Interaction between Microscopic Fungus Stem Foul Disease (Phytophthora sp) in Sweet Orange (Citrus sinensis) with Antagonistic Fungus (Trichoderma sp) at pH 5

Abstract

Rotting diseases caused by pathogens can result in losses for farmers of sweet oranges (Citrus sinensis). Natural control is necessary to reduce the side effects of the use of chemical fungicides. The purpose of this study was to find out the interaction between pathogenic fungi (Phytophthora sp) with antagonist mushrooms (Trichoderma sp) in Petri cups and to know the effectiveness of antagonistic fungi (Trichoderma sp) in inhibiting the growth of pathogenic fungi (Phytophthora sp) with dual culture tests. Antagonist test with dual culture method is conducted on PDA pH 5 media by measuring the mycelium diameter of pathogenic fungi (Phytophthora sp) to determine the antagonist's tasteless power in suppressing the growth of pathogenic fungi. The result obtained is the diameter of the antagonistic fungal mycelium (Trichoderma sp) develops and suppresses the mycelium of pathogenic fungi (Phytophthora sp) characterized by reduced diameter of pathogens within 4 days of observation. The interaction formed i.e. the growth of the diameter of the mycelium antagonist mushroom accumulates in pathogenic fungi on the 2nd day after inoculation. This study concludes that antagonistic fungi (Trichoderma sp) are able and effective in inhibiting the growth of pathogenic fungi (Phytophthora sp).Keywords: Sweet orange (Citrus sinensis), Microorganisms, Rotting diseases stems, Antagonistic test.