Jennings7 reported that max i mal growth rates are obtained with these three nitrogen sources, namely: am mo ni um, glutamate and glutamine, and that growth in medium sup ple mente d with them leads to the most intense depression of a whole range of ac tiv i ties, including membrane trans port linked to utilisation of other ni tro gen ‘com pounds.’ This de pres sion of activities (termed nitrogen catabolite con trol, reg u la tion or re pres sion) must be lifted if de novo synthesis of en zymes metabolising other nitrogen com pounds is to take place. Thus, it is pos si ble that the repression re sult ing from the in tro duc tion of am mo ni um inhibited the synthesis of ox i da tive enzymes which de pressed the oxidation of glucose in PDA, hence there was no growth. Generally, the growth rates of T. viride on PDA and BPA were similar (Table 5). This study has indicated that growth of T. viride on BPA compared well with its growth on PDA. Bean pod may therefore serve as a carrier medium when applying T. viride in biocontrol programmes for which it has a wide range of applications.