Koleroga or Mahali is a major disease of arecanut causing serious losses. The pathogen is a fungus Phytophthora palmivora. Spraying the. PDF | On Jan 1, , R Ramesh and others published Management of fruit rot ( Koleroga/ Mahali) disease of arecanut. Koleroga (kole = rotting, roga = disease) as it is called in Karnataka is in the same orchard (as found in Karnataka where arecanut, cocoa, cardamom, black.
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Wind is required for dispersal of the inoculum once it reaches the air. In the s P. Coleman  Pythium palmivorum E. Genetic Recombination in Bacteria: Continuous heavy rainfall coupled with low temperature 20 to 23 degree Celsiushigh relative humidity and intermittent rain and sunshine hours are factors that favour the occurrence of fruit rot.
This disease was first reported in India in and has been serious on areca palms Areca catechu; supari in the western peninsular parts of our country. Care should be taken to prepare the mixture to get the right quality as other wise an acidic mixture will lead to copper injury and subsequent heavy shedding of nuts, according to the scientist. Sexual reproduction in Phytophthora palmivora requires the presence of opposite mating types known as A1 and A2.
Waterlogged conditions appear to weaken the defense mechanism of papaya roots against invasion by the pathogen. Though the sexual reproduction is uncommon in nature, the formation of antheridia and oogonia producing oospores after fertilization has been found in cultures.
Related Topics Karnataka Mangalore. Similar diseases of palms are also known to occur kolerogx Sri KolwrogaMauritiusand Sumatra.
‘Kole roga’ strikes arecanut plantations in Dakshina Kannada again
Although the height of palms and the situation of affected parts of the top make spraying difficult, the latter is found to be very effective. Collar rots are found on citrus, mango, and black pepper infected with P. It is believed that where many crops are grown simultaneously in the same orchard as found in Karnataka where arecanut, cocoa, cardamom, black pepper, and citrus are grown simultaneously in the same plantationand they are infected by two to three species of the some pathogen e.
Although the common name of Phytophthora palmivora is bud rot of palms, it affects many tropical plants and has a moderately broad host range. Printable version Dec 31, 7: Leave a Reply Click here to cancel reply. A fine spray will be needed for effective spread of spray fluid over the surface of the nuts. Articles with ‘species’ microformats.
Trees established with the virgin soil method in the replant fields produce fruit as abundantly as those growing in the first planting fields. Contact Us – Report a Bad Link. Bipolaris incurvata Botryosphaeria cocogena Bursaphelenchus cocophilus Cadang-cadang Capnodium footii Cephaleuros virescens Corticium penicillatum Cytospora palmarum Marasmiellus cocophilus Periconiella cocoes Pestalotiopsis palmarum Phaeochoropsis mucosa Phyllosticta palmetto Phytophthora palmivora Pseudoepicoccum cocos Ramularia okleroga Stigmina palmivora.
In the presence of nutrients, chlamydospores germinate by producing germ tubes that continue to grow and form mycelial masses. The zoospore-containing droplets may be arcanut dispersed by wind and become the inoculum for infecting fruit and occasionally stems of papaya in the fields. Cleanliness and sanitary cultural practices, particularly the destruction of diseased tops of the palms and other plant parts, are of foremost importance in disease management.
The causative organism was first identified as Phytophthora palmivora by Edwin John Butler in However, close planting of palms provides ideal conditions for areanut spread.
From Wikipedia, the free encyclopedia. Rain splash is needed for liberation of sporangia of P. Saraswathy and Nambiar stated that the systemic fungicides such as Aliette and Ridomil at 0. The green colour of the nut-shell turns darker green and the early symptoms ov spread ultimately covering the entire surface of the nut.
August 20, The disease leads to heavy shedding of fruits,”explains Dr. The chamydospores formed arecant the infected fallen nuts on the soil serve as the perennating arfcanut of the pathogen. Kawakamia carica Hara  Phytophthora arecae L. Images may be used in any software application that supports JPEG file format or viewed in an Internet browser as local files.
The disease appears usually 15 to 20 days after the onset of regular monsoon rains and may continue up to the end of the rainy season.
It has also been reported from Assam.
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Zoospores are capable of long-term survival but do not play a significant role in the disease cycle because sexual kooeroga in P. Butler Phytophthora palmivora var. Sporangia produced from primary infection lesions serve as the source of secondary infections during the growing season. Phytophthora Water mould plant pathogens and diseases Coconut palm diseases.
Companion crops are planted in the same fields as the host plant and are used to divert some of the pathogen away from the hosts, an example being planting bananas and avocados in the same field. Therefore, Phytophthora root rot may occur on papaya at any age in poorly drained areas.
Plant Disease Management Reports. In mangoes, the pathogen is known to kill young plants, specifically nursery plants. The lesions on kolroga fruits gradually spread covering the whole surface before or after shedding.
Careers In Plant Pathology.