scholarly journals Timing Aminopyralid to Prevent Seed Production Controls Medusahead (Taeniatherum caput-medusae) and Increases Forage Grasses

2018 ◽  
Vol 11 (1) ◽  
pp. 61-68 ◽  
Author(s):  
Matthew J. Rinella ◽  
Josh S. Davy ◽  
Guy B. Kyser ◽  
Fadzayi E. Mashiri ◽  
Susan E. Bellows ◽  
...  
Keyword(s):  
Seed Production ◽  
Flag Leaf ◽  
Treatment Options ◽  
Growing Season ◽  
Growth Stages ◽  
Forage Grasses ◽  
Downy Brome ◽  
Forage Production ◽  
Annual Grasses ◽  
Exotic Annual Grasses

AbstractExotic annual grasses such as medusahead [Taeniatherum caput-medusae(L.) Nevski] and downy brome (Bromus tectorumL.) dominate millions of hectares of grasslands in the western United States. Applying picloram, aminopyralid, and other growth regulator herbicides at late growth stages reduces seed production of most exotic annual grasses. In this study, we applied aminopyralid toT. caput-medusaeto determine how reducing seed production in the current growing season influenced cover in the subsequent growing season. At eight annual grassland sites, we applied aminopyralid at 55, 123, and 245 g ae ha−1in spring just beforeT. caput-medusaeheading. The two higher rates were also applied pre-emergence (PRE) in fall to allow comparisons with this previously tested timing. When applied in spring during the roughly 10-d period between the flag leaf and inflorescence first becoming visible, just 55 g ae ha−1of aminopyralid greatly limited seed production and subsequently reducedT. caput-medusaecover to nearly zero. Fall aminopyralid applications were less effective againstT. caput-medusae, even at a rate of 245 g ae ha−1. The growing season of application, fall treatments, but not spring treatments, sometimes reduced cover of desirable winter annual forage grasses. The growing season after application, both spring and fall treatments tended to increase forage grasses, though spring treatments generally caused larger increases. Compared with other herbicide treatment options, preheading aminopyralid treatments are a relatively inexpensive, effective approach for controllingT. caput-medusaeand increasing forage production.

Effects of Growth Regulator Herbicide on Downy Brome (Bromus tectorum) Seed Production

2013 ◽  
Vol 6 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Matthew J. Rinella ◽  
Robert A. Masters ◽  
Susan E. Bellows
Keyword(s):  
Seed Production ◽  
Growth Regulators ◽  
Growth Regulator ◽  
Bromus Tectorum ◽  
Field Studies ◽  
Growth Stages ◽  
Downy Brome ◽  
Greenhouse Study ◽  
Point Estimates ◽  
Annual Grasses

AbstractPrevious research showed growth regulator herbicides, such as picloram and aminopyralid, have a sterilizing effect on Japanese brome (Bromus japonicus Thunb.) that can reduce this invasive annual grass's seed production nearly 100%. This suggests growth regulators might be used to control invasive annual grasses by depleting their short-lived seed banks. The goal of this study was to extend the previous Japanese brome research to downy brome (Bromus tectorum L.), the most damaging invasive annual grass of U.S. grasslands. In a greenhouse, we found picloram did not greatly influence downy brome seed production, while point estimates suggest aminopyralid reduced seed production 55 to 80%. If not for a highly abnormal retillering response that we somewhat doubt would occur in the field, point estimates suggest aminopyralid would have reduced downy brome seed production approximately 90% when applied at the heading stage and approximately 98% when applied at three earlier growth stages. Our greenhouse study should encourage field studies designed to further explore the potential for using growth regulators to control downy brome and other invasive annual grasses.

First-Year Establishment, Biomass and Seed Production of Early vs. Late Seral Natives in Two Medusahead (Taeniatherum caput-medusae) Invaded Soils

2014 ◽  
Vol 7 (2) ◽  
pp. 291-302 ◽  
Author(s):  
Shauna M. Uselman ◽  
Keirith A. Snyder ◽  
Elizabeth A. Leger ◽  
Sara E. Duke
Keyword(s):  
Seed Production ◽  
Aboveground Biomass ◽  
Native Species ◽  
Sandy Loam ◽  
Growing Season ◽  
Perennial Grasses ◽  
Soil Types ◽  
Clay Loam ◽  
Annual Grasses ◽  
Exotic Annual Grasses

AbstractRe-seeding efforts to restore or rehabilitate Great Basin rangelands invaded by exotic annual grasses are expensive and have generally achieved limited success. There is a need to identify new strategies to improve restoration outcomes. We tested the performance of a native early seral seed mix (annual forbs, early seral grasses and shrubs) with that of a native late seral mix representative of species commonly used in restoration when growing with medusahead in soils of contrasting texture (sandy loam and clay loam) through the first growing season after seeding. Natives were also seeded without medusahead. We found that the grasses and forbs in the early seral mix established significantly better than those in the late seral mix, and the early seral mix significantly reduced aboveground biomass and seed production of medusahead by 16 and 17% respectively, likely because of competition with the early seral native forb, bristly fiddleneck. Medusahead performance was reduced in both soil types, suggesting utility of bristly fiddleneck in restoration is not limited to only one soil type. In contrast, the late seral mix did not suppress medusahead establishment, aboveground biomass or seed production. Although the native perennial grasses, particularly early seral species, were able to establish with medusahead, these grasses did not appear to have a suppressive effect on medusahead during the first growing season. Medusahead was able to establish and produce seeds on both soil types, demonstrating an ability to expand its current range in the Intermountain West, though aboveground biomass and seed production was higher in the clay loam. Our results suggest that certain species may play a key role in restoration, and that targeting early seral species in particular to find additional native species with the ability to suppress exotic annual grasses is an important next step in improving restoration outcomes in desert ecosystems.

Control of Downy Brome (Bromus tectorum) with Herbicides and Perennial Grass Competition

1998 ◽  
Vol 12 (2) ◽  
pp. 391-396 ◽  
Author(s):  
Tom D. Whitson ◽  
David W. Koch
Keyword(s):  
Dry Matter ◽  
Perennial Grass ◽  
Integrated Approach ◽  
Growth Stages ◽  
Downy Brome ◽  
Cool Season ◽  
Growing Seasons ◽  
Annual Grasses ◽  
Russian Wildrye

Long-term control of downy brome with an integrated approach is needed in order to sustain range productivity. Studies were conducted to study the effectiveness of a combination of downy brome control practices. In two studies, glyphosate and paraquat were evaluated at various rates for up to three successive years for control of downy brome in rangeland. A third study evaluated the competitiveness of perennial cool-season grasses against downy brome in the absence of herbicides. Glyphosate, at 0.55 kg/ha, and 0.6 kg/ha paraquat provided selective downy brome control on rangeland when applications were combined with intensive grazing. Downy brome control was greater than 90% following two sequential years of 0.6 kg/ha paraquat at either the two- to eight-leaf stage or bloom stage at both study locations. At one study location, 0.55 kg/ha glyphosate provided 97% control after the first application at both growth stages. In the second study, control averaged greater than 92% following three sequential applications of glyphosate. When perennial cool-season grasses were seeded in the spring following fall tillage (no herbicides) and allowed to establish for three growing seasons, three of the five species were effective in reducing the reestablishment of downy brome. ‘Luna’ pubescent wheatgrass, ‘Hycrest’ crested wheatgrass, ‘Sodar’ streambank wheatgrass, ‘Bozoisky’ Russian wildrye, and ‘Critana’ thickspike wheatgrass controlled 100, 91, 85, 45, and 32% of the downy brome, respectively. Yields of perennial grass dry matter were 1,714, 1,596, 1,135, 900, and 792 kg/ha. Replacing noncompetitive annual grasses with competitive cool-season perennials will provide a longer term solution to a downy brome problem than the use of herbicides alone or with intensive grazing.

Preventing Downy Brome (Bromus tectorum) Seed Production with DPX-Y6202 and Fluazifop

Weed Science ◽  
1987 ◽  
Vol 35 (2) ◽  
pp. 277-281 ◽  
Author(s):  
Jesse M. Richardson ◽  
David R. Gealy ◽  
Larry A. Morrow
Keyword(s):  
Seed Production ◽  
Bromus Tectorum ◽  
Butyl Ester ◽  
Propanoic Acid ◽  
Growth Stages ◽  
Downy Brome ◽  
Seed Formation ◽  
Foliar Absorption ◽  
Reproductive Phase ◽  
Application Rates

Ethyl ester of DPX-Y6202 {2-[4-[(6-chloro-2-quinoxalinyl)oxy] phenoxy] propanoic acid} and butyl ester of fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} applied during the reproductive phase of development at 0.07 and 0.28 kg ai/ha prevented seed formation in downy brome (Bromus tectorumL. # BROTE). Fluazifop prevented seed formation over a wider range of application rates and growth stages than did DPX-Y6202. Seed production was prevented most readily by herbicide applications made early in the reproductive phase. Environmental factors during reproduction affected herbicide performance. Foliar absorption and translocation of14C-fluazifop into the developing spikelets was greater than that of14C-DPX-Y6202 in downy brome.

Relative effectiveness of various sources, methods, times and rates of copper fertilizers in improving grain yield of wheat on a Cu-deficient soil

2005 ◽  
Vol 85 (1) ◽  
pp. 59-65 ◽  
Author(s):  
S. S. Malhi ◽  
L. Cowell ◽  
H. R. Kutcher
Keyword(s):  
Grain Yield ◽  
Protein Concentration ◽  
Growth Stage ◽  
Foliar Application ◽  
Leaf Growth ◽  
Flag Leaf ◽  
Relative Effectiveness ◽  
Growing Season ◽  
Growth Stages ◽  
Cu Deficiency

A field experiment was conducted to determine the relative effectiveness of various sources, methods, times and rates of Cu fertilizers on grain yield, protein concentration in grain, concentration of Cu in grain and uptake of Cu in grain of wheat (Triticum aestivum L.), and residual concentration of DTPA-extractable Cu in soil on a Cu-deficient soil near Porcupine Plain in northeastern Saskatchewan. The experiment was conducted from 1999 to 2002 on the same site, but the results for 2002 were not presented because of very low grain yield due to drought in the growing season. The 25 treatments included soil application of four granular Cu fertilizers (Cu lignosulphonate, Cu sulphate, Cu oxysulphate I and Cu oxysulphate II) as soil-incorporated (at 0.5 and 2.0 kg Cu ha-1), seedrow-placed (at 0.25 and 1.0 kg Cu ha-1) and foliar application of four solution Cu fertilizers (Cu chelate-EDTA, Cu sequestered I, Cu sulphate/chelate and Cu sequestered II at 0.25 kg Cu ha-1) at the four-leaf and flag-leaf growth stages, plus a zero-Cu check. Soil was tilled only once to incorporate all designated Cu and blanket fertilizers into the soil a few days prior to seeding. Wheat plants in the zero-Cu treatment exhibited Cu deficiency in all years. For foliar application at the flag-leaf stage, grain yield increased with all four of the Cu fertilizers in 2000 and 2001, and in all but Cu sequestered II in 1999. Foliar application at the four-leaf growth stage of three Cu fertilizers (Cu chelate-EDTA, Cu sequestered I and Cu sulphate/chelate), soil incorporation of all Cu fertilizers at 2 kg Cu ha-1 and two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 0.5 kg Cu ha-1 rate, and seedrow placement of two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 1 kg Cu ha-1 increased grain yield of wheat only in 2001. There was no effect of Cu fertilization on protein concentration in grain. The increase in concentration and uptake of Cu in grain from Cu fertilization usually showed a trend similar to grain yield. There was some increase in residual DTPA-extractable Cu in the 0–60 cm soil in Cu lignosulphonate, Cu sulphate and Cu oxysulphate II soil incorporation treatments, particularly at the 2 kg Cu ha-1 rate. In summary, the results indicate that foliar application of Cu fertilizers at the flag-leaf growth stage can be used for immediate correction of Cu deficiency in wheat. Because Cu deficiency in crops often occurs in irregular patches within fields, foliar application may be the most practical and economical way to correct Cu deficiency during the growing season, as lower Cu rates can correct Cu deficiency. Key words: Application time, Cu source, foliar application, granular Cu, growth stage, placement method, rate of Cu, seedrow-placed Cu, soil incorporation

Ecological Characteristics of Three Winter Annual Grasses

1998 ◽  
Vol 12 (3) ◽  
pp. 478-483 ◽  
Author(s):  
R. L. Anderson
Keyword(s):  
Winter Wheat ◽  
Seed Production ◽  
Cultural Practices ◽  
Seedling Emergence ◽  
Cultural Control ◽  
Downy Brome ◽  
Jointed Goatgrass ◽  
Annual Grasses ◽  
Winter Annual ◽  
Feral Rye

Producers rely on cultural practices to manage downy brome, jointed goatgrass, and feral rye in winter wheat because there are no effective herbicides for in-crop control. This study characterized seedling emergence, growth, and development of these winter annual grasses, with the goal of suggesting or improving cultural control strategies. Feral rye seedlings emerged within 4 wk, whereas downy brome and jointed goatgrass seedlings emerged over a 10-wk period. Emergence patterns of these grasses suggest that delay of winter wheat planting may be effective in reducing feral rye densities, but this strategy most likely will be ineffective with downy brome or jointed goatgrass. Downy brome began anthesis 1 to 2 wk earlier than the other two grasses and winter wheat. Both downy brome and jointed goatgrass were shorter than winter wheat during the growing season, whereas feral rye was at least as tall as wheat. Producers mow infested wheat to prevent weed seed production, but this practice may not be effective with jointed goatgrass and downy brome because of their short stature and downy brome's earlier development. Conversely, mowing has potential in preventing feral rye seed production. The grasses produced between 340 and 770 seeds/ plant.

Living with exotic annual grasses in the sagebrush ecosystem

2021 ◽  
Vol 288 ◽  
pp. 112417
Author(s):  
Kirk W. Davies ◽  
Elizabeth A. Leger ◽  
Chad S. Boyd ◽  
Lauren M. Hallett
Keyword(s):  
Sagebrush Ecosystem ◽  
Annual Grasses ◽  
Exotic Annual Grasses

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

scholarly journals Detection of QTLs for Outcrossing-Related Traits in CSSL Population Derived from Primitive Japonica Accession Ludao in the Genetic Background of O. sativa spp. Japonica Restorer C-bao Using RSTEP-LRT Method

Agronomy ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Lal Bux ◽  
Dalu Li ◽  
Muhammad Faheem ◽  
Nour Ali ◽  
Muzafar Hussain Sirohi ◽  
...  
Keyword(s):  
Seed Production ◽  
Hybrid Rice ◽  
Oryza Sativa L ◽  
Flag Leaf ◽  
Leaf Angle ◽  
Ratio Test ◽  
Phenotypic Variance ◽  
Rice Seed ◽  
Hybrid Seed Production ◽  
Cms Line

The outcrossing traits in rice (Oryza sativa L.) affect the yield of hybrid seed production. Using a cytoplasmic male sterile (CMS) line with good outcrossing traits, such as short flag leaf length (FLL), narrow flag leaf width (FLW), wide flag leaf angle (FLA), and elongated panicle neck length (PNL), for hybrid rice seed production, it is possible to avoid the procedure of cutting flag leaves and make the supplementary pollination feasible by machine. In this study, a japonica restorer C-bao as the receptor parent and a primitive japonica accession Ludao as the donor parent were used to construct a chromosome segment substitution line (CSSL) population. The CSSL population was used to detect quantitative trait loci (QTLs) for the four outcrossing traits using a likelihood ratio test based on the stepwise regression (RSTEP-LRT) method. The CSSL population constructed consisted of 163 lines covering 90.7% of the donor genome. Among the seven QTLs detected in the CSSL population, four QTLs were detected in both years. qFLL-4 explained 6.70% of the two-year-averaged phenotypic variance, and the alleles from Ludao decreased FLL 5.1 cm. qFLA-1.1 and qFLA-1.2 explained 7.85% and 21.29% of the 2-year-averaged phenotypic variance respectively, and the alleles from Ludao increased FLA 17.38° and 31.50°. qPNL-8 explained 8.87% of the 2-year-averaged phenotypic variance, and the alleles from Ludao increased PNL 4.44 cm. These favorable alleles identified could be used to improve the outcrossing traits of parents for hybrid rice seed production in rice.

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