scholarly journals Response of giant foxtail and wild proso millet to artificial light quality alteration

2021 ◽  
pp. 26-31
Author(s):  
Jenipher Bisikwa ◽  
Roger L. Becker ◽  
Vince A. Fritz ◽  
Kevin Natukunda ◽  
Martha I. Natukunda
Keyword(s):  
Interspecific Competition ◽  
Plant Height ◽  
Growth And Development ◽  
Light Quality ◽  
Plant Competition ◽  
The United States ◽  
Weed Suppression ◽  
Weed Species ◽  
Proso Millet ◽  
Giant Foxtail

Light is an essential requirement for proper plant growth and development. Growth chamber experiments were conducted to determine whether artificial alteration of light quality (reducing the red to far-red ratio-R:FR) differentially affected the growth and development of giant foxtail and wild proso millet, two troublesome annual grass weeds in the United States. Growth phenotypes of both weeds were examined under two R:FR regimes (0.28-reduced R:FR and 1.12-unaltered R:FR) in the absence of competition (control conditions) and under intraspecific and interspecific competition. The reduced R:FR simulated shaded (below-canopy) R:FR conditions in the field while the unaltered R:FR treatment simulated direct sunlight (above-canopy) conditions. Averaged across weed species, reducing the R:FR increased plant height, but reduced tiller production and above-ground biomass under no plant competition (P<0.05). In the presence of competition, reducing the R:FR increased plant height and internode length but reduced the number of tillers and leaf area across weed species. No phenotypic differences were observed for weeds tested under intraspecific or interspecific competition. Our study has shown that the response of both weeds to artificial R:FR alteration is similar to that observed under shaded field conditions. Therefore, by replacing bordering plants with a crop, controlled experiments can be used to test the effect of crop canopies on weed suppression when selecting cultivars to be planted in areas where certain weed species are prevalent, minimizing weed-related yield losses.

Growth and Development of Johnsongrass Ecotypes

Weed Science ◽  
1971 ◽  
Vol 19 (2) ◽  
pp. 141-147 ◽  
Author(s):  
C. G. McWhorter
Keyword(s):  
United States ◽  
Plant Height ◽  
Growth And Development ◽  
The United States ◽  
Mature Leaf ◽  
Sorghum Halepense ◽  
Lateral Growth ◽  
Foreign Countries ◽  
Culm Density

Studies were conducted on the growth and development of 55 morphologically distinct vegetative types of johnsongrass (Sorghum halepense(L.) Pers.) collected throughout the United States and from several foreign countries. Observations were made also on the growth of sorghum almum (Sorghum almumParodi) from three foreign countries. Mature leaf-blades of the different johnsongrass ecotypes varied in length from 31 to 59 cm and in width from 1.7 to 3.4 cm. Plant height and culm density varied 2 to 4-fold for the different ecotypes. Floret production varied from 87 to 352 sessile spikelets for representative panicles of the different ecotypes. The number and arrangement of branchlets within panicles also varied as did the size of various spikelet components. Sorghum almum produced much taller plants than did johnsongrass although culm density and lateral growth were less than that of johnsongrass.

Giant Foxtail Seed Predation byHarpalus pensylvanicus(Coleoptera: Carabidae)

Weed Science ◽  
2014 ◽  
Vol 62 (4) ◽  
pp. 555-562 ◽  
Author(s):  
Meredith J. Ward ◽  
Matthew R. Ryan ◽  
William S. Curran ◽  
Jeffrey Law
Keyword(s):  
Weed Management ◽  
Management Practices ◽  
Field Experiments ◽  
The United States ◽  
Future Research ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Giant Foxtail ◽  
Seed Preference ◽  
Activity Density

The utility of biological control for weed management in agroecosystems will increase with a greater understanding of the relationships between common weed and granivore species. Giant foxtail is an introduced, summer annual grass weed that is common throughout the United States and problematic in numerous crops.Harpalus pensylvanicus(DeGeer) (Coleoptera: Carabidae) is a common, native, omnivorous carabid beetle with a range that overlaps giant foxtail. In 2004 and 2005,H. pensylvanicuswas captured from farm fields in Centre County, PA, and subjected to laboratory feeding trials to test the preference of giant foxtail and other species on predation byH. pensylvanicus. Weed species seed preference experiments that included “Choice” and “No Choice” treatments were conducted using giant foxtail, common lambsquarters, and velvetleaf. When given a choice amongst the three weed species,H. pensylvanicuspreferred giant foxtail and common lambsquarters seeds equally compared to velvetleaf seeds. When given the choice,H. pensylvanicuspreferred newly dispersed giant foxtail seeds over field-aged seeds. Phenology of giant foxtail seed shed relative toH. pensylvanicusactivity density was also quantified in field experiments in 2005 and 2006. Giant foxtail seed rain was determined by collecting shed seeds from August through October using pan traps. Activity density ofH. pensylvanicuswas monitored for 72-h periods using pitfall traps from June to October. Peak activity density ofH. pensylvanicusoccurred at the onset of giant foxtail seed shed in both years; however, giant foxtail seed shed peaked approximately 30 to 50 d afterH. pensylvanicusactivity density. Future research should focus on management practices that enhance and supportH. pensylvanicuspopulations later in the growing season to maximize suppression of giant foxtail and other weeds that shed palatable seeds later in the season.

scholarly journals Seed shattering phenology at soybean harvest of economically important weeds in multiple regions of the United States. Part 1: broadleaf species

Weed Science ◽  
2020 ◽  
pp. 1-29
Author(s):  
Lauren M. Schwartz-Lazaro ◽  
Lovreet S. Shergill ◽  
Jeffrey A. Evans ◽  
Muthukumar V. Bagavathiannan ◽  
Shawn C. Beam ◽  
...  
Keyword(s):  
The United States ◽  
Ambrosia Artemisiifolia ◽  
Retention Rates ◽  
Weed Species ◽  
Physiological Maturity ◽  
Seed Retention ◽  
Northern Latitudes ◽  
Multiple Regions ◽  
Broadleaf Species ◽  
Crop Maturity

Abstract Potential effectiveness of harvest weed seed control (HWSC) systems depends upon seed shatter of the target weed species at crop maturity, enabling its collection and processing at crop harvest. However, seed retention likely is influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter phenology in thirteen economically important broadleaf weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after physiological maturity at multiple sites spread across fourteen states in the southern, northern, and mid-Atlantic U.S. Greater proportions of seeds were retained by weeds in southern latitudes and shatter rate increased at northern latitudes. Amaranthus species seed shatter was low (0 to 2%), whereas shatter varied widely in common ragweed (Ambrosia artemisiifolia L.) (2 to 90%) over the weeks following soybean physiological maturity. Overall, the broadleaf species studied shattered less than ten percent of their seeds by soybean harvest. Our results suggest that some of the broadleaf species with greater seed retention rates in the weeks following soybean physiological maturity may be good candidates for HWSC.

The Effect of Piperonyl Butoxide and Adjuvants on Sulfonylurea Herbicide Activity

1996 ◽  
Vol 10 (1) ◽  
pp. 127-133 ◽  
Author(s):  
Chae Soon Kwon ◽  
Donald Penner
Keyword(s):  
Seed Oil ◽  
Oxidase Inhibitor ◽  
Piperonyl Butoxide ◽  
Mixed Function Oxidase ◽  
Sulfonylurea Herbicide ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Giant Foxtail ◽  
Herbicide Activity ◽  
Grass Weed

Greenhouse studies showed that the mixed function oxidase inhibitor, piperonyl butoxide (PBO), tank-mixed with the sulfonylurea herbicides, nicosulfuron, primisulfuron, and thifensulfuron, in the absence of effective adjuvants enhanced herbicide activity on both broadleaf and grass weed species. Effective adjuvants for nicosulfuron were K-3000 for common lambsquarters, Sylgard® 309 Surfactant for velvetleaf, K-2000 for barnyardgrass, and K-2000, K-3000, and Scoil® methylated seed oil for giant foxtail control. K-3000 and Sylgard 309 enhanced velvetleaf control with primisulfuron and thifensulfuron. The 28% urea and ammonium nitrate (UAN) was more effective as an adjuvant with thifensulfuron for velvetleaf than for common lambsquarters control. The enhancement of sulfonylurea herbicide activity with PBO was most apparent when other adjuvants were least effective.

Weed Control with Reduced Rates of Chlorimuron Plus Metribuzin and Imazethapyr in No-Till Narrow-Row Soybean (Glycine max)

1998 ◽  
Vol 12 (1) ◽  
pp. 32-36 ◽  
Author(s):  
William G. Johnson ◽  
Jeffrey S. Dilbeck ◽  
Michael S. Defelice ◽  
J. Andrew Kendig
Keyword(s):  
Glycine Max ◽  
Weed Control ◽  
Field Studies ◽  
Weed Suppression ◽  
Crop Response ◽  
Soybean Production ◽  
No Till ◽  
Giant Foxtail ◽  
The Difference ◽  
Narrow Row

Field studies were conducted at three locations in 1993 and 1994 to evaluate weed control and crop response to combinations of glyphosate, metolachlor, 0.5 X and 1 X label rates of chlorimuron plus metribuzin applied prior to planting (PP), and 0.5 X and 1 X label rates of imazethapyr applied early postemergence (EPOST) or postemergence (POST) in no-till narrow-row soybean production. Giant foxtail densities were reduced with sequential PP followed by (fb) EPOST or POST treatments. Large crabgrass was reduced equivalently with all herbicide combinations involving chlorimuron plus metribuzin PP fb imazethapyr. Common cocklebur control was variable but was usually greater with treatments that included imazethapyr. Ivyleaf morningglory densities were not reduced with any herbicide combinations. Sequential PP fb EPOST or POST treatments tended to provide slightly better weed suppression than PP-only treatments, but the difference was rarely significant. Soybean yields with treatments utilizing 0.5 X rates were usually equal to 1 X rates.

Enhanced Biodegradation of Herbicides in Soil and Effects on Weed Control

1987 ◽  
Vol 1 (4) ◽  
pp. 341-349 ◽  
Author(s):  
R. Gordon Harvey ◽  
J. H. Dekker ◽  
Richard S. Fawcett ◽  
Fred W. Roeth ◽  
Robert G. Wilson
Keyword(s):  
Weed Species ◽  
North Central ◽  
Herbicide Degradation ◽  
Proso Millet ◽  
The North ◽  
Central United States ◽  
Enhanced Biodegradation ◽  
Long Time ◽  
Previously Treated ◽  
Repeated Use

Research conducted since 1979 in the north central United States and southern Canada demonstrated that after repeated annual applications of the same thiocarbamate herbicide to the same field, control of some difficult-to-control weed species was reduced. Laboratory studies of herbicide degradation in soils from these fields indicated that these performance failures were due to more rapid or “enhanced” biodegradation of the thiocarbamate herbicides after repeated use with a shorter period during which effective herbicide levels remained in the soils. Weeds such as wild proso millet [Panicum miliaceumL. spp.ruderale(Kitagawa) Tzevelev. #3PANMI] and shattercane [Sorghum bicolor(L.) Moench. # SORVU] which germinate over long time periods were most likely to escape these herbicides after repeated use. Adding dietholate (O,O-diethylO-phenyl phosphorothioate) to EPTC (S-ethyl dipropyl carbamothioate) reduced problems caused by enhanced EPTC biodegradation in soils treated previously with EPTC alone but not in soils previously treated with EPTC plus dietholate. While previous use of other thiocarbamate herbicides frequently enhanced biodegradation of EPTC or butylate [S-ethyl bis(2-methylpropyl)carbamothioate], previous use of other classes of herbicides or the insecticide carbofuran (2,3 -dihydro-2,2 -dimethyl-7-benzofuranyl methylcarbamate) did not. Enhanced biodegradation of herbicides other than the thiocarbamates was not observed.

scholarly journals Çeşitli Biyoaktivatör Uygulamalarının Çarkıfelek ve Guava Bitkilerinin Fidan Gelişimi Üzerine Etkileri

2020 ◽  
Vol 8 (2) ◽  
pp. 421
Author(s):  
Canan Nilay Duran ◽  
Gizem Demirkaplan ◽  
Sevinç Şener
Keyword(s):  
Plant Height ◽  
Growth And Development ◽  
Ornamental Plants ◽  
Nutrient Content ◽  
Psidium Guajava ◽  
Stem Diameter ◽  
Sapling Growth ◽  
Number Of Leaves ◽  
Average Plant ◽  
Average Plant Height

Passionflower is a member of Passifloraceae family, it can be used as medicinal and ornamental plants in addition to its consumption as fruit in the world. Guava (Psidium guajava L.) fruits, which has a rich nutrient content, are consumed both fresh and processed. Passionfruit and guava plants, which can only be cultivated in temperate southern coasts in our country, have gained commercial importance because of the fruits' export potential, high medical importance and nutrient. This study was carried out to determine the effects of some bioactivator applications on the criteria of sapling growth and development of passionflower and guava plants. The experiment was conducted between 2018-2019 under greenhouse conditions. Saplings obtained from seed germination in Akdeniz University Faculty of Agriculture Research and Experiment Area were used as plant material. 3 different commercial preparations called Messenger, Crop-set and ISR-2000 were used as bioactivators. Plant height (cm), stem diameter (mm) and number of leaves (number / plant) were measured weekly, in order to determine the effect of the applications on the growth and development of saplings. At the end of the study, it was determined that the highest average plant height (10.17 cm), stem diameter (13.53 mm) were obtained in ISR-2000 application. The highest average plant height (11.93 cm), stem diameter (16.44 mm) and number of leaves (9.07 units / plant) were obtained from Messenger application in guava plant. When the results obtained are evaluated, it is recommended that ISR-2000 bioactivator can be applied in passionflower sapling cultivation and Messenger bioactivator can be applied for guava sapling cultivation.

scholarly journals Intellectual property rights in Brazilian floriculture: innovations for the growth and development of the market

2017 ◽  
Vol 23 (3) ◽  
pp. 296 ◽  
Author(s):  
Antonio Helio Junqueira ◽  
Marcia Peetz
Keyword(s):  
Growth And Development ◽  
Ornamental Plants ◽  
Genetic Material ◽  
The United States ◽  
Consumer Market ◽  
International Trends ◽  
Recent Developments ◽  
Cultivated Species ◽  
The Impact ◽  
Sectoral Policy

One of the most important demands imposed by the consumer market on the Brazilian Productive Chain of Flowers and Ornamental Plants is the constant launching of innovations in cultivated species and varieties. Such innovations include the constant introduction of flowers and plants not yet grown and commercialized, both native and adapted exotic species, as well as transformations and changes in size, shape, coloring and conduction patterns and presentation of these goods to the market. Brazil does not have a relevant breeding and cultivation industry. In this sense, it is highly dependent on imports of genetic material developed by countries such as the Netherlands, Germany, Japan, the United States of America, Thailand, among others. Recent developments in the sectoral policy to protect the rights of genetic developers, in the development of internationally adequate legislation and in the control of the use and trade of cultivars, has allowed Brazil greater access to new genetic materials of high quality and in line with contemporary international trends in the consumption. This article aims to discuss the state of the art of protection of cultivars in Brazil, pointing to the advances that the legislation and the inspection have allowed in relation to the introduction of genetic innovations, evaluating the impact of these measures on the growth and development of the market of consumption of flowers and ornamental plants in the country.

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