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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Techniques for controlling moisture include: Although sporangia and zoospores arecqnut survive in soil for short periods, chlamydospores are the main survival structure for P.
An affected nut with leslons.
Waterlogged conditions appear to weaken the defense mechanism of papaya roots against invasion by the pathogen. The infection of heartleaf results in bud rot and the outermost leaf sheath leads to crown rot. The green colour of the nut-shell turns darker green and the early symptoms gradually spread ultimately covering the entire surface of the nut.
‘Kole roga’ strikes arecanut plantations in Dakshina Kannada again
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Other means of cultural control for P. Phytophthora palmivora produces abundant sporangia on V-8 agar under continuous fluorescent light. 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.
The disease spreads from palm to palm and from orchard to orchard. Related Topics Karnataka Mangalore. They are deciduous, pedicellate, and papillate.
Water soaked areas usually manifest towards the base of the nuts. The sporangiophores are irregularly branched and are about 2. Images may be used in any software application that supports JPEG file format or viewed in an Internet browser as local files.
During the onset of the rainy season, these structures are carried to young nuts by various agencies and germinate there upon causing primary infection. Chlamydospores formed in fallen fruit survive in soil and serve arecanug the main source of inoculum for infection of roots of papaya seedling in subsequent plantings.
Control of fruit rot or koleroga disease of arecanut (Areca catechu L.) 
The first appearance of the koleroga is on the nuts two or three weeks after rains begin. Scientists areecanut the Central Plantation Crops Research Institute’s CPCRI’s Regional Station at Vittal, Karnataka, have come out with suitable package of practices to effectively manage the disease and make areca nut cultivation more remunerative to the growers.
Leave koleroba Reply Click here to cancel reply. Root rots are another symptom of P. This page was last edited on 19 Septemberat Incidence of Phytophthora root rot of mature trees in waterlogged areas during the rainy periods can be greatly reduced by improving drainage in the orchards. The antheridia are diclinous and amphigynous. Topical Meetings koledoga Workshops. From Wikipedia, the free encyclopedia.
Although the disease is predominant arfcanut the nuts, it occasionally attacks the crown of the palm resulting in rotting and drying. In water, chlamydospores germinate by producing short germ oof, each with a sporangium at the tip. Please enter an answer in digits: The signs of P.
Infected fruit on the trees and those that have fallen to kolerroga ground should be removed to reduce the inoculum for aerial infection of fruit and stems, and infection of seedling roots in subsequent plantings. A fine spray will be needed for effective spread of spray fluid over the surface of the nuts. Another symptom is the presence of cankers which are found in red maple, papaya, rubbermangosand cacao. During the corresponding period last year, the district received 2, Control measures As mechanical control measure, the areca bunches can be covered with polythene covers before the start of the heavy monsoon showers.
Coleman Orellana  Phytophthora parasitica var. This impacts the cost of cacao, and thus the pathogen controls agecanut cost and availability of products such as chocolate.
Control of fruit rot or koleroga disease of arecanut (Areca catechu L.)
Phytophthora Water mould plant pathogens and diseases Coconut palm diseases. The chamydospores formed in the infected fallen nuts on the soil serve as the perennating kooeroga of the pathogen. Sporangia produced from primary infection lesions serve as the source of secondary infections during the growing season.
Roots of papaya plants are protected by the virgin soil during the susceptible stage, and become resistant to the pathogen when they extend to the infested soil. The Aliette Fosetyl-Al shows anti-sporulant activity resulting in reduced amount of secondary inoculum. It severely affects the fruits nuts of the areca palm during June to September when there is heavy rainfall cm in these areas. The virgin arecajut method has arecanht advantages of being relatively inexpensive, very effective and nonhazardous.
These are among the most serious diseases caused by fungi and moulds in South India. As the intensity of rains did not come down, many farmers were not able to spray the usual first round of prophylactic solutions in the last week of May or the first week of June to prevent the disease. Common Names of Plant Diseases. Bud rots can also be seen in papaya and coconuts infected with P.
Rain and wind are the two major factors in the epidemiology of Phytophthora fruit rot of papaya. Therefore, intermittent rains maintaining constant humidity in the atmosphere with alternating sunshine abundant light are more conducive for the rapid spread of Koleroga.
Therefore, wind-blown rain is essential for initiation of the primary infection and the development of epidemics in papaya orchards.