Effect of season, trash and fungicides on fungi associated with subterranean clover

1986 ◽  
Vol 26 (4) ◽  
pp. 431 ◽  
Author(s):  
MJ Barbetti
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Field Studies ◽  
Population Changes ◽  
Fusarium Spp ◽  
Fungal Population ◽  
Trichoderma Spp ◽  
Disease Symptoms ◽  
Previous Season ◽  
Clover Pasture

In field studies we monitored the effects of time of season, trash and fungicides on the populations of fungi associated with leaves and petioles of newly sown subterranean clover, particularly in relation to the development of disease symptoms. These effects were compared with the fungal population changes occurring in a nearby established subterranean clover pasture. A range of fungi, notably Leptosphaerulina trifolii, Phoma medicaginis and Stemphylium globuliferum, were found to colonise subterranean clover cotyledons, leaves and petioles readily throughout the growing season from as early as 1 week after emergence. The incidence of L. trifolii and S. globuliferum was reasonably consistent throughout the growing season. Alternaria spp., Cladosporium spp., Myrothecium verrucaria, P. medicaginis and Trichoderma spp. were more prevalent later in the season. Fusarium avenaceum and other Fusarium spp. were more prevalent early in the season, while Pithomyces chatarum and S. botryosum were more prevalent midseason. The fungi isolated showed no ability, under the conditions of this investigation, to cause disease, and there was no correlation between fungi isolated and disease symptoms observed. The incidence of several fungi, especially L. trifolii and P. medicaginis, was greatly increased by the presence of trash from the previous season but was greatly decreased by regular applications of fungicide.

FACTORS INFLUENCING INFESTATION AND INJURY OF RUTABAGAS BY ROOT MAGGOTS (DIPTERA:ANTHOMYIIDAE) IN PRINCE EDWARD ISLAND. I. FIELD STUDIES

1958 ◽  
Vol 38 (2) ◽  
pp. 188-198 ◽  
Author(s):  
D. C. Read
Keyword(s):  
Sandy Soil ◽  
Prince Edward Island ◽  
Growing Season ◽  
Field Studies ◽  
Clay Loam ◽  
High Moisture Content ◽  
High Moisture ◽  
Previous Season ◽  
Hylemya Brassicae ◽  
Root Maggot

Examinations of more than 100 rutabaga fields per year, from 1951 to 1955, showed that Hylemya brassicae (Bouché) was the only species of root maggot that injured rutabagas in Prince Edward Island. H. liturata (Mg.) (= H. trichodactyla (Rond.)), H. cilicrura (Rond.), and Muscina stabulans (Fall.) were associated with H. brassicae but did not injure the roots. H. brassicae flies [note Whitcomb (12) for illustrations] began to emerge from overwintered puparia early in June in sandy soil areas and late in July in clay loam areas. Heavy texture and high moisture content of soils were closely correlated with the delay in emergence. The flies laid their eggs near rutabaga plants, usually in crevices in the soil, and upon hatching the larvae entered and fed on the roots. Larvae generally entered the roots at a depth of one inch or more below the surface of the soil. In general, early-planted rutabagas in sandy soil areas and late plantings in clay loam areas were severely damaged by larvae of H. brassicae, whereas late plantings in sandy areas and early plantings in clay loam areas were lightly infested. However, in the sandy soil areas where all of the rutabaga crops were harvested early in August damage was relatively light. Also, fields isolated by other rutabaga fields from sources of infestation such as storage bins and infested rutabaga crops, of either the current or the previous season, were usually slightly damaged. Use of barnyard manure increased H. brassicae infestations early in the season but did not significantly influence the damage caused during the whole growing season.

scholarly journals Use of bulk hybrid populations to select for adaptation to contrasting environments in subterranean clover

2006 ◽  
Vol 12 ◽  
pp. 157-162
Author(s):  
Phillip Nichols ◽  
Philip Cocks
Keyword(s):  
Subterranean Clover ◽  
Farming Systems ◽  
Growing Season ◽  
Fine Tuning ◽  
Hybrid Population ◽  
Population Changes ◽  
Trial Management ◽  
Pasture Legumes ◽  
Different Populations ◽  
Selection For

Population changes were measured over 17 years within a highly variable bulk hybrid population of subterranean clover in a short and long growing season mediterranean-type environment in Western Australia. Flowering time was used as an indicator of evolutionary change and was highly responsive to environment. Markedly different populations evolved, with rapid selection for early flowering at the short growing season site and later flowering at the long growing season site. The use of bulk hybrid populations is suggested as a low-input means of breeding and selecting annual pasture legumes adapted to target environments and farming systems. While adapted genotypes can be selected after just 3 seasons, further adaptive fine-tuning occurs with increased homozygosity. The success of the method hinges on the original parents containing genes for desirable characters, trial sites being representative of target environments and trial management being representative of typical farm practice

The effect of grazing on a perennial veldt grass, subterranean clover pasture

1952 ◽  
Vol 3 (2) ◽  
pp. 148 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Perennial Grass ◽  
Subterranean Clover ◽  
Late Summer ◽  
Growing Season ◽  
Early Summer ◽  
Pasture Production ◽  
Continuous Grazing ◽  
Winter Grazing ◽  
Consistent Treatment ◽  
Clover Pasture

The results of a grazing trial with Merino wether sheep on perennial veldt grass with subterranean clover are presented. During the four years 1944-45 to 1947-48 total pasture production under continuous grazing was almost identical with that under rotational grazing (one week's grazing followed by five weeks' rest). No consistent treatment differences were observed in sheep body-weight trends. In each year the weights increased during the growing season, remained stationary during early summer, and declined in late summer. The contribution of the perennial grass (Ehrharta calycina Sm.) declined rapidly with time, though more so under continuous grazing. This was associated with an increase in the proportion of subterranean clover in the sward. The lack of persistence of Ehrharta calycina is attributed to selective grazing, together with susceptibility to drastic defoliation. Alternative schemes for the use of this grass, involving restricted winter grazing, are suggested.

scholarly journals Efficacy of Azoxystrobin on Mycotoxins and Related Fungi in Italian Paddy Rice

Toxins ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 310 ◽  
Author(s):  
Paola Giorni ◽  
Umberto Rolla ◽  
Marco Romani ◽  
Annalisa Mulazzi ◽  
Terenzio Bertuzzi
Keyword(s):  
Experimental Design ◽  
Growing Season ◽  
Paddy Rice ◽  
Aspergillus Versicolor ◽  
Fusarium Spp ◽  
Fungal Population ◽  
Fungicide Treatment ◽  
Maximum Value ◽  
Mycotoxigenic Fungi ◽  
Rice Samples

The efficacy of azoxystrobin was evaluated in the presence of mycotoxigenic fungi and relative mycotoxins in Italian paddy rice during the growing season in the field. Three experimental fields were considered and the applied experimental design was a strip plot with three replicates; rice samples were collected at four different growing stages. The efficacy of the fungicide treatment on rice fungal population was demonstrated with around 20% less total fungal incidence in sprayed samples compared to untreated ones; the same decrease was noted also in Fusarium spp. species but not in Aspergillus versicolor. Of the mycotoxins considered, ochratoxin A (OTA) and aflatoxins (AFBs) were never detected, deoxynivalenol (DON) was found in 46% of samples at levels always lower than 100 µg/kg, while sterigmatocystin (STC) occurred in all the paddy rice samples collected after flowering, with a maximum value of 15.5 µg/kg. Treatment with azoxystrobin was not effective in reducing DON contamination, but it had an important and significant effect on STC content, showing a decrease of 67% in the sprayed samples.

scholarly journals Anaerobic Soil Disinfestation Reduces Germination and Affects Colonization of Sclerotium rolfsii Sclerotia

2018 ◽  
Vol 108 (3) ◽  
pp. 342-351 ◽  
Author(s):  
Utsala Shrestha ◽  
Mary E. Dee ◽  
Bonnie H. Ownley ◽  
David M. Butler
Keyword(s):  
Field Study ◽  
C:N Ratio ◽  
Sclerotium Rolfsii ◽  
Field Studies ◽  
Growth Chamber ◽  
Fusarium Spp ◽  
Trichoderma Spp ◽  
Soil Disinfestation ◽  
Anaerobic Soil Disinfestation ◽  
Sclerotial Germination

Growth chamber and field studies were conducted with organic amendment mixtures of carbon (C) and nitrogen (N) at C:N ratios 10:1, 20:1, 30:1, and 40:1 and amendment rates of C at 2, 4, 6, and 8 mg/g of soil (C:N ratio 30:1) to evaluate anaerobic soil disinfestation (ASD) effects on germination and colonization of Sclerotium rolfsii. In the growth chamber, sclerotial germination was reduced in all ASD treatments regardless of C:N ratio (0.6 to 8.5% germination) or amendment rate (7.5 to 46%) as compared with nonamended controls (21 to 36% and 61 to 96%, respectively). ASD treatment increased Trichoderma spp. colonization of sclerotia, with consistently higher colonization in ASD treatments with amendment rates of C at 2 or 4 mg/g of soil (>87% colonization) compared with nonamended controls (<50% colonization). In the 2014 field study, sclerotial germination was reduced by 24 to 30% in ASD treatments when compared with the nonamended control. Sclerotial colonization by Trichoderma spp. was predominant; however, other potential mycoparasites (i.e., Aspergillus spp., Fusarium spp., zygomycetes, and other fungi) were present in the field study. Amendment C:N ratios in the range of 10:1 to 40:1 were equally effective in reducing sclerotial germination and enhancing colonization by potentially beneficial mycoparasites of sclerotia.

The effects of grazing on the phosphorus requirement of an annual pasture

1971 ◽  
Vol 22 (1) ◽  
pp. 81 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Maximum Growth ◽  
Grazing Pressure ◽  
Light Interception ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Phosphorus Requirement ◽  
Root Size

The applied phosphorus requirement of a pasture sown to subterranean clover was measured with and without grazing. Under moderate grazing pressure, in the year of establishment, the pasture required about 50 % more phosphorus than when ungrazed. In the following season, at a higher stocking rate, the grazed areas needed twice as much phosphorus as the ungrazed to make 90% of their maximum growth. In both years this difference in requirement between stocked and unstocked treatments was present throughout the growing season. Increased phosphorus requirement under grazing is associated with the need for greater uptake of phosphorus under conditions where redistribution of absorbed phosphorus within the plant is prevented by defoliation. It does not appear to be due to effects of defoliation on root size. Nor does it depend on differential light interception or on changes in botanical composition.

Influence of legume cover crops and conservation tillage on soil populations of selected fungal genera

1988 ◽  
Vol 34 (3) ◽  
pp. 201-206 ◽  
Author(s):  
C. S. Rothrock ◽  
W. L. Hargrove
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Conservation Tillage ◽  
Field Studies ◽  
Macrophomina Phaseolina ◽  
Hairy Vetch ◽  
Fusarium Spp ◽  
Crimson Clover ◽  
Legume Cover Crops ◽  
Legume Cover Crop

The influence of winter legume cover crops and of tillage on soil populations of fungal genera containing plant pathogenic species in the subsequent summer sorghum crop were examined in field studies. Legume cover crops significantly increased populations of Pythium spp. throughout the sorghum crop compared with a rye cover crop or no cover crop. This stimulation of the populations of Pythium spp. was not solely due to colonization of cover-crop residue, as populations were significantly greater at the time the legume cover crop was desiccated. Removal of aboveground residue generally decreased populations of Pythium spp. in soil. Incorporation of residue by tillage increased populations of Pythium spp. at some sampling dates. Legumes differed in the magnitude of stimulation, with hairy vetch stimulating Pythium spp. more than crimson clover. Cover crop treatments did not consistently influence soil populations of Fusarium spp., Rhizoctonia solani, Rhizoctonia-like binucleate fungi, or Macrophomina phaseolina. Macrophomina phaseolina populations were significantly greater under no tillage.

scholarly journals PRODUCTIVITY OF PERENNIAL GRASSES AND MIXTURES WITH DIFFERENT SOWING DATES IN WESTERN SIBERIA

2020 ◽  
pp. 24-32
Author(s):  
V. A. Petruk
Keyword(s):  
Dry Matter ◽  
Crop Yields ◽  
Growing Season ◽  
Single Species ◽  
Field Studies ◽  
Perennial Grasses ◽  
First Year ◽  
Sowing Dates ◽  
Second Year ◽  
Sowing Period

The results of field studies for 2017 - 2019 are presented. yields of perennial grasses sown at different times of the growing season. Spring, summer, and winter sowing periods were compared. Alfalfa, clover, rump, and also their mixtures were sown in 2017 under the cover of barley. The value of the cover crop yield of spring and summer sowing periods did not differ significantly and amounted to 4-5 t / ha of absolutely dry matter. Winter barley crops have not formed. On average, over 2 years of use, the highest yields were observed in alfalfa-crust grass mixtures - 3.4 t / ha of absolutely dry matter. The lowest yield was obtained in the single-species seeding of the rump. Correspondingly, in the spring, summer and winter periods of sowing, the yield of rump was 1.6; 1.1 and 1.3 t / ha. With a late sowing period, the yield of perennial grasses is significantly lower compared to spring and summer. With winter sowing periods, the yield was the highest for grass stands of alfalfa and alfalfacrust grass mixture - 2.3 and 2.4 t / ha. It should be noted that in the second year of use, the yield by the sowing dates in single-species crops and grass mixtures is leveled. The winter crops of perennial grasses in the first year of use formed a low yield. Only in the second year (third year of life) the productivity of perennial grasses of winter sowing began to increase. Consequently, in the area under perennial grasses of the winter sowing period, during one growing season (the next year after sowing), the crop was not actually formed. Based on the data obtained, production can be recommended for spring and summer planting of perennial grasses under the cover of barley. The winter sowing period provides economically valuable crop yields only by the third year of life.

scholarly journals Occurrence of potentially toxigenic mould species in fresh salads of different kinds of ready-for-use vegetables

2010 ◽  
pp. 33-45 ◽  
Author(s):  
Suncica Kocic-Tanackov ◽  
Gordana Dimic ◽  
Jelena Levic ◽  
Dusanka Pejin ◽  
Jelena Pejin ◽  
...  
Keyword(s):  
Human Health ◽  
Ochratoxin A ◽  
Isolated Population ◽  
Fusarium Spp ◽  
Trichoderma Spp ◽  
Identification Of Species ◽  
Mycotoxin Biosynthesis ◽  
Isolated Species

In the mycological survey of fresh salads of different vegetables, the collected samples were tested for total counts of moulds with special attention paid to the presence of potentially toxigenic species. The survey also included the isolation and the identification of species, as well as the evaluation of mycotoxin biosynthesis ability of potential producers of ochratoxin A (OA) and sterigmatocystin (STC). Mould counts ranged from 10.0 to 4.7x102 cfu g-1. The most common moulds found in fresh salads were Cladosporium (42.89%), Penicillium (25.78%), Aspergillus (14.67%) and Alternaria (6.89%). C. cladosporioides (40.44%), followed by A. niger (10.22%), P. aurantiogriseum (7.55%), A. alternata (6.89%) and Fusarium spp. (3.11%) were the most dominating species. Other species were represented with 2.22% (Eurotium spp.), 1.56% (Botrytis spp.), 0.67% (Phoma spp.), 0.44% (Geotrichum spp., Mucor spp., Phialophora spp.) and 0.22% (Emericella spp., Paecilomyces spp., Trichoderma spp., Xeromyces spp.). Twenty-two of 41 identified mould species were potentially toxigenic, which accounted for 46.18% of the total isolated population. The most frequent were the potential producers of ochratoxin A (17.77%). Potential producers of moniliformin were isolated in 3.11% of samples, while producers of fumonisin and STC were found in 2.67% and 2.44% of samples, respectively. The tested isolates of OA producers did not demonstrate the ability to biosynthetise this mycotoxins, but two out of five isolates of A. versicolor were found to biosynthesise STC in doses of 109.2 ng mL-1 and 56.3 ng mL-1. The obtained results indicate that such products may threaten human health, considering that isolated species were potentially toxigenic, while isolates of A. versicolor also biosynthesised STS.

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