ENVIRONMENTAL AND NUTRITIONAL FACTORS AFFECTING THE IN-VITRO INHIBITION OF THE VEGETATIVE GROWTH OF VENTURIA-INAEQUALIS BY 5 ANTAGONISTIC FUNGI

The environmental (temperature, pH, and light) and nutritional (carbon sources) factors that affect the inhibition of mycelial growth of Ven turia inaequalis by five fungi (Aureobasidium sp. (P26A), unidentified fungus (P28A), Phoma sp. (P59A), Phoma sp. (P66A), and Ophiostoma sp. (P164A)) were evaluated. Cold temperatures slightly reduced the inhib ition of V. inaequalis by Phoma sp. (P66A). A neutral pH increased the inhibition by the unidentified isolates and by a Phoma sp. (P66A). Co ntinuous darkness enhanced the inhibition of the pathogen by the isola te Aureobasidium sp., and continuous light favored the inhibition by t he Phoma sp. (P66A). The conidial germination of V. inaequalis was sig nificantly reduced by all the isolates, and the inhibition was stronge r closer to the fungal colony. Ophiostoma sp. inhibited 100% of the pa thogen's growth regardless of temperature, pH, and light regime. Only the presence of peptone in the medium diminished the inhibition by 8%. Since Ophiostoma sp. strongly inhibited V. inaequalis (92 - 100% inhi bition) and was not influenced by environmental and nutritional condit ions, this fungal isolate could be considered in the development of a biocontrol agent against the apple scab pathogen.