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Management of black scurf of potato caused by Rhizoctonia solani with organic amendments and their effect on different parameter of potato crop.

The mechanisms involved in disease suppression are varied and complex and may differ depending upon the pathogen involved but there is evidence that organic amendments added to the soil can induce disease suppression by stimulating antagonist microorganisms (Cook, 1990). The addition of readily available carbon source to the soil, such as a green manure, compost and any organic amendments like plant extracts stimulates microbial activity and could cause intense competition for resources and produce fungistasis. Conversely, when C is added above the needs of the saprotrophic competitors, the germination of pathogens may be stimulated and fungistasis broken (Campbell, 1989). Kundu and Nandi (1985) reported that when the C: N ratio of soil increased, fungal populations decreased, but populations of bacteria increased. This is related closely to the level of organic matter decomposition. Another suppression mechanism could be pathogen propagule destruction. This can occur due to predation and/or parasitism by a biological control agent that feeds directly on or the pathogen resulting in a destruction of pathogen propagules or structures (Chernin and Chet 2002).

Black scurf is one of the most wide spread disease and found in all potato growing areas of the world. The typical symptoms are characterized by appearance of black coloured sclerotia on the tuber surface and brownish necrotic lesions on stem and stolon which can kill the eyes, delay in emergence, increases tuber defects (cracks, misshapen, netted skin with reduced quality and market value (Fig. no. 7. B). The Black scurf and stem canker (Fig. no. 7. D) or stolon canker of potato caused by Rhizoctonia solani Kuhn [also known by the name of its sexual stage Thanetophorus cucumeris (Frank) Donk] is a serious disease of potato worldwide and distributed in India in different regions in low to severe form. Biocontrol agents like Trichoderma and Pseudomonas are antagonistic to the Rhizoctonia solani and have been widely used to manage the disease (Elad, Y. et. al., 1983). The organic amendments such as Vermicompost, Neem cake, FYM and many more organic agricultural byproducts have been used to manage the diseases in plants. In hills as well as in plains major damage to yield is by stem canker. In recent year the fungus causes significant yield reduction. It can cause a significant change in size distribution of tubers (too small or too large). As a result, farmers have to bear 5-7% economic loss (Shekhawat, et. al., 1993, Singh and Shekhawat, 1994a).


The present investigation on "Role of Organic amendments for the management of Black Scurf of Potato caused By Rhizoctonia solani (Kuhn)" was carried out Crop Research Center, Sardar Vallabhbhai Patel University of Agriculture & Technology, Modipuram, Meerut, Uttar Pradesh. The black scurf susceptible variety Kufri Bahar was selected for the study of black scurf disease. The seed tubers were already infected with sclerotia of R. solani and germinated. The plot size was 5x4 m. with nine rows. The row to row space was maintained at 60 cm and plant to plant space was maintained at 20 cm. Central seven rows were used to record the observations. The organic amendments (Vermicompost, Farm Yard Manure and Neem cake) were applied as soil treatment and the chemicals (Bavistin and Boric acid) and biocontrol agent (Trichoderma harzianum and Pseudomonas fluorescence) were used as tuber treatment. The Trichoderma harzianum was also used in combination with each of organic amendment and with the Bavistin too, a treatment of Trichoderma harzianum and Pseudomonas fluorescence were also used as combination of both. The observation of Black Scurf disease Index (BSDI) were calculated on the basis of rating system as given below:

Black scurf disease index

Five plants were selected randomly in each plot before cutting of stem of plant in field. The tubers were collected in polyethylene begs. Then the visual observation was taken to observe the black scurf incidence and severity.

Black scurf disease severity and incidence was expressed as Black Scurf Disease Index (BSDI) and was calculated with following formula;

BSDI = 0(n1)+1(n2)+2(n3) + 3(n4) + 4(n5) + 5(n6) x100 N (Total number of tubers) 5


n1= Numbers of tuber in 0 rating

n2= Numbers of tuber in 1 rating

n3= Numbers of tuber in 2 rating

n4= Numbers of tuber in 3 rating

n5= Numbers of tuber in 4 rating

n6= Numbers of tuber in 5 rating

Disease severity was assessed on a visual disease rating scale 0-5 based on per cent tuber surface showing disease showing disease symptom as described by Ahmad et. al., (1995). Where:

0= no symptoms on tuber present

1= less than 1% tuber area affected

2= 1-10% tuber are affected

3= 11 -20% tuber are affected

4= 21-50% tuber are affected

5= 51% or more tuber area affected


Results indicate that there was no significance effect of different treatments on the plant emergence. While in the case of tillers per mother tuber per plot there was significant effect of different treatments over check. Maximum number of tillers per mother tuber per plot was observed when the Vermicompost was applied as soil application followed by the neem cake. It was found that plant obtained maximum shoot length (23.05 cm) when vermicompost was applied in soil with combination of Trichoderma harzianum while in case of vermicompost alone it was 20.18 cm. in case of neem cake alone it was 19.72 cm and in case of neem cake with combination of Trichoderma harzianum it was 19.80 cm as shown in figure six.

As compared to all treatments plant obtained better shoot length in case of vermicompost and neem cake when applied alone or combination with Trichoderma harzianum. The observation on tuber per plant indicates that vermicompost and neem cake also gave better performance in formation of tubers per plant when applied alone and combination with Trichoderma harzianum. In the case of seed size there was no significance difference among the treatments as well as over control maximum tuber size of progeny 4.53 (in inches) was observed when vermicompost was applied alone as soil application (figure. 2).

The stolon canker incidence was also minimum (22.54 and 18.77%) as in Fig. no.7 (C). when vermicompost was applied as alone and in combination with Trichoderma harzianum respectively. Maximum stolon canker (42.07%) was observed in the case of T. harzianum + P. flourescens and minimum was when Bavistin was applied with combination of Trichoderma harzianum as seed treatment. The sclerotia formation (Black Scurf) on tuber were higher (1.82 and 1.15 BSDI) when FYM was applied alone and in combination with Trichoderma harzianum. The table indicates that Neem cake has synergistic effect in reducing the sclerotia formation (0.27 BSDI) when applied in combination with soil environment i.e. Physical, chemical and biological changes. These changes influence many plant diseases due to decomposition of organic matter present in amendments. Organic amendments may influence the soil and the incidence of the soil borne diseases in one or more way like alternation of soil structure, biotic environment and biochemical effect on the plant

Trichoderma harzianum as compared to applied alone (0.53 BSDI).


Application of organic amendments is old practices for the management of plant diseases. The use of organic amendments allows changes in pathogens as Scholte et al., (1998) Used the Farm Yard Manure (FYM) alone and with a combination of white mustard as a soil amendment in already infested soil and found that organic amendment reduced the disease severity and increased the population of mycophagous soil organisms. Effect of different treatments on different growth parameter of potato crop in field condition. Results indicates that the application of biological agents, chemicals and organic amendments alone or in combination with Trichoderma harzianum and Pseudomonas fluorescens have no effect on sprouting of tubers and while the vermicompost alone and in combination with T. harzianum has batter in improving tuber formation, increasing the size of the tubers as well as reducing the incidence of stolon canker as well as sclerotia formation on tuber. Neem cake obtained second position in improving the growth parameter as well as crop health in field trial over other treatment. Several study of researcher were found to similar as described by Singh et al., (1972) Used various oil cakes with the combination of fertilizers and reported that all the treatments which used as the organic amendments caused significance reducing in black scurf of potato caused by Rhizoctonia solani. Hazarika et al., (2000), Rauf et al., (2003), Dey et al., (2004), Mamta et al., (2005), AlMughrabi (2006), Larkin et al., (2008).


(1.) Graves, L.G. & Taber, C.W., A dictionary of food and nutrition. F.A. Davis, Philadelphia. Also available on home.asp? pid=14 30; 1942.

(2.) Shekhawat, G. S., B. P. Singh and M. D. Jeswani. Soil and tuber borne diseases. Tech. Bull No. 41, Central Potato Research Institute, Shimla, H.P India. 1993; 47.

(3.) Singh, Rajpal and G. S. Shekhawat., Status of soil and tuber borne diseases of potato in U.P In: Potato, present and future (G. S. Shekhawatet al., Eds.), pp. 211-15. Indian Potato Association, Shimla, India, 1994a.

(4.) Ahmad, I., S. Iftikhar, M.H. Soomro, S. Khalid and A. Munir. Diseases of potato in Northern areas during 1992. CDRI-PSPDP, PARC, Islamabad, Pakistan, 1995; 38.

(5.) Singh, R.S., Chaube, H.S. and Singh N., Studies on the control of black scurf of potato. Indian Phytopath. 1972; 25: 343.

(6.) Scholte, K, Lootsma, M., Effect of farmyard manure and green manure crops on populations of mycophagous soil fauna and Rhizoctonia stem canker of potato. Pedobiologia; 1998; 42(3): 223-231.

(7.) Hazarika, D.K., Phookan, A.K., Das, K.K., Dubey, L.N., Das, B.C., Biological management of black scurf of potato. Potato global research and development Proceedings of the Global Conference on Potato, New Delhi, India, 2000; 1: 401-404.

(8.) Rauf, C.A., Rahman, F., Effect of bio-pesticides on mycelial growth of Rhizoctonia solani and management of black scurf of potato. Mycopath (Pakistan). 2003; 1(2): 131-135.

(9.) Dey, T.K., Bari, M.A., Saha, A.K., Rahman, M., Ayub, A., Effectiveness of organic amendments and chemicals in controlling black scurf disease of potato Bangladesh-Journal-ofPlant-Pathology. 2004; 20(1/2): 17-20.

(10.) Mamta, Jha, M.M., Sanjeev Kumar., Influence of organic manure, irrigation interval and cropping sequence on the yield and black scurf disease of potato. Annals of Agri. Bio. Research; 2005; 10(1): 61-64.

(11.) Al Mughrabi, K. I., Antibiosis ability of aerobic compost tea against foliar and tuber potato diseases Biotechnology. 2006; 5(1): 69-74.

(12.) Larkin, R.P., Relative effects of biological amendments and crop rotations on soil microbial communities and soil borne diseases of potato. Soil-Biology-and-Biochemistry.; 2008; 40(6): 1341-1351.

(13.) Elad, Y., I. Chet, P Boyle and Y. Henis., Parasitism of Trichoderma spp. on Rhizoctonia solani and Sclerotium rolfsii -Scanning electron microscopy and fluorescence microscopy. Phytopathology 1983; 73: 85-88.

(14.) Cook, R.J., Twenty-five years of progress towards biological control. In: Hornby (Eds.), Biological Control of Soil-Borne Pathogens. C.A.B. International, Wallingford, UK, 1990.

(15.) Campbell, R., Biological Control of Microbial Plant Pathogens. Cambridge University Press, Cambridge, Great Britain, 1989.

(16.) Kundu, P.K., Nandi, B., Control of Rhizoctonia disease of cauliflower by competitive inhibition of the pathogen using organic amendments in soil. Plant Soil 1985; 83: 357-362.

(17.) Chernin, L., Chet, L., In: Burns, R.G., Dick, R.P. (Eds.), Enzymes in the Environment. Activity, Ecology and Applications. Marcel Dekker Inc., New York, Basel, 2002.

Siddarth N. Rahul, Kamal Khilari, Sachin K. Jain, R. K. Dohrey [2] and Ashish Dwivedi [1]

Department of Plant Pathology, [1] Department of Agronomy Sardar; Vallabhbhai Patel Uni. of Ag. & tech. Meerut--250110, India.

[2] Department of Extension Education, N.D.U.A. &T., Narendra Nagar (Kumarganj), Faizabad (U.P.)--224 229, India.

(Received: 10 March 2016; accepted: 02 May 2016)

* To whom all correspondence should be addressed.


Caption: Fig. 7. Different plant parts of potato crop form the infected field; (A) Infected and healthy plant with the stem canker, (B) Tuber showing the typical symptoms of Black Scurf with the whitish growth of fungus, (C) Stolon canker and (D) Canker on stem
Fig. 1. Effect of different treatment on formation of tubers per plant

Neem cake                       16.46
Vermicompost                    18.26
FYM                             15.93
Boric acid                      13.86
Bavistin                        14.93
Trichoderma harzianum           12.93
Pseudomans fluorescents         15.8
FYM + T. harzanium              14.2
Neem cake + T. harzanium        17.46
Vermicompost + T. harzianum     18.13
T. harzianum + P. flourescens   15.2
Bavistin + T. harzianum         14.53
Control                         12.46

Note: Table made from bar graph.

Fig. 2. Effect of different treatments on seed size of progeny tubers

Neem cake                       3.9
Vermicompost                    4.53
FYM                             3.8
Boric acid                      3.55
Bavistin                        3.56
Trichoderma harzianum           3.73
Pseudomans fluorescents         3.8
FYM + T. harzanium              3.65
Neem cake + T. harzanium        4.25
Vermicompost + T. harzianum     4.26
T. harzianum + P. flourescens   3.7
Bavistin + T. harzianum         3.63
Control                         3.11

Note: Table made from bar graph.

Fig. 3. Effect of different treatments on stolon canker incidence

Neem cake                       31.97
Vermicompost                    22.54
FYM                             41.76
Boric acid                      26.45
Bavistin                        20.76
Trichoderma harzianum           29.76
Pseudomans fluorescents         37.16
FYM + T. harzanium              42.66
Neem cake + T. harzanium        28.79
Vermicompost + T. harzianum     18.77
T. harzianum + P. flourescens   42.07
Bavistin + T. harzianum         17.97
Control                         56.37

Note: Table made from bar graph.

Fig. 4. Effect of different treatments on black scurf in field

Neem cake                       0.53
Vermicompost                    0.47
FYM                             1.82
Boric acid                      0.43
Bavistin                        0.31
Trichoderma harzianum           0.6
Pseudomans fluorescents         0.9
FYM + T. harzanium              1.15
Neem cake + T. harzanium        0.27
Vermicompost + T. harzianum     0.49
T. harzianum + P. flourescens   0.3
Bavistin + T. harzianum         0.29
Control                         2.22

Note: Table made from bar graph.

Fig. 5. Effect of different treatments on yield

Neem cake                       176.66
Vermicompost                    188.33
FYM                             171.66
Boric acid                      146.66
Bavistin                        153.33
Trichoderma harzianum           156.66
Pseudomans fluorescents         131.6
FYM + T. harzanium              165
Neem cake + T. harzanium        175
Vermicompost + T. harzianum     178.33
T. harzianum + P. flourescens   118.33
Bavistin + T. harzianum         128.33
Control                         126.54

Note: Table made from bar graph.

Fig. 6. Effect of different treatments shoot length

Neem cake                       19.72
Vermicompost                    20.18
FYM                             19.85
Boric acid                      15.36
Bavistin                        15.15
Trichoderma harzianum           17.13
Pseudomans fluorescents         15.91
FYM + T. harzanium              18.46
Neem cake + T. harzanium        19.2
Vermicompost + T. harzianum     23.05
T. harzianum + P. flourescens   16.21
Bavistin + T. harzianum         16.85
Control                         14.11

Note: Table made from bar graph.
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Author:Rahul, Siddarth N.; Khilari, Kamal; Jain, Sachin K.; Dohrey, R.K.; Dwivedi, Ashish
Publication:Journal of Pure and Applied Microbiology
Article Type:Report
Date:Sep 1, 2016
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