Postharvest Kochia (Kochia scoparia) Management with Herbicides in Small Grains

2004 ◽  
Vol 18 (2) ◽  
pp. 426-431 ◽  
Author(s):  
James A. Mickelson ◽  
Alvin J. Bussan ◽  
Edward S. Davis ◽  
Andrew G. Hulting ◽  
William E. Dyer
Keyword(s):  
Leaf Area ◽  
Seed Production ◽  
Field Experiments ◽  
Optimal Timing ◽  
Viable Seed ◽  
Kochia Scoparia ◽  
Application Timing ◽  
Herbicide Treatments ◽  
Small Grains ◽  
Viable Seeds

Uncontrolled kochia plants that regrow after small-grain harvest can produce substantial numbers of seeds. An average of 4,100 seeds per plant were produced between harvest (late July to mid August) and the first killing frost (late September) at three locations in Montana. Field experiments were conducted to determine the optimal timing of postharvest herbicide applications to prevent kochia from producing viable seeds. Herbicide treatments were applied at three timings from late August to mid September. The most effective treatments were glyphosate (631 g/ha) and paraquat (701 g/ha) applied at the second application timing (late August to early September). These treatments reduced kochia seed production by 92% or greater at each site. Kochia regrowth by this time had sufficient leaf area for herbicide absorption, but few viable seed had been produced. Herbicide treatments at the first and third application timings were generally less effective and more variable in reducing kochia seed production. Sulfentrazone (157 g/ha) and 2,4-D (561 g/ha) were not as effective at reducing seed production as other herbicide treatments.

Seed Production and Control of Sicklepod (Senna obtusifolia) and Pitted Morningglory (Ipomoea lacunosa) with 2,4-D, Dicamba, and Glyphosate Combinations

2016 ◽  
Vol 30 (1) ◽  
pp. 76-84 ◽  
Author(s):  
Ramon G. Leon ◽  
Jason A. Ferrell ◽  
Brent A. Sellers
Keyword(s):  
Seed Production ◽  
Crop Production ◽  
Field Experiments ◽  
Effective Control ◽  
Weed Species ◽  
Application Timing ◽  
Pitted Morningglory ◽  
Herbicide Treatments ◽  
Viable Seeds ◽  
And Control

Sicklepod and pitted morningglory are two of the most important weed species in row-crop production in the southeastern United States. The upcoming introduction of soybean and cotton varieties resistant to 2,4-D and dicamba will increase the reliance on these auxinic herbicides. However, it is not clear how these herbicides will affect sicklepod and pitted morningglory control. Field experiments were conducted in 2013 and 2014 in Jay, FL to determine whether 2,4-D (560 and 1,120 g ae ha−1), dicamba (420 and 840 g ae ha−1), and glyphosate (1,060 g ae ha−1) alone or in combination applied when weed shoots were 11 (early POST [EPOST]) and 22 (late POST [LPOST]) cm long effectively control and prevent seed production of sicklepod and pitted morningglory. LPOST provided more effective control of sicklepod than EPOST. This was attributed to emergence of sicklepod seedlings after the EPOST application. When glyphosate was tank mixed with 2,4-D or dicamba, sicklepod control was higher (78 to 89% and 87 to 98% in 2013 and 2014, respectively) than for single-herbicide treatments (45 to 77% and 38 to 80% in 2013 and 2014, respectively) 6 wk after treatment (WAT). Pitted morningglory control was not affected by application timing, and 2,4-D provided 91 to 100% 6 WAT, which was equivalent to treatments with tank mixtures containing glyphosate. Dicamba applied at 420 g ha−1had the lowest pitted morningglory control (44 to 70% and 82 to 86% in 2013 and 2014, respectively). Sicklepod and pitted morningglory plants that survived and recovered from herbicide treatments produced the same number of viable seeds as nontreated plants in most treatments. The results of the present study indicated that the use of 2,4-D and dicamba alone will not provide adequate extended control of sicklepod, and the use of tank mixtures that combine auxinic herbicides with glyphosate or other POST herbicides will be necessary to manage sicklepod adequately in 2,4-D- or dicamba-resistant soybean and cotton. Because sicklepod plants that survived a single herbicide application are capable of producing abundant viable seeds, integrated approaches that include PRE herbicides and sequential POST control options may be necessary to ensure weed seed bank reductions.

scholarly journals Do applications of systemic herbicides when green fruit are present prevent seed production or viability of Alliaria petiolata (garlic mustard)?

2021 ◽  
pp. 1-17
Author(s):  
Leo Roth ◽  
José Luiz C. S. Dias ◽  
Christopher Evans ◽  
Kevin Rohling ◽  
Mark Renz
Keyword(s):  
Seed Production ◽  
Seed Viability ◽  
Early Spring ◽  
Alliaria Petiolata ◽  
Late Spring ◽  
Garlic Mustard ◽  
Viable Seed ◽  
Application Timing ◽  
Control Seed ◽  
Second Year

Garlic mustard [Alliaria petiolata (M. Bieb.) Cavara & Grande] is a biennial invasive plant commonly found in the northeastern and midwestern United States. Although it is not recommended to apply herbicides after flowering, land managers frequently desire to conduct management during this timing. We applied glyphosate and triclopyr (3% v/v and 1% v/v using 31.8% and 39.8% acid equivalent formulations, respectively) postemergence to established, second-year A. petiolata populations at three locations when petals were dehiscing, and evaluated control, seed production and seed viability. Postemergence glyphosate applications at this timing provided 100% control of A. petiolata by 4 weeks after treatment at all locations whereas triclopyr efficacy was variable, providing 38-62% control. Seed production was only reduced at one location, with similar results regardless of treatment. Percent seed viability was also reduced, and when combined with reductions in seed production, we found a 71-99% reduction in number of viable seed produced plant-1 regardless of treatment. While applications did not eliminate viable seed production, our findings indicate that glyphosate and triclopyr applied while petals were dehiscing is a viable alternative to cutting or hand-pulling at this timing as it substantially decreased viable A. petiolata seed production. Management Implications Postemergence glyphosate and triclopyr applications in the early spring to rosettes are standard treatments used to manage A. petiolata. However, weather and other priorities limit the window for management, forcing field practitioners to utilize more labor-intensive methods such as hand-pulling. It is not known how late in the development of A. petiolata these herbicides can be applied to prevent viable seed production. Since prevention of soil seedbank replenishment is a key management factor for effective long-term control of biennial invasive species, we hypothesized late spring foliar herbicide applications to second year A. petiolata plants when flower petals were dehiscing could be an effective management tool if seed production or viability is eliminated. Our study indicated that glyphosate applications at this timing provided 100% control of A. petiolata plants by 4 weeks after treatment at all locations, whereas triclopyr efficacy was inconsistent. Although both glyphosate and triclopyr decreased viable seed production to nearly zero at one of our three study locations, the same treatments produced significant amounts of viable seed at the other two locations. Our findings suggest late spring glyphosate and triclopyr applications should not be recommended over early spring applications to rosettes for A. petiolata management, as our late spring application timing did not prevent viable seed production, and may require multiple years of implementation to eradicate populations. Nonetheless, this application timing holds value in areas devoid of desirable understory vegetation compared to no management practices or mechanical management options including hand-pulling when fruit are present, as overall viable seed production was reduced to similar levels as these treatments.

Sulfur Cinquefoil (Potentilla recta) Response to Defoliation on Foothill Rangeland

2012 ◽  
Vol 5 (4) ◽  
pp. 408-416 ◽  
Author(s):  
Rachel A. Frost ◽  
Jeffrey C. Mosley
Keyword(s):  
Seed Production ◽  
Aboveground Biomass ◽  
The United States ◽  
Livestock Grazing ◽  
Optimal Timing ◽  
Western Canada ◽  
Viable Seed ◽  
Southwestern Montana ◽  
Aboveground Productivity ◽  
Control Response

AbstractSulfur cinquefoil is an invasive, perennial forb on rangelands of western Canada and the United States. Sulfur cinquefoil reproduces solely by seed and it is a prolific seed producer. Our 2-yr study (2006, 2007) investigated the optimal timing and intensity of defoliation to decrease aboveground productivity and seed production of sulfur cinquefoil plants on foothill rangeland in southwestern Montana. Each year, 150 sulfur cinquefoil plants within a 430-m2 enclosure were tagged for identification and randomly assigned to one of 15 clipping treatments with 10 plants per treatment. Clipping treatments were conducted at three timings: (preflower [early June], flowering [late June], and seedset [mid-July]) and all possible combinations of timings for a total of seven timing treatments clipped to two stubble heights (7.5 cm or 15 cm), comprising 14 unique treatments. The final (15th) treatment consisted of an unclipped control. Response variables collected at senescence (late July) included aboveground biomass; number of buds, flowers and fruits on each plant; and number and viability of seeds produced. Results indicated that defoliation of sulfur cinquefoil can effectively reduce its yield and seed production. All clipping treatments reduced aboveground biomass of sulfur cinquefoil compared with control plants (P ≤ 0.05), except clipping to 15 cm during preflowering in the wetter year of 2006. Clipping to either 7.5 cm or 15 cm at all times or combinations of timings reduced the number of buds, flowers, fruits, and seeds produced by sulfur cinquefoil (P ≤ 0.05). Viable seed production was reduced 99 to 100% when plants were clipped once to either 7.5 or 15 cm during flowering or seedset. Results suggest that targeted livestock grazing or mowing applied one time per season during flowering or seedset could effectively suppress the biomass production and viable seed production of sulfur cinquefoil.

Impact of Clipping Timing on Japanese Hedgeparsley (Torilis japonica) Seed Production and Viability

2014 ◽  
Vol 7 (3) ◽  
pp. 511-516
Author(s):  
Mark J. Renz ◽  
R. Menyon Heflin
Keyword(s):  
United States ◽  
Seed Production ◽  
Management Strategy ◽  
Invasive Plant ◽  
Vegetative Stage ◽  
Effective Management ◽  
Viable Seed ◽  
Torilis Japonica ◽  
Forested Areas ◽  
Viable Seeds

AbstractJapanese hedgeparsley is a biennial plant that invades roadsides, rights-of way, and forested areas in the midwestern United States. Interest in managing populations by mechanical or hand-clipping techniques exists, but no information is available on the appropriate timing to maximize mortality and prevent the production of viable seed. To assess that, we applied clipping treatments at five periods throughout the summer to three Japanese hedgeparsley populations in southern Wisconsin and measured the number and viability of seeds produced by each plant during the year of treatment and the survival of plants clipped. Japanese hedgeparsley plants began producing seed by mid-July, but production was not maximized until early August. Viable seeds were not produced until early or mid-August, coinciding with the presence of ripened brown fruit. Clipping at any timing resulted in > 95% mortality by the fall of the treatment year. All plants that resprouted were in the vegetative stage when clipped, and no plants survived the following year. Results indicate that clipping Japanese hedgeparsley plants when they are in a reproductive phase before fruit turns brown is an effective management strategy for this invasive plant.

scholarly journals The Relationship between Flower Age and Seed Production in Hatiora gaertneri and Schlumbergera truncata (Cactaceae)

HortScience ◽  
2005 ◽  
Vol 40 (7) ◽  
pp. 1988-1991
Author(s):  
Thomas H. Boyle
Keyword(s):  
Seed Production ◽  
Late Phase ◽  
Viable Seed ◽  
Flower Longevity ◽  
Degree Polynomial ◽  
Flower Opening ◽  
Production Studies ◽  
Flower Age ◽  
Viable Seeds ◽  
The Relationship

Flowers of two cacti [Hatiora gaertneri (Regel) Barthlott `Crimson Giant' and Schlumbergera truncata (Haworth) Moran `Eva'] were pollinated at different times between anthesis and senescence to determine the effect of floral age on seed production. Studies were conducted in a growth chamber (20 ± 0.5°C) to minimize temperature effects. Mean flower longevity (time from anthesis to first signs of senescence) was 4.7 days for S. truncata and 10.5 days for H. gaertneri. Stigmas of both species were receptive to pollination on the day of anthesis. The maximum number of viable seeds per pollinated flower was obtained when flowers of S. truncata and H. gaertneri were pollinated (respectively) on the second and fourth days after anthesis. For both species, the relationship between floral age and number of viable seeds per pollinated flower was described by a second-degree polynomial. The rate of pollen tube growth in the style was about 1.7 mm·h–1 for S. truncata and about 0.9 mm·h–1 for H. gaertneri. Some senesced flowers of H. gaertneri were capable of setting fruit with viable seed. Flowers of S. truncata did not set fruit when pollinated during the late phase of flower opening or after they had senesced. Senesced flowers of S. truncata failed to set fruit due to an insufficient number of pollen tubes reaching the ovary.

Giant Ragweed (Ambrosia trifida) Control in Soybean (Glycine max)

1992 ◽  
Vol 6 (1) ◽  
pp. 13-18 ◽  
Author(s):  
Jerry A. Baysinger ◽  
Barry D. Sims
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Seed Production ◽  
Field Experiments ◽  
Ambrosia Trifida ◽  
Early Season ◽  
Giant Ragweed ◽  
Herbicide Treatments ◽  
Southeast Missouri

Two field experiments were established in 1988 and 1989 in southeast Missouri to evaluate several herbicides and herbicide combinations for giant ragweed control in soybean. In 1988, a timely rainfall was not received for soil-applied herbicides and giant ragweed control was less than 75%. However, in 1989 soil moisture was sufficient for uptake of soil-applied herbicides and early season giant ragweed control was generally greater than 80%. Chlorimuron, chlorimuron plus 2,4-DB, imazaquin plus 2,4-DB, acifluorfen followed by naptalam plus 2,4-DB, fomesafen, and imazethapyr applied to 2.5 to 5-cm giant ragweed controlled more than 85% in 1988. In 1989, all POST treatments except imazaquin controlled more than 81% of giant ragweed 2 wk after treatments. Imazethapyr controlled seedling giant ragweed at heights up to 12 to 25 cm. Giant ragweed regrowth and/or reinfestation and giant ragweed seed production occurred with all herbicide treatments.

Postemergence Small Broomrape (Orobanche minor) Control in Red Clover

2005 ◽  
Vol 19 (2) ◽  
pp. 411-415 ◽  
Author(s):  
Ryan D. Lins ◽  
Jed B. Colquhoun ◽  
Charles M. Cole ◽  
Carol A. Mallory-Smith
Keyword(s):  
Seed Production ◽  
Field Experiments ◽  
Seed Viability ◽  
Red Clover ◽  
Future Research ◽  
Parasitic Weed ◽  
Herbicide Treatments ◽  
Clover Seed ◽  
High Level ◽  
Orobanche Minor

Small broomrape is an annual, parasitic weed that was discovered recently in Oregon's red clover seed production system. Field experiments were conducted in 2002 and 2003 at two locations to evaluate 10 herbicide treatments applied after small broomrape emergence in red clover. Bentazon, bromoxynil, glyphosate, imazamox, imazamox plus bentazon, imazethapyr, MCPA, and pendimethalin were evaluated. Small broomrape density, small broomrape seed viability after treatment, and clover injury and seed yield were quantified. Small broomrape control with imazamox, glyphosate, and imazamox plus bentazon treatments was greater than the nontreated check in both years. However, imazamox and imazamox plus bentazon treatments were the only herbicide treatments that consistently exhibited a high level of crop safety, reduced small broomrape density, and did not reduce red clover yield. Herbicide treatments did not prevent production of viable small broomrape seeds. Future research is needed to develop control options that will prevent red clover yield loss and viable small broomrape seed production when applied before small broomrape emergence.

Integrating Reduced Rates of Postemergence Herbicides and Cultivation for Broadleaf Weed Control in Soybeans (Glycine max)

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 541-545 ◽  
Author(s):  
Lawrence E. Steckel ◽  
Michael S. Defelice ◽  
Barry D. Sims
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Seed Production ◽  
Field Experiments ◽  
Soybean Yield ◽  
Application Timing ◽  
Late Season ◽  
Full Rate ◽  
Reduced Rate ◽  
Postemergence Herbicides

The interaction of reduced rates of bentazon, chlorimuron, imazaquin, and imazethapyr with cultivation for broadleaf weed control in soybeans was investigated in field experiments conducted at three sites in Missouri in 1987 and 1988. Single reduced-rate herbicide applications provided soybean yields equal to full rates although visual weed control was slightly lower. Sequential applications of all four herbicides at reduced rates provided weed control and soybean yields equal to full-rate applications. The number of velvetleaf plants m−2and seeds plant−1were not influenced by herbicide, herbicide rate, or application timing. Cultivation improved weed control and soybean yield and decreased late-season weed populations and seed production.

Common Milkweed Seed Maturation

Weed Science ◽  
1973 ◽  
Vol 21 (6) ◽  
pp. 568-569 ◽  
Author(s):  
L. L. Evetts ◽  
O. C. Burnside
Keyword(s):  
Seed Production ◽  
Seed Weight ◽  
Close Association ◽  
Seed Maturation ◽  
Time Interval ◽  
Viable Seed ◽  
Asclepias Syriaca ◽  
Hypocotyl Length ◽  
Viable Seeds ◽  
Germinated Seeds

A 2-year experiment was conducted to determine the time interval between flowering and viable seed production in common milkweed (Asclepias syriacaL.). A high percentage of seeds harvested 6 weeks after flowering germinated. Seeds harvested 6 and 7 weeks after flowering resulted in seedlings with significantly shorter radicles and hypocotyls than seeds harvested 8 weeks after flowering. There was a close association between seed weight and radicle and hypocotyl length. Common milkweed produced viable seeds 5 to 6 weeks after flowering.

Control of Sulfonylurea-Resistant Kochia (Kochia scoparia)

1997 ◽  
Vol 11 (2) ◽  
pp. 270-276 ◽  
Author(s):  
Dennis J. Tonks ◽  
Philip Westra
Keyword(s):  
Population Dynamics ◽  
Field Experiments ◽  
Control Strategies ◽  
Growth Stages ◽  
Kochia Scoparia ◽  
Alternative Control ◽  
Application Timing ◽  
Selection Of

Greenhouse and field experiments were conducted to assess the effectiveness of herbicide tank mixtures for control of sulfonylurea (SU)-resistant and -susceptible kochia biotypes. Kochia control at three growth stages was evaluated for fluroxypyr, dicamba, 2,4-D, bromoxynil, and bromoxynil plus MCPA. Control decreased as kochia size increased, especially at less than full labeled herbicide rates. Treatments containing bromoxynil provided best overall control in the greenhouse but were less effective on larger kochia plants in the field. Dicamba and fluroxypyr provided similar, effective kochia control both in greenhouse and field experiments. 2,4-D did not provide acceptable kochia control regardless of formulation, rate, or application timing. All kochia biotypes responded similarly to non-SU herbicides. In the field, inclusion of an SU herbicide in the treatment generally resulted in no increased R-kochia control above that provided by the non-SU herbicide. R-kochia population dynamics can affect selection of alternative control strategies.

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