Diagnosis And In Vitro Control Of Tomato Leaf Spot Caused By Alternaria alternata In Sulaimani Governorate

Jalal Hama salih Ismael 1 & Shallaw Adulrahman Omer2

1 College of Agricultural science- University of Sulaimani

2Technical Agricultural Institute, Bakrajo, University of Sulaimani Polytechnic 


Tomato leaf spot and stem canker is a serious disease in Sulaimani Governorate, and causes significant losses in tomato plant, this study carried out at two different locations well-known for tomato production belong to Sulaimani governorate namely; Bainjan located at Bazian district and Kanimanga at Penjween district for this purpose 3 fields at each location randomly taken to study the incidence, severity of the disease, identification the isolates and using 4 different plant extracts namely,  (Hypericum triquetrifolium L,  Punica granatum L, Allium sativum L and Thymus vulgaris L) for their antifungal activities against A. alternate. The results detected that the highest value of the disease incidences of Alternaria leaf spot of tomato in the two locations were 74.65, 73.19% in Bainjan and Kanimanga respectively, and the maximum disease severities were recorded 78.06 and 67.70% in Kanimanga and Bainjan fields respectively. The data from this fungus, and its isolates indicated that there were two different isolates, each isolate has specific morphological characteristics in their mycelial growth and also different in conidia measurement and their beaks and the number of cells in each conidium. The mean length and width of the Ka isolate conidia were 31.93, 12.36 μm and the mean of beak was 6.52, 4.15 μm for length and width respectively while the mean of Ba isolates was reached 27.68, 9.84 μm for length and width respectively, the mean of conidia beaks was 4.04, 9.84 μm for width and length respectively. Regards to the number of cell, transverse and longitudinal septa Ka for another time recorded superior against Ba isolate. P. granatum extract was revealed the highest mycelial growth inhibition (MGI 100%) for both isolates when used at 80000 µg ml-1, and the next was H. triquetrifolium also recorded maximum (MGI 100%) for Ba isolate and (93.08%) for Ka isolate, when used at 8%. Aquatic extracts of A. sativum significantly inhibited the fungus growth (89.44%), (83.02%) for Ka and Ba isolates respectively at 30%. T. vulgaris comes next in fungus inhibition efficacy beyond A. sativum and recorded (80.58, 78.11%) for Ka and Ba isolates respectively at 30%, 50 ppm of Salicylic acid and Tabsin-Top70 proved minimum mycelial inhibition rate and recorded (23.02 and 45.11%) for Ba, and (41.14 and 22.38%) for Ka isolate at the same concentration. Meanwhile, the MGI reached to 100%when salicylic acid used at 400ppm for both isolates. The MGI were 84.64 and 89.11% when used Tabsin-Top70 at 600ppm for Ka and Ba isolates respectively. 

Key Words: Tomato leaf spot, Alternaria alternata, Plant extracts, Salicylic acid,Tabsin-Top70


[1] Agrios, G. N. “Plant pathology”: 5th ed. New York, Elsevier Academic Press pp. 948. (2005).

[2] Cerkauskas, R. “Early blight”: Shanhua. Taiwan. AVRDC, The World Vegetable Center. (2005).

[3] Momel, T., and Pemezny, K. “Florida plant disease management guide: tomato”: Florida. (2006)

[4] Mathur, K., and Shekhawat, K. S. “Chemical control of early blight in kharif sown tomato”: Indian Journal of Mycology and Plant Pathology, Vol. (16), No. 2, pp. 235-236. (1986).

[5] Shalini V, and Dohroo, N. P. “Novel approach for screening different antagonists against Fursrium oxysporum f.sp. pisi causing Furarium wilt of autumn pea”: Plant Disease Research, Vol. (20), pp, 58-61. (2005).

[6] Ellis, C., Karafyllidis, I., and Turner, J. G. “Constitutive activation of jasmonate signaling in an Arabidopsis mutant correlates with enhanced resistance to Erysiphe cichoracearum, Pseudomonas syringae, and Myzus persicae”: Molecular Plant-Microbe Interactions, Vol. (15), No.10, pp. 1025-1030. (2002).

[7] Bowers, J. H., and Locke, J. C. “Effect of botanical extracts on the population density of Fusarium oxysporum in soil and control of Fusarium wilt in the greenhouse”: Plant disease, Vol. (84), No. 3, pp. 300-305. (2000).

[8] Datar, V. V. and Mayee, C. D., “Chemical management of early blight of tomato”: J. Maharashtra Agric. Univ., Vol. (10), pp. 278-280. (1986).

[9] Wheeler, B. E. J. “An introduction to plant diseases”: John Wiley and Sons Limited; London. (1969).

[10] Riaz, T., Khan, S. N., and Javaid, A. “Management of Fusarium corm rot of gladiolus (Gladiolus grandiflorus sect. Blandus cv. Aarti) by using leaves of allelopathic plants”: African Journal of Biotechnology, Vol. (9), No.3, pp. 4681-4686. (2010).

[11] Arunakumara, K. T. “Studies on Alternaria solani (Ellis and Martin) Jones and Grout causing early blight of tomato”: MSc. thesis, University of Agricultural Sciences, Dhardwad, India. (2006).

[12] Phapale, A. D., Solanky, K. U., Tayade, S. C., and Sapkale, P. R. “Screening of fungicides against okra leaf spot under laboratory condition”: International Journal of Plant Protection, Vol. (3), No. 2, pp. 282-284. (2010).

[13] Shakir, A. S., Mirza, J. H., and Akhtar, K. P. “New records of Alternaria species from Pakistan”: Pakistan Journal of Phytopathology, Vol. (9), No.1, pp. 102-104. (1997).

[14] Al-Askar, A. A. A. “In vitro antifungal activity of three Saudi plant extracts against some phytopathogenic fungi”: Journal of Plant Protection Research, Vol. 52, No.4, pp. 458-462. (2012).

[15] Bhat, N.M. and Sivaprakasan, K. “Antifungal activity of some plant extracts. In: Crop innovation techniques and management” (Sivaprakasan, K. and Seetharaman, I. eds.). Kalyani publishers, New Delhi, India, pp. 335-339. (1994).

[16] Taskeen-Un-Nisa, W. A., Bhat, M. Y., Pala, S. A., and Mir, R. A. “In vitro inhibitory effect of fungicides and botanicals on mycelial growth and spore germination of Fusarium oxysporum”: Journal of Biopesticides, Vol. (4), No.1, pp. 53-56. (2011).

[17] Nene, Y. L., and Thapliyal, P. N. “Fungicides in plant disease control”: 3rd edition Oxford and IBH Publishing Co. New Delhi. (1993).

[18] Nashwa, S. M., and Abo-Elyousr, K. A. “Evaluation of various plant extracts against the early blight disease of tomato plants under greenhouse and field conditions”: Plant Protection Science, Vol, 48, No., 2, pp. 74-79. (2012).

[19] Mukhtiar H., Farooq M., Farzana G. “In Vitro Evaluation of Some Fungicides against Common Fungal Pathogen of Early Blight and Fruit Rot of Tomatoes”: J. Appl. Environ. Biol. Sci., Vol. (4), No.9, pp. 424-429. (2014).

[20] Doolittle, S. P. “Vegetable crops”: Homer, G. Thompson and William, C. Kelly (Eds.). New York and London, pp.486. (1948).

[21] Lengia, M. R., Niazmanda, A. R., and Kianoushb, M. “Genetic differences in Alternaria alternata isolates associated with brown spot in tangerine cultivars”: Science Asia, Vol, 40, pp. 263-267. (2014).

[22] Devappa, V., and Thejakumar, M. “Morphological and physiological studies of Alternaria alternata causing leaf spot disease of Chilli (Capsicum annuum L.)”: International journal of applied and pure sciences and agriculture, Vol,2, No.5, pp.26-30. (2016).

[23] Kumar, K.; Garg, S.K. and Sakena, H.K. “Seed-borne nature of Alternaria alternate in linseed and it selection”: Indian Phytopathology, Vol. (38), pp. 162-163. (1985).

[24] Blanchard, D. “Tomato diseases: identification, biology and control”: Color handbook, Manson publishing, 2nd edition, pp, 688. (2012).

[25] Klimesova, M. and Prasil, K. “Morphological variability of the conidia of Alternaria alternata (Hypomycetes). Novitates”: Botanicae Universities Carolinae, Vol. (5), pp.7-27. (1989).

[26] Simmons, E. G. “Alternaria themes and variations, the host-specific toxin producers “: Mycotaxon, Vol. (70), pp, 325-369. (1999).

[27] Dube, J. P. “Characterization of Alternaria alternata isolates causing brown spot of potatoes in South Africa”: Ph.D. dissertation, University of Pretoria. South Africa, (2014).

[28] Abubakar, L., and Ado, S. G. “Genotype × environment interaction for resistance to purple blotch (Alternaria porri L.(Ellis) Cif.) in onion (Allium cepa L.) in Nigeria”: Asian Journal of Crop Science, Vol. 1, No.1, pp. 15-2. (2009).

[29] Vloutoglou, I., and Kalogerakis, S. N. “Effects of inoculum concentration, wetness duration and plant age on development of early blight (Alternaria solani) and on shedding of leaves in tomato plants”: Plant pathology, Vol. (49), No.3, pp. 339-345. (2000).

[30] Shishkoff, N., and Lorbeer, J. W. “Etiology of Stemphylium leaf blight of onion”: Phytopathology, Vol. (79), No.3, pp. 301-304. (1989).

[31] Vloutoglou, I. “Epidemiology of Alternaria linicola on linseed (Linum usitatissimum L.)” Ph.D. dissertation, University of Nottingham. England. (1994).

[32] Hong, C. X., and Fitt, B. D. “Effects of inoculum concentrate on, leaf age and wetness period on the development of dark leaf and pod spot (Alternaria brassicae) on oilseed rape (Brassica napus)”: Annals of applied biology, Vol. (127), No.2, pp. 283-295. (1995).

[33] Balai, L. P., and Ahir, R. R. “Role of temperature and relative humidity on mycelial growth of Alternaria alternata infecting brinjal”: Trends in Biosciences, Vol. (6), No.3, pp. 307-308. (2013).

[34] Li, Y., Zhang, D., Xu, W., Wu, Z., Guo, M., and Cao, A. “Alternaria tenuissima causing leaf spot and fruit rot on pepper (Capsicum annuum): first report in China”: New Dis Rep, Vol. (24), No.3, (2011).

[35] Abd-Ellatif, S., Abdel Rahman, S. M., and Deraz, S. F. “Promising antifungal effect of some folkloric medicinal plants collected from El-Hammam habitat, Egypt against dangerous pathogenic and toxinogenic fungi”: ARPN J. Agric. Biol. Sci, Vol. (6), No. 9, pp. 25-32. (2011).

[36] Vinayaka KS, Kekuda PTR, Nawaz NAS, Junaid S, Dileep N, Rakesh KN. “Inhibitory activity of Usnea pictoides G. Awasthi (Parmeliaceae) against Fusarium oxysporum f.sp. zingiberi and Pythium aphanidermatum isolated from rhizome rot of ginger”: Life Sciences Leaflets, Vol, 49, pp. 17-22. (2014).

[37] Srinivas, T., Rao, K. C., and Chattopadhayay, C. “Effect of botanicals and chemicals on the management of blight (Alternaria alternata; Alternaria helianthi) of sunflower (Helianthus annuus)”: Journal of Plant Diseases and Protection, Vol. (49), pp. 523-527. (1997).

[38] El-Mougy, N. S. “In vitro studies on antimicrobial activity of salicylic acid and acetylsalicylic acid as pesticidal alternatives against some soil-borne plant pathogens”: Egypt. J. Phytopathol, Vol. (30), No.2,

[39] Karade, V. M., and Sawant, D. M. “Effect of some plant extracts on the spore germination of Alternaria alternata”: Plant Disease Research, Vol. (14), No.1, pp. 75-77. (1999).

[40] Daniel, C. K., Lennox, C. L., and Vries, F. A. “In-vitro effects of garlic extracts on pathogenic fungi Botrytis cinerea, Penicillium expansum and Neofabraea alba”: South African Journal of Science, Vol. (111), No.7-8, pp. 1-8. (2015).

[41] Thakur, K. D., Khune, N. N., and Sabley, J. E. “Inhibition of some cotton pathogens by plant extracts”: Punjabrao Krishi Vidyapeeth Research Journal, Vol. (19), pp. 39-41. (1995).

[42] Kalemba, D. A. A. K., and Kunicka, A. “Antibacterial and antifungal properties of essential oils”: Current medicinal chemistry, Vol. (10), No.10, pp. 813-829. (2003).