Growth Studies of Aspergillus niger (Van Tieghem) inciting storage Rot of Onions and its Control using Different Concentrations of Neem (Azadirachita indica) parts in Umudike, Abia State

Abstract

The study was carried out at the laboratory of Plant Health Department, Michael Okpara University of Agriculture, Umudike, Abia State, Nigeria to evaluate the fungitoxicity of different concentrations of crude extracts of neem plant parts against Aspergillus niger associated with onion storage rots. A.niger was isolated from infected onion bulbs on PDA media and the pathogenicity was determined by testing its ability to induce rot in healthy onion bulbs. Results showed that the A. niger treated with the crude extracts of different concentrations of neem parts significantly (P<0.05) inhibited the mycelia growth of the pathogen in-vitro when compared with the control (Sterile water) 3 days after incubation at 28  20C. Neem leaves significantly (P < 0.05) gave the highest growth inhibition at 75% concentration (82%). Neem root extracts were also effective at all levels of concentrations studied while the neem stem/bark extracts gave the least growth inhibition at 75% concentration.