The antimicrobial activities of cassia alata on the causal organisms of melon fruit rot

Abstract

The objectives of this study were to observe the antimicrobial activities of Cassia alata (Gelenggang) extractions at different concentration and to evaluate the difference between disk diffusion and spore suspension methods. The crude extract of C.alata were prepared from its leaves parts. The antimicrobial activities were measured from the inhibition zone of the Fusarium oxysporum and Fusarium solani which is the causal organism for fruit rot diseases. The results showed that, from six concentrations that were used, the 10 mg/ml showed the best results because its yields higher inhibition zone in both methods and it is followed by 5 mg/ml, 2 mg/ml, 1 mg/ml, 0.1 mg/ml and 0.01 mg/ml. The difference between this two methods were the spore suspension provides early inhibition compare to disk diffusion method but the disk diffusion methods yields better results in terms of area of the inhibition zone. Besides that, this two different strain also gives effect to the inhibition zone where the F solani were re-growth on the inhibition sites after day 4 but for the F oxysporum, the inhibition zone are maintained until day 8 because they are more susceptible compare to F solani. From the analysis by using Tukey test, it showed that there were significance different (P<0.05) between the oncentration especially for 10 mg/ml of extraction, compare with the control.