Journal of Applied Biosciences (J. Appl. Biosci.) [ISSN 1997 - 5902]
Volume 35: 2287 - 2293. Published November 8, 2010.
In vitro and in vivo control of pearl millet midrib spot using plant extracts
Zarafi, A. B. and Moumoudou, U.
Dept. of Crop Protection, Faculty of Agriculture, Ahmadu Bello University, PMB 1044 Zaria
Corresponding author e-mail: afinikiz@yahoo.comABSTRACT
Objective: To evaluate the efficacy of cold and hot water extracts of neem leaf and seed, mahogany seed, ginger rhizome and shea butter leaf against Curvularia eragrostidis.
Methodology and results: The efficacy of cold and hot water extracts of neem leaf and seed, garlic bulb, mahogany seed, ginger rhizome and shea butter leaf was tested in the control of Curvularia eragrostidis isolated from pearl milletin vitro and in vivo. Twenty grams each of ethanol sterilized plant material was either suspended in 100 ml of sterile water for 24 hr to get cold water extract or suspended in 100 ml of sterile water and placed in a water bath at 90 oC for 1.5hr to get hot water extracts. The filtered extracts were incorporated into PDAS used to culture Curvularia eragrostidis. Radial mycelia growth, sporulation and spore length and width were determined from these cultures at 7 and 14 days after inoculation. Cold water extracts were staggered applied on potted pathogen inoculated pearl millet plants to get application at 2 days before inoculation (DBI), 2days after inoculation (DBI) and at symptom appearance time (SAP).Disease incidence and severity were assessed on these plants. The cold water extract of each tested plant material reduced mycelial growth, sporulation and spore size of the pathogen better than cold water extracts. The efficacy of garlic was significantly (P= 0.05) reduced by heat the most while that of ginger was significantly (P= 0.05) the least. Application of the cold water plant extracts 2 days before inoculation (2DBI) and 2 days after inoculation (2DAI) resulted in a significant (P= 0.05) reduction of the disease incidence and severity compared to application of plant extracts at symptom appearance time (SAP)
Conclusion and application: The conclusion of this study is that cold water plant extracts could be used successfully as environmentally safe and economical fungicides against Curvularia eragrostidis causal agent of pearl millet midrib spot.
Key words: Pearl millet, Curvularia eragrostidis, plant extracts.
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