Comparative Bioefficacy of Fungicides and Trichoderma spp. against Pestalotiopsis theae, Causing Grey Blight in Tea (Camellia sp.): An In Vitro Study

Abstract

A b s t r a c t A r t i c l e I n f oThe grey blight, caused by Pestalotiopsis theae is a serious problem in almost all tea growing regions of India. A large number of tea cultivars were found to be susceptible to this disease. Evaluation of four selected fungicides (carbendazim 12% a.i + mancozeb 63% a.i., hexaconazole 5 EC, copper oxychloride 50 WP and copper hydroxide 77 WP) have been found effective in suppressing the pathogen to the considerable degree under in vitro conditions. Results indicated that, maximum control (70.8%) was achieved in the case of combi fungicidal formulation (carbendazim 12% a. i. + mancozeb 63% a. i.) followed by hexaconazole 5 EC and copper hydroxide 77 WP and copper oxychloride 50 WP, respectively. Effort has been made to evaluate the effectiveness of the indigenous Trichoderma viride (KBN-24) and T. asperellum (KBN-29) in inhibiting the mycelial growth of P. theae in dual culture method and the results indicated significant inhibition of the pathogen. Results on the compatibility study indicated that the tested fungicides adversely affected the growth of T. viride to varying degree. The maximum inhibition (79.0%) was noted in case of combi fungicide formulation followed by copper oxychloride (75.8%) and hexaconazole (70.4%). Thus the results of this current investigation highlighted the fact that the local Trichoderma isolates were found effective in controlling the targeted phytopathogen. However, use of such fungicides soon after the application of Trichoderma formulation, should be discouraged to have a better control of the disease.

In vitro Antagonism of Trichoderma Isolates and Efficacy of Chemical Fungicides against Mycelial Growth of Pestalotiopsis theae

“…The overall results are in line with the study by Kumhar et al (2016), where Hexaconazole and mixture of fungicides like Mancozeb, Carbendazim provided significant growth inhibition of over 70% against P. theae. Sanjay et al (2008) reported 6.6% of grey leaf blight incidence with Carbendazim application which was most effective in protection against P. theae.…”

“…Beside many other things Trichoderma also compete for nutrient and space against pathogen. The findings are synchronous with the result by Kumhar et al (2016) who reported significant inhibition of 61.5% by T. viride and 57% by T. harzianum against Pestalotiopsis theae. The increase in usage of Trichoderma isolates as bio-control agent is credit to its multifaceted advantages.…”

“…The primary strategy in controlling grey blight is fungicide application (Sanjay et al, 2008). Fungicides like Mancozeb, Copper oxychloride, Carbendazim, Hexaconazole, Tridemorph, Azoxystrobin, Triflumizole, Bitertanol and Copper hydroxide are used in controlling this disease (Sanjay et al, 2008;Kumhar et al, 2016). But more work has to be done in dictating appropriate formulation, thereby preventing over and under application of fungicides.…”

Neopestalotiopsis chrysea Causing Leaf Spot Disease of Strawberry Plants in Bangladesh

“…is known to inhibit pathogenic fungal invasion via mycoparasitism, antibiosis, competition and lysis of fungal hyphae. Besides, Kumhar et al 26 tested Trichoderma viride and T. asperellum against the mycelial growth of Pestalotiopsis theae and found that these antagonistic fungi inhibited the growth of the fungus.…”

Can Genus Trichoderma Manage Plant Diseases under Organic Agriculture?

“…There was no incidence of anthracnose and crown rot [41]. It was noted that T. viride, T. harzianum, and T. asperellum were potential antagonists for the management of F. solani and Pestalotiopsis theae causing dieback and grey leaf spot disease of tea [48,49]. Foliar spray of T. asperellum and T. atroviride could manage the dieback disease of tea (Camelliasp) and enhance the vegetative growth in terms of more number of pluckable shoots [50].…”