Isolation, Identification and In vitro Management of Phytophthora nicotianae Casuative Agent of Citrus Gummosis

Various species of Phytophthora have long been reported to cause different diseases in citrus such as gummosis, root rot, and fruit brown rot, and the decline of citrus all over world including India. Among these, Phytophthora nicotianae have attracted considerable attention due to its ability to cause gummosis in citrus which is a major cause of citrus yield loss. It has been observed thatit can cause about 10-30% citrus yield losses due to gummosis. Considering these facts, the present study is aimed to isolate the pathogen from infected plants, its identification based of morphological and microscopic characteristics followed by their in vitro management using novel fungicides. The pathogen was isolated from gummosis infected soil sample by using leaf bait method and showed cottony dense mycelium, aseptate hypae as a morphological characteristics. Tested fungicides showed 100% prominent inhibition of P. nicotianae at 2500 ppm concentration under laboratory conditions.