Azadirachta indica

The study was conducted to evaluate the antimicrobial activity of neem (Azadirachta indica) leaf extract against fungal phytopathogens isolated from diseased tomato (Lycopersicum esculentum) fruit. Diseased tomato fruits were obtained and to establish a mixed culture. Two distinctive fungi were identified on the mixed cultures and subculture into freshly prepared potato dextrose agar medium.

The anticoccidial efficacy of the aqueous neem leaf extract in comparison to amprolium showed that the aqueous extract dose of 800mg/kg compared favourably with 10mg/litre of amprolium in treating the disease, both showed 100% survival rates for infected and treated chickens with zero oocyst per gram at day 4 post treatment. Also, the mean weight (grams) of infected and treated chickens improved significantly (P<0.05) at day 7-post treatment.

The piscicidal potential of water-extract mesocarp of Azardirachta indica was investigated in static biossay experiment with continuous aeration to determine its acute toxicity. The 96-hLC50 was 97.42mg/l while the threshold value was 31.12mg/l. The extract led to an initial increase in opercula ventilation rates which then decreased significantly. The computed regression equation (y) = 4.624 + 6.352 Logc. (r=0.72) and the fish exhibited respiratory distress, loss of balance and erratic swimming prior to mortality. The usefulness of A. indica as piscicidal plant is discussed.