objective: the aim of this study was to estimate genetic variability and phonetic relationships of 50 isolates of p. sojae from iran. methods: during 2005–2007, 142 isolates of phytophthora sojae were collected from soil samples and diseased soybean plants from lorestan, mazandaran, golestan and ardabil provinces. races of the isolates were determined. dna of p. sojae fifty isolates was amplifi...

Phytophthora root rot of avocado, a soilborne disease caused by Phytophthora cinnamomi Rands, continues to be devastating to the cultivation of avocados despite more than 70 years of research on control methods. Phytophthora root rot has been estimated to be present in two-thirds of the avocado groves in California, causing losses of almost 30% of the total value of the crop (5). P. cinnamomi m...

Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quali...

during 2001-2005, 79 isolates of rhizoctonia from seed rot, seedling damping –off, root rot and dry rot canker of sugar beet were collected. based on morphological characteristics, number of nuclei per cell and hyphal diameter, isolates were classified in two groups, binucleate (4 isolates) and multinucleate (75 isolates). among 75 multinucleate isolates ,27 isolates were identified as  ag4, 28...

Different species of Phytophthora cause serious and economically important soilborne diseases of citrus throughout the World. Tree and crop production losses occur from damping-off of seedlings in the seedbed, root and crown rot in nurseries, foot rot and fibrous root rot, and brown rot of fruit in groves. Foot rot results from infection of the bark near the ground level producing lesions on th...

Incidence and severity of root-rot caused by the fungus Macrophomina phaseoli was increased in screenhouse-grown kenaf (Hibiscus cannabinus L.) seedlings simultaneously infected by the nematode Meloidogyne javanica. In seedlings inoculated at 5, 10 and 15 days of age, root rot lesions increased 70.3, 44.1 and 21.8%, and nematode penetration increased 49.0, 36.7, and 12.3% when both fungus and n...

Severe violet root rot occurred in a field of membranous milk vetch in Bonghwa, Korea, in October 2010. Two fungal isolates from the diseased plants were identified as Helicobasidium mompa based on their morphological, cultural, and molecular characteristics. This is the first report that H. mompa causes violet root rot on membranous milk vetch in Korea.