Influence of irrigation on survival of Poa pratensis infected by Ustilago striiformis and Urocystis agropyri

1977 ◽  
Vol 55 (2) ◽  
pp. 216-218 ◽  
Author(s):  
Clinton F. Hodges
Keyword(s):  
Poa Pratensis ◽  
Growing Season ◽  
Flag Smut ◽  
Shoot Production

Irrigation increased the number of surviving plants of Poa pratensis 'Merion' infected with Ustilago striiformis (stripe smut) and Urocystis agropyri (flag smut) and stimulated the production of healthy shoots from infected plants. These effects were more pronounced with plants infected by U. striiformis. Nonirrigated plants infected by U. agropyri had died by the end of the second growing season: irrigation increased the survival of some U. agropyri infected plants to a third growing season and increased the survival of many U. striiformis infected plants for the same period. The number of healthy plants established from irrigated plants infected by U. striiformis also was much greater than those established from plants infected by U. agropyri. The pattern of development for healthy shoot production from infected plants differed for the respective pathogens. The reaction of U. striiformis and U. agropyri to irrigation suggests that U. agropyri is the more destructive of the two pathogens. The production of healthy shoots from infected plants may provide a means for evaluation of P. pratensis for resistance to U. striiformis.

The effects of summer shoot production on height growth components of seedlings of California red and white fir

1992 ◽  
Vol 22 (5) ◽  
pp. 690-698 ◽  
Author(s):  
Stephen W. Hallgren ◽  
John A. Helms
Keyword(s):  
Soil Moisture ◽  
Growing Season ◽  
Shoot Elongation ◽  
Height Growth ◽  
Shoot Morphology ◽  
Apical Dome ◽  
White Fir ◽  
Shoot Production ◽  
Terminal Shoot ◽  
Needle Primordia

Morphogenesis of the terminal shoot was studied in 2-year-old seedlings of California red fir (Abiesmagnifica A. Murr.) and two elevational sources of white fir (Abiesconcolor (Gord. & Glend.) Lindl.). Seedlings were either watered or left unwatered during the growing season in order to produce different shoot morphologies and seedlings with and without a summer shoot. Under favorable soil moisture, the frequency of summer shoot production was 32, 53, and 82% for red fir and high- and low-elevation white fir, respectively. Drought from mid-May to mid-September reduced summer shoot production to less than 1% in both species. Spring shoot morphology was not an indicator of capacity to produce a summer shoot. Rate of primordium production was directly related to apical dome diameter. However, when the normal spring increase in apical dome diameter was arrested by summer shoot elongation, the rate of primordium production appeared to be unaffected. Although the apical and subapical meristems were active at the same time, they did not appear to be antagonistic. The major effects of producing a summer shoot were as follows: (i) elongation of 60–120% more intemodes in the current growing season, (ii) production of 15–40% more needle primordia in the overwintering bud, (iii) production of 30–60% more primordia annually, and (iv) increase in the percentage of total primordium production that developed into needles from 60% to 75–80%.

Chemical Control of Reed Canarygrass on Irrigation Canals

Weed Science ◽  
1968 ◽  
Vol 16 (4) ◽  
pp. 465-468 ◽  
Author(s):  
J. M. Hodgson
Keyword(s):  
Chemical Control ◽  
Trichloroacetic Acid ◽  
Poa Pratensis ◽  
Ammonium Thiocyanate ◽  
Growing Season ◽  
Kentucky Bluegrass ◽  
Early Winter ◽  
Irrigation Canals ◽  
Reed Canarygrass ◽  
Irrigation Project

From 1962 to 1967, we evaluated herbicides for control of natural infestations of reed canarygrass (Phalaris arundinacea L.) on canal banks of the Huntley, Montana irrigation project. Two,2-dichloropropionic acid (dalapon) and 3-amino-1,2,4-triazole ammonium thiocyanate (hereinafter referred to as amitrole-T) controlled reed canarygrass. These herbicides were compared with a number of others. Spring foliage treatments with a combination of amitrole-T at 2 1b/A and dalapon or trichloroacetic acid (TCA) at 5 or 10 1b/A were more effective than amitrole-T at 4 1b/A. Amitrole-T was more tolerant to fine grasses such as Kentucky bluegrass (Poa pratensis L.) or redtop (Agrostis alba L.) than dalapon and in some situations it was more desirable than dalapon. Dalapon and TCA were more effective as late fall or early winter treatments to control reed canarygrass during the following growing season. Rates of 20 or 40 1b/A controlled the grass for one season even at the water's edge where it is usually more persistent. At 5 to 10 1b/A, 2,3,5-trichloro-4-pyridinol (pyriclor) controlled reed canarygrass, and it also was effective at 2 1b/A with 2 1b/A of amitrole-T.

scholarly journals The role of antioxidants in the mechanisms of adaptation of Poa Pratensis L. under the influence of wooden plants

2021 ◽  
pp. 109-116
Author(s):  
O. L. Tsandekova ◽  
E. Yu. Kolmogorova
Keyword(s):  
Ascorbic Acid ◽  
Phenolic Compounds ◽  
Scots Pine ◽  
Poa Pratensis ◽  
Ground Cover ◽  
Growing Season ◽  
Antioxidant Defense System ◽  
Inhibitory Effect ◽  
Water Soluble ◽  
Mutual Regulation

The article analyzes the results on the content of peroxidase, phenolic compounds and ascorbic acid in the leaves of meadow bluegrass during the growing season under plantations of woody plants (scots pine and ash-leaved maple). The peroxidase activity in the leaves of plant samples was determined by the method of A.N. Boyarkin, the content of ascorbic acid - by the titrimetric method using sodium 2,6-dichlorophenolindophenol, water-soluble phenolic compounds - by the Leventhal-Neubauer method. Mutual regulation of the plant antioxidant defense system was established, expressed in an increase in the level of ascorbic acid, but a decrease in the activity of peroxidase and phenolic compounds. The accumulation of metabolites in the studied plants varied depending on the phases of the growing season and growing conditions. Scots pine had the greatest inhibitory effect on the studied species than ash-leaved maple. The results obtained can be used to assess the state of the ground cover and the structure of the phytocenosis.

RESPONSE OF KENTUCKY BLUEGRASS (Poa pratensis L.) TO AMOUNT AND FREQUENCY OF NITROGEN APPLICATION

1984 ◽  
Vol 64 (2) ◽  
pp. 369-374 ◽  
Author(s):  
S. H. NELSON
Keyword(s):  
Root Growth ◽  
Ammonium Nitrate ◽  
Poa Pratensis ◽  
Growing Season ◽  
Kentucky Bluegrass ◽  
Nitrogen Application ◽  
Color Yield ◽  
Triple Super Phosphate ◽  
Color Response ◽  
Annual Application

Ammonium nitrate (34-0-0) at varying rates and frequency of application was applied to established Kentucky bluegrass (Poa pratensis L.) between 15 May and 15 Aug. during 1980 and 1981. The area received a single annual application of triple super-phosphate (0-45-0). Color scores were taken weekly, spring and fall, but only monthly during the summer. Oven-dry clipping yields were determined weekly during the growing season and roots were harvested to a depth of 45 cm at the end of the trial. A rate as low as 0.8 kg N∙100 m−2 per season gave satisfactory low maintenance color during summer, but even minimal color response in spring and fall required a rate of at least 1.25 kg N∙100 m−2. Nitrogen amounts greater than 2.5 kg∙100 m−2 per season were considered excessive although color continued to increase up to the 5-kg rate before the effect started to level off. Yield showed essentially the same trend. Split applications did not appreciably affect overall yield, but are recommended to reduce growth surges from the heavier application. Very poor color and growth effects were noted at rates below 0.8 kg N∙100 m−2 per season as was evident in both yield and color. Root growth was inversely affected by nitrogen. Root growth declined markedly as the rates increased from 0.8 kg N to 3.33 kg N∙100 m−2 season then declined at a reduced rate.Key words: Kentucky bluegrass, Poa pratensis, nitrogen, color, yield, roots, minimum maintenance

Propagation of Abiesfraseri by cuttings: orthotropic shoot production from hedged stock plants

1986 ◽  
Vol 16 (2) ◽  
pp. 226-231 ◽  
Author(s):  
Farrell C. Wise ◽  
Frank A. Blazich ◽  
L. Eric Hinesley
Keyword(s):  
Growing Season ◽  
Shoot Formation ◽  
Low Fertility ◽  
Separate Study ◽  
Stock Plant ◽  
Rooted Cuttings ◽  
Fraser Fir ◽  
Chemical Treatments ◽  
Christmas Trees ◽  
Shoot Production

Fraser fir (Abiesfraseri (Pursh) Poir.) stock plants grown as transplants (4 years old) or sheared Christmas trees (14 years old) were subjected to independent combinations of hedging and chemical treatments to induce orthotropic shoot production. Decapitation treatments that removed the most top growth produced the greatest number of orthotropic shoots in each age-class after one growing season. Sprays of dikegulac at 1000 and 3000 ppm did not stimulate orthotropic shoot formation. Orthotropic shoots induced on maturing Christmas trees rooted in lower percentages than plagiotropic cuttings from similar nondecapitated trees. Since rooting and survival of the severed shoots were largely or totally unaffected by hedging treatments, decapitation treatments that produced the most shoots the 1st year continued to exhibit the most rooted cuttings at the end of the following season. At that time, superior treatments on 4- and 14-year-old plants had produced less than three and five rooted orthotropic shoots per stock plant, respectively. The stock plants received no additional hedging and were evaluated for shoot production after a second season. No treatment differences occurred within the older plants, but superior treatments from the 1st year tended to be retained within the transplants. In a separate study, orthotropic shoot production by severe decapitation was enhanced by maintaining low fertility.

Characterizing nitrogen transfer from red clover populations to companion bluegrass under field conditions

2012 ◽  
Vol 92 (6) ◽  
pp. 1163-1173 ◽  
Author(s):  
R. M. M. S. Thilakarathna ◽  
Y. A. Papadopoulos ◽  
A. V. Rodd ◽  
A. N. Gunawardena ◽  
S. A. E. Fillmore ◽  
...  
Keyword(s):  
Soil Water ◽  
Trifolium Pratense ◽  
Poa Pratensis ◽  
Red Clover ◽  
Growing Season ◽  
Field Conditions ◽  
Nitrogen Transfer ◽  
Nitrate Content ◽  
N Fixation ◽  
N Transfer

Thilakarathna, R. M. M. S., Papadopoulos, Y. A., Rodd, A. V., Gunawardena, A. N., Fillmore, S. A. E. and Prithiviraj, B. 2012. Characterizing nitrogen transfer from red clover populations to companion bluegrass under field conditions. Can. J. Plant Sci. 92: 1163–1173. The ability of two red clover (Trifolium pratense L.) cultivars, AC Christie (diploid) and Tempus (tetraploid), to transfer fixed nitrogen (N) to companion bluegrass (Poa pratensis L.) was evaluated under field conditions. Plant samples were harvested three times during the 2009 growing season and N transfer from the red clover cultivars to bluegrass was determined using the natural abundance method for first harvest and 15N dilution techniques for second and third harvests. Soil and soil water samples were used to evaluate cultivar effects on soil N conditions. Both red clover cultivars derived more than 90% of their N from biological N fixation. The proportion of bluegrass N derived from interplant N transfer was 7, 11, and 26% for the first, second, and third harvests, respectively. Soil KCl extractable nitrate increased along the three cuts for Tempus in the 0 to 15-cm soil zone. Soil-water nitrate content increased periodically for AC Christie and remained constant for Tempus throughout the growing season. This result indicates that the two cultivars have distinctly different N cycling patterns.

scholarly journals Composition and Characteristics of Blended Kentucky Bluegrass Stands

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1124-1126 ◽  
Author(s):  
Darin W. Lickfeldt ◽  
Thomas B. Voigt ◽  
Andrew M. Hamblin
Keyword(s):  
Moisture Content ◽  
Dna Markers ◽  
Poa Pratensis ◽  
Growing Season ◽  
Kentucky Bluegrass ◽  
Seedling Development ◽  
Initial Composition ◽  
Seed Moisture Content ◽  
Seed Moisture ◽  
Percent Germination

Kentucky bluegrass (Poa pratensis L.) cultivars are often blended to incorporate diverse characteristics. Factors that may contribute to the actual cultivar composition have not been evaluated. Through the use of DNA markers, individual plants in blended stands can be identified. This study evaluated changes in cultivar composition of `Blacksburg', `Midnight', and `Unique' Kentucky bluegrass blends. Characteristics such as seed size, seed moisture content, percent germination, and seedling development did not affect the initial composition of blends at time of seeding. DNA markers were used to demonstrate how the composition of a blended `Blacksburg', `Midnight', and `Unique' turf changed during the first growing season following establishment. The composition of blends did not significantly change from time of seeding in Sept. 1999 to Apr. 2000 or from Apr. 2000 to Oct. 2000. Two of the three blends were significantly different by Oct. 2000 relative to the percentages seeded in Sept. 1999.

Growth, Reproduction, and Management of Chinese Yam (Dioscorea oppositifolia)

2006 ◽  
Vol 20 (3) ◽  
pp. 773-777 ◽  
Author(s):  
Christopher L. Main ◽  
Joseph E. Beeler ◽  
Darren K. Robinson ◽  
Thomas C. Mueller
Keyword(s):  
United States ◽  
Growing Season ◽  
Reproductive Capacity ◽  
First Year ◽  
Small Populations ◽  
Eastern United States ◽  
Management Options ◽  
Lateral Shoot ◽  
Chinese Yam ◽  
Shoot Production

Chinese yam is an exotic perennial vine that invades natural areas in the temperate regions of the eastern United States. Research was conducted from 2001 to 2004 to evaluate growth, reproduction, and management options for this weed. Vine length, lateral shoot production, and reproductive capacity were lower in the first year of growth compared to 2 subsequent years. During the second and third growing season, plants were more mature and tended to flower earlier and produce larger bulbils compared to the first growing season. Maximum vine length was not reached prior to frost in the first year and was approximately 480 cm in each of the subsequent years. Both glyphosate and triclopyr were effective in controlling plants growing from bulbils and plants growing from tubers. Triclopyr did not display acropetal translocation, in that only the treated tissue died. However, both products displayed excellent basipetal translocation resulting in elimination of tubers and no shoot regrowth the year following treatment. Native area managers should attempt to eradicate small populations of Chinese yam prior to establishment of an extensive tuber system.

scholarly journals Seasonal dynamics of lawn coverages of Nikopol city (Dnepropetrovsk area)

2019 ◽  
Vol 48 ◽  
pp. 14-24
Author(s):  
O. I. Lisovets ◽  
A. A. Polischuk
Keyword(s):  
Species Composition ◽  
Lolium Perenne ◽  
Seasonal Dynamics ◽  
Urban Areas ◽  
Poa Pratensis ◽  
Growing Season ◽  
Ambrosia Artemisiifolia ◽  
Projective Cover ◽  
Polygonum Aviculare ◽  
Poaceae Family

The features of the seasonal dynamics of the species composition, the total projective cover, the ecomorphic structure and the decorative score of the lawn coverings of the city of Nikopol are studied. It was revealed that during the growing season, representatives of the Poaceae family dominate in the projective cover and species composition of grass communities in urban areas. In spring, the participation of Brassicaceae and Lamiaceae is increased, in summer and autumn – Fabaceae and Asteraceae. A study of the dynamics of the species composition showed that Poa angustifolia L. and Polygonum aviculare L. dominate in the majority of Nikopol's lawns in spring. In summer, Lolium perenne L. and Ambrosia artemisiifolia L. are added to them. In autumn, the most active are Lolium perenne and Poa pratensis L. Analysis of the seasonal dynamics of the total projective coverage of test areas showed that the average values ​​of this indicator are observed at the beginning of the growing season. In summer, the total area of ​​the green parts of the plants is reduced. At the end of the growing season, due to the increase in productive soil moisture, the photosynthetically active plant area increases significantly in areas with low anthropogenic impact, remains at summer levels in places of medium anthropogenic loading and significantly decreases in areas with high anthropogenic load. In the species composition, throughout the entire growing season in the biomorph spectrum, hemicryptophytes are the most active, among ecomorphs are xeromesophytes, mesotrophs, ruderants and stepants. Decorativeness is quite low, on a five-point scale, ranges from 2.23 to 3.49, due to the presence of weeds and high anthropogenic stress. In order to improve the decorative, phytomeliorative and hygienic properties of the grass cover, it is advisable to recommend systematic grass cutting (to reduce the activity of annual weeds), as well as the spread of perennial forest and meadow species.

Late Fall Sod Installation Produces Equivalent or Greater Rooting Strength of Poa pratensis Than Typical Spring Installations During the Subsequent Growing Season

2009 ◽  
Vol 6 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Jason Henderson ◽  
Nathaniel Miller ◽  
Karl Guillard ◽  
Ofer Harel ◽  
Balaji Raman
Keyword(s):  
Poa Pratensis ◽  
Growing Season ◽  
Late Fall
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