Green synthesis of copper and zinc nanoparticles using different varieties of banana starch, latex and sap and evaluation of their antifungal activity against Fusarium oxysporum cubense

Soil borne diseases which are caused to various plants include a wide variety of soil microbes like fungi and bacteria, among which Fusarium wilt is one such disease caused by Fusarium oxysporum cubense in banana plants. Wilt disease or the panama disease of plant is among the most destructive disease of banana in the tropics and even the control methods like field sanitation, soil treatments and crop rotations have not been a long term control for this disease. An alternative method of treating Fusarium oxysporum was adopted by using various banana parts mainly its peel, pulp sap and its latex of varieties such as Robusta (B1) Musa acuminate Colla (AAA), Etha (B2) Musa x paradisiaca (AAB), Poovan (B3) Musa x paradisiaca (AAB), Sundari (B4) Musa acuminate Colla (AA), Njalipoovan (B5) Musa acuminate Colla (AB), Palayamkodan (B6) Musa x paradisiaca (AAB), Kannan (B8) Musa acuminate Colla (AAA), Pachakadali (B9) Musa acuminate Colla (AAA). Nanoparticles are small particles with a dimension of 10-9 and 10-10. Green synthesis is a new method developed for the synthesis of nanoparticles which is small in size, large surface area and eco- friendly. Leaf extracts of these plants were used for synthesis of copper and zinc nanoparticles, as nanoparticles are powerful antimicrobial agents. The results shows that dry skin and fruit extracts of Palemkodan, Njalipoovan, Etha, Pachakhadali with solvents, propane, ethanol, methanol and acetone and the fresh extract latex and sap of Palemkodan and Poovan with solvents isoproponol, ethanol, methanol with 1/10 and 1/50 dilution are used for the synthesis of copper and zinc nanoparticles. Copper and zinc nanoparticle shows greater antifungal activity than copper sulphate and zinc sulphate, respectively and dry extract. The maximum zone of inhibition was at 50 and 100 µl for all the test plates. This indicates that the zone of inhibition increases with as the concentration of nanoparticles increased. An overall result showed that ethanol, methanol and isoropane could be used as a good solvents and skin of Njalipoovan and Etha could be used for controlling the Fusarium oxysporum cubense under invitro conditions.