scholarly journals Hot foam and hot water for weed control: A comparison

2021 ◽  
Vol 52 (3) ◽  
Author(s):  
Luisa Martelloni ◽  
Christian Frasconi ◽  
Mino Sportelli ◽  
Marco Fontanelli ◽  
Michele Raffaelli ◽  
...  

Thermal weed control plays an important role in managing weeds in synthetic herbicide-free systems, particularly in organic agriculture and in urban areas where synthetic herbicides are prohibited. This study compares the impact on weed control of increased doses of hot water and hot foam (i.e. 0, 0.67, 1.67, 3.33, 5.00, 6.67 and 8.33 kg m–2). The doses were applied using the same machine. The temperatures, weed control effectiveness, weed regrowth after the death of the aboveground vegetative weed tissues, and weed dry biomass 30 days after the treatments were studied in two experimental fields with a different weed composition (i.e. Site I and Site II). The results showed that difficult weeds to control, such as Cynodon dactylon (L.) Pers., Digitaria sanguinalis (L.) Scop. and Taraxacum officinale Weber, like all the other species in the initial weed populations in the two experiments, died after lower doses of hot foam compared to hot water. Adding foam to hot water made it possible to lower the required dose of water by at least 2.5-fold compared to hot water used alone. By insulating the weeds, the foam led to higher peak temperatures and slower temperature decay, thus determining an effective weed control with lower doses compared to hot water. Starting from 11 days and 16 days after treatments (for Site I and Site II, respectively), there were no statistically significant differences in weed regrowth between hot foam and hot water at all the doses applied. There were no differences between the dry biomass of weeds collected 30 days after treatments when the same doses of hot foam and hot water were used.

Agronomy ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 490 ◽  
Author(s):  
Luisa Martelloni ◽  
Christian Frasconi ◽  
Mino Sportelli ◽  
Marco Fontanelli ◽  
Michele Raffaelli ◽  
...  

Thermal weed control technology plays an important role in managing weeds in synthetic herbicide-free systems, particularly in organic agriculture. The use of hot foam represents an evolution of the hot water weed control thermal method, modified by the addition of biodegradable foaming agents. The aim of this study was to test the weeding effect of different five hot foam doses, in two sites of different weed composition fields [i.e., Festuca arundinacea (Schreb.), Taraxacum officinale (Weber) and Plantago lanceolata (L.)], by evaluating the devitalisation of weeds, their regrowth, the weed dry biomass at the end of the experiment and the temperature of hot foam as affected by different foam doses. The results showed that the effect of the hot foam doses differed with the different infested weed species experiments. In the Festuca arundinacea (Schreb.) infested field, all doses from 3.33 L m−2 to 8.33 L m−2 led to a 100% weed cover devitalisation and a lower weed dry biomass compared to the dose of 1.67 L m−2, whereas the weed regrowth was similar when all doses were applied. In the Taraxacum officinale (Weber) and Plantago lanceolata (L.) infested fields, doses from 5.00 L m−2 to 8.33 L m−2 in site I and from 3.33 L m−2 to 8.33 L m−2 in site II led to 100% of weed cover devitalisation. The highest doses of 6.67 L m−2 and 8.33 L m−2 led to a slower weed regrowth and a lower weed dry biomass compared to the other doses. The time needed for weeds to again cover 50%, after the 100% devitalisation, was, on average, one month when all doses were applied in the Festuca arundinacea (Schreb.) infested field, whereas in the Taraxacum officinale (Weber) and Plantago lanceolata (L.) fields, this delay was estimated only when doses of 6.67 L m−2 and 8.33 L m−2 were used in site I and a dose of 8.33 L m−2 in site II. Thus, in the Festuca arundinacea (Schreb.) field experiments hot foam doses from 3.33 L m−2 to 8.33 L m−2 were effective in controlling weeds, and the use of the lowest dose (i.e., 3.33 L m−2) is recommended. However, for Taraxacum officinale (Weber) and Plantago lanceolata (L.) the highest doses are recommended (i.e., 6.67 L m−2 and 8.33 L m−2), as these led to 100% weed devitalisation, slower regrowth, and lower weed dry biomass than other doses. A delay in the regrowth of weeds by 30 days can lead to the hypothesis that the future application of hot foam as a desiccant in no-till field bands, before the transplant of high-income vegetable crops, will provide a competitive advantage against weeds.


1995 ◽  
Vol 13 (2) ◽  
pp. 104-108
Author(s):  
B. Jack Johnson

Abstract When a postemergence (POST) herbicide is used to control large crabgrass [Digitaria sanguinalis (L.) Scop.] in common bermudagrass [Cynodon dactylon (L.) Pers.], the herbicide should maintain optimum weed control for 8 to 10 weeks without causing undesirable injury to the turfgrass. A field experiment was conducted during 1993 and 1994 to determine the lowest rate of Drive (quinclorac) needed to control large crabgrass without causing undesirable injury to bermudagrass turf. Drive (quinclorac) applied at 0.28 kg ai/ha (0.25 lb ai/A) initially in early May and repeated at the same rate at a 2-week interval, controlled 85% large crabgrass for 16 weeks in 1993 and 70% for 10 weeks in 1994. The control in 1994 was 96% for 17 weeks when the herbicide was applied at 0.28 kg ai/ha (0.25 lb ai/A) in each of three applications on May 2, May 29, and June 13. The maximum bermudagrass injury in 1993 from Drive (quinclorac) applied at 0.28 kg ai/ha (0.25 lb ai/A) in each of two applications at 2- to 4-week interval was ≤ 27% compared to ≥ 33% when ≥ 0.56 kg ai/ha (≥ 0.5 lb ai/A) was applied as a single application. Bermudagrass treated initially with Drive (quinclorac) at 0.28 kg ai/ha (0.25 lb ai/A) was injured higher in 1994 (≤ 35%) than in 1993 (≤ 14%). Bermudagrass injury was ≥ 40% when the second application was delayed until mid- to late June either year or when the herbicide was applied in three applications during May and June 1994.


1998 ◽  
Vol 12 (4) ◽  
pp. 707-711 ◽  
Author(s):  
Robert H. Walker ◽  
Glenn Wehtje ◽  
John S. Richburg

Field experiments were conducted at two locations in central Alabama to evaluate competitiveness of large crabgrass and southern sandbur with ‘Tifton 78’ hybrid bermudagrass as influenced by diuron application and sprigging rate. Large crabgrass was the more competitive species. In late season, bermudagrass ground cover with no weed competition was 96% compared with 72 and 81% where large crabgrass and southern sandbur, respectively, were present. Similarly, large crabgrass and southern sandbur reduced the proportion of bermudagrass in the cumulative harvested forage by at least 59 and 38%, respectively. Application of diuron preemergence (PRE) at 1.1 kg ai/ha was more effective than postemergence (POST) application, both in terms of weed control and bermudagrass safety. With diuron applied PRE, large crabgrass and southern sandbur reduced the proportion of bermudagrass in the harvested forage only 32 and 25%, respectively. Increasing bermudagrass sprigging rate was beneficial for weed control but of relatively minor importance compared with diuron PRE.


Weed Science ◽  
1982 ◽  
Vol 30 (1) ◽  
pp. 116-124 ◽  
Author(s):  
B. J. Johnson

Four herbicides were applied in the spring and fall over a 3-yr period to Kentucky bluegrass [Poa pratensis (L.) ‘Common′] in the Mountain Region and bermudagrass [Cynodon dactylon (L.) Pers. ‘Common′] in the Piedmont Region of Georgia at different frequencies of treatments for summer and winter weed control. Large crabgrass [Digitaria sanguinalis (L.) Scop.] was controlled throughout the 3-yr period from spring treatments of bensulide [O,O-diisopropyl phosphorodithioate S-ester with N-(2-mercaptoethyl)benzenesulfonamide] at 11.2 kg/ha and oxadiazon [2-tert-butyl-4-(2,4-dichloro-5-isopropoxyphenyl)-δ2-1,3,4-oxadiazolin-5-one] at 4.5 kg/ha in the first year followed by 5.6 kg/ha for bensulide and 2.3 kg/ha for oxadiazon the following 2 yr. To control large crabgrass with benefin (N- butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine) it was necessary to apply 3.4 kg/ha for 2 consecutive yr before rates could be reduced to 1.7 kg/ha. Oxadiazon was the only herbicide that controlled goosegrass [Eleusine indica (L.) Gaertn.] completely. Control was excellent throughout the 3-yr period when oxadiazon was applied at full rate in the spring of the first year with no additional treatments during the following 2 yr. Optimum control of winter weeds was obtained throughout the 3-yr period when herbicides were applied at full rates for the spring and fall treatments the first year followed by one-half rates at similar dates the following 2 yr. Bensulide treatments increased cover of corn speedwell (Veronica arvensis L.) and hop clover (Trifolium agrarium L.); DCPA (dimethyl tetrachloroterephthalate) and benefin increased spur weed (Soliva spp.) and wild parsnip (Pastinaca sativa L.); and oxadiazon increased wild parsnip and thymeleaf sandwort (Arenaria serpyllifolia L.).


1987 ◽  
Vol 5 (2) ◽  
pp. 82-84 ◽  
Author(s):  
Sharon A. Duray ◽  
Fred T. Davies

Applications of preemergent herbicide prodiamine 65 WDG (wettable dry granule) (2,4-dinitro-N3,N3-dipropyl-6(trifluoromethyl)-1,3-benzenediamine) at 1.12, 2.24, 4.48, and 8.96 kg ai/ha (1.0, 2.0, 4.0 and 8.0 lb ai/A) controlled large crabgrass (Digitaria sanguinalis L. Scop.), bermudagrass (Cynodon dactylon L. Pers.), purslane (Portulaca oleracea L.), and red sorrel (Rumex acetosella L.) for 16 weeks after application. A granular application at 1.12 kg ai/ha (1.0 lb ai/A) resulted in unsatisfactory weed control and subsequently decreased shoot weight of container grown landscape plants. Prodiamine 65 WDG did not cause phytotoxic effects to landscape plants at any rate evaluated.


Author(s):  
Marco Ravina ◽  
Costanza Gamberini ◽  
Alessandro Casasso ◽  
Deborah Panepinto

Domestic hot water heat pumps (DHW HPs) have spread fast in recent years in Europe and they now represent an interesting opportunity for implementing renewable energy sources in buildings with a centralized/district heating system, where DWH is generally produced by a gas boiler or an electric water heater. Replacing these appliances has several environmental benefits, including the removal of air pollution sources and the reduction of Green House Gasses (GHG) emissions. In this work, we present the techno-economic and environmental evaluation of implementing DHW HPs in Turin, where 66% of the DHW demand is covered by dedicated gas boilers. The impact of such boilers was assessed through numerical air dispersion modeling conducted with the software SPRAY (Aria Technologies, Paris, French). Results show that removing these sources would reduce yearly average concentrations of NOx up to 1.4 µg/m3, i.e., about 1% of monitored concentrations of NOx, with a benefit of 1.05 ÷ 15.15 M€/y of avoided health externalities. Replacing boilers with DHW HPs is always financially feasible with current incentives while, in their absence, it would be convenient for residential units with 3 cohabitants or more (51.22% of the total population), thanks to scale economies.


Weed Science ◽  
1974 ◽  
Vol 22 (5) ◽  
pp. 434-436
Author(s):  
B. J. Johnson

EPTC (S-ethyl dipropylthiocarbamate) was applied to sand traps to evaluate weed control and the prevention of bermudagrass (Cynodon dactylon (L.) Pers.) encroachment. EPTC applied at 6.7 kg/ha in each of two applications at 6 to 7-week intervals, controlled an average of 88% common bermudagrass and 99% large crabgrass [Digitaria sanguinalis (L.) Scop.]. Although EPTC prevented bermudagrass from spreading into sand traps, the treatments did not cause permanent injury when applied directly to several bermudagrass varieties.


Weed Science ◽  
1985 ◽  
Vol 33 (3) ◽  
pp. 366-371 ◽  
Author(s):  
B. Jack Johnson ◽  
Robert E. Burns

Large crabgrass [Digitaria sanguinalis(L.) Scop. ♯ DIGSA] control was higher when either DCPA (dimethyl tetrachloroterephthalate) or napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] was applied to bermudagrass [Cynodon dactylon(L.) Pers. ‘Common’] growing in soil with a pH of 5 than in soil with a pH of 6.4 in 2 of 3 yr. Soil pH did not influence the response of large crabgrass to oxadiazon [2-tert-butyl-4(2,4-dichloro-5-isopropoxyphenyl)-Δ2-1,3,4-oxadiazolin-5-one] or benefin (N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine). Herbicides alone did not produce high-quality turf unless fertilizer was applied annually at 300 kg N/ha or more. Bermudagrass quality was higher after three yearly applications of 300 kg N/ha or more of fertilizer when soil pH was 5 than when soil pH was 5.6 or 6.4.


Weed Science ◽  
1976 ◽  
Vol 24 (5) ◽  
pp. 512-517 ◽  
Author(s):  
B. J. Johnson

Methazole [2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione] and metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazine-5(4H)one] were evaluated in separate experiments for postemergence control of large crabgrass [Digitaria sanguinalis(L.) Scop.] and goosegrass [Eleusine indica(L.) Gaertn.] and on tolerance of centipedegrass [Eremochloa ophiuroides(Munro) Hack.], St. Augustinegrass [Stenotaphrum secundatum(Walt.) Kuntze], and bermudagrass [Cynodon dactylon(L.) Pers. ‘Common’]. Methazole was also evaluated on tolerance of Kentucky bluegrass (Poa pratensisL. ‘Common’). Metribuzin applied at 0.6 kg/ha and methazole at 1.1 kg/ha as single treatments controlled 82 and 87% goosegrass, respectively. Repeated treatments were needed for similar control of large crabgrass. These treatments did not permanently injure bermudagrass or centipedegrass. St. Augustinegrass was severely injured when treated with single applications of methazole at 1.1 kg/ha or metribuzin at 0.6 kg/ha while Kentucky bluegrass was severely injured by methazole applied at any rate. Methazole caused moderate to severe injury to bermudagrass when applied at 2.2 kg/ha in each of two applications and to centipedegrass when applied at 4.4 kg/ha in each of two applications.


Weed Science ◽  
1978 ◽  
Vol 26 (6) ◽  
pp. 650-653 ◽  
Author(s):  
B. J. Johnson

Two applications of benefin (N-butyl-N-ethyl-α,α,α,-trifluoro-2,6-dinitro-p-toluidine), profluralin [N-(cyclopropylmethyl)-α,α,α-trifluoro-2,6-dinitro-N-propyl-p-toluidine], prosulfalin N-[[4-(dipropylamino)-3,5-dinitrophenyl]sulfonyl]-S,S-dimethylsulfilimine, and napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] provided full-season large crabgrass [Digitaria sanguinalis (L.) Scop.] control in turfgrass. Benefin was applied at 3.3 kg/ha in March and 2.2 kg/ha in May while other herbicides were applied at 2.2 kg/ha in March and May. Satisfactory goosegrass [Eleusine indica (L.) Gaertn.] control was obtained with a single March treatment with prosulfalin, but two applications of napropamide in March and May were required for similar control. None of the herbicide treatments severely injured common bermudagrass [Cynodon dactylon (L.) Pers.] or Kentucky bluegrass [Poa pratensis (L.) ‘Common’] in these studies. Prosulfalin at 6.6 kg/ha applied as single treatment or 3.3 kg/ha in each of two applications resulted in moderate injury to Kentucky bluegrass in 1 of 2 yr.


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