure extending or advancing over central Europe. Based on parameters calculated from the ERA-5 re-analysis for the period of 1979–2018, most of these tornadoes occurred over a wide range of Convective Available Potential Energy (CAPE) values and moderate-to-strong vertical wind shear. The discussion herein also addresses uncertainties in tornado selection from documentary data, the broader context of Czech significant tornadoes, and the environmental conditions surrounding their origins.


Author(s):  
SYAIMAK ISMAIL ◽  
MOHAMAD SAUPI BIN ISMAIL ◽  
MUHAMMAD SAIFUL ISLAM ISMAIL ◽  
AEMY AZIZ

In the state of Melaka, there are eighteen islands recorded by the Melaka State Museum Corporation (PERZIM). Part of this island serves as a tourist island, and developed islands are also uninhabited islands. However, three islands are recorded to have amazing coral reefs that are still in good condition. The Penang Batu Maung Fisheries Research Institute (AkuaTAR) has conducted a study on the biodiversity of coral reefs around the waters of Pulau Dodol, Pulau Serimbun, and Pulau Undan. AkuaTAR researchers are using scuba diving methods, and at the same time, they did conservation on coral reefs that have been identified in the waters of the Straits of Melaka. The objective of this study is to record the types of community forms such as living corals and identify the species of coral reefs found in three islands in the state of Melaka in Pulau Undan, Pulau Dodol, and Pulau Serimbun. The study also implemented method observation by conducting field studies on the islands involved by doing scuba diving. Results and discussion of the search, these three islands are located in very clean, uninhabited waters. They have a wide range of coral biodiversity using soft coral reefs and hard coral reefs. The study also found that the three islands in the state have the largest coral reefs in the waters of the Straits of Melaka. Keywords: Biodiversity; Conservation; Coral; Three island; Melaka


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