International Journal of Food and Biosystems Engineering, October 2017, Vol 6(1): 38-50 Antifungal Activity of Azadirachta indica Aqueous and Non-Aqueous Extracts on Colletotrichum gloeosporioides, Botryodiplodia theobromae and Fusarium solani. A First Approach Stefanos Leontopoulos ∗ , Prodromos Skenderidis, Vassiliki Anatolioti, Maria Kokkora, Sotiria Tsilfoglou, Konstantinos Petrotos, Ioannis Vagelas Technological Educational Institute of Thessaly, School of Agricultural Technology-Food Technology-Nutrition and Dietetics, Dept. of Agricultural Engineering Technologists, 41110 Larissa, Greece Abstract The possibility to use compounds of natural origin with fungicidal activity for protection of crop plants has been gaining an increasing interest. Preliminary work suggests that a simple aqueous extract of Azadirachta indica reduced the growth of three fungi commonly associated with root rots. The purpose of this project is to challenge these findings by carrying out a bioassay consisting of aqueous and non aqueous extracts of plant material against three test root rotting fungi: Colletpotrichum gloeosporioides, Fusarium solani and Botryo- diplodia theobromae. Two different samples of plant tissues (old and young) were used for the experiments. The non-aqueous extracts that were used were methanol, acetone and hexane. The methanol extract inhibited the growth of F. solani by 42%. Water, acetone and hexane extracts inhibited the growth of F. solani by 32%, 25% and 16%, while C. gloeosporioides mycelium growth was inhibited by 37% in the case of methanol extracts and 14% in acetone and water extracts In all cases old plant tissues extracts gave better results than the young did controlling more sufficient the tested fungi. More specific a concentration of 26% of the old plant tissues with the aqueous solvent gave the LD50 of the F. solani followed by a 32% concentration of the same plant material; and aqueous solvent, which gave the LD 50 of C. gloeosporioides. For the young plant tissues the inhibited concentrations in F. solani and C. gloeosporioides was 39% and 43%. Comparing the three fungi the water extract solution was more effective in F. solani then in C. gloeosporiodes and non-effective in B. theobromae. It can ∗ Corresponding author e-mail: s − leontopoulos@yahoo.com 38