Efficacy experiment against turmeric leaf spot

1. Pesticide Research Journal Vol. 24(1): 104-106, June 2012
Fungicidal Performance in Managing Colletotrichum
Leaf Spot of Turmeric
SK Chawda1*
, AN Sabalpara2
, JR Pandya3
and HV Patel1
1
Department of Entomology, N.M. College of Agriculture,
Navsari Agricultural University, Navsari 396 450, Gujarat, India
2
Director of Research and Dean PG Studies, Office of the Director of Research,
Navsari Agricultural University, Navsari-396 450, Gujarat, India
3
Office of the Director of Research, Sardarkrushinagar
Dantiwada Agricultural University, Dantiwada-385 506, Gujarat, India
Colletotrichum leaf spot (CLS) occurred regularly in South Gujarat. It was found as a major constraint in successful
cultivation of turmeric in this heavy rainfall zone. The control of CLS is difficult because of rapid disease
development. It causes considerable losses of quality and quantity of produce. Therefore farmers need to take
immediate control measures to reduce the incidence of leaf spot intensity as early as possible. The objective of
this two year farmer’s field study (2008-10) was to evaluate the performance of nine different fungicides against
this disease as well as to identify most apposite fungicide. Carbendazim@0.5 g/L was found most efficient
fungicide as it gave lowest leaf spot intensity and maximum yield during the study.
Key words: Carbendazim, Colletotrichum leaf spot, turmeric
Turmeric (Curcuma longa L.) (Family: Zingiberaceae) is one
of the major spices cultivated for its underground rhizome,
which is also called as “hidden Lilly” or “turmeric of
commerce”. It suffers from a serious foliar disease i.e. leaf
spot caused by Colletotrichum gloeosporioides. In Gujarat,
leaf spot caused by C. gloeosporioides was first reported
in Sugandham variety (Patel, 2005)1
. Since then, it was
found increasing and occurring regularly every year. The
disease manifested in the form of elliptic or oblong spots of
variable sizes. In the initial stage, the spots were pin head
dot like, but very soon increased in size and coalesced to
form large patches involving major portion of the leaf. The
centre of the spots were grayish white with numerous black
dots like acervuli on both the surfaces of the spots. When
the incidence of the disease was severe most of the leaves
became yellowish followed by drying and the field presented
a blighted appearance which become major constraint in
successful cultivation of turmeric in South Gujarat. The
disease resulted in drastic reduction in rhizome yield. Such
reduction in yield was earlier found accompanied by a slight
increase in the oil content and a moderate increase in
curcumin (Nair and Ramakrishnan, 1973)2
. The control of
Colletotrichum leaf spot (CLS) is difficult because of rapid
disease development. CLS causes considerable losses of
quality and quantity of produce so it is advisable to take
the immediate control measure to manage the disease as
early as possible. Fungicide application has become almost
routine management in farming community as an immediate
control measure. The objective of this two year farmer’s
field study was to evaluate most efficient fungicide for their
ability to inhibit development of CLS in South Gujarat (heavy
rainfall zone). Therefore, to find out the most suitable
fungicides for the disease management, nine fungicides
belonging to different chemical groups were evaluated to
control CLS and to gain maximum yield.
MATERIALS AND METHODS
To evaluate the most apposite fungicide for the
management of the disease, nine fungicides belonging to
different chemical groups were tested during two
consecutive years (2008-09 and 2009-10). The experiment
was carried out in randomized block design with plot size
of 4.5×3.0 m2
at farmer’s field (Village- Ghala) of Surat
district. Turmeric plantations were carried out in the field
with a spacing of 45×30 cm. All the treatments were
performed in triplicate and standard package of practices
were adopted in whole experiment as recommended by
Navsari Agricultural University. Two sprays of the fungicides
were applied, first at the time of initiation of disease and
*Corresponding author E-mail: sk_pathology@yahoo.com
NOTE

2. Managing Colletotrichum leaf spot of turmeric 105
Pestic Res J 24(1): 104-106 (2012)
second at 15 d after first spray. The efficacy of these
fungicides was compared with the control (without
fungicides) plot, which was sprayed with water only. Ten d
after second spraying, five plants from each of the plot were
selected for observations. The disease rating was recorded
by adopting standard 0-6 scale (Palarpawar and Ghurde,
1989)3
at weekly interval, where, 0= no infection, 1= 0.1 to
10% necrotic leaf area, 2= 10.1 to 20.0% necrotic leaf area,
3= 20.1 to 30% necrotic leaf area, 4= 30.1 to 40% necrotic
leaf area, 5= 40.1 to 50% necrotic leaf area, 6= more than
50% necrotic leaf area (Figure 1). The percent disease
intensity (PDI) was calculated according to the following
formula suggested by Datar and Mayee (1981)4
. The fresh
rhizome yield was also recorded at the time of harvest.
Σ of rating of infected leaves on plant
PDI = –––––––––––––––––––––––––––––––––––––––––– x 100
No. of leaves observed x Maximum disease score
RESULTS AND DISCUSSION
Percent leaf spot intensity: During the year 2008-09, two
sprayings with each of nine selected fungicides over the
leaves of the turmeric plants in the field caused significant
reduction in disease intensity over untreated control.
Carbendazim proved the most proficient fungicide with
minimum leaf spot intensity (8.88%), which was found
statistically at par with propiconazole (9.23%),
carbendazim+mancozeb (9.46 %) and mancozeb (10.40%).
Next best in merit was hexaconazole (12.87%) followed by
iprodine+carbendazim (14.75%) and thiophanate methyl
(17.33%). Chlorothalonil and flusilazole were found
comparatively less effective against the leaf spot of turmeric.
Water spray alone showed maximum disease intensity
(25.39%). Almost similar trend was observed during the
second year (2009-10), Lowest leaf spot intensity (10.27%)
was recorded in carbendazim, which was found at par with
propiconazole (10.62%), carbendazim+mancozeb
(10.85%) and mancozeb (11.79%). The next best in order
of merit was hexaconazole (14.26%) followed by iprodine+
carbendazim (16.14%) and thiophanate methyl (18.72%).
Chlorothalonil and flusilazole were found comparatively less
effective against the leaf spot of turmeric. Pooled data of
both the years showed that all the fungicides were
significantly efficient against the Colletotrichum leaf spot
as compared to the control (Table 1). Among them,
carbendazim showed least per cent disease intensity
(9.57%), which was found at par with propiconazole (9.93%)
followed by carbendazim+mancozeb (10.15%) and
mancozeb (11.09%). The next best fungicide was
hexaconazole (13.57%) followed by iprodine+carbendazim
(15.44%). Chlorothalonil and flusilazole were found less
effective against leaf spot of turmeric. The protection due
to fungicide application was significant, although the
efficacy of different fungicides differed from each other.
Yield: The results of fresh rhizome yield during the season
2008-09 (Table 1) revealed that all the treatment resulted
in significantly higher yield as against control except,
thiophanate methyl and flusilazole. Among them,
significantly higher yield (35.20 t/ha) was recorded with
Figure 1. Disease scale (0-6) for turmeric leaf spot

3. 106 SK Chawda et al. Pestic Res J 24(1): 104-106 (2012)
propiconazole, which was found statistically at par with
carbendazim (34.20 t/ha) followed by mancozeb (33.61 t/
ha), carbendazim+mancozeb (30.18 t/ha) and
hexaconazole (30.01 t/ha). The rest of the treatments viz.,
thiophanate methyl (24.52 t/ha), iprodine+carbendazim
(26.34 t/ha), chlorothalonil (27.56 t/ha) and flusilazole (25.12
t/ha) proved inferior in yield performance. During the year
2009-10, highest fresh rhizome yield was recorded in the
blocks treated with carbendazim (37.55 t/ha), which was
found at par with propiconazole (37.42 t/ha) and
carbendazim+mancozeb (33.54 t/ha). The rest of the
treatments proved comparatively poor in yield. Pooled data
of both the years revealed significantly higher yield as
recorded in the blocks treated with propiconazole (36.31 t/
ha), which was found at par with carbendazim (35.82 t/ha),
mancozeb (34.41 t/ha) and carbendazim+ mancozeb (31.86
t/ha). Next best treatment was hexaconazole (28.46 t/ha),
iprodine+carbendazim (27.43 t/ha), chlorothalonil (27.04 t/
ha) and flusilazole (25.92 t/ha). Only water spray gave
lowest yield (20.74 t/ha).
These results confirm the findings of Thamburaj (1991)5
who recommended two sprays of carbendazim (0.1%) at
the initiation of disease and 15 d later for the control of
turmeric leaf spot (C. capsici). Dakshinamurthi et al. (1966)6
suggested four sprayings with captan (0.2%) or Dithane Z-
78 (0.2%) at monthly interval (September to December).
Table 1. Field evaluation of different fungicides for the management of Colletotrichum leaf spot (CLS) of turmeric
Sr. No. Fungicides Concentration Percent Leaf Spot Intensity Yield (t/ha)
2008-09 2009-10 Pooled 2008-09 2009-10 Pooled
1 Carbendazim 0.5 g/L 17.30*(8.88)** 18.62(10.27) 17.97(9.57) 34.10 37.55 35.82
2 Thiophanate Methyl 1 ml/L 24.59(17.33) 25.63(18.72) 25.11(18.02) 24.52 26.86 25.69
3 Mancozeb 2.5 g/L 18.75(10.40) 20.03(11.79) 19.40(11.09) 33.61 35.21 34.41
4 Propiconazole 1 ml/L 17.64(9.23) 18.93(10.62) 18.30(9.93) 35.20 37.42 36.31
5 Hexaconazole 1 ml/L 21.02(12.87) 22.19(14.26) 21.66(13.57) 30.01 26.91 28.46
6 Carbendazim 12% 2 g/L 17.90(9.46) 19.18(10.85) 18.55(10.15) 30.18 33.54 31.86
+Mancozeb 63%
7 Iprodine 25% 2g/L 22.40(14.75) 23.67(16.14) 23.08(15.44) 26.34 28.52 27.43
+Carbendazim 25%
8 Chlorothalonil 2.5 g/L 26.28(19.61) 27.22(21.00) 26.76(20.30) 27.56 26.52 27.04
9 Flusilazole 0.5 ml/L 26.16(19.55) 27.19(20.94) 26.68(20.25) 25.12 26.75 25.92
10 Control - 30.25(25.39) 31.16(26.78) 30.71(26.08) 20.72 20.76 20.74
(Water spray)
S.Em± - 01.16 01.05 01.03 01.84 25.46 16.72
CD at 5 % (p=0.05) - 03.71 03.37 03.29 05.47 75.66 49.70
*Figures outside parenthesis are arcsine (angular) transformed values
This adequately checked the leaf spot of turmeric caused
by C. capsici and also resulted in higher yield. Narasimhudu
and Balasubramanian (2002)7
reported Topsin M (0.1%)
as the most effective fungicide for the control of leaf spot of
turmeric (C. capsici) followed by Indofil M-45 and Bavistin.
They also found negative correlation between the
percentage of infection and yield.
REFERENCES
1. Patel RV, Joshi KR, Solanky KU and Sabalpara AN (2005)
Colletotrichum gloeosporioides: A new leaf spot pathogen of
turmeric in Gujarat. Indian Phytopath 58: 125.
2. Nair MC and Ramakrishnan K (1973) Effect of Colletotrichum
leaf spot disease of Curcuma longa L. on the yield and quality
of rhizomes. Curr Sci 42: 549–550.
3. Palarpawar MY and Ghurde VR (1989) Fungicidal control of
leaf spot of turmeric incited by Colletotrichum curcumae.
Indian Phytopath 42: 576-578.
4. Datar VV and Mayee CD (1981) Assessment of losses in
tomato yield due to early blight. Indian Phytopath 34: 191-
195.
5. Thamburaj S (1991) Research in spice crops at TNGDNAU.
Spice India 4: 17-18.
6. Dakshinamurthi V, Reddy GS, Rao DK and Rao PG (1966)
Fungicidal control of turmeric leaf spot caused by C. capsici.
Andhra Agric J 13: 69-72.
7. Narasimhudu Y and Balasubramanian KA (2002) Fungicidal
management of leaf spot of turmeric incited by Colletotrichum
capsici. Indian Phytopath 55: 527-528.
Manuscript No. PRJ/06/12-01
Received 01 June, 2012; Accepted 30 June, 2012