8. Study of the influence of plant extracts on the mycelium growth of Alternaria solani

Author: Katya Vasileva

Abstract

The response of fungus Alternaria solani to plant extracts originating from the Fabaceae family and orange oil was investigated by a modified in vitro method of Thornberry. The sensitivity of the pathogen to five different extracts at a concentration of 1 ml/l, 2 ml/l, and 3 ml/l was accessed. The results showed that an orange oil extract (number 7) has the strongest inhibitory effect on the mycelium growth when compared to the other extracts. The effect of this extract has also been observed with all used concentrations. The insignificant effect on mycelium growth was obtained for extract 4; at dose of 1 ml/l since the inhibitory effect reached 25% and at 2 ml/l – 25.45%. Over 50% of inhibitory effect was found for extract number 3. The percentage distribution of the tested products at the lowest dose (1 ml/l) showed that the orange oil extract has the strongest inhibitory effect on mycelium growth when compared to the other plants extracts – 36%. The effect of extract number 4 and number 9 was relatively weak, only 11% and 12%, respectively. Compared to the highest administered dose, the best limiting effect was observed with orange oil – 31%, and with treatment with plant extract number 3 – 26%. It has been shown that the increased concentration of plant extracts increased the sensitivity of the pathogen.

Keywords: Alternaria solani, in vitro, inhibitory effect, extracts