J.Mycopathol.Res. 62(2) : 443-446, 2024, ISSN : 0971-3719 (Print), 2583-6315 (Online)© Indian Mycological Society, Department of Botany,
University of Calcutta, Kolkata 700 019, India

10.57023/JMycR.62.2.2024.443

Management of walnut anthracnose in a sustainable production systemusing inputs acceptable in organic agriculture
SHAHID MUSHTAQ1, FAROOQ AHMAD BHAT1, IMTIYAZ AHMAD LONE2, ALI ANWAR1, NAZIR AHMADGANAI2, MUDASIR GANI BHAT3, SUBAYA MANZOOR1, ZAKIR AMIN11
Division of Plant Pathology, 2Division of Horticulture, 3Division of Entomology, Faculty of Agriculture,
Sher-e-Kashmir University of Agri. Sc. & Tech. of Kashmir (J&K)-193 201
Received : 05.03.2024

Accepted : 15.05.2024

Published : 24.06.2024

Anthracnose is an important fungal foliar disease of walnut worldwide and in Kashmir it is the only threat ofthis nature to this crop so far. This study was carried out to devise a fungicidal spray module for managementof walnut anthracnose such that the organic status of walnut crop is maintained. In this regard some sulphurbased fungicides, copper-based fungicides, horticultural mineral oil (HMO) and some of their suitablecombinations were evaluated. In preliminary studies, sulphur 80 WP (0.3%), lime sulphur (0.3%) and copper
oxychloride 50 WP (0.20%) + HMO (0.75%) supported >50 % disease inhibition up to 12th day as compared
to copper oxychloride (0.20% and 0.25%), Bordeaux mixture (0.75% and 1.0%) and HMO (0.75%) wherein
50 % disease inhibition lasted for 6-9 days only. In subsequent studies on spray modules against thisdisease, alternate sprays of copper oxychloride 50 WP (0.20%) + HMO (0.75%) and Sulphur 80 W P (0.3%)
post-rains was found to be the best suitable strategy for giving 65.65-67.57 % disease inhibition and theresults were at par with those observed in another module wherein same chemicals were sprayed at fixedinterval of 12 days. As such, Post-rains spray module is applicable when rain events are scanty while as thelater one should be followed when rainy events will be relatively more frequent.
Keywords: Anthracnose, fungicides,organic agriculture, sulphur, sustainable, walnut

INTRODUCTION
Walnut (Juglans regia L.), a major dry fruit cropin the valley of Kashmir where it is affected byanthracnose [Marssonina juglandis (Lib.)
Magnus] (Hassan et al. 2017; Shahid et al. 2024).
From Kashmir, Shahid et al. (2024) recently
reported its teleomorph as Gnomonia leptostyla(Fr.) and de Not. and cited anthracnose as awidely spread fungal disease that poses a
significant threat to walnut crop in the valley. It isalso known as black spot/blotch and affects blackwalnut (Juglans nigra L.) and other Juglans spp.
besides J. regia throughout the world ( Belisario,2002; Belisario et al.2008).
Symptoms of walnut anthracnose are mostcommonly observed on leaves, twigs and also
on fruits. Brown to black, roughly circular tocircular spots appear on the leaves and in severe* Correspondence: farooqbhat@skuastkashmir.ac.incases these infected leaves turn yellowish anddrop off prematurely. Although this disease canbe managed by use of any of the chemical
fungicides, the health hazards due to chemical
inputs in agriculture are reportedly alarming andneed to be overcome or minimized at least whiledevising disease management strategies. Ascopper, sulphur and horticulture grade mineral oils
are being allowed in organic agriculture(Anonymous, 2008; Beckerman, 2008),
management of walnut anthracnose in a similarmanner is also possible. Therefore, some copperand sulphur based fungicides were evaluated fortheir bio-efficacy against this disease so that an
eco-friendly strategy is worked out for the farming
community.
MATERIAL AND METHODSThe experiments on efficacy of some selectedfungitoxicants against M.juglandis vis-à-viseffective persistence and bio-efficacy wereconducted in FoA SKUAST-Kashmir at Wadura

444Management of walnut anthracnose

Sopore. For effective persistence, treatments viz.
copper oxychloride 50 WP (CoC) @ 0.25 and0.20 %, Bordeaux mixture (BM) @ 0.75 and 1.00%, HMO @ 0.75 %, CoC + HMO @ 0.20% and0.75%, lime sulphur @ 0.30 %, sulphur 80 WP@ 0.30 % were evaluated under polyhouseconditions (Temp. 27±20 C and RH >90%) in CRD
with three replications.The qualifying effective
persistence of a chemical would mean aminimum of 50 % disease inhibition for aminimum period of 7 days. Test concentrationsof different chemicals were prepared on
formulation basis and then sprayed with a babysprayer. After applying treatments, the pathogen
was inoculated on 0, 3rd, 6th, 9th, 12th and 15th day
post-treatment and persistence of a fungitoxicant
was tested by recording leaf spot incidence on
14 th day post-inoculation. Disease inhibition%was worked out on the primary data of spotting
incidence by formula [(C-T)/C]×100, where C =No. of leaf spots in check and T = No. of leaf spots
in treatment.In subsequent studies, two mosteffective treatments as obtained in previous
experiment were evaluated in five different
modules based on varying gaps between twosprays. The experiment was conducted on twothree year old grafted walnut plants under field
conditions during 2021 and 2022. As such there
were five modules which were evaluated in RBD
with four replications and in each module, there
were alternate sprays of most ef fectivetreatments for a period of two months. In present
case, most effective treatments adjudged for thestudy were CoC (0.20%) + HMO (0.75%) andsulphur 80 W P (0.30 %). Their eff ective
persistence period was 12 days and the detailsof different spray modules is given in Table1.
Disease intensity on leaves were recorded while
using 0-7disease scoring scale where 0 = nodisease, 1 d” 20, 3 = 21-40, 5 = 41-60 and 7 >60% diseased leaf area on the basis of visualobservations. Disease intensity was calculated
by using formula [“(n×v)/N×G]×100, where n =number of diseased leaves in each category, v =numerical value of the category N = total numberof leaves examined, and G = highest grade valuei.e., 7 in this case. Based on this data the diseaseinhibition over untreated check was also
calculated by using formula (C-T)/C as given
above.

[J.Mycopathol.Res :RESULTS AND DISCUSSION
The data on efficacy of fungitoxicants against
M.juglandis vis-à-vis effective persistence (Table2) reveals that all the treatments were foundeffective initially. However, three treatments viz.,sulphur 80 WP (0.3%), lime sulphur (0.3%), andmixture of CoC (0.20%) and HMO (0.75%)
showed effective persistence period of 12 days
for giving 50 % disease inhibition up to 12th day
as compared to copper oxychloride, BM and sole
HMO which showed effective persistence of 6-9
days only. Previous reports mentioning
effectiveness of CoC and BM against walnut
anthracnose also support the present
observations ( Zamani et al. 2011). Additionally,present research showed that the effective
persistence of sulphur compounds is greater thanthat of copper compounds. Moreover, combined
application of CoC and HMO produced acomplimentary effect. This complimentary effectmay be the inherent tenacity and sticky nature of
HMO which consequently retained CoC on leaf
surface for relatively longer time. Similar results

Fig.1 : Fungic ide spray modules and inhibition of walnut
anthracnose

were found by Rae et al. (2002). However, they
have not mentioned any reasons for the enhanced
persistence.
Five spray modules evaluated against walnut
anthracnose under open field conditions exhibited
varied results which were also comparable
across two seasons (Table 3 and Fig. 1). Perusalof data reveals that Module-IV significantlyreduced the disease intensity to 12.68 % andinhibited the disease by 70.21 % during 2021.
Module-III which inhibited disease by 65.65 % was
2nd best closely following Module-IV. Module-I
which reduced the disease intensity to 16.51 %was statistically at par with Module-III. However,Shahid Mushtaq and others

62(2) June, 2024]

445

Table 1. Different spray modules evaluated against walnut anthracnose

Table 2: Efficacy of fungitoxicants against walnut anthracnosevis-à-vis effective persistence

Leaf spot incidence for different post treatment inoculationintervals (No./leaf)
Fungitoxicants

91215

36

91215

1.26 2.53

3.80

4.45

5.36

84.08

68.16

52.26

44.00

32.66

1.46 2.73

3.86

4.72

5.57

81.57

65.65

49.74

40.65

30.02

1.23 2.36

3.53

4.16

5.22

84.54

70.34

55.60

45.55

34.33

BM (1%)

1.10 2.20

3.40

4.29

5.16

86.13

72.27

57.28

47.73

36.00

HMO (0.75%)

1.80 3.20

4.50

5.50

6.30

77.02

59.79

43.46

30.90

19.59

CoC (0.20%) + HMO(0.75%)

1.04 1.93

3.06

3.93

5.04

86.84

75.35

61.47

50.58

36.59

Lime sulphur (0.3%)

0.99 1.86

2.86

3.86

4.93

87.55

75.83

63.98

51.42

38.01

0.88 1.73

2.59

3.66

4.86

88.85

77.49

67.45

53.93

38.85

7.96

--

0.915

0.734

0.630

0.998

0.888

2.276

2.219

1.930

3.019

2.684

CoC (0.25%)
CoC (0.20%)
BM (0.75%)

Sulphur 80 WP(0.3%)
Check (only water)

36

Disease inhibition for different post treatment
inoculation intervals (%)-SE (m)CD (P ≤ 0.05)

Module-V which reduced the disease intensity tomere 24.71 % and exhibited disease inhibition of
43.66 % was found least effective. During year
2022, it was again Module-IV that produced best
effect with lowest disease intensity (10.97 %) andhighest disease inhibition (71.82 %). Module-III thatexhibited the respective figures as 12.88 % and67.57 % was found 2nd best. Similar effect wasalso exhibited by Module-I. While as minimal
effect was shown by M-II with a disease inhibitionof 57.25 % and least effect was shown by ModuleV with a disease intensity of as much as 20.78%
as compared to check where disease intensityof 38.95% was recorded. Spraying at maximumeffective interval i.e., 12 days in present caseoffered results similar to those of post-rain

application. Although 7 day’s application interval
produced best results, it involves high input costs
and may add more fungicide residues toenvironment. Therefore, Module-I and Module-III
are considered more suitable for managementof walnut anthracnose. Spray modules have notbeen evaluated earlier but the efficacy of somechemicals against this disease has been reported(Hassan et al. 2017; Zamani et al. 2011). Effective
results obtained with Module-I and the results ofprevious study on effective persistence period ofthese test formulations also draw support fromeach other. The better results obtained with postrains application as compared to those of prerain application in the present investigation waspossible as the rainy spells were of short duration.

446Management of walnut anthracnose[J.Mycopathol.Res :Table 3. Evaluation of Copper and Sulphur based spray modules for management of walnut anthracnose.

Disease intensity (%)

Disease inhibition over control (%)

Year 2021

Year 2022*

Year 2021

Year 2022

Spray Module

InitialFinal

Incremental

Incremental

M-I4.22

20.73

16.51

13.26

61.85

65.87

M-II

2.07

21.90

19.83

16.29

54.43

57.25

M-III

3.12

17.99

14.87

12.88

65.65

67.57

M-IV

3.20

15.88

12.68

10.97

70.21

71.82

M-V

2.00

26.71

24.71

20.78

43.66

46.65

Check

3.57

46.93

43.36

38.95

--0.661
2.011

0.567
1.725

SE, CD (P ≤ 0.05)

SE ( m) will be under check ( 1st column)- and will be in same row as
0.661 . there will be no values in 2nd and 3rd columns
CD ( P d” 0.05). will be below SE (m) and will be in same row as 2.011.
There will be no values in the row in columns 2 and 3*Initial disease score was Zero in all treatments

Long rainy spells would have facilitated spore
germination and subsequent infection, and thus
the results of these contact fungicides with postrain application would have been poor. Moreover,
it is presumed that the post-rain application ofthese contact fungicides effectively protected theinfection court by neutralizing the germinatingconidia without getting washed away as was thefate of pre-rain application.
Alternate sprays of CoC (0.20 %) + HMO (0.75%) and Sulphur 80 WP (0.3 %) at fixed interval of
12 days will effectively inhibit walnut anthracnose
in case there are frequent rains in a growing
season and post-rains spraying of thesechemicals is recommended for management of
this diseases in case the rainy events are scanty/
widely distributed.
ACKNOWLEDGEMENT
This research was conducted with all the supportof SKUAST-K.
DECLARATIONSConflict of Interest. Authors declare no conflict ofinterest.

REFERENCES
Anonymous, 2008. List of active substances approved for use
in EU organic agriculture under EU Regulation (EC) No889/2008. Pes ticide Ac tion Network UK. https ://www.p an - uk .org /s i te/wp- c on tent / up load s / L is t- of ac t ive- s u bs t an c es - ap p r oved - f or - u s e- in - or g an i c agriculture.pdf.
Beckerman, J. 2008. Using organic fungicides. In: Disease
Management Strategies for Horticultural Crops. Purdue
Extension BP-69-W, Purdue University. Indiana US. https://www.extension.purdue.edu/extmedia/bp/bp-69-w.pdf
Belisario, A., Scotton, M., Santori,A., Onori,S. 2008. Variability inthe Italian population of Gnomonia leptosty la,homothallism and res istance of Juglans species toanthracnose. Forest Path. 38:129-145.
Belisario, B. 2002. Anthracnose. In: Compendium of Nut Crop
Dis eases in Temperate Zones (eds. Teviotdale,B.L.,Michailides,T.J. and Pscheidt,J.W.) APS Press,USA.pp. 77-78.
Hassan, M., Ahmad, K., Khan,N.A. 2017. Disease prevalenceand evaluation of fungitoxicants against Marsonina
juglandis causing anthracnose of walnut. Res. J. ofAgri. Sc.8:917-922.
Rae, D.J.,Beattie, G.A.C.,Watson,D.M.,Stevens,M.L. and SpoonerHart,R.N. 2002. Us e of spray oils with s ynthetic
insecticides, acaricides and fungicides. In:Spray Oils
Bey ond 2000: Sustainable Pest and Diseas eManagement(Eds. A. Beattie, D.Watson, M. Stevens, D.D.
Rae, R. Spooner-Hart).University of W estern Sydney,
Australia. pp. 248-288.
Shahid, M., Bhat, F. A., Rather, T. R., Dar, K. R., Avinash, P.,
Gulzar, H., and Shabir, Z. 2024. First report of theteleomorphofM ars sonina
juglandis(Gnomonialeptostyla) in Kashmir. J. Mycopathol. Res.
62: 207-209.
Zamani, A.R.,Imami, A.,Mirza,M.A., Mohammadi,R. 2011. A study
and c omparison of control methods of anthracnose
disease in walnut trees of Roodbar region. Int. J.of Nuts
and Related Sc.2:75-81