scholarly journals Southern Redcedar and Southern Magnolia Wood Chip Mulches for Weed Suppression in Containerized Woody Ornamentals

2008 ◽  
Vol 18 (2) ◽  
pp. 266-270 ◽  
Author(s):  
James Ferguson ◽  
Bala Rathinasabapathi ◽  
Clinton Warren
Keyword(s):  
Field Trial ◽  
Wood Chip ◽  
Inhibitory Effect ◽  
Amaranthus Retroflexus ◽  
Weed Suppression ◽  
Wood Chips ◽  
Magnolia Grandiflora ◽  
Redroot Pigweed ◽  
Weed Growth ◽  
Large Crabgrass

Wood chip mulches from southern redcedar (Juniperus silicicola) and southern magnolia (Magnolia grandiflora) were evaluated for their effectiveness in weed control in nursery containers. In greenhouse tests, southern redcedar and southern magnolia wood chip mulches significantly inhibited the germination of redroot pigweed (Amaranthus retroflexus) and large crabgrass (Digitaria sanguinalis). In a field trial, nursery containers with ‘Carolina Beauty’ crape myrtle plants (Lagerstroemia indica) were sown with large crabgrass and redroot pigweed seeds, mulched with southern redcedar or southern magnolia wood chips, and compared with plants without mulch and plants treated with a mixture of isoxaben and trifluralin (Snapshot). Wood chips from both southern redcedar and southern magnolia were as effective as a mixture of isoxaben and trifluralin in suppressing weed growth in nursery containers. The wood chip mulches had no inhibitory effect on the growth of crape myrtle plants. In a similar, longer-term field trial using containerized dogwood (Cornus florida) plants sown with large crabgrass and redroot pigweed, the southern redcedar wood chip mulch was most effective in weed suppression when used in combination with a low dose of the chemical herbicide.

scholarly journals Improving weed control in sustainable agro-ecosystems: role of cultivar and termination timing of rye cover crop

2021 ◽  
Author(s):  
Roberta Boselli ◽  
Nico Anders ◽  
Andrea Fiorini ◽  
Cristina Ganimede ◽  
Nadia Faccini ◽  
...  
Keyword(s):  
Weed Control ◽  
Biomass Production ◽  
Seedling Growth ◽  
Cover Crop ◽  
Inhibitory Effect ◽  
Amaranthus Retroflexus ◽  
Weed Suppression ◽  
Weed Biomass ◽  
Redroot Pigweed ◽  
Field Level

Highlights - One month after rye termination, the weed biomass under mulching is reduced by 4 times, compared with the control. - When rye is terminated early, the weed biomass production is reduced by the allelochemical content in rye tissues. - When rye is terminated late, the weed biomass production is reduced by the amount of rye biomass. - Lambsquarters, redroot pigweed, and purslane growth is inhibited by rye mulching, while velvetleaf is not affected.   Abstract Alternative strategies to control weeds are required at field level to reduce herbicides and derived pollution. Rye (Secale cereale L.) cultivation as cover crop is adopted mainly because of its allelopathic weed control, which takes place throughout a strong inhibition of germination and seedling growth in several grass and broad-leaved weeds.  The present study consisted of: i) a field trial, focused on evaluation of biomass production and allelochemical concentration in the biomass, and in situ weed control at 30 days after termination (with two termination timings: T1 - heading phase and T2 - 10 days later) of 8 rye varieties; ii) a pot experiment, focused on the inhibition effect of mulches derived by those 8 rye varieties on four summer weeds: velvetleaf (Abutilon theophrasti Med.), lambsquarters (Chenopodium album L.), redroot pigweed (Amaranthus retroflexus L.), and common purslane (Portulaca oleracea L).  Results showed that biomass production was the highest with Protector, closely followed by Primizia, Sito 70, Hellvus, Forestal, and Hymonta. In any case, rye mulching always reduced the weed biomass, especially with Fasto and Forestal. The allelochemical concentration in the biomass was the highest with Fasto and Forestal, and decreased on average from T1 to T2 (-38% for total BX and -57% for isovitexin). Conversely, the rye biomass production increased (on average + 77%) passing from T1 to T2. We found also that the reduction of weed biomass, compared with the control, is highly correlated with the allelochemical content in rye biomass in the case of T1 termination, while with the biomass production in the case of T2. In pots, a strong inhibitory effect on seedling growth due to rye mulching was observed for C. album (-76%), A. retroflexus (-56%), and P. olearcea (-84%), while not for A. theophrasti. We concluded that, whatever the variety, adopting rye as cover crop may be considered as a suitable practice to reduce weed pressure at the field level. Among all the varieties tested, Forestal and Protector showed the greatest weed suppression potential, as a consequence of high amount of allelochemicals production for Forestal, and high biomass production for Protector.

scholarly journals Interaction of Insects and Weeds in a Snap Bean Agroecosystem

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Joseph N. Aguyoh ◽  
John B. Masiunas ◽  
Catherine Eastman
Keyword(s):  
Weed Management ◽  
Leaf Beetle ◽  
Amaranthus Retroflexus ◽  
Integrated Weed Management ◽  
Trifoliate Leaf ◽  
Snap Bean ◽  
Redroot Pigweed ◽  
Snap Beans ◽  
Bean Leaf Beetle ◽  
Large Crabgrass

Integrated weed management strategies maintain sub-threshold levels of weeds. The remaining weeds may impact the feeding and habitation patterns of both potato leafhoppers and bean leaf beetles in a snap bean agroecosystem. The objective of our study was to determine the effect of interference between snap beans (Phaseolus vulgaris L.) and either redroot pigweed (Amaranthus retroflexus L.) or large crabgrass (Digitaria sanguinalis L.) on populations of potato leafhopper [Empoasca fabae (Harris)] and bean leaf beetle [Cerotoma trifurcata (Forster)]. Plots were seeded with redroot pigweed or large crabgrass at either the same time as snap bean planting (early) or when snap bean had one trifoliate leaf open (late). The weed density averaged two plants per meter of row. Bean leaf beetle populations, snap bean pod damage, and leaf defoliation were lower in weed-free plots compared to those with either early emerging pigweed or crabgrass. Leafhopper nymphs and adults were 31% to 34% less in plots with crabgrass emerging with snap beans compared to those in weed-free snap bean plots. Thus, the effect of sub-threshold densities of pigweed and crabgrass on insect pests in snap bean varied depending on the species and should be considered when deciding to integrate weed management approaches.

Influence of Time of Planting and Distance from the Cotton (Gossypium hirsutum) Row of Pitted Morningglory (Ipomoea lacunosa), Prickly Sida (Sida spinosa), and Redroot Pigweed (Amaranthus retroflexus) on Competitiveness with Cotton

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 568-572 ◽  
Author(s):  
G. A. Buchanan ◽  
J. E. Street ◽  
R. H. Crowley
Keyword(s):  
Gossypium Hirsutum ◽  
Amaranthus Retroflexus ◽  
Fresh Weight ◽  
Weed Species ◽  
Ipomoea Lacunosa ◽  
Redroot Pigweed ◽  
Weed Growth ◽  
Pitted Morningglory ◽  
Sida Spinosa ◽  
Prickly Sida

Influence of time of planting and distance from the cotton row of pitted morningglory (Ipomoea lacunosaL.), prickly sida (Sida spinosaL.), and redroot pigweed (Amaranthus retroflexusL.) on yield of seed cotton (Gossypium hirsutumL. ‘Stoneville 213’) was determined on Decatur clay loam during 1975 through 1978. Weed growth was measured in 1977 and 1978. Seeds of the three weed species were planted 15, 30, or 45 cm from the cotton row at time of planting cotton or 4 weeks later. Weeds planted 4 weeks after planting cotton grew significantly less than did weeds planted at the same time as cotton. When planted with cotton, redroot pigweed produced over twice as much fresh weight as did prickly sida or pitted morningglory. The distance that weeds were planted from the cotton row did not affect weed growth in 1978, but did in 1977. The distance that weeds were planted from the cotton row did not affect their competitiveness in any year as measured by yield of cotton. However, in each year, yields of cotton were reduced to a greater extent by weeds planted with cotton than when planted 4 weeks later. In 3 of 4 yr, there were significant differences in competitiveness of each of the three weed species with cotton.

scholarly journals Evaluation of Allelopathic Potential of Wood Chips for Weed Suppression in Horticultural Production Systems

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 711-713 ◽  
Author(s):  
Bala Rathinasabapathi ◽  
James Ferguson ◽  
Mark Gal
Keyword(s):  
Production Systems ◽  
Wood Chip ◽  
Organic Production ◽  
Weed Suppression ◽  
Water Soluble ◽  
Wood Chips ◽  
Red Maple ◽  
Allelopathic Potential ◽  
Red Cedar ◽  
Southeastern Us

Shredded and chipped wood mulches are used for weed suppression in perennial fruit crops, in urban landscapes, and occasionally in vegetable crops. Wood chip mulches with weed-suppressing allelochemicals may be more effective for weed control, especially under sustainable and organic production systems, than mulches without such properties. The objective of this study was to test for the presence of water-soluble allelochemicals in wood chips derived from tree species, often found in wood resource recovery operations in the southeastern US. Presence of allelochemicals in water eluates of woodchips and leaves was evaluated in a lettuce bioassay. Eluates of wood chips from red maple (Acer rubrum L.), swamp chestnut oak (Quercus michauxii Nutt.), red cedar (Juniperus silicicola L.H. Bailey), neem (Azadirachta indica A. Juss.), and magnolia (Magnolia grandiflora L.) highly inhibited germinating lettuce seeds, as assessed by inhibition of hypocotyl and radicle growth. The effects of wood chip eluates from these five species were more than that found for eluates from wood chips of black walnut (Juglans nigra L.,) a species previously identified to have weed-suppressing allelochemicals. Tests on red cedar, red maple, and neem showed that water-soluble allelochemicals were present not only in the wood but also in the leaves. In greenhouse trials, red cedar wood chip mulch significantly inhibited the growth of florida beggarweed (Desmodium tortuosum DC.), compared to the gravel-mulched and no-mulch controls.

scholarly journals Assessment of some medicinal plants for their allelopathic potential against redroot pigweed (Amaranthus retroflexus)

2014 ◽  
Vol 54 (1) ◽  
pp. 90-95 ◽  
Author(s):  
Marzieh Sabagh Nekonam ◽  
Jamshid Razmjoo ◽  
Hasan Kraimmojeni ◽  
Bahram Sharifnabi ◽  
Hajar Amini ◽  
...  
Keyword(s):  
Ricinus Communis ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Amaranthus Retroflexus ◽  
Crocus Sativus ◽  
Nerium Oleander ◽  
Aqueous Extracts ◽  
Allelopathic Potential ◽  
Natural Herbicides ◽  
Redroot Pigweed

Abstract The study was conducted to determine the allelopathic effects of Crocus sativus L., Ricinus communis L., Nicotiana tabacum L., Datura inoxia Mill., Nerium oleander L., and Sorghum vulgare L. on the germination and growth of Amaranthus retroflexus (redroot pigweed). Powder and aqueous extracts of these plants were used to run the experiment under laboratory and greenhouse conditions. In the laboratory, all aqueous extracts showed a significant inhibitory effect on the germination, seedling length and weight of redroot pigweed plants. The most allelopathic against the redroot pigweed were R. communis, N. tabacum, and D. inoxia. In the greenhouse experiment, extracts and the powder of these plants also showed significant inhibitory effects on pigweed dry weight, height, leaf area, number of survivor plants, and amount of chlorophyll. In the germination bioassay and application of powder, the inhibitory effect was dosage dependent - the higher the concentration, the strongest the inhibitory effect. From the obtained results, it can be concluded that the powder and extracts of the tested species have an herbicidal potential against redroot pigweed and could be used as natural herbicides and mulches.

scholarly journals Wood Chip Drying through the Using of a Mobile Rotary Dryer

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1590 ◽  
Author(s):  
Angelo Del Giudice ◽  
Andrea Acampora ◽  
Enrico Santangelo ◽  
Luigi Pari ◽  
Simone Bergonzoli ◽  
...  
Keyword(s):  
Moisture Content ◽  
Power Plants ◽  
Black Locust ◽  
Thermal Power ◽  
Initial Moisture Content ◽  
Wood Chip ◽  
Wood Chips ◽  
Cocurrent Flow ◽  
Drying Process ◽  
Rotary Dryer

Drying is a critical point for the exploitation of biomass for energy production. High moisture content negatively affects the efficiency of power generation in combustion and gasification systems. Different types of dryers are available however; it is known that rotary dryers have low cost of maintenance and consume 15% and 30% less in terms of specific energy. The study analyzed the drying process of woody residues using a new prototype of mobile rotary dryer cocurrent flow. Woodchip of poplar (Populus spp.), black locust (Robinia pseudoacacia L.), and grapevine (Vitis vinifera L.) pruning were dried in a rotary drier. The drying cycle lasted 8 h for poplar, 6 h for black locust, and 6 h for pruning of grapevine. The initial biomass had a moisture content of around 50% for the poplar and around 30% for grapevine and black locust. The study showed that some characteristics of the biomass (e.g., initial moisture content, particle size distribution, bulk density) influence the technical parameters (i.e., airflow temperature, rate, and speed) of the drying process and, hence, the energy demand. At the end of the drying process, 17% of water was removed for poplar wood chips and 31% for grapevine and black locust wood chips. To achieve this, result the three-biomass required 1.61 (poplar), 0.86 (grapevine), and 1.12 MJ kgdry solids−1 (black locust), with an efficiency of thermal drying (η) respectively of 37%, 12%, and 27%. In the future, the results obtained suggest an increase in the efficiency of the thermal insulation of the mobile dryer, and the application of the mobile dryer in a small farm, for the recovery of exhaust gases from thermal power plants.

scholarly journals Improvement of Enzymatic Saccharification of Cellulose-Containing Raw Materials Using Aspergillus niger

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1360
Author(s):  
Ekaterina Budenkova ◽  
Stanislav Sukhikh ◽  
Svetlana Ivanova ◽  
Olga Babich ◽  
Vyacheslav Dolganyuk ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Aspergillus Niger ◽  
Filter Paper ◽  
Raw Materials ◽  
Enzymatic Saccharification ◽  
Wood Chip ◽  
Cellulase Activity ◽  
Wood Chips ◽  
Acid Pretreatment ◽  
Hydrolysis Of

Enzymatic hydrolysis of cellulose-containing raw materials, using Aspergillus niger, were studied. Filter paper, secondary cellulose-containing or starch-containing raw materials, miscanthus cellulose after alkaline or acid pretreatment, and wood chip cellulose, were used as substrates. The study focused on a wild A. niger strain, treated, or not (control), by ultraviolet (UV) irradiations for 45, 60, or 120 min (UV45, UV60, or UV120), or by UV irradiation for 120 min followed by a chemical treatment with NaN3 + ItBr for 30 min or 80 min (UV120 + CH30 or UV120 + CH80). A mixture of all the A. niger strains (MIX) was also tested. A citrate buffer, at 50 mM, wasthe most suitable for enzymatic hydrolysis. As the UV exposure time increased to 2 h, the cellulase activity of the surviving culturewas increased (r = 0.706; p < 0.05). The enzymatic activities of the obtained strains, towards miscanthus cellulose, wood chips, and filter paper, were inferior to those obtained with commercial enzymes (8.6 versus 9.1 IU), in some cases. Under stationary hydrolysis at 37 °C, pH = 4.7, the enzymatic activity of A. niger UV120 + CH30 was 24.9 IU. The enzymatic hydrolysis of secondary raw materials, using treated A. niger strains, was themost effective at 37 °C. Similarly, the most effective treatment of miscanthus cellulose and wood chips occurred at 50 °C. The maximum conversion of cellulose to glucose was observed using miscanthus cellulose (with alkaline pretreatment), and the minimum conversion was observed when using wood chips. The greatest value of cellulase activity was evidenced in the starch-containing raw materials, indicating that A. niger can ferment not only through cellulase activity, but also via an amylolytic one.

scholarly journals Effects of microwave irradiation on the moisture content of various wood chip fractions obtained from different tree species

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Monika Aniszewska ◽  
Krzysztof Słowiński ◽  
Ewa Tulska ◽  
Witold Zychowicz
Keyword(s):  
Moisture Content ◽  
Microwave Irradiation ◽  
Microwave Power ◽  
Irradiation Time ◽  
Initial Moisture Content ◽  
Radiant Energy ◽  
Wood Chip ◽  
Wood Chips ◽  
Chip Size ◽  
Drying Rates

AbstractThe paper proposes the use of microwave irradiation to lower the initial moisture content of wood chips. The study involved willow and fir chips fractionated by means of a sieve separator and unfractionated ash chips. The wood chips were exposed to a constant microwave power of 800 W for 30 s, 60 s, 120 s and 180 s. The chips were weighed before and after irradiation to measure loss of moisture. It was found that the decline in moisture content increased with wood chip size for a given irradiation time and microwave power. The initial moisture content of wood chips was not found to significantly affect loss of moisture as the drying rates of wood chips with higher and lower moisture content exposed to microwaves were not statistically different. The results showed that irradiation intensity increased with the time of exposure to microwaves and unit radiant energy per unit of evaporated moisture decreased with increasing wood chip size in the 3.15–31.50 mm range.

scholarly journals Electrical Capacitance Characteristics of Wood Chips at Low Frequency Ranges: A Cheap Tool for Quality Assessment

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3494
Author(s):  
Jakub Lev ◽  
Václav Křepčík ◽  
Egidijus Šarauskis ◽  
František Kumhála
Keyword(s):  
Moisture Content ◽  
Linear Models ◽  
Economic Value ◽  
Wood Chip ◽  
Principal Component ◽  
Dissipation Factor ◽  
Industrial Applications ◽  
Wood Chips ◽  
Electrical Capacitance ◽  
Low Frequencies

Moisture content is one of the most important parameters related to the quality of wood chips that affects both the calorific and economic value of fuel chips. For industrial applications, moisture content needs to be detected quickly. For this purpose, various indirect moisture content measurement methods (e.g., capacitance, NIR, microwave, ECT, X-ray CT, and nuclear MR) have been investigated with different results in the past. Nevertheless, determining wood chip moisture content in real time is still a challenge. The main aim of this article was therefore to analyze the dielectric properties of wood chips at low frequencies (10 kHz–5 MHz) and to examine the possibility of using these properties to predict wood chip moisture content and porosity. A container-type probe was developed for this purpose. The electrical capacitance and dissipation factor of wood chips with different moisture content was measured by an LCR meter at 10 kHz, 50 kHz, 100 kHz, 500 kHz, 1 MHz, and 5 MHz frequencies. Wood chip porosity was also measured using a gas displacement method. Linear models for moisture content and porosity prediction were determined by backward stepwise linear regression. Mathematical model was developed to better understand the physical relationships between moisture content, porosity, and electrical capacitance. These models were able to predict the moisture content of observed quantities of wood chips with the required accuracy (R2 = 0.9−0.99). This finding opens another path to measuring the moisture content and porosity of wood chips in a relatively cheap and fast way and with adequate precision. In addition, principal component analysis showed that it is also possible to distinguish between individual wood chip fraction sizes from the information obtained.

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