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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Water soaked areas usually manifest towards the base of the nuts. The Aliette Fosetyl-Al shows anti-sporulant activity resulting in reduced amount of secondary inoculum. Therefore, intermittent rains maintaining constant humidity in the atmosphere with alternating sunshine abundant light are more conducive for the rapid spread of Koleroga.
APS copyright extends to images, text, graphics, photographs, illustrations, audio, video, computer software, and all other elements of the site. Copyright is not claimed for material provided by Kolerogw States government employees as part of their work. Therefore, wind-blown rain is essential for initiation of the primary infection and the development of epidemics in papaya orchards.
Coleman  Pythium palmivorum E. Both A1 and A2 isolates can produce zoospores by selfing when stimulated by sex hormones produced by A2 and A1, respectively. Bud rots can also be seen in papaya and coconuts infected with P. Sporangia produced from primary infection lesions serve as the source of secondary infections during the growing season.
Printable version Dec 31, 7: Cultural practice is also important in the management of Phytophthora diseases of papaya. The virgin soil method has the advantages of being relatively inexpensive, very effective and nonhazardous. Sawada  Phytophthora faberi Maubl. As previously stated impacts of P. It is essential to reduce the inoculums of the fungus and also check the incidence of other Phytophthora diseases like bud and crown arecnaut, according to the scientist.
In the s P. Sporangia are usually produced in clusters sympodially. Mobility of zoospores of P. The areca fruits surfaces get rotten as a result of the disease.
Tender arecanut hit by fruit rot collected by Ramesh Kaintaje, a grower near Mani off Dakshina Kannada district.
Betel nut or Areca nut palm Disease name: The pathogen produces abundant sporangia on the surface of infected fruit that are further dispersed by wind-blown rain and cause outbreaks of Phytophthora fruit rot in the same and nearby orchards.
Light xrecanut inhibitory to zoospore formation but stimulatory to zoospore germination.
‘Kole roga’ strikes arecanut plantations in Dakshina Kannada again
The impact of falling rain drops may splash zoospores into air in droplets. The officer said the department would compile its data on Tuesday as it has sought details on the extent of land affected from its taluk offices. Another symptom is the presence of cankers which are found in red maple, papaya, rubbermangosand cacao.
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The hyphae invade inter- or intracellularly and produce sparsely distributed finger-shaped, occasionally branched haustoria in the host cells. Comment Name ov Email will not be published required Website Please enter an answer in digits: They are deciduous, pedicellate, and papillate.
Control of fruit rot or koleroga disease of arecanut (Areca catechu L.) 
In mangoes, the pathogen is known to kill young plants, specifically nursery plants. In water, however, zoospores are released from germinating sporangia. Though the farmers did take up the first round of spraying in July, the disease could not be controlled, he said, adding that his own plantation was hit. For PC, position your mouse cursor on the featured image, click the right mouse button, and choose “Save Picture As The first symptoms are water-soaked lesions on the nut surface near the calyx.
The infected fruits loose their natural green colour. Contact Us – Report a Bad Link. Continuous rain with good light disfavour disease spread because the plenty of sporangia and, in turn, the zoospores produced in these conditions are washed off by the continuous rain.
One common symptom of P. Phytophthora Water koleroag plant pathogens and diseases Coconut palm diseases. The green colour of the nut-shell aeecanut darker green and the early symptoms gradually spread ultimately covering the entire surface of the nut.
Root rots are another symptom of P. Arecant zoospore-containing droplets may be further dispersed by wind and become the inoculum for infecting fruit and occasionally stems of papaya in the fields.
Covering the arecanut branches with polythene bags as a prophylactic measure provides cent percent control of the disease but it is costlier than fungicide spray. The first appearance of the koleroga is on the nuts two or three weeks after rains begin.
‘Kole roga’ strikes arecanut plantations in Dakshina Kannada again – The Hindu
One spray of Bordeaux mixture in the month of May as prophylactic measure and arefanut after 6 weeks during break in the monsoon prove quite effective in controlling disease. They are easily washed off and each detached sporangium contains a short pedicel.
Kawakamia carica Hara  Phytophthora arecae L. Related Topics Karnataka Mangalore. 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.
Control raecanut As mechanical control measure, the areca bunches can be covered with polythene covers before the start of the heavy monsoon showers. 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.