JOURNAL OF PLANT PROTECTION RESEARCH
Vol. 49, No. 1 (2009)
EFFECT OF ADJUVANTS, SPRAY VOLUME AND
NOZZLE TYPE ON METCONAZOLE ACTIVITY AGAINST
LEPTOSPHAERIA BIGLOBOSA AND L. MACULANS DURING
LATE SPRING TREATMENTS IN WINTER OILSEED RAPE
Zbigniew Karolewski1*, Marek Wachowiak2, Henryk Ratajkiewicz3, Roman Kierzek2
University of Life Sciences in Poznań, Faculty of Horticulture, Department of Phytopathology, Dąbrowskiego 159, 60-594 Poznań
Institute of Plant Protection – National Research Institute
W. Węgorka 20, 60-318 Poznań
1
University of Life Sciences in Poznań, Faculty of Horticulture, Department of Plant Protection Methods, Zgorzelecka 4, 60-198 Poznań
1
2
Received: May 12, 2008
Accepted: March 6, 2009
Abstract: In two seasons 2005–2006 the metconazole (Caramba 60 SL at the dose of 0.75 l/ha) was applicated by spraying at the beginning of flowering against phoma stem canker (Leptosphaeria biglobosa and L. maculans) in winter oilseed rape. The effect of water volume
(200 and 400 l/ha), adjuvant type (Break Thru S 240 – 0.1% and Atpolan 80 EC – 0.5%), and nozzle type (XR11002 – fine droplet size and
DB11002 – course droplets at pressure 0.4 MPa) on the biological efficacy of fungicide spraying was investigated in the studies.
The results showed that adjuvants did not significantly influence biological efficacy of fungicide treatments against L. biglobosa and
L. maculans. Generally, control of both pathogens on the leaves and stem did not depend on spray characteristics (nozzle types-droplet
size). However, positive effect of air induction nozzles DB 11002 (course spray quality) on fungicide treatments against L. biglobosa,
particularly with addition of adjuvant Atpolan 80 EC was observed. Two different volumes of water tested (200 and 400 l/ha) did not
influence efficacy of metconazole in control L. maculans and L. biglobosa. The above suggests a possibility of decrease the volume of
water used with fungicide to 200 l/ha, without a negative biological effects on fungicidal activity.
Key words: adjuvants, spray volume, nozzle type, metconazole, fungicide, winter rape, Leptosphaeria biglobosa, L. maculans
INTRODUCTION
Phoma stem canker caused by two pathogens, Leptosphaeria biglobosa and L. maculans, is a worldwide disease
of oilseed rape, including Poland (Fitt et al. 2006; Jędryczka
2006). Amongst methods for control of the disease, spraying
plants with fungicides is one of the most important. According to recommendations made by the Institute of Plant Protection – National Research Institute, Poznań, Poland there
are two possible terms for fungicide application. The first
one should be done in autumn, at phase of 4 leaves occurring until rosette stage or when first symptoms are observed.
The second spraying is recommended in spring after start of
a plant vegetation or when first symptoms are observed.
The application of fungicides in spring might be connected with two problems. The first one is a possible occurrence of plants already infected in autumn and early
spring, as ascospores of pathogens can be realeased for
many months e.i. from September to May (Jędryczka
2006). Also winter oilseed rape plants treated with fungicides are usually high this time, so it can make difficulties
in precise achievement by droplets of these stem parts and
leaves located near soil surface. However, the later spray*Corresponding address:
karolew@up.poznan.pl
ing in spring should allow to remain an active ingredient in plant, which protects them against later infections,
caused in Poland mainly by L. biglobosa (Jędryczka 2006).
There are several active ingredients which can be used
for phoma stem canker control. Majority of them belong
to triazoles and benzimidazoles, which are systemic and
can be transported inside plants. However, the efficacy of
such application depends on precise covering of plants
by chemicals, retention, deposition and ability of fungicide penetration into plant tissue. Those features can be
modified by an addition of adjuvants, spray volume and
a droplets size (Gaskin et al. 2000; Holloway et al. 2000).
The aim of the study was to assess the efficacy of metconazole (Caramba 60 SL) in control of phoma stem canker
(L. biglobosa and L. maculans) in winter oilseed rape as affected by adjuvants, volume of liquid per hectare and size
of spray droplets.
MATERIALS AND METHODS
The experiment was carried out in Wielkopolska
province on winter oilseed rape cv. Lisek in two seasons:
114
Journal of Plant Protection Research 49 (1), 2009
2005–2006 at Skórzewo and 2006–2007 at Złotniki. A randomized block design in 4 replications with dimension of
plots 2x10 m was used. The previous crop was also winter oilseed rape in both seasons, to increase the infection
pressure of Leptosphaeria sp. The fungicide Caramba 60 SL
was applied at the dose of 0.75 l/ha using knapsack sprayer at BBCH 59–61 (beginning of flowering). Spray boom
was established 25–30 cm above plant the canopy. In both
seasons the wind velocity during treatments did not exceed 2 m/s and the temperature was not higher than 25 °C.
The height of plants differed between years. In 2005 the
mean height was 71 cm but in 2006 – 130 cm. The effect
of 3 factors: i) volume of water (200 and 400 l/ha), ii) adjuvant type (Break Thru S 240 at concentration 0.1% and
Atpolan 80 EC at concentration 0.5%), and iii) nozzle type
(XR11002 – fine droplet size and DB11002 – course droplets at pressure 0.4 MPa) was investigated in the studies.
The control variant consisted of untreated plots. Control
of weeds, pests and other agrotechnical treatments was
carried out according to the respective recommendations
in the same way on the whole plantation.
The assessment of infection caused by pathogens was
done on 25 plants collected from each plot. Leaves infection was measured using a 5-degree scale:
0 – healthy
1 – 1–2
2 – 3–4
3 – 5–6
4 – 7 or more
spots on plant
For assessment of L. maculans stem infection 6 degree
scale was used (Aubertot et al. 2004):
1 – healthy
2 – < 25%
3 – 25–50%
4 – 50–75%
5 – 75–90%
6 – 90–100%
of infected stem section area
For assessment of L.biglobosa stem infection 6 degree
scale was used
1 – healthy
2 – 0–25%
3 – 25–50%
4 – 50–75%
5 – 75–90%
6 – 90–100%
RESULTS
The level of infection caused by L. maculans on stems
(untreated plots) was higher in 2005 than in 2006, whilst
the occurrence of L. biglobosa on stems was similar in both
seasons (Table 2).
Spraying with Caramba 60 SL decreased in 2005 the
degree of stem infection caused by L. maculans as assessed
before harvest (BBCH 87). The significant differences in
comparison to untreated plots were found for both type
of nozzles when adjuvant Atpolan 80 EC was added to
the fungicide in water volume of 200 l/ha and when adjuvant Break Thru was used in the same volume of water
but using XR type nozzle. The lower incidence of L. maculans was also found for 400 l/ha of water volume when
plants were sprayed with Atpolan 80 EC addition using
XR nozzles or sprayed with Break Thru using DB nozzles. However, in stem infection no significant difference
between treatments for interaction of nozzle type, spray
volume and adjuvants was observed.
There were not significant differences between the
occurrence of L. biglobosa on winter oilseed rape stems
(BBCH 87) in 2005 on treated with fungicide and untreated plots. In that case the efficacy of fungicide treatments
was not influenced by nozzle type (droplet size), spray
volume and addition of adjuvants.
The application done in 2006 was efficient in control
of L. maculans on winter oilseed rape leaves, when the assessment was made at BBCH 67–68 (Table 3). Obtained
data showed that the lower level of leaf infection was observed for fungicide treatments without addition of adjuvants, especially at spray volume of 400 l/ha. However
there were no differences between treated and untreated
plots in stem infection (BBCH 77 and 87) caused by this
fungus.
Spraying plants with fungicide metconazole did not reduce leaf and stem infection caused by L. biglobosa in 2006
(see results for treated and untreated plots) (Table 3).
Interaction of adjuvants, nozzles type and volume water had no effect on the level of winter oilseed rape leaves
infection caused by L. biglobosa in 2006 (BBCH – 67–68).
In the next assessment done on stems (BBCH 77) similar
tendency was observed. No significant differences between tested objects were observed in the latest assessment (BBCH 87) done on winter oilseed rape stems just
before harvest (Table 2).
of infected stem surface
Sampling of plants was done once in 2005 at the pod
ripening (BBCH 87 – stem infection), whilst in 2006 there
were three assessments: at the BBCH 67–68 (25.05 – leaves
infection), 77 (27.06 – stem infection) and 87 (17.07 – stem
infection).
Statistical analysis of the experiments was carried out
using Duncan test at significance level α = 0.05.
DISCUSSION
Chemical control of phoma stem canker (L. maculans)
in winter oilseed rape can be done in autumn and/or in
spring. However, the fungicide spraying in spring at the
beginning of plant flowering might be more yield producing than those done in autumn (Gwiazdowski 2002).
L. maculans can infect oilseed rape leaves in autumn
via airborne ascospores and then it grows through petioles to stems (Fitt et al. 2006, Jędryczka 2006). On the contrary, the majority of L. biglobosa infections occur usually
in spring. In May 2005 rainfall was 36% higher than in
2006 (Table 1), which could increase Leptosphaeria spp. infections. At the latest assessment of stems, the degree of
115
Effect of adjuvants, spray volume and nozzle type on metconazole activity…
Table 1. Meteorological conditions during field experiments
2005 (Skórzewo)
Month
Decade
sum
2006 (Złotniki)
mean
[oC]
I
9
9.29
II
0
III
relative
humidity
[mm]
[oC]
65.15
0.6
7.32
77.40
11.15
74.47
6
9.04
77.89
7.4
8.35
61.67
23.4
11.47
84.44
sum/mean
16.40
9.59
67.10
30.00
9.28
79.91
I
29.2
11.49
86.04
11.6
14.80
61.00
II
21.8
10.10
79.77
13.6
14.87
75.33
III
11.2
19.20
67.51
20.4
12.59
80.73
sum/mean
62.20
13.59
77.77
45.60
14.09
72.35
I
8.6
13.33
75.85
6.8
12.80
80.36
II
8
16.94
73.02
0.4
20.83
67.91
III
0.2
19.71
63.28
14.4
21.92
64.60
sum/mean
16.80
16.66
70.72
21.60
18.52
70.96
June
[mm]
relative
humidity
temperature
May
temperature
mean
rainfall
April
rainfall
sum
%
[%]
I
9.4
19.98
69.51
0.0
22.44
44.02
II
3.6
21.08
63.07
20.2
22.73
62.80
sum/mean
108.40
14.60
70.85
117.40
15.53
70.59
July
Table 2. Influence of Caramba 60 SL spraying (0.75 l/ha) on the winter oilseed rape stem infection caused by L. biglobosa and L. maculans at BBCH 87 (before harvest) depending on spray volume, adjuvant and nozzle type
Spray
volume
Adjuvant
[l/ha]
–
200
Atpolan 80 EC
Break Thru S 240
Leptosphaeria biglobosa
Nozzle
type
2005
mean
XR 11002
1.65 a
DB 11002
1.53 a
XR 11002
1.79 a
DB 11002
1.68 a
XR 11002
1.78 a
DB 11002
1.79 a
mean
–
400
Atpolan 80 EC
Break Thru S 240
XR 11002
1.86 a
DB 11002
1.73 a
XR 11002
1.69 a
DB 11002
1.71 a
XR 11002
1.79 a
DB 11002
1.65 a
mean
–
Mean
Atpolan 80 EC
Break Thru S 240
mean
1.59 a
1.75 a
1.79 a
1.71 A
1.80 a
1.69 a
1.72 a
2005
mean
1.54 a
1.52 a
1.60 a
1.56 a
1.53 a
1.55 a
1.58 a
1.63 a
1.61 a
1.56 a
1.55 a
1.53 a
1.58 a
1.54 a
1.55 A
1.61 a
1.59 a
1.61 a
1.67 a
1.73 A
Control (Untreated plots)
Leptosphaeria maculans
2006
1.82
A
2006
mean
1.68 a
1.79 a
1.57* a
1.46* a
1.55* a
1.68 a
1.65 a
1.70 a
1.55* a
1.75 a
1.65 a
1.74 a
1.52 a
1.62 a
1.62 A
1.68 a
1.65 a
1.62 a
1.59* a
1.60 A
1.77
mean
1.62 a
1.70 a
1.61 a
1.64 a
1.62 a
1.57 a
1.60 a
1.62 a
1.58 a
1.61 a
1.64 a
1.66 a
1.63 a
1.60 a
1.63 A
1.61 a
1.60 a
1.62 a
1.59 a
1.64 A
2.07
1.61 A
1.67
XR 11002
1.76 a
1.56 a
1.67 a
1.61 a
DB 11002
1.63 a
1.58 a
1.75 a
1.66 a
XR 11002
1.74 a
1.61 a
1.56 a
1.60 a
DB 11002
1.60 a
1.56 a
1.61 a
1.63 a
XR 11002
1.79 a
1.54 a
1.60 a
1.63 a
DB 11002
1.72 a
1.61 a
1.64 a
1.58 a
1.76 a
1.56 a
1.67 a
1.61 a
a, b or A – entries followed by the same letter were not significantly different using Duncan test at α = 0.05
* mean significantly different from control (untreated) using Duncan test at α = 0.05
116
Journal of Plant Protection Research 49 (1), 2009
Table 3. Influence of Caramba 60 SL spraying (0.75 l/ha) on the winter oilseed rape infection in 2006 caused by L. biglobosa and
L. maculans at BBCH 67–68 (leaf infection) and 77 (stem infection) depending on spray volume, adjuvant and nozzle type
Spray
volume
Leptosphaeria biglobosa
Adjuvant
[dm3 ha-1]
Atpolan 80 EC
Break Thru S 240
mean
–
400
leaves (BBCH
– 67–68)
25.05
–
200
Nozzle
type
Atpolan 80 EC
Break Thru S 240
XR 11002
0.19 a
DB 11002
0.22 a
XR 11002
0.21 a
DB 11002
0.12 a
XR 11002
0.25 a
DB 11002
0.23 a
XR 11002
0.22 a
DB 11002
0.19 a
XR 11002
0.19 a
DB 11002
0.14 a
XR 11002
0.27 a
DB 11002
0.16 a
mean
0.21 a
0.17 a
0.24 a
0.20 A
0.21 a
0.22 a
0.17 a
stems (BBCH 77)
27.06
1.52 ab
1.43 ab
1.44 ab
1.50 ab
1.55 b
1.49 ab
1.36 ab
1.40 ab
1.49 ab
1.30 a
1.43 ab
–
Atpolan 80 EC
Break Thru S 240
mean
1.48 a
1.47 a
1.52 a
1.49 A
1.38 a
1.40 a
1.46 a
1.48 ab
0.20 A
Control (untreated plots)
Mean
mean
Leptosphaeria maculans
0.29
leaves (BBCH
– 67–68)
25.05
0.55* a
0.42* a
0.57 a
0.55* a
0.54* a
0.48* a
0.41* a
0.42* a
0.41* a
0.62 a
0.68 a
mean
0.49 a
0.56 a
0.51 a
0.52 A
0.42 a
0.52 a
0.56 a
0.43* a
1.41 A
1.52
stems (BBCH 77)
27.06
1.46 a
1.47 a
1.38 a
1.27 a
1.55 a
1.52 a
1.44 a
1.50 a
1.57 a
1.36 a
1.24 a
mean
1.47 a
1.33 a
1.54 a
1.44 A
1.47 a
1.47 a
1.39 a
1.54 a
0.50 A
0.9
1.44 A
1.4
XR 11002
0.21 ab
1.44 a
0.48 a
1.45 a
DB 11002
0.21 ab
1.42 a
0.42 a
1.49 a
XR 11002
0.20 ab
1.47 a
0.49 a
1.48 a
DB 11002
0.13 a
1.40 a
0.59 a
1.32 a
XR 11002
0.26 b
1.49 a
0.61 a
1.40 a
DB 11002
0.20 ab
1.49 a
0.46 a
1.53 a
a, b or A – entries followed by the same letter were not significantly different using Duncan test at α = 0.05
*mean significantly different from control (untreated) using Duncan test at α = 0.05
infection caused by L. maculans on untreated plots in 2005
reached 2.07, whilst in 2006 only 1.67 (Table 2).
In the experiment done in 2005 at Skórzewo and in
2006 at Złotniki the fungicide Caramba 60 SL was applied in spring at the beginning of flowering. The used
dose (0.75 l/ha) was lower than it was recommended by
the producer (1–1.25 l/ha). The active ingredient (metconazole) did not reduce significantly the level of infection
of winter oilseed rape plants caused by L. biglobosa. It
suggested that the tested dose was too little and the date
of application did not match the pathogen spore release.
The fungicide spraying was efficient against L. maculans
infections, however, the positive effect of metconazole application concerned oilseed rape leaves only. The level of
stem infection was similar on treated and untreated plots.
It seemed, that the efficacy of fungicide was decreased by
plant development as a concentration of active ingredient
in plant became too low to inhibit L. maculans development in stem base.
Addition of adjuvants to fungicide did not increase
the efficacy of spraying against L. maculans, regardless
of water volume and nozzle type application. However,
oil adjuvant Atpolan 80 EC had good effect on fungicide
activity against stem infection caused by L. maculans for
both nozzle types (droplet size) and, especially at spray
volume of 200 l/ha. Results indicate a possibility of using
lower volume of water to metconazole treatment with
or without addition of adjuvants even when spray must
penetrate dense plant conopy (in spring, winter rape at
the beginning of flowering). The above confirmed Kutcher and Wolfs̀ (2006) conclusions that using conventional
nozzles with higher volume of water and low drift nozzles with lower volume are both appropriate for control
of Brassica stem diseases.
In general, biological activity of fungicide against
L. biglobosa was not depended on addition of adjuvants to
spray solution and nozzle type (droplet size). Although
the control with metconazole against L. biglobosa was
not fully efficient, spraying using air induction nozzle
DB 11002 with or without addition of adjuvants, gave
similar efficacy of pathogen control as compared with the
spraying using XR 11002. It indicated that the air induction nozzle DB 11002 producing larger droplets could be
recommended in winter oilseed rape, especially if the
spraying was done at high velocity wind. In crops such
oilseed rape larger droplets may penetrate deeper than
small ones. However, in other crops e.g. muskmelon,
where Alternaria leaf blight affects leaves only, using of
nozzles with high pressure was not necessary (Egel and
Harmon 2001). Grayson et al. (1996) and Kierzek and
Wachowiak (2003) suggested that addition of adjuvants
could not improve the efficacy of fungicide spraying
without taking into consideration other parameters of the
application. If spraying was performed in less favourable
climatic conditions (stronger wind, lower humidity, higher temperature) application of fungicide with DB 11002
nozzle against L. biglobosa should be helpful.
Effect of adjuvants, spray volume and nozzle type on metconazole activity…
117
Two different amounts of water tested (200 and 400 l/ha)
for spraying against L. maculans and L. biglobosa did not
influence the efficacy of metconazole. It indicates a possibility of decrease the volume of water to 200 l/ha, without
any negative effect on fungicide efficacy.
Kierzek R. Wachowiak M. 2003. Effect of nozzle types and adjuvants on the leaf coverage and biological efficacy of fungicides in potato. J. Plant Protection Res. 43 (2): 181–189.
Kutcher H.R., Wolf T.M. 2006. Low-drift fungicide application
technology for sclerotinia stem rot control in canola. Crop
Protection 25: 640–646.
ACKNOWLEDGEMENTS
POLISH SUMMARY
His work has been supported by grant 2 P06R 029 27
from the Ministry of Higher Education, Poland
REFERENCES
Aubertot J.-N., Schott J.-J., Penaud A., Brun H., Doré T. 2004.
Methods for sampling and assessment in relation to the
spatial pattern of phoma stem canker (Leptosphaeria maculans) in oilseed rape. Eur. Plant Pathol. 110: 183–192.
Egel D.S., Harmon P. 2001. Effects of nozzle type and spray pressure on control of Alternaria leaf blight of muskmelon with
chlorothalonil. Plant Dis. 85 (10)L: 1081–1084.
Fitt B.D.L., Brun H., Barbetti M.J., Rimmer S.R. 2006. World-wide
importance of phoma stem canker (Leptosphaeria maculans and L. biglobosa) on oilseed rape (Brassica napus). Eur.
J. Plant Pathol. 114: 3–15.
Gaskin R.E., Murray R.J., Krishna H.,Carpenter A. 2000. Effect of
adjuvants on the retention of insecticide spray on cucumber and pea foliage. N. Z. Plant Protection 53: 355–359.
Grayson B.T., Price P.J. Walter D. 1996. Effect of volume rate of application on the glasshouse performance of crop protection
agent/adjuvant combinations. Pesticide Sci. 48: 205–217.
Gwiazdowski R. 2002. Wpływ terminów opryskiwania fungicydami na plon rzepaku ozimego. Prog. Plant Protection/
Post. Ochr. Roślin 42 (2): 856–859.
Holloway P.J., Butler Ellis M.C., Webb D.A., Western N.M., Tuck
C.R. Hayes A.L., Miller P.C.H. 2000. Effects of some agricultural tank-mix adjuvants on the deposition efficacy of
aqueous sprays on foliage. Crop Protection 19: 27–37.
Jędryczka M. 2006. Epidemiologia i szkodliwość suchej zgnilizny
kapustnych na rzepaku ozimym w Polsce. Rozprawy
i Monografie. Inst. Genetyki Roślin PAN, Poznań, 150 pp.
WPŁYW ADIUWANTÓW, ILOŚCI CIECZY
UŻYTKOWEJ I TYPU ROZPYLACZA NA
SKUTECZNOŚĆ DZIAŁANIA METKONAZOLU
W WIOSENNEJ OCHRONIE RZEPAKU
OZIMEGO PRZED LEPTOSPHAERIA BIGLOBOSA
I L. MACULANS
W latach 2005 i 2006 na początku kwitnienia rzepaku ozimego zastosowano metkonazol (Caramba 60 SL
w dawce 0,75 l/ha) przeciwko suchej zgniliźnie kapustnych (Leptosphaeria biglobosa i L. maculans). W badaniach
oceniono znaczenie ilości wody (200 i 400 l/ha), rodzaju
adiuwanta (Break Thru S 240 – 0,1% i Atpolan 80 EC –
0,5%) oraz rodzaju rozpylacza (XR 11002 – drobnokroplisty i DB11002 – grubokroplisty przy ciśnieniu 0,4 MPa)
dla biologicznej skuteczności opryskiwania fungicydem.
Wyniki badań wskazują, że dodatek adiuwantów do
metkonazolu nie wpływał istotnie na skuteczność zwalczania sprawców suchej zgniliźny kapustnych (L. biglobosa i L. maculans). Generalnie efektywność zwalczania
obydwóch patogenów na liściach i łodygach rzepaku nie
była uzależnona od użytych do zabiegu typów rozpylaczy (wielkości kropel). Stwierdzono, że zastosowanie
rozpylaczy eżektorowych DB 12002, wytwarzających krople grube, w korzystny sposób wpłynęło na skuteczność
zwalczania L. biglobsa, szczególnie gdy metkonazol stosowano z dodatkiem adiuwanta olejowego Atpolan 80 EC.
Obie oceniane ilości wody nie wpływały istotnie na
skuteczność metkonazolu przeciwko L. maculans jak
i L. biglobosa. Wskazuje to na możliwość zmniejszenia
objętości wody używanej do rozcieńczania fungicydu do
200 l/ha, bez negatywnego wpływu na jego biologiczną
skuteczność.