Evaluation of growth of Neosartorya spp. on some Nigerian fruit products.

Growth of Neosartorya fischeri, N. fischeri var. spinosa and N. quadricincta on inoculated fruit juice agars (FJAs) consisting of 1% agar and juices from mango (MJA), orange (OJA) and pineapple (PJA) containing various levels of added sucrose was studied in terms of the average number of colonies produced by their ascospores, time (days) required before colonies were formed and developed to confluent mycelial mat as well as the level of reproductive spores produced. The means of the number of colonies on PJA and OJA without added sucrose were significantly (p = 0.05) higher than that of MJA. Addition of sucrose at levels of 10% to PJA, 11.5% to OJA and 9% to MJA increased the numbers of colonies whereas sucrose levels of 30% or more in PJA, 31.5% or more in OJA and 29% or more in MJA decreased the number of colonies produced. At any level of added sucrose to FJAs, a significant (p = 0.05) delay occurred before the colonies were formed and developed to confluent mycelial mat except in PJA containing 10% sucrose. All cultures produced abundant cleistothecia on all FJAs without added sucrose. Addition of sucrose at levels of 30% to PJA, 31.5% to OJA and 29% to MJA resulted in the production of abundant conidial heads with a corresponding decrease in the proportion of cleistothecia.