In-vitro evaluation of plant extracts against Lasiodiplodia theobromae causing cashew inflorescent blight

Abstract

Extracts of four plant species, red acalypha (Acalypha hispida), siam weed (Chromolaena odorata), aidan (Tetrapleura tetraptera), and neem (Azadirachta indica) were screened in-vitro for fungitoxicity against Lasiodiplodia theobromae (cashew inflorescence blight pathogen) at four different concentrations viz., 10, 20, 40 and 80%. The result shows that the plants extracts significantly (P < 0.05) reduced mycelia growth of the fungus. The fungitoxicity of the plant extracts against L. theobromae also varied with concentration. Extract from T. tetraptera exhibited maximum efficacy in reducing the mycelia growth of L. theobromae to 9.83 mm at 80% concentration while the highest mycelia growth of 59.33 mm was recorded in extract of A. hispida at 40% concentration. C. odorata at 10% concentration reduced the colony diameter to 50.50 mm while 20% T. tetraptera inhibited the pathogen to 42.33 mm. The percentage reduction in colony diameter by each of the phytoextracts ranged between 30.20 and 88.44%. Findings from this study reveal the possibility of utilizing naturally available plant chemicals for controlling L. theobromae with the ultimate goal of eliminating pesticide residues in the marketable products of cashew.

In vitro efficacy of some plant aqueous extracts against two species of Lasiodiplodia associated to mango decline in Burkina Faso

“…Findings from this study were in agreement with previous researchers, who reported that most the mycelial growth of most isolates of L. theobromae and L. pseudotheobromae from mango and other crops were significantly inhibited by leaf extracts from various medicinal herbs and spices (Rahee et al, 2018). About, acalypha (Acalypha hispida), siam weed (Chromolaena odorata), aidan (Tetrapleura tetraptera), and neem (Azadirachta indica) were reported to significantly inhibit L. theobromae isolates of cashew inflorescence blight in Nigeria (Dele and Abiodun, 2015). In the same country, in vitro tests showed antimicrobial activity of crude extracts against Botryodiplodia, one of fungal pathogens of yam.…”

“…The plants used in this study were collected at Farako-Bâ site located at 10 km from Bobo Dioulasso. They were selected based on their medicinal properties reported by several authors (Sahi et al, 2012;Dele and Abiodun, 2015) and availability from farm lands within Farako-Bâ near Bobo-Dioulasso. These plants include A.…”

“…Plants and their derivatives have been extensively studied for the control of pathogenic fungi. Indeed, the extracts of acalypha (Acalypha hispida), siam weed (Chromolaena odorata), aidan (Tetrapleura tetraptera), and neem (A. indica) were reported to significantly inhibit L. theobromae isolates of cashew inflorescence blight in Nigeria (Dele and Abiodun, 2015). In another study, the extracts of J. curcas had inhibitory effects against this fungal, pathogenic on Rhizophora racemosa (Ukoima et al, 2013).…”