Non-Chemical Alternatives for Weed Control in Containerized Plants
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Non-Chemical Alternatives for Weed Control in Containerized Plants
P. Frangi, R. Piatti and G. Amoroso A. Fini
Fondazione Minoprio – Centro MiRT Dipartimento di Ortoflorofrutticoltura
22070 Vertemate con Minoprio (CO) University of Florence
Italy 50019 Sesto Fiorentino (FI)
Italy
Keywords: container production, ornamentals, oxadiazon, Photinia ×fraseri, Prunus
laurocerasus, Thuja plicata
Abstract
Weeds are a serious problem in nursery for container production, because
air, nutrient and water are limited by the container volume. Chemical weeding is the
main method to control weeds in nurseries but problems as proper calibration,
herbicide run-off, need for multiple applications and product cost must be taken
into account. The aim of this work was to investigate the degradation time and cost
of some environmental-friendly materials used to control weeds in three widely used
container-grown shrubs (Photinia ×fraseri ‘Red Robin’, Prunus laurocerasus
‘Rotundifolia’, Thuja plicata ‘Atrovirens’). 120 plants per species were potted into 3
L containers. Four non-chemical mulching materials were used: 1) coconut fibre
discs; 2) vegetal and synthetic fibre discs; 3) viscose fibre discs; 4) a mineral grain
mixture without chemical additives (Gerval®). The effectiveness of these materials
was compared with a chemical control (oxadiazon) and with a hand weeding control.
Weeds in container were counted and removed every 45 days during two growing
seasons (2006 and 2007). Plant height and biomass were recorded at the beginning
and at the end of the trial. Vegetal/synthetic fibre discs allowed a weed control as
good as the chemical in all the species tested. Due to its short duration this material
was replaced at the beginning of the second growing season. Coconut discs and
Gerval® assured a satisfying weed control. No differences between these treatments
and vegetal/synthetic fibre discs were found. These materials were applied at the
beginning of the experiment and were not replaced in the second year. Serious
damages to the root flare were caused by Gerval®. The viscose fibre discs did not
allow a satisfying weed control, because of their quick degradation, and they had to
be replaced during the trial. No significant differences in plant height and biomass
production were found among treatments. Total cost of weed control (including
installation) in the two years of the trial was 0.19 €/pot for coconut discs and 0.20
€/pot for vegetal/synthetic fibre discs. Chemical control allowed weed control with
half of the cost, but this value does not take into account chemical externalities and a
possible rise of resistances in weeds. Costs of Gerval®, viscose fibre discs and manual
weed removal did not give a result acceptable for nursery production.
INTRODUCTION
Weed control is an essential component of nursery crop production and sales
(Malinich, 2007). Weeds compete with plant crops for water and nutrients thereby
reducing growth, quality and marketability of the crops (Fretz, 1972; Berchielli-
Robertson et al., 1990; Gilliam et al., 1990; Norcini and Stamps, 1994; Neal, 1999; Roul
and Lemay, 2000). There are a few weed species that are major problems in many
nurseries. Mostly, they are short-lived annuals that have propagules, which are hard to
control and can easily move into and around the nursery (Senesac, 2006). A typical
method to control container weeds is the use of granular herbicides. Depending of
container spacing, growth habit, methods and frequency of the chemical distribution, non-
target loss can be as high as 86% (Gilliam et al., 1992; Mathers, 2003). In another
experiment, certain strains of herbicide-resistant weeds were observed (Mathers, 2002).
Hand weeding is not usually an economic solution as a consequence of the high cost of
Proc. Ist IS on Woody Ornamentals 119
Eds.: F. Šrámek et al.
Acta Hort. 885, ISHS 2010
labour. Nursery growers estimate that they spend up to 4000 $/acre (9880 $/ha) of
containers to remove manually weeds from the containers, and that this cost is highly
dependent on weed species (Mathers, 2003). Economic losses due to weeds infestation
have been estimated up to 7000 $/acre (17290 $/ha) (Chong, 2003). Thereby, there is an
increasing interest among producers in non-chemical alternatives for weed control.
Organic mulches can be used to this purpose and these materials also supply important
benefits: they conserve moisture in the substrate, regulate container temperature and
decrease weed seeds germination, improving plant growth and reducing labour (Samtani
et al., 2007). In order to achieve environmental sustainability and reduce chemical
externalities, alternative methods for weed control have been tested in this experiment.
MATERIALS AND METHODS
This research was conducted in an experimental nursery located at Fondazione
Minoprio (Vertemate con Minoprio, Como, Italy; 45°44’ N, 9°04’ E) in 2006 and 2007.
One-years-old uniform cuttings of Photinia ×fraseri ‘Red Robin’, Prunus laurocerasus
‘Rotundifolia’ and Thuja plicata ‘Atrovirens’ were planted on May 2006 into 3L plastic
containers, filled with 80% (v/v) of sphagnum peat and 20% (v/v) of pumice, amended
with 4 kg·m-3 of calcium carbonate. A slow-release fertilizer, Ficote® (15-8-12), was
incorporated at the rate of 4 kg·m-3 before potting. A total of 360 container-grown plants
(120 per species) were placed in 6 randomized blocks, repeated 4 times.
Treatments compared were: 1) discs made of coconut fibre (Zoccarato, Santa
Giustina in Colle, PD, IT); 2) discs made of vegetal (90%) and synthetic fibre (10%)
(Loraschi, Cellatica, BS, IT). Due to fast degradation time these discs were replaced at the
beginning of the second growing season; 3) discs constituted by viscose fibre (98%) and
polyvinyl alcohol (2%) (Giotto Industrial Networking, Riva San Vitale, CH). Since in
previous studies (Amoroso et al., 2007) this material showed a quick degradation time, in
this experiment two overlapped discs per pot were used; 4) Gerval® (Gerval Srl, Reggio
Emilia, IT), a mineral mixture without chemical additives, distributed as a 1.5 cm layer.
The effectiveness of these four products was compared with a chemical control (one
application per year of 180 kg/ha of Ronstar® (oxadiazon) in granular formulation) and
with a hand weeding control. Plants were watered daily by overleaf sprinkle irrigation
during the experiment. Standard nursery procedures for pest control were used.
Plant height was recorded at the beginning and at the end of the trial. Shoot dry
weight was measured at the end of the each growing season on eight plants per species
and per treatment. The above-ground part was oven-dried (105°C) till constant weight
was reached in order to determine aerial part dry weight. Weeds grown in the pots were
counted and removed every 45 days during both growing seasons. All data were subjected
to one-way analysis of variance (ANOVA) using Statgraphics® Plus (Manugistic Inc.,
Rockville, MD, US) and means were separated by Duncan’s multiple range test (P≤0.05).
An economic evaluation of compared treatments was performed assuming a
hourly wage of 22.32 € (Assoverde, 2006).
RESULTS AND DISCUSSION
Effectiveness of Weed Control
the efficacy of the different materials tested was directly related to their duration
(Table 1). After a certain period, the progressive degradation of the materials allowed
weeds to start growth. Coconut fibre discs and vegetal/synthetic fibre discs assured a very
satisfying weed control for the whole growing season. The effectiveness of these
materials didn’t differ in most cases from chemical control (oxadiazon). Minimal
degradation signs were observed in coconut fibre discs at the end of experiment, so this
material could be reused even in a third year. Duration of vegetal/synthetic fibre discs was
limited to only one growing season, so it was necessary to replace it after the first year of
the experiment. These findings agree with those reported in a previous research (Amoroso
et al., 2007). Fibre viscose discs shown the shortest degradation time and they assured a
120
good weed control for only 90 days from their laying. At the end of the growing season
this material had completely deteriorated and its effectiveness was similar to the hand
weeding control. Gerval® allowed an adequate weed control but, as found in previous
research (Amoroso et al., 2007), this product caused serious damages to the root flare,
because its rigidity didn’t allow stem secondary growth. This led to phloem disruption
and to stem fragility. Among all mulching materials, no significant differences in plant
height and biomass production were found in this experiment (data not reported).
Differences among the species for the number of weeds per pot were due to ornamental
crop ability to quickly shade substrate. So, P. laurocerasus, the fastest growth species
tested, showed the lowest number of weeds per pot (data not shown).
Cost of Weed Control
chemical weeding (oxadiazon) was the cheapest way to control weeds (0.04
€/container per application), but this value doesn’t take into account chemical
externalities, such as environmental damage and the inefficiency of application and
distribution that can lead up to 80% of products loss (Gilliam et al., 1992). Total cost per
disc (including installation) was 0.10 €/container for vegetal/synthetic fibre disc and 0.19
€/container for the coconut disc. Anyway, the long duration of coconut fibre allowed to
share out its cost over two-three years, while vegetal/synthetic fibre discs has to be
replaced at the end of each growing season. Viscose fibre disc cost 0.23 €/container per
year but this material was used in double layer and was replaced at the beginning of the
second growing season. Gerval® cost (including installation) was 0.34 €/container.
Moreover, it requires a particular care for a correct application. Cost for manual removal
of weeds per pot was set in a range between 0.11 and 0.39 €/container per year,
depending on the growing rate of the species.
CONCLUSIONS
Coconut disc and vegetal/synthetic fibre discs allowed the best weed control and
their effectiveness can be compared with the chemical control (oxadiazon). The cost of
these materials at the end of two growing season was similar (about 0.20 €/container).
Chemicals allowed weed control with about half of the cost, but this value doesn’t take
into account chemical externalities and a possible rise of resistances in weeds. Costs of
Gerval®, viscose fiber disc and manual weed removal did not give a result acceptable for
nursery production. Moreover, Gerval® causes severe damages to the root flare.
Currently the cost of these materials is the main limit to their widespread use for
weed control in nurseries. But the oncoming reduction of chemicals due to environmental
impact can result in a possible spread of non-chemical alternatives to control weeds, with
a reduction of their costs.
ACKNOWLEDGMENTS
This work has been done as a research project called “Tecniche eco-compatibili
innovative per le produzioni florovivaistiche” financed by Regione Lombardia -
Agricultural Department, according to the Plan of Research and Development 2005.
Literature Cited
Amoroso, G., Frangi, P. and Fini, A. 2007. Sustainable methods for weed control in
nurseries. Proc. 52nd SNA Res. Conf., Weed control session:5-9.
Assoverde. 2006. Prezzi informativi dei principali lavori di manutenzione e costruzione
del verde e delle forniture di piante ornamentali. Associazione Italiana Costruttori del
Verde, Monteveglio (BO), Italy.
Berchielli-Robertson, D.L., Gilliam, C.H. and Fare, D.C. 1990. Competitive effects of
weeds on the growth of container-grown plants. HortScience 25:77-79.
Chong, C. 2003. Experiences with weed discs and other nonchemical alternatives for
container weed control. HortTechnology 13:23-27.
Fretz, T.A. 1972. Weed competition in container-grown japanese holly. HortScience
121
7:485-486.
Gilliam, C.H., Fare, D.C. and Beasley, A. 1992. Nontarget herbicide losses from
application of granular Ronstar to container nurseries. J. Environ. Hort. 12:1-8.
Gilliam, C.H., Foster, W.J., Adrian, J.L. and Schumack, R.L. 1990. A survey of weed
control costs and strategies in container production nurseries. J. Environ. Hort. 8:133-
135.
Malinich, T. 2007. Ornamental weed control. American Nurseryman 206(1):30-34.
Mathers, H. 2002. Get tough on weeds. Landscape Mgt. 41:72-79.
Mathers, H. 2003. Novel methods of weed control in containers. HortTechnology
13(1):28-31.
Neal, J. 1999. Weed and you. Nursery Management Production 15:60-65.
Norcini, J.G. and Stamps, R.H. 1994. Container nursery weed control. Florida Coop. Ext.
Serv., Inst. Food and Agr. Serv. University of Florida. Cir. 678.
Samtani, J.B., Kling, G.J., Mathers, H.M. and Case, L. 2007. Rice hulls, leaf-waste
pellets, and pine bark as herbicide carriers for container-grown woody ornamentals.
HortTechnology 17(3):289-295.
Senesac, A. 2006. A war of weeds. American Nurseryman 203(11):30-34.
Roul, I.T. and Lemay, M.A. 2000. Innovations for container weed control. Landscape
Trades 23(5):20-21.
Tables
Table 1. Overall number of weeds removed from containers at the end of the first and the
second growing season in the three species tested.
End of first End of second
Treatment growing season growing season
Photinia ×fraseri ‘Red Robin’
Coconut disc 6.4 bc 14.8 c
Vegetal and synthetic fiber disc (Discoplus®) 6.3 bc 11.6 cd
Fiber viscose disc 10.1 b 32.1 b
Mineral mixture (Gerval®) 3.7 bc 19.6 c
Chemical control (Ronstar®) 0.0 c 1.2 d
Hand weeding 28.2 a 52.1 a
P value 0.00 0.00
Prunus laurocerasus ‘Rotundifolia’
Coconut disc 2.2 c 3.6 b
Vegetal and synthetic fiber disc (Discoplus®) 2.3 c 3.1 bc
Fiber viscose disc 4.8 b 9.1 a
Mineral mixture (Gerval®) 2.1 c 3.8 b
Chemical control (Ronstar®) 0.1 d 0.3 c
Hand weeding 7.9 a 11.5 a
P value 0.00 0.00
Thuja plicata ‘Atrovirens’
Coconut disc 4.3 cd 18.1 b
Vegetal and synthetic fiber disc (Discoplus®) 9.4 bc 22.3 b
Fiber viscose disc 14.1 ab 51.9 a
Mineral mixture (Gerval®) 2.3 d 24.0 b
Chemical control (Ronstar®) 5.8 cd 13.3 b
Hand weeding 17.8 a 56.6 a
P value 0.00 0.00
For each species means within the same column with different letters are significantly different, Duncan’s
multiple range test (P≤0.05).
122
28 LINEAVERDE
Sperimentazione
Quali alternative ai trattamenti
chimici per le infestanti nei vasi?
Le malerbe da sempre sono un dannoso problema soprattutto per
le colture in vaso perché sottraggono grosse quantità di elementi
nutritivi e acqua, occupano lo spazio destinato allo sviluppo delle
radici delle piante ornamentali e in molti casi sono vettori di afidi,
funghi, parassiti e nematodi. Vediamo di seguito i risultati di
alcuni esperimenti condotti nel Centro MIRT della Fondazione
Minoprio per risolvere questo annoso problema.
e malerbe che si sviluppano in un lo spazio destinato alle piante ornamentali sia con
L vaso, quindi in un volume limitato,
diventano concorrenti temibili per le
specie coltivate, soprattutto quando
queste si trovano all’inizio del loro sviluppo. Le
malerbe sottraggono copiose quantità di elementi
la parte aerea sia con l’apparato radicale che, in
molti casi, può raggiungere dimensioni cospicue
(Gilliam et al., 1990; Mervosh, 1999; Roul e
Lemay, 2000). A questo va aggiunto un ‘danno
indiretto’ che le malerbe possono apportare alle
nutritivi e di acqua, occupando meccanicamente piante coltivate quando vettori di afidi, funghi
Veduta
d’insieme
della prova
subito dopo
l’invasatura.
di G. Amoroso,
R. Piatti,
P. Frangi
Fondazione
Minoprio –
Centro MiRT –
Vertemate con
Minoprio (Como)
Febbraio 2007
LINEAVERDE 29
Dischi in fibra di cocco al termine Discoplus al termine
della stagione vegetativa. della stagione vegetativa.
parassiti o addirittura di nematodi (Rota et al.,
1987).
Spesso le metodologie di contenimento delle
malerbe in contenitore si limitano all’impiego, il
più delle volte non razionale, di diserbanti e,
quando questi non sono sufficienti, alla scerba-
tura manuale; però numerosi risultano i fattori
penalizzanti di questo modus operandi (Mathers,
2003; Case et al., 2005). Prima di tutto i prodotti
chimici devono essere utilizzati con grande pre-
cisione perché per nessun altro prodotto è richie-
sto un così accurato dosaggio come per i diser-
banti, in quanto anche un piccolo errore in più o
in meno può avere come conseguenza l’ineffica-
cia del trattamento, oppure gravissimi danni sulla Telo in fibra di viscosa al termine
coltura a cui si applica (Rota et al., 1987). della stagione vegetativa.
Inoltre, in un ottica di tutela ambientale, sarebbe
auspicabile evitare di disperdere prodotti chimici la rimozione manuale delle malerbe nei vivai
nell’ambiente, anche se di modesta tossicità nordamericani si attesti tra 1.200$ e 10.000$/ha
acuta verso l’uomo. A riguardo, in un lavoro pub- (Mathers, 2003).
blicato negli Stati Uniti (Gilliam et al., 1992), In un ottica di riduzione dei trattamenti chimici,
viene messo in evidenza come la distribuzione di di tutela ambientale e di contenimento dei costi
diserbanti granulari mediante soffiatori, pratica dovuti all’impiego di manodopera per la scerba-
molto diffusa nei vivai nordamericani, possa tura delle infestanti, assume un’importanza più
comportare una dispersione del prodotto uguale o rilevante la possibilità d’impiegare materiali pac-
addirittura maggiore del 86% della quantità dis- ciamanti a basso impatto ambientale nella colti-
tribuita! E’ inoltre da tenere in considerazione la vazione di specie ornamentali in vaso. Per tale
comparsa, sempre più frequente, di malerbe resi- scopo sono diversi i materiali saggiati e già dis-
stenti ai principi attivi normalmente impiegati. ponibili sul mercato, come ad esempio fibre natu-
Ciò costringe i vivaisti ad un ricorso sempre rali, corteccia di conifere, scarti dell’industria tes-
maggiore alla onerosa pratica della scerbatura sile e alimentare e numerose sostanze inerti (Case
manuale. Si è infatti calcolato come il costo per »»
Febbraio 2007
30 Quali alternative ai trattamenti chimici per le infestanti nei vasi? LINEAVERDE
Danno dovuto a Gerval
al colletto di una pianta.
Materiali e metodi
La sperimentazione è stata condotta presso la
Fondazione Minoprio (CO) nel periodo compreso
tra maggio e novembre 2006, in tunnel coperto con
rete antigrandine. Tre specie arbustive di diffuso
impiego commerciale (Photinia x fraseri ‘Red
Robin’, Prunus laurocerasus ‘Rotundifolia’, Thuja
plicata ‘Atrovirens’) sono state coltivate in vasi di
diametro 18 centimetri mettendo a confronto:
1) un telo biodegradabile costituito per il 98% da
fibre di viscosa e per il 2% da alcol polivinilico
(PVA) di peso pari a 100 g/m2. Da questo telo sono
stati ritagliati dischi dal diametro di 18 centimetri,
fissati al substrato mediante l’impiego di 3 chiodi.
et al., 2005). A causa della rapida degradazione del materiale,
Per valutare l’efficacia ed i costi d’impiego di osservata in prove precedenti (Amoroso et al.,
alcuni di questi nuovi materiali è stata allestita 2007; Piatti et. al. 2006), si è deciso di impiegare
una prova sperimentale della durata di due anni. due dischi sovrapposti per vaso;
Di seguito verranno presentati i risultati prelimi- 2) una miscela minerale granulare, priva di
nari inerenti al primo anno di sperimentazione. »»
Tabella 1
COMPARAZIONE DEI COSTI IN FUNZIONE DELLA METODOLOGIA DI CONTENIMENTO DELLE INFESTANTI
Tipologia di Costo Costo Costo totale Note
pacciamatura materiale manodopera annuo
(€/vaso) (€/vaso) (€/vaso)
Non pacciamato - Prunus: 0,27 Prunus: 0,27 Il costo della manodopera è stato calcolato ipotizzan-
Photinia: 0,73 Photinia: 0,73 do 3 interventi di scerbatura nel corso della stagione
Thuja: 0,72 Thuja: 0,72 vegetativa. E’ stato inoltre stimato in 27 il numero di
infestanti estirpate in un minuto da un operatore.
Oxadiazon Il prodotto viene utilizzato alla dose di 180 Kg/ha (0,5
0,003 0,037 0,04 g/vaso). Sono stati stimati 6 sec. per la distribuzione
del prodotto a vaso.
Dischi in fibra
vegetale (Discoplus) 0,07 0,03 0,10 Sono stati stimati 5 sec. per la sistemazione del disco
al colletto delle piante.
Dischi in fibra
di cocco 0,16 0,03 0,19
Miscela inerte Il calcolo è stato effettuato ipotizzando lo spessore
(Gerval) 0,24 0,10 0,34 delle strato di inerte pari a 1,5 cm. Sono stati stimati
15-16 sec. per la posa del materiale sulla superficie
del substrato.
Telo biodegradabile Il materiale pacciamante è venduto in rotoli al costo
in fibra di viscosa 0,04 0,19 0,23 di 0,45 €/m2. E’ stato considerato un tempo di taglio
e posizionamento del disco di circa 15 sec./vaso (per
ogni vaso è stato posizionato un doppio disco).
Febbraio 2007
32 Quali alternative ai trattamenti chimici per le infestanti nei vasi? LINEAVERDE
Figura 1: numero
medio di infestanti
per vaso, rilevato
in P. laurocerasus
‘Rotundifolia’,
nel corso della
sperimentazione.
Per ciascun rilievo
a lettere uguali
corrispondono valori
non significativamen-
te differenti al test
di Duncan
(**: significativo
per P
LINEAVERDE 33
Figura 3: numero
medio di infestanti
per vaso, rilevato in
Thuja plicata, nel corso
della sperimentazione.
Per ciascun rilievo
a lettere uguali
corrispondono valori
non significativamente
differenti al test
di Duncan
(**: significativo
per P34 Quali alternative ai trattamenti chimici per le infestanti nei vasi? LINEAVERDE
paragonabile a quella ottenuta mediante l’impie- biodegradabile in fibra di viscosa, pur posiziona-
go del prodotto chimico di riferimento (oxadia- to in doppio strato, non ha permesso un controllo
zon). Inoltre questo materiale pacciamante ha efficace delle infestanti, principalmente a causa
presentato una limitata degradabilità nel tempo, della sua rapida degradazione. Ciò richiederebbe,
presentandosi ancora integro e riutilizzabile al nella pratica vivaistica, almeno un intervento di
termine della stagione vegetativa, confermando scerbatura nel mese di settembre. Appare quindi
quanto già osservato in precedenti sperimentazio- evidente come, per la diffusione di questo prodot-
ni (Peretti, 2005; Amoroso et al., 2007). La pos- to, si renda necessario da parte dell’azienda pro-
sibilità di ripartire il costo iniziale dei dischi in duttrice una modifica delle caratteristiche chimi-
fibra di cocco su più anni rende questo prodotto che del materiale, tale da permettere una degrada-
decisamente vantaggioso anche dal punto di vista bilità più lenta.
economico. Anche Gerval e Discoplus hanno La presente sperimentazione ha permesso di osser-
mostrato una discreta efficacia nel contenimento vare come è possibile un approccio alternativo alla
della flora infestante, seppur non sempre ottima- lotta chimica per il controllo delle malerbe nella
le, in particolar modo verso il termine della sta- produzione vivaistica in contenitore. Al momento il
gione vegetativa. Se per Discoplus il costo d’im- fattore penalizzante di questi prodotti permane il
piego è paragonabile a quello della fibra di cocco prezzo, ancora maggiore rispetto al trattamento chi-
ripartito su due anni, non è così per Gerval. mico tradizionale. E’ però ipotizzabile che la diffu-
Questo prodotto presenta un valore decisamente sione su larga scala di questi prodotti, resa necessa-
più elevato, imputabile in particolar modo alla ria anche in seguito alle crescenti limitazioni d’uso
manodopera necessaria per un accurato posizio- degli erbicidi, ne riduca i costi.
namento del materiale sulla superficie dei conte-
nitori. Inoltre Gerval ha arrecato seri danni al col- Ringraziamenti
letto delle piante; questo inconveniente era già Sperimentazioni effettuate nell’ambito del progetto
stato osservato in una precedente prova sperimen- “Tecniche eco-compatibili innovative per le produ-
tale effettuata impiegando una formulazione zioni florovivaistiche” (Regione Lombardia, Piano
diversa di questo materiale (Peretti, 2005). Il telo per la ricerca e lo sviluppo 2005). ■
BIBLIOGRAFIA
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infestanti in vaso. Colture Protette, (in press).
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niture di piante ornamentali - “edizione 2006 / 2007”.
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HortTechnology, 15(3): 535-544.
• Gilliam C.H., Fare D.C., Beasley (1992) – Nontarget herbicide losses from application of granular Ronstar to
container nurseries. Journal of Environmental Horticulture, 12: 1-8.
• Gilliam C.H.; Foster W.J.; Adrian J.L.; Schumack R.L. (1990) – A survey of weed control costs and strategies
in container production nurseries. Journal of Environmental Horticultural, 8: 133-135.
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Febbraio 2007Sustainable Methods for Weed Control in
Nurseries
Gabriele Amoroso1, Piero Frangi1 and Alessio Fini2
corresponding author: frangi@fondazioneminoprio.it
(1) Fondazione Minoprio – Centro MiRT – Viale Raimondi, 54, 22070 Vertemate con Minoprio (CO), Italy
(2) Dipartimento di Ortoflorofrutticoltura – Università di Firenze – Viale delle Idee, 30, 50019 Sesto Fiorentino (FI), Italy
This research was conducted in an experimental nursery located
Fig. 1 Fig. 2
nearby Milan (Italy; 45°44’ N, 9°04’ E), during 2006 summer (May
– October), to evaluate the effectiveness, degradation time, and
costs of some environmentally-friendly materials used to control
weeds in containers.
The non-chemical materials used to prevent weed growth were:
1) Discs made of coconut fiber (fig. 1);
2) Discs constituted by vegetal fiber and synthetic fiber (fig. 2);
3) Discs constituted by viscose fiber (98%) and polyvinylic alcohol
(2%) (fig. 3).
Fig. 3 Fig. 4
4) Gerval® (Gerval Srl, Reggio Emilia, IT) constituted by a
mineral grain mixture without chemical additives (fig. 4).
The effectiveness of these materials was compared with a
chemical control (a single application of Ronstar®) and with an
untreated control.
Average number of weeds removed from containers after 45, 90 and 135 days
from potting (DFP). Different letters show significantly differences,
Duncan’s multiple range test (P≤0.05).
15
After a certain period, the progressive degradation of the materials Photinia x fraseri ‘Red Robin’
a
covering the substrate surface allowed weed growth. Among the 12
different materials, coconut fiber discs provided weed control as a
good as Ronstar®, because of its resistance to degradation; no
9 b
degradation was observed during the time of the trial. Moreover, as
observed in previous works, coconut discs breakdown was so a
limited that they can be used the following season. 6
b bc
bc bc
1
As found in previous research, Gerval® causes serious damage to 3
b cd bc
bc
.
the root flare because its rigidity does not allow secondary growth of c c c d d
c
the stem (Fig. 5). This leads to phloem disruption and to stem 0
fragility (Fig. 6). 45 DFP 90 DFP 135 DFP
** ** **
Gerval damage on root flare of Photinia x fraseri. 10
Prunus laurocerasus ‘Rotundifolia’
Fig. 5 Fig. 6
8
6
a
4
a a
a
b b b b
2 bc b b b bc bc
cd cd d . .
c
0
45 DFP 90 DFP 135 DFP
** ** **
Cost of weed control: 15
Thuja plicata ‘Atrovirens’
Total cost/disc a
materials used 12 a
(including installation) a
coconut fiber disc $0.26/pot * 9
vegetal-synthetic fiber disc $0.14/pot a
6 b b
viscous fiber disc $0.14/pot a b
3 b
Gerval® $0.47/pot b b b b b b b b
b
Ronstar® $0.06/pot for distribution 0
45 DFP 90 DFP 135 DFP
manual removal of weeds $0.37/pot - $1.00/pot ** ** **
Coconut discs Vegetal and synthetic fiber discs
* can be used for more than one growing season, its cost can be
Fiber viscose discs Mineral mixture (Gerval®)
amortized in two or three years
Chemical control (Ronstar®) Untreated control
We would like to thank Regione Lombardia Project “Tecniche eco-compatibili innovative per le produzioni florovivaistiche”
(Piano per la ricerca e lo sviluppo 2005).The Effect of Cyclic Irrigation
and Fertilization on Growth of
Two Container Grown Shrubs
Piero Frangi1, Francesco Ferrini2, Gabriele Amoroso1, Alessio Fini2 and Riccardo Piatti1
1Fondazione Minoprio, viale Raimondi, 54, 22070, Vertemate con Minoprio (Como)
2Dipartimento di Ortoflorofrutticoltura, Viale delle Idee, 30, 50019 - Sesto Fiorentino (Firenze)What is “cyclic irrigation”? Consists in applying the daily water allotment with multiple irrigation events with a resting interval between irrigation
When the medium is saturated with water above
Field-Capacity, the gravitational fraction of
water is lost by percolation. This part greatly
contributes to irrigation inefficiency.
Distributing the same amount of water with multiple
events, cyclic irrigation can avoid the saturation of the
substrate and maintain it near to Field-Capacity, limiting
therefore percolation of water and nutrient leaching.The study was
conducted in an
experimental nursery at
the Fondazione
Minoprio in the
neighbourhood of Milan,
during summer 2006.The aim of this work was to test, at two
fertilization rates, different scheduling and
timing for pulse irrigation in order to :
• achieve maximum irrigation efficiency
• reduce nutrient leaching.
One-year-old
In order uniform
to collect leached volumes,rooted cuttings
one bucket of (32
per block Prunus
buckets
Theper species) was
laurocerasus
irrigation „Rotundifolia‟
tightly
treatments placed
were: andcontainers.
under plant Viburnum tinus „Eve
The fertilization
Price‟ were potted rates were:
into 0.8 gal plastic containers.
1) Single daily irrigation at 7:00 A.M.
1) 5.6 lb∙yd-3
2) 4 daily application: 5:00, 6:00,Leached volumes were evaluated
7:00, 8:00 A.M.
2) 10.1 lb∙yd-3 every 4 days (from July to
3) 4 daily application: 4:00, 6:00,September)
8:00, 10:00withA.M.
the exception of
rainy events
4) 4 daily application: 5:00, 10:00 A.M.; 3:00, 8:00 P.M.Height increase (cm)
Prunus laurocerasus Viburnum tinus
100 50
80 40
60 30
40 20
20 10
0 0
1 2 3 4
1 2 3 4
5.6 lb/yd-3 10.1 lb/yd-3 5.6 lb/yd-3 10.1 lb/yd-3
1 - 1 event at 7:00
2 - 4 events at 5:00/6:00/7:00/8:00
3 - 4 events at 4:00/6:00/8:00/10:00
4 - 4 events at 4:00/9:00/14:00/19:00Plant dry weight (g)
Prunus laurocerasus Viburnum tinus
150 100
120 80
90 60
60 40
30
20
0
0
1 2 3 4 1 2 3 4
5.6 lb/yd-3 10.1 lb/yd-3 5.6 lb/yd-3 10.1 lb/yd-3
1 - 1 event at 7:00
2 - 4 events at 5:00/6:00/7:00/8:00
3 - 4 events at 4:00/6:00/8:00/10:00
4 - 4 events at 4:00/9:00/14:00/19:00Daily mean quantity of water leached from containers
(ml/day)
Prunus Viburnum
laurocerasus tinus
Irrigation
1- One event at 7:00 352.1 137.6 az
2 - 4 events at
348.6 159.8 a
5:00/6:00/7:00/8:00
3 - 4 events at
330.5 125.3 a
4:00/6:00/8:00/10:00
4 - 4 events at
278.2 73.3 b
4:00/9:00/14:00/19:00.
P-value 0.740 0.007
Fertilization
5.6 lb∙yd-3 326.8 154.3 a
10.1 lb∙yd-3 327.9 93.8 b
P-value 0.983 0.001
Irrigation x Fertilization
P-value 0.605 0.448Cyclic irrigation with 5 h
resting interval can be
considered a useful mean to
reduce chemical
externalities from nurseriesKeep on
supporting
research
Research funded by Regione Lombardia
within the “ECOFLO” project.Puoi anche leggere
