Give the role of following mycoherbicides(a) Phytophthora(b) Alternaria(c) Fusarium

Answer: They are fungi used as biological weedicides: Phytophthora controls milkweed vine, Alternaria controls water hyacinth, Fusarium controls broomrape and similar weeds.

Mycoherbicides are fungal pathogens (or their preparations) used to kill specific weeds without harming the crop or the environment.

• (a) Phytophthora palmivora: used to control the milkweed vine (Morrenia odorata), a weed of citrus orchards.
• (b) Alternaria (e.g. A. crassa, A. eichhorniae): used to control the aquatic weed water hyacinth (Eichhornia crassipes); A. cassiae controls sicklepod in fields.
• (c) Fusarium (e.g. F. oxysporum): used to control parasitic weeds such as broomrape (Orobanche) and witchweed, and some weeds like cocklebur.