scholarly journals Stem rust (Puccinia graminis ssp. graminicola Urban) its hosts and harmfulness in grasses grown for seed

2013 ◽  
Vol 55 (1) ◽  
pp. 285-298
Author(s):  
Maria Prończuk

Stem rust development on four species of grasses was studied in field experiments conducted at Radzików in 1997-2001. Population of <i>Puccinia graminis</i> ssp. <i>graminicola</i> from different hosts was characterised and their harmfulness for grass grown for seed was estimated. The materials for study were ecotypes and strains of <i>Lolium perenne</i>, <i>Festuca rubra, Poa pratensis</i> and <i>Deschampsia caespitosa</i> collected in breeding nursery and cultivars and strains of <i>L.perenne, F.rubra, P.pratensis</i> cultivated for seed. It was found that the changes in environmental conditions during last years influenced earlier occurrence of stem rust on grasses in Poland. All examined species were the host of <i>P.graminis</i> ssp. <i>graminicola</i>, however the period of infection of particular hosts were different. <i>L.perenne</i> and <i>D.caespitosa</i> were infected in early summer but <i>F.rubra</i> and <i>P.pratensis</i> in late summer or in the autumn. Morphological analysis of spores of <i>P.graminis</i> ssp. <i>graminicola</i> have shoved significant differences between populations obtained from <i>L.perenne</i> and <i>D.caespitosa</i>. Some differences were found between populations from <i>F.rubra</i> and <i>P.pratensis</i> also, but they need more study. Every year occurrence of stem rust on <i>L.perenne</i> and <i>D.caespitosa</i> and its relation with spring temperature in Radzików indicated that populations of patogen could overwinter in local turf. Incidental appearance of stem rust on <i>F.rubra</i> and <i>P.pratensis</i> in centre of Poland allowed to suppose that spores of these forms might be transfer by wind from other regions. The investigation revealed that stem rust can be dangerous for <i>L.perenne</i> grown for seed when infection occurs at flowering time. It has been established that infection of <i>F.rubra</i> and <i>P.pratensis</i> in autumn should not be disregarded. Damages of leaves by <i>P.graminis</i> ssp. <i>graminicola</i> substantially limited plant heading in the next year.

1988 ◽  
Vol 36 (4) ◽  
pp. 315-325 ◽  
Author(s):  
W.J.M. Meijer ◽  
S. Vreeke

In field experiments in 1981-86, Poa pratensis cv. Kimono and Baron and Festuca rubra cv. Agram and Koket were undersown in companion crops of winter wheat cv. Arminda. Cuts were made immediately after wheat harvest or 4-6 weeks later. N application as autumn and spring dressings did not alter the effects of cutting. In most experiments, cutting treatments increased production of inflorescence and seed yield, mainly due to better illumination, and increased survival of the late elongating reproductive tillers. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1997 ◽  
Vol 48 (7) ◽  
pp. 999 ◽  
Author(s):  
R. F. Park

Levels of stem rust (Puccinia graminis) in Australian wheat and barley crops were generally low from 1980 to 1992. Exceptionally wet conditions in South Australia (SA) during early summer 1992-93 resulted in the establishment of vast areas of self-sown cereals, in which stem rust increased rapidly. The disease was also more common in Western Australia during the summer months of 1992-93. Collections from rusted wheat, barley, and selected grass species were analysed in greenhouse tests using an array of differential cereal genotypes. Five pathotypes of P. graminis f. sp. tritici were recovered from SA, 3 of which had not been isolated over the previous 10 years in Australia and for up to 20 years in SA. The recurrence of these pathotypes highlights the need for caution in redeploying resistance genes for which virulence has not been detected for several years. The majority (79%) of isolates taken from stem-rusted barley in SA were either P. graminis f. sp. secalis or `scabrum" rust, both of which do not infect wheat. In total, 6 of 7 isolates of pathotype 21-2,7 recovered from SA came from stem-rusted barley, and as most wheats in this region are resistant to this pathotype, it appears that hosts other than wheat must be important in perpetuating such avirulent pathotypes.


Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 94-97 ◽  
Author(s):  
Donald L. Wyse ◽  
Laddie J. Elling ◽  
Donald B. White ◽  
Robert L. McGraw

Sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one}, RO-13-8895 {acetone-O-[d-2-[p-[α,α,α-trifluoro-p-tolyl-oxy]phenoxy] propionyl] oxime}, and KK-80 {4-[4-[4-(trifluoromethyl)phenoxy] phenoxyl]-2-pentenoic} were evaluated for potential use for controlling quackgrass [Agropyron repens(L.) Beauv., # AGRRE] in perennial ryegrass (Lolium perenneL. ‘NK200’), smooth bromegrass (Bromus inermisLeyss. ‘Sac’), orchardgrass (Dactylis glomerataL. ‘Nordstern’), timothy (Phleum pratenseL. ‘Climax’), Kentucky bluegrass (Poa pratensisL. ‘Park’), Reed canarygrass (Phalaris arundinaceaeL. ‘Rise’), meadow fescue (Festuca elatiorL.), and red fescue (Festuca rubraL.). The three herbicides, when applied postemergence at 1.1 kg ai/ha, caused severe injury to all species except red fescue. ‘Pennlawn’, ‘Ruby’, ‘Dawson’, MN67123, MN673, and MN6354 red fescue entries were tolerant to the three herbicides in both greenhouse and field experiments. Sethoxydim and RO-13-8895 effectively controlled quackgrass in Pennlawn red fescue, but KK-80 was not effective.


2017 ◽  
Vol 35 (1) ◽  
pp. 243-248 ◽  
Author(s):  
Danuta Urban ◽  
Antoni Grzywna

AbstractThe objective of this study was to examine the vegetation cover and describe the floristic diversity of selected plant communities of extensive and abandoned grasslands within the Forest of Parczew PLB060006 – a Natura 2000 protected area. Floristic surveys were conducted in the meadows in years 2001 and 2013 under the conditions of natural succession of the communities Poa pratensis-Festuca rubra. The area is situated in the northern part of the Lublin Voivodeship, in the physiographic mesoregion the Łęczna-Włodawa Lakeland. Those communities were characterized by average species richness and floristic diversity index values. The cover index decreased considerably in the case of 8 species, and increased for 12 species. A large increase in the cover index of Holcus lanatus, Deschampsia caespitosa, Galium mollugo, Anthriscus sylvestris and Polemonium caeruleae is particularly noteworthy. In 2001, 39 species of plants were recorded in all relevés, compared to 41 species recorded in 2013. Over 12 years, 11 species disappeared, but 13 new ones emerged. For the time being, the average species richness N increased from 12 to 16 per relevé. The biodiversity index H' increased from 2.8 to 3.6.


1985 ◽  
Vol 25 (2) ◽  
pp. 440 ◽  
Author(s):  
AH Mayfield

The potential commercial use of fungicides for control of stem rust (Puccinia graminis) of wheat was assessed in field experiments at two sites. Foliar sprays containing either triadimefon or propiconazole were the most effective in reducing disease severity. Chlorothalonil was effective only when applied at an early stage of disease development and where stem rust was not severe in control plots. Dichlone, fenarimol, nuarimol and 2-(thiocyanomethylthio) benzothiazole did not significantly reduce stem rust severity at either site. Even though treatments were applied at an early stage ofthe disease epidemic at one site, disease control on heads, peduncles and sheaths did not exceed 63,36 and 19%, respectively, with any treatment. Increases in grain yield and density, of up to 0.27 t/ha and 8.6 kg/hectolitre, respectively, were barely sufficient to cover the cost of treatment.


2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 12-13
Author(s):  
Jordan Adams ◽  
Rodney Farris ◽  
Scott Clawson ◽  
Earl Ward ◽  
Paul Beck

Abstract We evaluated the effects of supplementing dried distillers’ grains cubes (DDGS) and re-implantation of steers (n = 149; BW = 238 ± 13.8 kg) grazing tall fescue (Festuca arundinacea)/bermudagrass (Cynodon dactylon) pastures (n = 9 pastures, 7.2 ± 2.90 ha) from 14 April to 17 September 2020 (n = 155 d) in a split-plot design on steer performance and forage production. Main plot supplemental treatments (n = 3 pastures/treatment) included 1) Fertilized Control (FC), no supplementation on fertilized pastures (112 kg N/ha); 2) Fertilized Supplement (FS), supplemental DDGS fed at 2.9 kg 3-d/wk on fertilized pastures; and 3) Supplement (S), supplemented DDGS at 0.75% BW/d on unfertilized pastures prorated for 5-d/wk feeding. Steers were previously implanted during receiving with 40 mg trenbolone acetate and 8 mg estradiol (REV-G; Revalor G, Merck Animal Health). On July 7, steers in each pasture were randomly assigned to one of three re-implant treatments: 1) no re-implant; 2) REV-G; or 3) 200 mg progesterone and 20 mg estradiol (Synovex S, Zoetis Animal Health). Steers in FS and S gained more (P &lt; 0.01) than FC throughout the trial and final BW was greater (P &lt; 0.01) for FS and S compared with FC. Unexpectedly, re-implanting had no effect on ADG (P = 0.57) or BW (P = 0.34), but statistical power may be lacking. Supplemental efficiency was greater in the late summer for FS (P = 0.05) compared to S. Fertilizing pastures in FS and FC did not affect biomass (P = 0.39), however, CP was increased (P = 0.01) and acid and neutral detergent fibers tended to decrease (P = 0.06) relative to S in the early summer (April, May, June, and July), but did not differ in late summer (August and September). Based upon our analysis, DDGS is a suitable supplement and can replace N fertilizer for steers grazing introduced pastures.


2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 46-46
Author(s):  
Zane N Grigsby ◽  
Paul A Beck ◽  
Stacey A Gunter

Abstract This research was conducted to determine effects of supplementation and implanting on BW gain by steers grazing mixed grass prairie (n = 12 pastures, 19.9 ± 0.7 ha) in northwest Oklahoma. Three main plot treatments were: 1) Negative Control (NC), no supplementation, 2) Positive Control (PC), supplemented with DDGS cubes, 1.8 kg/steer on alternate days in late summer, 3) High Supplement (HS), 1/3 increase in stocking rate with 0.75% BW supplemental DDGS cubes all season. Steers (n = 125, BW = 223.1 ± 23.2 kg) were stocked at 2.2 ha/steer for PC and NC, 1.3 ha/steer for HS. Grazing was from May 17 – September 27 (132 d). All steers were implanted with 200 mg progesterone and 20 mg estradiol benzoate (SYN, Synonvex S, Zoetis Animal Health) on May 17. On July 18 three reimplant treatments were applied: 1) no reimplant; 2) SYN; or 3) 40 mg trenbolone acetate and 8 mg estradiol (Revalor G, Merck Animal Health). Data were analyzed using the PROC MIXED in SAS as a split-plot experimental design. In early summer HS had 0.26 kg greater (P &lt; 0.01) ADG than NC and PC. Late summer gains of PC were 0.33 kg/d more (P ≤ 0.01) than NC; and HS gained 0.49 and 0.16 kg/day more (P ≤ 0.04) than NC and PC, respectively. Gain per hectare for PC (46 kg/ha) were greater (P &lt; 0.01) than NC (35 kg/ha) and more than doubled (P &lt; 0.01) with HS (89 kg/ha). Reimplanting had no effect on ADG (P ≥ 0.28). Late season supplementation with PC resulted in supplemental efficiency of 2.7 kg supplement/kg added gain compared with NC. Increased stocking rates with season long supplementation in HS resulted in supplemental efficiency of 3.8 kg supplement/kg added gain per hectare. Based on these data, a 100% DDGS cube is an effective supplement option to increase BW gain during the late summer or increase carrying capacity and gain during the summer grazing period in northwestern Oklahoma.


1977 ◽  
Vol 55 (11) ◽  
pp. 1445-1452 ◽  
Author(s):  
D. J. Samborski ◽  
W. K. Kim ◽  
R. Rohringer ◽  
N. K. Howes ◽  
R. J. Baker

Seedlings of resistant (Sr6) and susceptible (sr6) near-isogenic lines of wheat (Triticum aestivum L.) were inoculated with a race of stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. & E. Henn.) that was avirulent on the line with Sr6 and they were kept at 19, 25, 26, and 27 °C. Fluorescence microscopy was used to detect autofluorescing necrotic host cells and rust colonies after these were stained with a fiuorochrome (Calcofluor White M2R New).In leaves containing the Sr6 gene, a smaller percentage of colonies grown at 25 °C had necrotic cells associated with them than those that were grown at 19 °C. The incidence of colony-associated necrosis in these leaves could be further reduced by increasing the temperature to 26 °C and 27 °C. Similarly, the number of necrotic host cells per colony decreased with an increase in temperature. Colonies in genotypically resistant leaves were usually smaller than those in genotypically susceptible leaves, but the differences in colony sizes between these two lines decreased at the higher temperatures.When infected plants containing the Sr6 gene were kept for varying times at 25 °C and then were transferred to 19 °C, there was significantly less fungal growth and more necrosis than in plants kept continuously at 25 °C. This necrosis occurred largely in those cells that were invaded after the transfer to 19 °C, when the Sr6 gene was activated.


2017 ◽  
Vol 57 (3) ◽  
pp. 539 ◽  
Author(s):  
P. Beck ◽  
T. Hess ◽  
D. Hubbell ◽  
M. S. Gadberry ◽  
J. Jennings ◽  
...  

The objective of this study was to evaluate the effects of including alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) on herbage nutritive value compared with monocultures of bermudagrass fertilised with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha over four grazing seasons. In autumn, at the end of the fourth year and in the spring before the fifth grazing season, alfalfa and clover plants were killed and the carryover N benefit of CLVR or ALF was compared with N fertilisation rates during the fifth year. Across years, N fertilisation rate increased herbage mass and carrying capacity linearly; whereas herbage production from CLVR and ALF swards was equivalent to 56N, were greater than 0N and less than 112N. Herbage mass in CLVR and ALF swards was greater than fertilised bermudagrass swards in the spring and did not differ from fertilised bermudagrass in the early summer. In late summer herbage accumulation of CLVR and ALF swards appeared to decrease, limiting the herbage mass in the legume pastures compared with 56N and 112N. Carrying capacity of CLVR and ALF swards was greater than fertilised bermudagrass in the spring and early summer, but did not differ from fertilised swards in the late summer. The N benefit of including legumes in bermudagrass swards can alleviate the reliance on synthetic N fertilisation with little overall effect on pasture carrying capacity.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Carmelo Peter Bonsignore

The phenology ofCapnodis tenebrionisadults was presented with reference to two different climate conditions. In a temperate moderate-warm climate, adult density showed two separate peaks during the year: one in early summer of the overwintering generation and one with beetles emerging in the late summer. In a warmer semiarid climate, the overwintering adults and the new generation overlapped during summer with a continuous increase of adult density. The difference in the average annual temperature between areas during the study period was almost3∘C, and, in the warmer area, the new generation ofC. tenebrionisemerged at least one month earlier. To make a prediction of adult presence, a model utilizing degree-days was developed from data collected over a five-year period. Models obtained from equations (Logistic 4-parameter,y(x)=yo+a/(1+(x/xo)b)) of each year were developed to describe the relationship between degree-day accumulation (with a minimal threshold activity temperature of14.21∘Ccalculated in the laboratory) and the cumulative percentage of adult presence. According to the overall model, the 50% of overwintering beetles occurred at 726 degree-days (Biofix: 1st March) and the emerging beetles occurred at 801 degree-days (Biofix: 1st July). The results show that a change in temperature is an important aspect that highlights the adaptability of this species.


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