Potential of fungal pathogens on seeds and seedlings of Milicia excelsa inthree ecological zones of Ghana

An experimental study was undertaken to investigate the microflora populati on of Milicia excelsa seedlings grown on three ecologically distinct sites. Pathogenicity tests were done on seeds and seedlings in the greenhouse. Se eds of M, excelsa were used as bait to obtain soil-borne fungi at three for est sites in Ghana and 165 micro-organisms were isolated. Potential pathoge nic fungal species isolated were Cylindrocarpon spp., Fusarium spp. and Las iodiplodia theobromae. The genus Fusarium was the most common group and inc luded numerous pathogenic species including Fusarium solani found on both s eeds and seedlings. To test the pathogenicity off. solani on seeds and seedlings, the inocula o f two isolates (10(6) conidia/ml) were used to infect top soils from Amanti a and Abofour subsequently grown with 300 seeds of each genotype (G12, G15 from Amantia and G28, G30 from Abofour). Infected soils caused a substantia l reduction in seed viability. All seedlings on inoculated soil exhibited s tunted growth, a lower number of true leaves, and a less developed root sys tem. Sporadic chlorosis and seedling mortality were common, bur only with s eedlings grown on soils from Abofour.