scholarly journals Thermal Weed Control in Photinia x fraseri “Red Robin” Container Nurseries

2017 ◽  
Vol 33 (3) ◽  
pp. 345-356 ◽  
Author(s):  
Christian Frasconi ◽  
Luisa Martelloni ◽  
Marco Fontanelli ◽  
Michele Raffaelli ◽  
Paolo Marzialetti ◽  
...  
Keyword(s):  
Weed Control ◽  
Control Level ◽  
Plant Production ◽  
Thermal Treatments ◽  
Liquefied Petroleum Gas ◽  
Two Phase ◽  
Total Period ◽  
Photinia X Fraseri ◽  
Container Nurseries ◽  
Flame Weeding

Abstract. A near-zero tolerance policy on weeds by markets for nursery crops calls for weed-free container-grown plants, and forces growers to frequently remove weeds. Thermal weed control could represent a novel method to control weeds in shrubs from container nurseries, thus avoiding the use of herbicides and mulches. The aims of this study were to develop custom-built machinery for thermal weed control in container nurseries and to test the weed control efficiency of flame weeding and steaming in Photinia x fraseri “Red Robin” containers. A liquefied petroleum gas (LPG) fed flamer and a steamer with a dedicated diffuser were built. Four treatments were applied for a total period of 24 months: steaming once every four months, steaming once every two months, flame weeding once every two months or once a month. Temperature values measured at different depths in the substrate after thermal applications were recorded and analyzed. Photinia x fraseri features (height, diameter, and dry biomass) and aesthetic parameters as affected by thermal treatments were also evaluated. The trend in temperature values of the substrate over time followed a two-phase exponential decay. All the thermal treatments lead to a continuous near-100% weed control level, which is the level required by growers for aesthetic reasons. No damages caused by heat on Photinia x fraseri were observed. Container nursery producers could thus adopt thermal methods as a substitute for chemical solutions for weed control management. Keywords: Container nurseries, ornamental plant production, Thermal weed control, Flame weeding, Steaming, Photinia x fraseri “Red Robin”, Two-phase temperature decay model.

scholarly journals Flaming to control weeds in seashore paspalum (Paspalum vaginatum Sw.) turfgrass

2019 ◽  
Author(s):  
Luisa Martelloni ◽  
Marco Fontanelli ◽  
Lisa Caturegli ◽  
Monica Gaetani ◽  
Nicola Grossi ◽  
...  
Keyword(s):  
Weed Control ◽  
Urban Areas ◽  
Optimal Dose ◽  
Liquefied Petroleum Gas ◽  
Seashore Paspalum ◽  
The Third ◽  
Paspalum Vaginatum ◽  
Weed Cover ◽  
The University ◽  
Flame Weeding

Weed control is crucial to ensure that turfgrass is established effectively. Although herbicides are commonly used to control weeds in turfgrasses, environmental and public health concerns have led to limiting or banning the use of synthetic herbicides in urban areas. The species seashore paspalum (Paspalum vaginatumSw.) is susceptible to such herbicides. Flame weeding could be an alternative to the use of synthetic herbicides for selective weed control in seashore paspalum. In this study, five different liquefied petroleum gas (LPG) doses of flaming (0, 61, 91, 157 and 237 kg ha-1) were tested in order to find the optimal dose, in terms of weed control and costs. The aim was to maintain a seashore paspalum (cultivar ‘Salam’) turf free of weeds during spring green-up, and at the same time avoid damaging the turfgrass. Using a self-propelled machine designed and built at the University of Pisa, flaming was applied three times when weeds started growing and the turfgrass started green-up. Our results highlight that an LPG dose of 157 kg ha-1was the most economic dose that led to a significant reduction in initial weed cover and density, enabling the turfgrass to recover three weeks after the third application.

scholarly journals On-farm Evaluations of Wood-derived, Waste Paper, and Plastic Mulch Materials for Weed Control in Florida Container Nurseries

2019 ◽  
Vol 29 (6) ◽  
pp. 866-873
Author(s):  
S. Christopher Marble ◽  
Shawn T. Steed ◽  
Debalina Saha ◽  
Yuvraj Khamare
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Guar Gum ◽  
Plant Production ◽  
Management Tool ◽  
Plastic Mulch ◽  
Pine Sawdust ◽  
Container Nurseries ◽  
Growth Differences ◽  
Hand Weeding

Mulches have been evaluated extensively as a weed management tool in container plant production, but most research has focused on loose-fill wood-derived mulch materials, such as pine bark or wood chips. In this experiment, pine (mixed Pinus sp.) bark (PB), shredded hardwood (HW), and pine sawdust were evaluated for weed control and crop response both alone and in combination with a guar gum tackifier alongside a plastic film mulch, a paper slurry mulch, and the paper slurry mulch + PB and compared with a nonmulched, nontreated control and a single application of preemergence herbicide (oxyfluorfen + pendimethalin). Mulch materials were applied to nursery containers ranging from 7 to 25 gal at two different nurseries and at two research centers in central Florida in 2017 and 2018. Results showed that the plastic mulch provided more than a 90% reduction in hand weeding time and weed weight over a 6-month period, and similar control was achieved with PB, paper slurry + PB, and the HW treatment (64% to 91% reduction in weeding time and weed weight). No growth differences were observed with any mulch treatment in any species evaluated including ligustrum (Ligustrum japonicum), Chinese elm (Ulmus parvifolia), or podocarpus (Podocarpus macrophyllum).

scholarly journals Effects of Flame Weeding on Organic Garlic Production

2018 ◽  
Vol 28 (4) ◽  
pp. 502-508 ◽  
Author(s):  
Lara Abou Chehade ◽  
Marco Fontanelli ◽  
Luisa Martelloni ◽  
Christian Frasconi ◽  
Michele Raffaelli ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Crop Production ◽  
Control Program ◽  
Growth Stages ◽  
Liquefied Petroleum Gas ◽  
Additional Tool ◽  
Hand Weeding ◽  
Physical Weed Control ◽  
Flame Weeding

A lack of efficient machines and strategies for cropping practices are still problems on small farms and in difficult landscapes, especially in organic crop production. The aim of this study was to develop a new weed control strategy for a typical organic garlic (Allium sativum) grown in Liguria, Italy. Flaming was proposed as an additional tool for the physical weed control program. A field experiment was conducted to test the effects of different flaming doses and timing on weed control and garlic production. The treatments consisted of a broadcast flaming at 16, 22, 37, and 112 kg·ha−1 of liquefied petroleum gas (LPG) at three different crop growth stages—emergence (BBCH 9), three to four leaves (BBCH 13) and six to seven leaves (BBCH 16)—once (at each growth stage separately), twice (at BBCH 9 and BBCH 13, BBCH 9 and BBCH 16, and BBCH 13 and BBCH 16 stages) or three times (all stages combined). Treatments were compared with a weedy control and hand weeding. One flaming treatment was effective in controlling weeds during the growing season. Frequent flaming treatments did not further reduce the weed biomass measured at harvest. A higher production than the weedy control, in terms of the number of marketable bulbs and yield, was obtained for all the flaming interventions carried out at more than 16-kg·ha−1 LPG dose. Garlic flamed once at BBCH 13 at any LPG dose or three times at more than 16 kg·ha−1 led to a comparable number of bulbs as hand weeding. Three flamings at an LPG dose of 22 kg·ha−1 also gave a statistically similar yield to hand weeding. In general, garlic was shown to tolerate up to three flaming treatments without a decline in the production. The decline in yield compared with hand weeding could be offset by the economical savings of the mechanization process and by integrating flaming with other mechanical tools used for weed management.

scholarly journals Mechanical weed control on small-size dry bean and its response to cross-flaming

2016 ◽  
Vol 14 (1) ◽  
pp. e0203 ◽  
Author(s):  
Luisa Martelloni ◽  
Christian Frasconi ◽  
Marco Fontanelli ◽  
Michele Raffaelli ◽  
Andrea Peruzzi
Keyword(s):  
Weed Control ◽  
Growth Stages ◽  
Liquefied Petroleum Gas ◽  
Dry Bean ◽  
Bean Plants ◽  
Yield Responses ◽  
Row Space ◽  
Flame Weeding ◽  
Mechanical Weed Control ◽  
Similar Yield

Dry bean (<em>Phaseolus vulgaris </em>L.) can be a profitable crop for farmers; however controlling weeds effectively without a decrease in yield remains a problem. An example where mechanical weed control is difficult to conduct is dry bean ‘Toscanello’, which is a small sized high-income niche product growing low to the ground. Concerning intra-row weed control, also flame weeding could be an opportunity but the dry bean heat tolerance needs to be studied. The aims of this research were to study the weed control efficacy of a spring-tine harrow and an inter-row cultivator in this bean variety, and to test the tolerance of dry bean cultivated under weed-free conditions to cross-flaming applied with different liquefied petroleum gas (LPG) doses. Flame weeding was applied at BBCH 13 and BBCH 14 bean growth stages by pairs of burners producing direct double flame acting into the intra-row space, with bean plants placed in the middle. The results suggest that the spring-tine harrow used two times at BBCH 13 and 14, respectively, lead to a yield similar to that of the weedy control. The inter-row cultivator could be an opportunity for small-sized dry bean crops producers, enabling them to obtain a similar yield compared to the hand-weeded control. Concerning the bean tolerance to cross-flaming<em> </em>the results showed that bean flamed at BBCH 13 stage had little tolerance to cross-flaming. Bean flamed at BBCH 14 stage was tolerant until an LPG dose of 39 kg/ha, giving yield responses similar to those observed in the non-flamed control.

scholarly journals Flaming to control weeds in seashore paspalum (Paspalum vaginatum Sw.) turfgrass

2019 ◽  
Vol 50 (3) ◽  
pp. 105-112
Author(s):  
Luisa Martelloni ◽  
Marco Fontanelli ◽  
Lisa Caturegli ◽  
Monica Gaetani ◽  
Nicola Grossi ◽  
...  
Keyword(s):  
Weed Control ◽  
Urban Areas ◽  
Optimal Dose ◽  
Liquefied Petroleum Gas ◽  
Seashore Paspalum ◽  
The Third ◽  
Paspalum Vaginatum ◽  
Weed Cover ◽  
The University ◽  
Flame Weeding

Weed control is crucial to ensure that turfgrass is established effectively. Although herbicides are commonly used to control weeds in turfgrasses, environmental and public health concerns have led to limiting or banning the use of synthetic herbicides in urban areas. The species seashore paspalum (Paspalum vaginatum Sw.) is susceptible to such herbicides. Flame weeding could be an alternative to the use of synthetic herbicides for selective weed control in seashore paspalum. In this study, five different liquefied petroleum gas (LPG) doses of flaming (0, 61, 91, 157 and 237 kg ha–1) were tested in order to find the optimal dose, in terms of weed control and costs. The aim was to maintain a seashore paspalum (cultivar ‘Salam’) turf free of weeds during spring greenup, and at the same time avoid damaging the turfgrass. Using a self-propelled machine designed and built at the University of Pisa, flaming was applied three times when weeds started growing and the turfgrass started green-up. Our results highlight that an LPG dose of 157 kg ha–1 was the most economic dose that led to a significant reduction in initial weed cover and density, enabling the turfgrass to recover three weeks after the third application.

scholarly journals Mulch Depth Affects Weed Germination

2009 ◽  
Vol 27 (2) ◽  
pp. 85-90
Author(s):  
Diana R. Cochran ◽  
Charles H. Gilliam ◽  
D. Joseph Eakes ◽  
Glenn R. Wehtje ◽  
Patricia R. Knight ◽  
...  
Keyword(s):  
Weed Control ◽  
Substrate Surface ◽  
The United States ◽  
Pine Bark ◽  
Plant Production ◽  
Control Technique ◽  
Weed Species ◽  
Container Nurseries ◽  
Fourth Experiment ◽  
Container Plant

Abstract With environmental concerns increasing, non-chemical weed control in container plant production is increasing in the United States. Pine bark mini-nuggets were evaluated as a non-chemical weed control technique for two weed species; Chamaesyce maculata (L.) Small (spotted spurge) and Eclipta alba (L.) Hassk.(eclipta). On June 19, 2006, seed (25 per container) were directly placed on the potting substrate surface of #3 containers before mulching with pine bark mini-nuggets to a depth of either 0, 1.27 or 2.54 cm (0, 0.5 or 1.0 in). Additional treatments consisted of applying the mini-nugget mulch at either 1.27 or 2.54 cm (0.5 or 1.0 in) on the potting substrate then overseeding with either spotted spurge or eclipta. Eclipta number per container were 87% less 60 days after seeding (DAS) with the 1.0 in mulch depth compared to non-mulched. Furthermore, spotted spurge fresh weight (FW) was reduced by 45 and 87% (0.5 and 1.0 in, respectively) compared to the non-mulched treatment. The experiment was repeated on August 30 and spurge number per container was 90% less 60 DAS in the 1.0 inch mulch treatment compared to the non-treated containers. A third and fourth experiment also demonstrated that pine bark mini-nuggets have potential to provide non-chemical weed control in nursery crops grown in #3 containers. Results, suggest that with proper application pine bark mini-nuggets can enhance weed control in container nurseries.

scholarly journals A combined flamer-cultivator for weed control during the harvesting season of asparagus green spears

2017 ◽  
Vol 15 (2) ◽  
pp. e0203 ◽  
Author(s):  
Luisa Martelloni ◽  
Marco Fontanelli ◽  
Christian Frasconi ◽  
Michele Raffaelli ◽  
Michel Pirchio ◽  
...  
Keyword(s):  
Weed Control ◽  
Lower Number ◽  
Yield Reduction ◽  
Weed Competition ◽  
Liquefied Petroleum Gas ◽  
Repeated Use ◽  
The Mean ◽  
Effectiveness And Efficiency ◽  
Flame Weeding ◽  
New Machine

Weed competition during spears harvesting reduces asparagus yields. The application of herbicides during this period is illegal, and alternative non-chemical practices are needed. This research tested the effectiveness and efficiency of a custom-built combined flamer-cultivator to control weeds (both in the inter- and intra- spears production bands) during the spears harvest season. It also analysed the effects of various liquefied petroleum gas (LPG) doses on total asparagus yield, mean spear weight, and total number of marketable spears. In both years, the asparagus spears were generally not damaged by flame weeding using LPG doses of between 43 to 87 kg/ha. The same LPG doses were effective in controlling weeds, showing the same total marketable yields as the weed-free control. At high LPG doses (e.g. 130 and 260 kg/ha), yields decreased as a consequence of the damage caused to the spears, resulting in a lower number of marketable spears. Flaming did not affect the mean spear weight, and can be applied repeatedly during harvesting to maintain the weeds at a level that does not lead to a yield reduction. The repeated use of the combined flamer-cultivator (every seven days) led to higher yields than plots where weed control was not conducted. The new machine can be used in a period when herbicides are not possible. Flaming could be introduced by asparagus producers as an alternative, or in addition to herbicides applied in the pre-emergence and post-harvest of spears.

scholarly journals A Mini Review on Lanthanum Ferrites-based Exsolved Perovskites as Fuel-flexible Anode for Solid Oxide Fuel Cells

2020 ◽  
Author(s):  
Massimiliano Lo Faro ◽  
Sabrina Campagna Zignani ◽  
Antonino S. Aricò
Keyword(s):  
Substrate Surface ◽  
Electronic Conductivity ◽  
Solid Oxide ◽  
Full Density ◽  
Thermal Treatments ◽  
Direct Oxidation ◽  
Ni Doping ◽  
Shell Nanoparticles ◽  
Two Phase ◽  
Sulphur Poisoning

Exsolved perovskites can be obtained from lanthanum ferrites, such as La0.6Sr0.4Fe0.8Co0.2O3, as result of Ni doping and thermal treatments. Ni can be simply added to the perovskite by an incipient wetness method. Thermal treatments include calcination in air (e.g., 500 &deg;C) and subsequent reduction in diluted H2 at 800 &deg;C to favor the exsolution process. The chemistry of the nanoparticles exsoluted on the substrate surface can be further modulated by a post treatment in air. These processes allow to produce a two-phase material consisting of a Ruddlesden-Popper type structure and a solid oxide solution e.g. &alpha;-Fe100-y-zCoyNizOx oxide. The formed electro-catalyst shows sufficient electronic conductivity under reducing environment at the SOFC anode. Outstanding catalytic properties are observed for the direct oxidation of dry fuels in SOFCs, including H2, methane, syngas, methanol, glycerol and propane. This anode electrocatalyst can be combined with full density electrolyte based on Gadolinia-doped Ceria or with La0.8Sr0.2Ga0.8Mg0.2O3 (LSGM) or BaCe0.9Y0.1O3-&delta; (BYCO) to form a complete perovskite structure-based cell. Moreover, the exsolved perovskite can be used as a coating layer or catalytic pre-layer of a conventional Ni-YSZ anode. Beside the excellent catalytic activity, this material also shows proper durability and tolerance to sulphur poisoning. In this mini review, preparation methods, physico-chemical characteristics, surface properties of exsoluted and core-shell nanoparticles encapsulated on the metal-depleted perovskite substrate surface, electrochemical properties for the direct oxidation of dry fuels and related electrooxidation mechanisms are examined and discussed.

scholarly journals Time-dependent alterations in the deformability of human neutrophils in response to chemotactic activation

Blood ◽  
1990 ◽  
Vol 76 (12) ◽  
pp. 2606-2612 ◽  
Author(s):  
RS Frank
Keyword(s):  
Mechanical Behavior ◽  
Control Level ◽  
Colchicine Treatment ◽  
Time Dependent ◽  
Cell Stiffness ◽  
Human Neutrophils ◽  
Partial Recovery ◽  
Cell Deformability ◽  
Two Phase ◽  
Transit Times

Abstract Transit times of individual human neutrophils through single capillary- sized pores were measured to determine the time-dependent changes in the mechanical behavior of the cells during activation by the chemotactic agent formyl-methionyl-leucyl-phenylalanine (FMLP) and in response to cytochalasin B (CTB) and colchicine. FMLP elicited a two- phase response consisting of a rapid increase in cell stiffness, which peaked between 2 and 3 minutes, followed by a partial recovery of deformability to a level significantly above that of control after 5 minutes. The mechanical changes closely followed changes in F-actin content, although the peak in cell stiffness appeared to lag the F- actin response. Treatment with 3 mumols/L CTB produced a transient decrease in cell rigidity followed by a return to control level in 10 minutes, whereas treatment with 30 mumols/L CTB resulted in a sustained decrease in cell transit times to a level 60% of control. Addition of 3 mumols/L CTB to cells prestimulated with FMLP produced a rapid (1 to 2 minutes) cessation of changes in cellular deformability produced by the FMLP. Colchicine treatment did not decrease cell rigidity, but produced a delayed increase in F-actin content accompanied by increased stiffness of the cells. These results implicate actin as the major determinant of the mechanical behavior of the neutrophil, as measured by whole cell deformability tests. The significant changes in cell deformability that occur in response to fractional changes in F-actin content suggest that changes in the structure of the actin network occur during these processes.

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