Heart Rot

Vanda and Phalaenopsis are especially susceptible to this disease . Cattleya and other genera are also affected . This disease is caused by Phytophthora omnovora , which is related to the potato wilt fungus . The disease starts in the interior of the plant and spreads to the leaves ,which turn yellow and drop off. If cut across ,the bulb will show dark rotted areas inside . Cut away infected bulbs , dip the plant in fungicide and repot in fresh medium.