Effect of Herbicides on Germination and Growth of Four Grass Weeds

Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 489-493 ◽  
Author(s):  
Frank L. Young ◽  
David R. Gealy ◽  
Larry A. Morrow
Keyword(s):  
Bromus Tectorum ◽  
Soil Surface ◽  
Dry Weight ◽  
Shoot Elongation ◽  
Downy Brome ◽  
Aegilops Cylindrica ◽  
Shoot Height ◽  
Shoot Dry Weight ◽  
Jointed Goatgrass ◽  
Germination And Growth

In the greenhouse, glyphosate [N-(phosphonomethyl)glycine] at 0.6 kg ae/ha applied directly to seeds alone or seeds on the soil surface reduced germination and shoot dry weight of common rye (Secale cerealeL. ♯3SECCE). Paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) applied similarly at 0.6 kg ai/ha reduced germination and shoot dry weight of downy brome (Bromus tectorumL. ♯ BROTE) and wheat (Triticum aestivumL. ‘Daws' ♯ TRZAX). Metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5 (4H)-one] at 0.6 kg ai/ha applied to seeds, soil, or seeds and soil had very little effect on germination, but significantly reduced shoot dry weight of common rye, downy brome, wheat, and jointed goatgrass (Aegilops cylindricaHost. ♯ AEGCY). Pronamide [3,5-dichloro(N-1,1-dimethyl-2-propynyl)benzamide] at 0.6 kg ai/ha, and propham (isopropyl carbanilate) at 3.4 kg ai/ha plus extender (p-chlorophenyl-N-methylcarbamate) at 0.4 kg ai/ha substantially reduced shoot height and dry weight of all species, regardless of application method, with pronamide completely inhibiting shoot elongation and dry-weight production in three of the four species.

Effect of Temperature on Root Absorption of Metribuzin and its Ethylthio Analog by Winter Wheat (Triticum aestivum), Jointed Goatgrass (Aegilops cylindrica), and Downy Brome (Bromus tectorum)

Weed Science ◽  
1992 ◽  
Vol 40 (4) ◽  
pp. 517-521 ◽  
Author(s):  
Robert A. Buman ◽  
David R. Gealy ◽  
Alex G. Ogg
Keyword(s):  
Winter Wheat ◽  
Water Absorption ◽  
Bromus Tectorum ◽  
Dry Weight ◽  
The Other ◽  
Effect Of Temperature ◽  
Downy Brome ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass ◽  
Root Absorption

Root absorption of subtoxic levels of metribuzin and its ethylthio analog (ethyl-metribuzin) by downy brome, jointed goatgrass, and winter wheat increased by a factor of three to five times as temperature increased from 10 to 20 C. Absorption of ethyl-metribuzin per gram dry weight was similar for all three species. Absorption and distribution of ethyl-metribuzin, but not metribuzin, were similar per gram dry weight in downy brome and jointed goatgrass. Absorption of metribuzin per gram dry weight was lower for winter wheat than for the other two species at 20 C. In general, the ratio of absorbed ethyl-metribuzin detected in shoots to that in roots was less in winter wheat and jointed goatgrass than in downy brome. The absorption by roots of14C-herbicides relative to water was similar for winter wheat and jointed goatgrass. Absorption of both14C-herbicides by winter wheat and jointed goatgrass was nonpreferential with respect to water absorption at 10 and 15 C. However, at 20 C14C-herbicide absorption was reduced 5 to 30% with respect to water absorption. Downy brome absorption of14C-herbicides with respect to water was 30 to 50% less than that of the other two species.

Vernalization Requirements for Flowering of Jointed Goatgrass (Aegilops cylindrica)

Weed Science ◽  
1984 ◽  
Vol 32 (5) ◽  
pp. 631-637 ◽  
Author(s):  
William W. Donald
Keyword(s):  
Dry Matter ◽  
Cold Treatment ◽  
Dry Weight ◽  
Field Studies ◽  
Vegetative Shoot ◽  
Aegilops Cylindrica ◽  
Shoot Dry Weight ◽  
Jointed Goatgrass ◽  
Matter Production ◽  
Growing Conditions

Jointed goatgrass (Aegilops cylindrica Host. ♯3 AEGCY) has a quantitative requirement for vernalization in order to flower. In greenhouse and field studies, increasing periods of vernalization progressively reduced the number of days needed for plants to mature following transfer from the cold treatment to favorable growing conditions. Plants that had been vernalized at 3 ± 2 C for 8 weeks as imbibed seed took 120 days to flower following transfer to the greenhouse. Unvernalized controls flowered 197 to 222 days after planting in the greenhouse. Lengthening periods of vernalization from 2 to 8 weeks increased the number of seedheads per plant and dry weight per seedhead. Vernalized plants partitioned more dry matter into seedheads than unvernalized controls. The ratio of seedhead dry weight to vegetative shoot dry weight increased with duration of vernalization, even though vernalization did not alter total shoot dry-matter production. In field studies, plants that were established in the fall flowered sooner and more synchronously after resumption of growth in the spring than those that were planted in the spring and flowered in the summer. Plants seeded after May failed to flower in the same summer.

Inhibition of Photosynthesis in Downy Brome (Bromus tectorum) and Jointed Goatgrass (Aegilops cylindrica) Protoplasts by Metribuzin and its Ethylthio Analog

Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 13-17 ◽  
Author(s):  
Robert A. Buman ◽  
David R. Gealy ◽  
Alex G. Ogg
Keyword(s):  
Bromus Tectorum ◽  
Net Photosynthesis ◽  
Downy Brome ◽  
Aegilops Cylindrica ◽  
Cold Temperatures ◽  
Jointed Goatgrass

Inhibition of net photosynthesis of jointed goatgrass and downy brome protoplasts by metribuzin and its ethylthio analog (ethyl-metribuzin) was greater at 25 than at 10 C. As temperature increased from 10 to 25 C, the concentration of ethyl-metribuzin required to inhibit net photosynthesis 50% (I50) decreased by a factor of 3.5 and 4.3, respectively, in jointed goatgrass and downy brome. I50values for metribuzin decreased by a factor of 1.5 and 2.5 in jointed goatgrass and downy brome, respectively, for the same 15 C increase in temperature. Based on I50values at 10 C, metribuzin was nine times more inhibitory than ethyl-metribuzin in jointed goatgrass and eight times more inhibitory in downy brome. At 25 C, metribuzin was only 4.7 and 3.9 times more inhibitory than ethyl-metribuzin in jointed goatgrass and downy brome, respectively. Thus, cold temperatures reduced the activity of ethyl-metribuzin more than metribuzin. The activity of both herbicides was reduced less in protoplasts of jointed goatgrass than in protoplasts of downy brome over the 15 C range.

Competitive Relationships Among Winter Wheat (Triticum aestivum), Jointed Goatgrass (Aegilops cylindrica), and Downy Brome (Bromus tectorum)

Weed Science ◽  
1988 ◽  
Vol 36 (4) ◽  
pp. 479-486 ◽  
Author(s):  
Gwen F. Fleming ◽  
Frank L. Young ◽  
Alex G. Ogg
Keyword(s):  
Triticum Aestivum ◽  
Soil Moisture ◽  
Winter Wheat ◽  
Bromus Tectorum ◽  
Relative Yield ◽  
Growth Chamber ◽  
Downy Brome ◽  
Replacement Series ◽  
Aegilops Cylindrica ◽  
Jointed Goatgrass

In three replacement series experiments, winter wheat (Triticum aestivumL.), jointed goatgrass (Aegilops cylindricaHost. #3AEGCY), and downy brome (Bromus tectorumL. # BROTE) were paired in all possible combinations to determine competitive relationships during vegetative growth. Under growth chamber conditions of ample fertility and soil moisture and day/night temperatures of 18/10 C, relative yield totals for the three species were similar, indicating that they compete for the same resources. Both winter wheat and jointed goatgrass had greater plant growth and higher relative crowding coefficients than downy brome, which indicated a hierarchy of relative competitiveness of winter wheat > jointed goatgrass >> downy brome. In other growth chamber studies, winter wheat was slightly more competitive than jointed goatgrass regardless of fertility levels. Winter wheat was the superior competitor at 18/10 C and −33 kPa (soil moisture), whereas jointed goatgrass was superior at 27/10 C and −300 kPa, conditions that are frequently encountered in the Pacific Northwest.

Jointed Goatgrass (Aegilops cylindrica) and Downy Brome (Bromus tectorum) Control in Perennial Grasses

1995 ◽  
Vol 9 (2) ◽  
pp. 255-259 ◽  
Author(s):  
K. George Beck ◽  
James R. Sebastian ◽  
Phillip L. Chapman
Keyword(s):  
Bromus Tectorum ◽  
Perennial Grasses ◽  
Downy Brome ◽  
Aegilops Cylindrica ◽  
Crested Wheatgrass ◽  
Jointed Goatgrass ◽  
Selective Control

Glyphosate and package mixtures of glyphosate plus dicamba or 2,4-D were evaluated for the selective control of jointed goatgrass and downy brome in seeded perennial grasses. Glyphosate at 560, glyphosate plus dicamba at 550 + 220, and glyphosate plus 2,4-D at 420 + 350 and 570 + 470 g ai/ha controlled 90% or more jointed goatgrass in 1988 and 1991. Glyphosate plus 2,4-D at 150 + 120 and 280 + 240 g/ha were the only treatments that controlled less than 90% of jointed goatgrass in 1991. In 1988, glyphosate at 210 g/ha and glyphosate plus dicamba at 210 + 80 g/ha were the only treatments that controlled less than 90% of downy brome. Glyphosate at 210, 280, 420, and 560 g/ha, glyphosate plus dicamba at 210 + 80, 280 + 110, 420 + 170, and 550 + 220 g/ha, and glyphosate plus 2,4-D at 150 + 120, 280 + 240, 420 + 350, and 570 + 470 g/ha controlled 90% or more downy brome in 1990. Pubescent wheatgrass and crested wheatgrass were stunted or killed if they were growing when herbicides were applied.

scholarly journals AVOCADO SEEDLINGS MULTIPLE STEMS PRODUCTION

2016 ◽  
Vol 38 (2) ◽  
Author(s):  
MARCUS VINICIUS SANDOVAL PAIXÃO ◽  
JOSÉ CARLOS LOPES ◽  
EDILSON ROMAIS SCHMILDT ◽  
RODRIGO SOBREIRA ALEXANDRE ◽  
CAROLINE MERLO MENEGHELLI
Keyword(s):  
Root Length ◽  
Dry Weight ◽  
Adventitious Rooting ◽  
Dry Mass ◽  
Stem Diameter ◽  
Experimental Unit ◽  
Shoot Height ◽  
Shoot Dry Weight ◽  
Federal Institute ◽  
Multiple Stems

ABSTRACT This study aimed to evaluate the potential of multi-stems in avocado seeds according to their mass as well as the adventitious rooting of multi-stem budding with or without the use of auxin. The research was carried out at the Vegetation House of Federal Institute of Espírito Santo, Campus Santa Teresa -ES, with seeds of different masses: <60 g, 61 to 80 g, 81 to 100 g and >100 g, in which each experimental unit was made of five seeds, distributed within five repetitions, under a completely randomized design. The seeds were put to germinate and the percentage number of emergence and multiple stems were evaluated. After 150 days, the following evaluations were carried out: survival of rooted cuttings; number of leaves; stem diameter; root length; root volume; root and shoot fresh mass; root and shoot dry mass; shoot height; absolute growth and shoot growth rate; shoot dry weight/root dry mass ratio; shoot height/stem diameter ratio; shoot height/root length and Dickson's quality index ratio. Avocado seeds with mass over 100 g and between 81-100 g presented higher percentage of multiple stems. Rods over 20 cm that were not treated with IBA (indole-3-butyric acid) resulted on avocado plants of better quality. The use of IBA (2000 mg L-1) does not affect the rooting and growth of avocado's multi-stem plants.

scholarly journals Reproducibility of suppression of Pythium wilt of cucumber by compost

2014 ◽  
Vol 23 (3) ◽  
pp. 236-245 ◽  
Author(s):  
Mauritz Vilhelm Vestberg ◽  
Sanna Kukkonen ◽  
Päivi Parikka ◽  
Dan Yu ◽  
Martin Romantschuk
Keyword(s):  
Raw Materials ◽  
Dry Weight ◽  
Shoot Height ◽  
Bacterial Diseases ◽  
Sphagnum Peat ◽  
Shoot Dry Weight ◽  
Suppressive Capacity ◽  
The Difference ◽  
Set Up

There is increasing global interest in using compost to suppress soil-borne fungal and bacterial diseases and nematodes. We studied the reproducibility of compost suppressive capacity (SC) against Pythium wilt of cucumber using nine composts produced by the same composting plant in 2008 and 2009. A bioassay was set up in a greenhouse using cucumber inoculated with two strains of Pythium. The composts were used as 20% mixtures (v:v) of a basic steam-sterilized light Sphagnum peat and sand (3:1, v:v). Shoot height was measured weekly during the 5-week experiment. At harvest, the SC was calculated as the % difference in shoot dry weight (DW) between non-inoculated and inoculated cucumbers. The SC was not affected by year of production (2008 or 2009), indicating reproducibility of SC when the raw materials and the composting method are not changed. Differences in shoot height were not as pronounced as those for shoot DW. The results were encouraging, but further studies are still needed for producing compost with guaranteed suppressiveness properties.

scholarly journals Emergence and Shoot Growth of Cosmos and Marigold from Paclobutrazol-treated Seed

2001 ◽  
Vol 19 (1) ◽  
pp. 11-14 ◽  
Author(s):  
Wallace G. Pill ◽  
James A. Gunter
Keyword(s):  
Growth Medium ◽  
Shoot Growth ◽  
Dry Weight ◽  
Tagetes Patula ◽  
Shoot Height ◽  
Shoot Dry Weight ◽  
Grade 5 ◽  
Treated Seed ◽  
Emergence Percentage ◽  
And Control

Abstract This study was conducted to determine whether treating seeds of ‘Sensation Mixed’ cosmos (Cosmos bipinnatus Cav.) and ‘Bonanza Gold’ marigold (Tagetes patula L.) with paclobutrazol (PB) could suppress seedling growth. Seeds were soaked in solutions of 0, 500 or 1000 mg PB/liter (ppm PB) for 16 hours at 25C (77F) or they were primed [−0.5 MPa (−5 bars) for 7 days at 20C (68F)] in Grade 5 exfoliated vermiculite moistened with 0, 500 or 1000 ppm PB solltuions. Soaked and primed seeds were dried for 1 day at 19C (65F) and 25% relative humidity. These seeds and control (non-treated) seeds were sown into plug cells containing peat-lite. Increasing PB concentration decreased cosmos shoot height at 32 days after planting (DAP), but decreased emergence percentage, responses that were more pronounced with priming than with soaking. A 1 ppm PB growth medium drench [30 ml/cell(0.2 mg PB/cell)] and, to a greater extent a 10 mg PB/liter (ppm PB) shoot spray [2 ml/shoot (0.02 mg PB/shoot)], both applied at 10 DAP, resulted in greater cosmos shoot height suppression at 32 DAP than treatment of seeds with 1000 ppm PB. Soaking marigold seeds in 1000 ppm PB failed to decrease shoot height below those of plants from non-treated seeds at 32 DAP. However, exposure to 1000 ppm PB during priming of marigold seeds resulted in a similar shoot height suppression (13%) as the growth medium drench, and similar shoot dry weight reduction (21%) as the shoot spray. Suppression of shoot growth by this seed treatment was short-term since by five weeks after transplanting into 15 cm (6 in) pots, only marigold plants that had received the growth medium drench or shoot spray were smaller than those of control plants. Treating marigold seeds with 1000 mg ppm PB used about one-fifth the PB used to drench the growth medium.

Influence of Soil Type and Depth of Planting on Downy Brome Seed

Weed Science ◽  
1971 ◽  
Vol 19 (1) ◽  
pp. 82-86 ◽  
Author(s):  
G. A. Wicks ◽  
O. C. Burnside ◽  
C. R. Fenster
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Soil Type ◽  
Bromus Tectorum ◽  
Seedling Emergence ◽  
Cropping System ◽  
Soil Surface ◽  
Downy Brome ◽  
Moldboard Plow

Downy brome (Bromus tectorumL.) seedling emergence was greatest from soil depths of 1 inch or less, but occasionally seedlings emerged from depths of 4 inches. Downy brome seed covered by soil germinated more rapidly than those seed on the soil surface. More downy brome seedlings emerged, and from greater depths, from coarse-textured soils than fine-textured soils when moisture was not limiting. Soil type did not influence longevity of downy brome seed buried in the soil. Most (98%) 8-month-old downy brome seed buried 8 inches in the soil germinated but did not emerge in 1 year; and none remained viable in the soil after 5 years. The moldboard plow was more effective in reducing downy brome populations than a sweep plow or one-way disk in a continuous winter wheat (Triticum aestivumL.) cropping system.

Downy Brome (Bromus tectorum) Interference and Economic Thresholds in Winter Wheat (Triticum aestivum)

Weed Science ◽  
1990 ◽  
Vol 38 (3) ◽  
pp. 224-228 ◽  
Author(s):  
Phillip W. Stahlman ◽  
Stephen D. Miller
Keyword(s):  
Winter Wheat ◽  
Bromus Tectorum ◽  
Yield Loss ◽  
Wheat Yield ◽  
Dry Weight ◽  
Quadratic Equation ◽  
Downy Brome ◽  
Economic Threshold ◽  
Weed Density ◽  
Economic Thresholds

Densities up to 100 downy brome m2were established in winter wheat in southeastern Wyoming and west-central Kansas to quantify wheat yield loss from downy brome interference and to approximate economic threshold levels. A quadratic equation best described wheat yield loss as a function of weed density when downy brome emerged within 14 days after wheat emergence. Densities of 24, 40, and 65 downy brome m2reduced wheat yield by 10, 15, and 20%, respectively. Wheat yield was not reduced when downy brome emerged 21 or more days later than wheat. Economic thresholds varied with changes in downy brome density, cost of control, wheat price, and potential wheat yield. In a greenhouse experiment, dry weight of 72-day-old wheat plants grown in association with downy brome was not affected by the distance between the weeds and wheat, whereas downy brome plant dry weight increased with increasing distance between the weeds and wheat.

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