Efficacy of two plant extracts in the management Of seed-borne fungi of cowpea

Abstract

Cowpea (Vigna unguiculata L. Walp) is an important grain legume in sub- Saharan Africa. It is useful both as grain and vegetable. The crop is affected by many factors that constrain its production, with pests and diseases being the most important. Seed-borne pathogens have been found to be foundation to a myriad of crop diseases that affect cowpea and it is imperative to find alternative means of controlling their abundance seeing that excessive use of synthetic pesticides can be baleful to both man and the environment. An experiment was set up to isolate and identify seed-borne pathogens of cowpea seeds obtained from Institute of Agriculture and Research, Samaru, Zaria and to investigate the efficacy of plant extracts as an alternative to synthetic fungicides. Three treatments [Ginger (Zingiber officinale), Garlic (Allium sativum) and Ciba plus (Jubaili Bros.)] were tested for their efficacy in inhibiting mycelial growth of seed-borne fungi of cowpea. A total of eight fungal pathogens were observed with Aspergillus flavus having the highest frequency of occurrence (70%) and Fusarium spp. having the highest mean mycelial growth (77.66% P<0.05). Garlic was highly effective in inhibiting the mycelial growth of Fusarium spp. (93.97% P < 0.05) and Cibaplus completely inhibited the growth of Macrophominaphaseolina and Aspergillus flavus (100% P<0.05). However, there were no significant differences in the efficacy of all three treatments in the control of Collectotrichum gleosporioides and Rhizoctonia. solani. Plant extracts which are ecofriendly, have shown that they have fungitoxic effects on seed-borne pathogens of cowpea but they require further investigations into their standardization and formulations to ensure sustainability.