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

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.

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Optimal seeding rate for organic production of lentil in the northern Great Plains

Canadian Journal of Plant Science ◽

10.4141/cjps08226 ◽

2009 ◽

Vol 89 (6) ◽

pp. 1089-1097 ◽

Cited By ~ 13

Author(s):

J M Baird ◽

S J Shirtliffe ◽

F L Walley

Keyword(s):

Great Plains ◽

Plant Density ◽

Production Systems ◽

Organic Production ◽

Weed Suppression ◽

Northern Great Plains ◽

Seeding Rate ◽

Nitrogen And Phosphorus ◽

Economic Return ◽

Conventional Production

Organic lentil (Lens culinaris Medik.) producers must rely upon the recommended rate for conventional production of 130 plants m-2, but this seeding rate may not be suitable, as organic and conventional production systems differ in management and inputs. The objective of this study was to determine an optimal seeding rate for organic production of lentil considering a number of factors, including yield, weed suppression, soil nitrogen and phosphorus concentrations, plant uptake of phosphorus, and economic return. A field experiment was conducted for 4 site-years at locations near Saskatoon, SK. Treatments included seeding rates of 15, 38, 94, 235 and 375 seeds m-2. Seed yield increased with increasing seeding rate up to 1290 kg ha-1. Weed biomass was reduced by 59% at the highest seeding rate as compared with the lowest seeding rate. Post-harvest soil phosphorus and nitrogen levels were similar between seeding rate treatments. Economic return was maximized at $952 ha-1 at the highest density of 229 plants m-2, achieved with a seeding rate of 375 seeds m-2. Organic farmers should increase the seeding rate of lentil to achieve a plant density of 229 plants m-2 to increase profitability and provide better weed suppression.Key words: Lentil, organic, seeding rate, weed suppression, economic return

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(415) Evaluation of Weed Control Practices in an Organic Bell Pepper Production System

HortScience ◽

10.21273/hortsci.40.4.1071d ◽

2005 ◽

Vol 40 (4) ◽

pp. 1071D-1071

Author(s):

Derek M. Law ◽

Brent Rowell

Keyword(s):

Weed Control ◽

Production Systems ◽

Wood Chip ◽

Continuous Cultivation ◽

Organic Production ◽

Bell Pepper ◽

Living Mulch ◽

Straw Mulch ◽

Corn Gluten ◽

Flat Ground

A 2-yearfield study in Lexington, Ky., evaluated the use of mulches in two organic production systems for bell peppers. Two planting strategies, flat ground and plastic-covered raised beds, and five weed control practices, straw mulch, compost mulch, wood chip mulch, corn gluten, and “living mulch” clover were tested. In 2003, the mulches were applied at planting, while in 2004, shallow soil cultivation was used for 6 weeks prior to mulch application. In 2003, the experimental field had been under a winter wheat cover crop; in 2004, the field had been cover cropped for more than a year prior to planting with sudex/cowpea (Summer 2003) and rye/hairy vetch (Winter/Spring 2004). Bell pepper yields in both bed treatments were very low in 2003 due to extensive weed competition. In 2004, plastic-covered raised beds coupled with mulching in-between beds resulted in significantly higher yields than the peppers grown on flat ground. These yields were as high as yields from a conventional pepper trial conducted on the same farm. Compost mulch, continuous cultivation, and wood chip mulch provided excellent weed control in 2004. Straw mulch was variable in its weed control efficacy; corn gluten and “living mulch” clover were ineffective.

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Organic and conventional sweetpotato production in the Southeastern of United States: a comparative analysis

Agriculture & Food Security ◽

10.1186/s40066-021-00298-6 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Sochinwechi Nwosisi ◽

Prabodh Illukpitiya ◽

Dilip Nandwani ◽

Ismail Tubosun Arebi ◽

Obinna Nwosisi

Keyword(s):

Production Systems ◽

Unit Cost ◽

Organic Production ◽

Farm Income ◽

Selling Price ◽

Economic Risk ◽

Net Return ◽

Southeastern Us ◽

Net Profit ◽

Conventional Production

Abstract Background There has been a piqued interest in alternative agricultural production systems that are environmentally friendly due to concerns on how sustainable it is to grow conventionally. However, in the producer’s point of view, economic returns are an important issue in decision-making in adaptation. The purpose of this study is to assess the economic risk of conventional and organic sweetpotato production in the Southeastern US. The primary and secondary data were used for the analysis. We identified risk variables in stochastic profit function and performed Monte Carlo simulation in analyzing profitability and economic risk of conventional and organic production systems. Results Findings from the meta-analysis suggest lower sweetpotato yields and higher selling prices, are to be expected in the organic sweetpotato production systems compared with the conventional. A higher probability of having positive net return from organically grown sweetpotato compared to conventional production systems was observed. Conclusions Increase in unit cost leads to a decrease in net profit in both conventional and organic production systems. Sweetpotato price has more effect on net return compared to its yield in conventional production systems. The higher selling price, lower yield and lower unit costs provide a higher net profit return for the organic sweetpotato production systems. Unit cost in conventional production was noted to be higher in general, inferring conventional sweetpotato production could potentially experience a higher variability in net farm income. Despite the high production cost, however, farmers are encouraged to go into sweetpotato production as it appears to be profitable. Further studies should be conducted on conventional treatments without synthetic pesticides and fertilizers as these systems perhaps, may display lower external input costs that might make them more profitable similar to organic systems.

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

HortTechnology ◽

10.21273/horttech.18.2.266 ◽

2008 ◽

Vol 18 (2) ◽

pp. 266-270 ◽

Cited By ~ 1

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.

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Wood Chip Drying through the Using of a Mobile Rotary Dryer

Energies ◽

10.3390/en12091590 ◽

2019 ◽

Vol 12 (9) ◽

pp. 1590 ◽

Cited By ~ 9

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.

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

Processes ◽

10.3390/pr9081360 ◽

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.

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

Journal of Wood Science ◽

10.1186/s10086-021-01958-8 ◽

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.

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Effect of Compost Amendments on Disease Severity and Yield of Tomato in Conventional and Organic Production Systems

Plant Disease ◽

10.1094/pdis.2002.86.2.156 ◽

2002 ◽

Vol 86 (2) ◽

pp. 156-161 ◽

Cited By ~ 83

Author(s):

P. A. Abbasi ◽

J. Al-Dahmani ◽

F. Sahin ◽

H. A. J. Hoitink ◽

S. A. Miller

Keyword(s):

Disease Severity ◽

Production Systems ◽

Disease Incidence ◽

Organic Production ◽

Fruit Rot ◽

High Rate ◽

Bacterial Spot ◽

Marketable Yield ◽

Tomato Production ◽

Compost Amendments

Field trials were conducted over 2 years to assess the effects of compost amendments on disease development in organic and conventional processing tomato (Lycopersicon esculentum L.) production systems. The incidence of anthracnose fruit rot was reduced in organic tomato plots amended with a high rate of composted cannery wastes compared with the incidence in nonamended control plots in 1998 when disease incidence was high. Marketable yield was increased by 33% in compost-amended organic plots. Plots amended with a high compost rate had more ripe fruit than the nonamended control. The incidence of anthracnose and of total disease on fruit was less on the cultivar OH 8245 than on Peto 696. Total fruit yield of OH 8245 but not Peto 696 in organic plots was increased by amendment with composted cannery wastes. In conventional tomato production, composted yard wastes increased disease severity on foliage both years but reduced bacterial spot incidence on fruit in 1997, when disease pressure was high. The incidence of anthracnose was not affected by composted yard wastes. Marketable and total fruit yields of Peto 696 were not increased in compost-amended conventional plots. The plant activator Actigard reduced foliar disease severity and the incidence of bacterial spot and anthracnose on fruit, while increasing yield of marketable fruit.

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

Sensors ◽

10.3390/s21103494 ◽

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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Can hemp hurd or paper mulch and biochar application improve weed management in matted-row strawberry production systems?

Renewable Agriculture and Food Systems ◽

10.1017/s1742170521000533 ◽

2021 ◽

pp. 1-11

Author(s):

Greta G. Gramig ◽

Samantha K. Hogstad ◽

Patrick M. Carr

Keyword(s):

Weed Management ◽

Production Systems ◽

Weed Suppression ◽

Plastic Mulch ◽

Yield Data ◽

Weed Biomass ◽

Soil Temperatures ◽

The Impact ◽

Hemp Hurd ◽

Amended Soil

Abstract During 2015 and 2016, studies were conducted at Absaraka and Dickinson, North Dakota to evaluate the impacts of hemp (applied at 1156 m3 ha−1) and commercial paper mulch, as well as soil-applied biochar (applied at 11.25 m3 ha−1), on weed suppression and strawberry growth during the establishment year, and on weed suppression and strawberry yield during the production year, in a matted row production (MRP) system. During 2015, biochar influenced dry weed biomass only within the hemp mulch, with slightly more weed biomass associated with biochar application compared to zero biochar (3.1 vs 0.4 g m−2), suggesting that biochar may have increased weed germination and/or emergence from beneath hemp mulch. Biochar application also slightly increased soil pH, from 6.9 in non-amended soil to 7.0 in amended soil. Strawberry runner number during 2015 was greater in association with hemp or paper mulch compared to zero mulch (4.5 and 4.9 vs 2.4 runners plant −1, respectively). This result mirrored a similar differential in per berry mass across sites (7.6 and 7.4 vs 6.2 g berry −1 for hemp mulch, paper mulch and zero mulch, respectively). These results may be related to hemp and paper mulch reducing maximum soil temperatures during summer 2015. During the establishment year, both hemp and paper mulch suppressed weeds well compared to zero mulch, although at Absaraka hemp mulch provided slightly better weed suppression than paper mulch. During the production year, both mulches continued to suppress weeds compared to zero mulch at Dickinson. However, at Absaraka, only hemp mulch provided weed suppression compared to zero mulch, possibly because of faster paper degradation caused by greater numbers of large precipitation events and greater relative humidity at Absaraka compared to Dickinson. Weeds were removed from plots during 2015 to allow separation of weed suppression from other possible mulch impacts; therefore, yield data do not reveal striking differences among mulch treatments. Because previous research has demonstrated the impact of weed management during the establishment of strawberries in a matted row system, we concluded that hemp mulch may provide more durable weed suppression compared to paper mulch, which would increase strawberry yield protection in an MRP system. Material cost may be an issue for implementing hemp mulch, as hemp hurd cost was 25 times paper mulch at the application rates used in this study. However, hemp mulch could still be a beneficial option, especially for organic strawberry growers desiring a renewable and environmentally sound replacement for plastic mulch who are able to find affordable local sources of this material.

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