Journal of Pharmacognosy and Phytochemistry 2017; 6(5): 2317-2319 E-ISSN: 2278-4136 P-ISSN: 2349-8234 Status of tomato early blight in Shivamogga and JPP 2017; 6(5): 2317-2319 Received: 05-07-2017 Davanagere districts Accepted: 06-08-2017 SB Mahantesh SB Mahantesh, C Karegowda, H Narayanaswamy, TG Manu and ND Department of Plant Pathology, Punithkumar College of Agriculture, University of Agricultural and Horticultural Sciences, Abstract Shivamogga, Karnataka, India Early blight (Alternaria solani) of tomato is most destructive disease in tropical and subtropical countries. It is a potential disease of tomato that reduces its production globally both in conventional and C Karegowda tunnel cultivations. Tomato crop is vulnerable to infection by bacterial, viral, nematode and fungal Department of Plant Pathology, diseases. Among the fungal diseases, early blight of tomato caused by A. solani and causing loss from 50 College of Agriculture, to 86 per cent in fruit yield. The survey was conducted during Kharif 2015 in Shivamogga and University of Agricultural and Davanagere districts of Karnataka, revealed that range of per cent disease index from 22.35 to 47.25. The Horticultural Sciences, highest PDI of 47.25 was recorded in Nyamati village followed by Savalanga (46.20 PDI) and Shivamogga, Karnataka, India Malebennuru (45.25 PDI) villages of Davangere district respectively. In Shivamogga district maximum H Narayanaswamy PDI was recorded at Kommanal (42.50). The minimum Per cent disease index 22.35 and 39.75 was Department of Plant Pathology, recorded in Avarekoppa (Shivamogga) and Kenchikoppa (Davangere) respectively. College of Agriculture, University of Agricultural and Keywords: Survey, Early blight, A. solani and PDI Horticultural Sciences, Shivamogga, Karnataka, India Introduction Tomato (Lycopersicon esculentum Mill) is one of the most important vegetable crops and is TG Manu Department of Plant Pathology, known as protective food both because of its special nutritive value and wide spread College of Agriculture, production. It is the world's largest vegetable crop after potato and sweet potato. In India University of Agricultural and tomato is cultivated in an area of 767.30 ha with a production of 16385.00 MT and Horticultural Sciences, productivity of 21.35 MT ha-1. Karnataka is producing about 2034.37 ' 000 tonnes of tomato Shivamogga, Karnataka, India from an area of about 64.25 '000 ha with a productivity of 31.66 MT/ha, which is highest in ND Punithkumar the country (Anon., 2015). Tomato crop is vulnerable to infection by bacterial, viral, nematode Department of Plant Pathology, and fungal diseases. Among the fungal diseases, early blight of tomato caused by A. solani is College of Agriculture, the worst damaging one (Abada, et al., 2008) and cause reduction in quantity and quality of University of Agricultural and the tomato crop. The disease appears on leaves, stems, petiole, twig and fruits under Horticultural Sciences, favourable conditions resulting in defoliation, drying off of twigs and premature fruit drop and Shivamogga, Karnataka, India [7] thus, causing loss from 50 to 86 per cent in fruit yield (Mathur and Shekhawat, 1986) . Material Methods In recent year, the disease has assumed serious proportions in tomato growing areas. Therefore, an investigation was carried out on survey of severity and incidence of the disease in Shivamogga and Davanagere districts. An intensive rowing survey was conducted during Kharif 2015 in Shivamogga and Davanagere districts of Karnataka, to assess the incidence and severity of early blight disease on tomato. The disease severity was observed by using 0-5 scale (Mayee and Datar, 1986) [4] and described as below. Scale Description 0 No symptoms on the leaf 1 0-5 per cent leaf area infected and covered by spot, no spot-on petiole and branches 2 6-20 per cent leaf area infected and covered by spot, some spots on petiole 21-40 per cent leaf area infected and covered by spot, spots also seen on petiole, 3 branches Correspondence 41-70 per cent leaf area infected and covered by spot, spots also seen on petiole, C Karegowda 4 Department of Plant Pathology, braches, stem College of Agriculture, >71 per cent leaf area infected and covered by spot, spots also seen on petiole, 5 University of Agricultural and branch, stem, fruits Horticultural Sciences, Shivamogga, Karnataka, India ~ 2317 ~ Journal of Pharmacognosy and Phytochemistry Per cent disease index (PDI) was calculated by using PDI) villages of Davangere district respectively. In following formula proposed by Wheeler (1969) [9]. Shivamogga district maximum PDI was recorded at Kommanal (42.50) and in Davanagere district maximum PDI was recorded at Nyamati (47.25). The minimum Per cent disease index 22.35 and 39.75 was recorded in Avarekoppa (Shivamogga) and Kenchikoppa (Davangere) respectively. Among four taluks of Shivamogga district, Shivamogga taluk Table 1a: Per cent disease index of tomato early blight in Shivamogga and Davanagere districts. recorded highest Per cent disease index (37.26) followed by Bhadravati (31.08), Thirthahalli (25.75) and the minimum per Per cent disease District Taluk Villages cent index was recorded in Shikaripura taluk (23.92). Among index (PDI) three taluks of Davangere district, Honnali taluk recorded Kommanala 42.50 highest Per cent disease index (44.36) followed by Harihar Abbalagere 35.80 (43.71) and Davangere (43.35). Overall, maximum disease Bannikere 40.10 severity of 43.80 PDI was observed in Davangere followed by Chikkagonahalii 37.25 Shivamogga Honnavile 35.25 Shivamogga (29.50) district. Mallapura 34.50 The overall Per cent disease index during Kharif season 2015 Harnahalli 35.65 was recorded with a range from 22.35 to 47.25 per cent. The Siddlipura 37.35 highest Per cent disease index of 47.25 was recorded in Muduvaala 37.00 Nyamati village of Davangere district and minimum Per cent Mean 37.26 disease index was recorded in Avarekoppa village of Shivamogga Bhadravati 28.25 Shivamogga district. Machenahalli 29.75 The disease severity was observed more in Davanagere Bhadravati Kalahalli 32.15 district compared to Shivamogga district. This may be due to Hallikere 34.20 farmers normally do not practice effective fungicidal spray Mean 31.08 against Alternaria leaf blight. Also, the rainfall was Avarekoppa 22.35 continuous throughout the season that it did not allow for the Shikaripura Shiralakoppa 25.50 fungicidal spray at least to those farmers who normally Mean 23.92 practiced it. Konanduru 26.00 Thirthahalli With respect to individual talukas, Nymati village (47.25 %) Hedduru 25.50 of Honnali taluk recorded highest disease severity. This may Mean 25.75 be due to susceptibility of the cultivars and / or favourable District mean 29.50 Nyamati 47.25 environmental conditions like temperature and continuous Savalanga 46.20 rainfall experienced during the period under study. Another Palavanahalli 43.75 reason for the outbreak of high disease in Nymati village may Kenchikoppa 39.75 be continuous cropping of tomato in farmers field year after Honnali Kodikoppa 44.25 year without following crop rotation system. So that the Malligehalli 45.00 infected debris left in the field serves as major source of Mean 44.36 infection, thus causing epidemic throughout the season. Davanagere Kunduru 43.25 From the survey it was revealed that the severity of this Basavanapatna 44.35 disease varied from locality to locality depending on the type Harihar Kumarapatna 42.00 of tomato variety cultivated. The severity of disease was also Malebennuru 45.25 dependent on inoculum load, agro-climatological situations Mean 43.71 prevailing in different localities. Cheluru 44.20 Davanagere The results obtained in the present study could be compared Hunasekatte 42.50 with the work of Prasad and Naik (2002) who recorded the Mean 43.35 per cent incidence of 28.60 to 65.36 recorded in northern District mean 43.80 districts of Karnataka. The results are also in conformity with the observation of Abhinandan et al. (2004) [2]; Kamble et al., Table 1b: Taluk wise Per cent disease index of tomato early blight [5] [6] 2007 ; Kumar and Srivatsava, 2013 . Mean Per cent S. No District Taluk disease incidence References Taluk District 1. Abada KA, Mostafa SH, Hillal Mervat R. Effect of some Shivamogga 37.26 chemical salts on suppressing the infection by early blight Bhadravati 31.08 1 Shivamogga 29.50 disease of tomato. Egypt J. Appl. Sci. 2008; 23:47-58. Shikaripura 23.92 2. Abhinandan D, Randhawa HS, Sharma RC. Incidence of Thirthahalli 25.75 Alternaria leaf blight in tomato and efficacy of Honnali 44.36 Harihara 43.71 commercial fungicides for its control. Ann. Biol. 2004; 2 Davangere 43.80 20:211-218. 43.35 Davangere 3. Anonymous, 2015, www.indiastat.com 4. Datar VV, Mayee CD. Phytopathometry Technical Results and Discussion Bulletin-1. Marathwad Agricultural University, The overall Per cent Disease Index of early blight during Parabhani, 1986, 25. Kharif 2015 was recorded with a range of 22.35 to 47.25. The 5. Kamble SB, Pawar DR, Sankeshwari SB, Parab MM, highest PDI of 47.25 was recorded in Nyamati village Arekar JS. Field screening of different tomato varieties followed by Savalanga (46.20 PDI) and Malebennuru (45.25 and advanced lines against early blight of tomato. Agril. ~ 2318 ~ Journal of Pharmacognosy and Phytochemistry Sci. Digest. 2007; 27(4):267-269. 6. Kumar S, Srivastava K. Screening of tomato genotypes against early blight (Altrenaria solani) under field conditons. The bioscan. 2013; 8(1):189-193. 7. Mathur K, Shekhawat KS. Chemical control of early blight in Kharif sown tomato Indian J Mycol. Pl. Pathol. 1986; 16:235-238. 8. Prasad Y, Naik MK. Status of Alternaria blight of tomato in North Eastern Karnataka. Karnataka J Agri. Sci. 2002; 17(3):607-608. 9. Wheeler BEJ. An Introduction to Plant Diseases. John Wiley and Sons Limited, London, 1969, 301.