Turfgrass species can be classified into two main groups: cool-season and warm-season species. Because of their different physiology, warm-season species need less water to produce the same dry matter weight, thus they are more suited to Mediterranean climates (Croce et al., 2004; Turgeon, 2012; Volterrani and De Bertoldi, 2012) and have superior wear resistance and recovery compared with cool-season turf species (Lulli et al., 2012).
Transplanting single-potted plants is an innovative technique developed in Italy to convert cool-season to warm-season turfgrasses (Volterrani et al., 2008). Transplanting is based on the quick groundcovering capacity by stolons and rhizomes of small turf plants grown in a nursery garden. Transplanting can be accomplished manually or mechanically, in untilled soil, and is significantly cheaper than sodding. Although transplanting is efficient in converting a cool-season turfgrass to a warm-season turfgrass when soil tillage is not performed, the previous turf has to be completely desiccated.
Desiccation is usually achieved with chemical methods, such as herbicides, and the most common active ingredients are glyphosate and glufosinate ammonium (Baldi et al., 2013; Del Viva, 2012; Volterrani et al., 2008). However, clause 16 of EU Directive 2009/128/CE strongly discourages or prohibits the use of chemical herbicides, such as glyphosate, in public gardens, parks, sport turfs, and schoolyards. As a possible alternative, turfgrass can also be desiccated using flaming and steaming as an alternative to chemical weed control in organic/integrated farming and urban hard surfaces (Bàrberi et al., 2009; Peruzzi et al., 2011, 2012; Raffaelli et al., 2013, 2016).
Weeds and turfgrass species respond differently to physical treatments depending on their particular characteristics. Grasses (Gramineae) are monocots. Monocots have evolved to develop meristems protected by several leaf sheets (Baldoin et al., 2010), whereas dicots usually have all their meristems above the ground and widely over the plant. Grass turf species are less sensitive than most dicots to physical desiccation because they grow back from the protected meristems after the treatment unlike many dicots (Melander et al., 2009; Ulloa et al., 2010a). Rask et al. (2012) found that grass turf species, such as perennial ryegrass, are difficult to control with physical methods because the parts affected are mainly above the ground. Several authors have tested the effects on sensitive species of a single treatment with different flaming doses (Ascard, 1995; Ulloa et al., 2010a, 2010b) and steaming doses (Hansson and Ascard, 2002). However, there is still very little understanding concerning the effects of such techniques on less sensitive species such as grass turf species (Rask et al., 2012). Rask and Kristoffersen (2007) suggest that more than one treatment is required to efficiently desiccate grass turf species using flaming and steaming because otherwise they recover. Flaming can also be used as an effective weed control method before turfgrass establishment (Hoyle et al., 2012).
Alternative methods to flaming and steaming have been applied and tested over the years to desiccate vegetation using physical techniques. Hansson and Ascard (2002) experimented with the use of hot water to control weeds growing in hard surfaces. Sartorato et al. (2006) applied microwaves for postemergence weed control. However, flaming is still the most frequently applied physical method to desiccate vegetation. Steaming has been described by various authors as a valid alternative to flaming (Hansson and Ascard, 2002; Kerpauskas et al., 2006) and several agricultural machines for steam application have been developed (Gay et al., 2010a, 2010b; Langshaw, 1995).
The aim of this study was to compare flaming and steaming, performed by dedicated prototype equipment, with a glufosinate-ammonium herbicide treatment to desiccate cool-season turfgrass for conversion to warm-season turfgrass in untilled soil using transplanting.
Baldi, A., Lenzi, A., Nannicini, M., Pardini, A. & Tesi, R. 2013 Growth and nutrient content of hybrid bermudagrass grown for nursery purposes at different nitrogen, phosphorus, and potassium rates HortTechnology 23 347 355
Baldoin, C., Sartorato, I., Friso, D., De Zanche, C., De Paoli, F. & Bietresato, M. 2010 Weed control by water steam using a self-propelled machine equipped with a condensation chamber. Proc. XVIIth World Congr. Intl. Commission Agr. Biosystems Eng. (CIGR). Québec City, QC, Canada. 13–17 June 2010. CSBE100427:1–10
Bàrberi, P., Moonen, A.C., Peruzzi, A., Fontanelli, M. & Raffaelli, M. 2009 Weed suppression by soil steaming in combination with activating compounds Weed Res. 49 55 66
Croce, P., De Luca, A., Mocioni, M., Volterrani, M. & Beard, J.B. 2004 Adaptibility of warm-season turfgrass species and cultivars in a Mediterranean climate Acta Hort. 661 365 368
Del Viva, M. 2012 Erbavoglio Hi Turf: Sistema avanzato di propagazione delle macroterme. Quaderno dei Georgofili. VIII edizione. Polistampa, Florence, Italy
Fox, J. & Weisberg, S. 2011 An R companion to applied regression. 2nd ed. Sage, Thousand Oaks, CA
Gay, P., Piccarolo, P., Ricauda Aimonino, D. & Tortia, C. 2010a A high efficiency steam soil disinfestation system, part I: Physical background and steam supply optimisation Biosyst. Eng. 107 74 85
Gay, P., Piccarolo, P., Ricauda Aimonino, D. & Tortia, C. 2010b A high efficacy steam soil disinfestation system, part II: Design and testing Biosyst. Eng. 107 194 201
Kerpauskas, P., Sirvydas, A.P., Lazauskas, P., Vasinauskiene, R. & Tamosiunas, A. 2006 Possibilities of weed control by water steam Agron. Res. 4 special issue 221 225
Knezevic, S.Z., Streibig, J.C. & Ritz, C. 2007 Utilizing R software package for dose-response studies: The concept and data analysis Weed Technol. 21 840 848
Kutznetsova, A., Brockhoff, B. & Christensen, R.H.B. 2015 Tests in linear mixed effects models. 5 July 2017. <https://cran.r-project.org/web/packages/lmerTest/index.html>
Langshaw, E. 1995 Hot water/steam weed killing system. U.S. Patent 5 385 106, Chemical Abstr. 65:2870
Lulli, F., Volterrani, M., Grossi, N., Armeni, R., Stefanini, S. & Guglielminetti, L. 2012 Physiological and morphological factors influencing wear resistance and recovery in C3 and C4 turfgrass species Funct. Plant Biol. 39 214 221
Melander, B., Holst, N., Grundy, A.C., Kempenaar, C., Riemens, M.M., Verschwele, A. & Hansson, D. 2009 Weed occurrence on pavements in five North European towns Weed Res. 49 516 525
Peruzzi, A., Raffaelli, M., Frasconi, C., Fontanelli, M. & Bàrberi, P. 2012 Influence of an injection system on the effect of activated soil steaming on Brassica juncea and the natural weed seedbank Weed Res. 52 140 152
Peruzzi, A., Raffaelli, M., Ginanni, M., Fontanelli, M. & Frasconi, C. 2011 An innovative self-propelled machine for soil disinfection using steam and chemicals in an exothermic reaction Biosyst. Eng. 110 434 442
R Core Team 2016 R: A language and environment for statistical computing. 21 Mar. 2016. <https://www.R-project.org>
Raffaelli, M., Martelloni, L., Frasconi, C., Fontanelli, M., Carlesi, S. & Peruzzi, A. 2016 A prototype band-steaming machine: Design and field application Biosyst. Eng. 144 61 71
Raffaelli, M., Martelloni, L., Frasconi, C., Fontanelli, M. & Peruzzi, A. 2013 Development of machines for flaming weed control on hard surfaces Appl. Eng. Agr. 29 663 673
Rask, A.M., Andreasen, C. & Kristoffersen, P. 2012 Response of Lolium perenne to repeated flame treatments with various doses of propane Weed Res. 52 131 139
Rasmussen, J., Nørremark, M. & Bibby, B.M. 2007 Assessment of leaf cover and crop soil cover in weed harrowing research using digital images Weed Res. 47 299 310
Syrvidas, A., Lazauskas, P., Vasinauskieneì, R. & Kerpauskas, P. 2002 Thermal weed control by water steam. Proc. 5th European Weed Res. Soc. Wkshp. Physical Weed Control. Pisa, Italy. 11–13 Mar. 2002. p. 253–262
Turgeon, A.J. 2012 Turfgrass management. 9th ed. Prentice Hall, Upper Saddle River, NJ
Ulloa, S.M., Datta, A. & Knezevic, S.Z. 2010a Growth stage influenced differential response of foxtail and pigweed species to broadcast flaming Weed Technol. 24 319 325
Ulloa, S.M., Datta, A. & Knezevic, S.Z. 2010b Tolerance of selected weed species to broadcast flaming at different growth stages Crop Prot. 29 1381 1388
Volterrani, M. & De Bertoldi, C. 2012 I generi di macroterme per i tappeti erbosi nel bacino del Mediterraneo: Cynodon, Paspalum e Zoysia. Quaderno dei Georgofili, VIII edizione, Polistampa, Florence, Italy
Volterrani, M., Grossi, N., Lulli, F. & Gaetani, M. 2008 Establishment of warmseason turfgrass species by transplant of single potted plants Acta Hort. 783 77 84
Wheeler, M.W., Park, R.M. & Bailer, A.J. 2005 Comparing median lethal concentration values using confidence interval overlap or ratio test Environ. Toxicol. Chem. 25 1441 1444