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MYCOFLORA INVOLVED IN POST HARVEST FRUIT ROT OF PAPAYA (Carica papaya L.) AND ITS MANAGEMENT

KrishiKosh

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Title MYCOFLORA INVOLVED IN POST HARVEST FRUIT ROT OF PAPAYA (Carica papaya L.) AND ITS MANAGEMENT
 
Creator PATEL, JITENDRA B.
 
Contributor MEHTA, B.P.
 
Subject fruits, diseases, papayas, fungi, biological phenomena, application methods, pathogens, markets, irrigation, harvesting
 
Description Papaya (Carica papaya L.) is one of the most important
commercially grown fruit crops in tropical and sub-tropical regions of
the world. India is one of the leading country in production of papaya,
Gujarat is major contributor in production. It is also grown extensively
in south Gujarat. During the survey, occurrence of fruit rot disease of
papaya was noticed in a serious proportion inflic ting heavy losses in
vegetable markets of Navsari and neighboring cities in popular variety
Taiwan Red Lady. Considering the seriousness of the problem, the
present investigation was carried out to find out exact cause and suitable
measures for the management of fruit rot disease of papaya .
Market survey of four major markets of the south Gujarat was
carried out in two consecutive years i.e. 2011 and 2012 for prevalence of
fruit rot of papaya disease which revealed average maximum per cent
disease incidence (PDI) in Sardar market, Surat as 15.13 % followed by
Dudhiya Talav market, (14.40%) Navsari, Sardar market, Billimora
(13.80%) and Morarji Market, Navsari (12.26%). Out of five months
observations, the maximum fruit rot (Av.19.50%) incidence was recorded
in the month of April. It was also found that maximum rotted fruits
yie lded Colletotrichum sp. (44.14%) followed by other five rotting
pathogens.
Isolations from rotted fruits collected from different markets
revealed association of different six fungal pathogens which based on
morphological features, cultural characteristics and as per report
received from Indian Type Culture Collection (ITCC), New Delhi, were
identified as Colletotrichum gloeosporioides (ITCC No.: 8173.11),
Fusarium solani (ITCC No.: 8176.11), Alternaria alternata (ITCC No.:
8174.11), Rhizopus stolonifer (ITCC No.: 8178.11),, Aspergillus flavus
(ITCC No.: 8175.11), and Aspergillus niger (ITCC No.: 8177.11). The
pathogenicity was proved by artificial inoculation viz., cork borer, knife
and pin prick injury methods and all the isolates gave higher per cent
infection of fruit rots.
Inoculation through various avenues revealed that the fungus
(C. gloeosporioides) can enter the fruits through natural opening of stem
end without pedicel and with pedicel as well rarely enters through lateral
end of the fruit and caused lower infection whereas, heavy infection was
found through the knife injury wounds.
Effect of different temperatures and humidity were studied on
the fruit rot (C. gloeosporioides ) of papaya which revealed that the
inoculated fruits incubated at 300C temperature cause faster symptom
initiation (1.2 days) as well as took less time (5.0 days) for 75 per cent
rotting as compared to other incubation temperatures. In case of
incubation at 95 per cent humidity, early symptom initiation (1.0 day)
was observed as well as quick rotting of the fruits (4.2 days for 75 %
rotting) occurred as compared to lower humidity incubation .
The effect of the papaya fruit latex on different six fruit
rotting fungal pathogens was studied by poisoned food technique using
15 per cent fruit latex in the medium (PDA) which showed highest
growth inhibition (73.70 %) in A. flavus, followed by A. niger, C.
gloeosporioides , A. alternata, R. stolonifer and F. solani.
Studies regarding nutritional content changes in fruits due to
infection of various fungal pathogens were undertaken showed
considerable decreased in the total soluble solids, total sugar and
ascorbic acid content of the infected fruits. Whereas, the reduc ing, nonreducing
sugar and titerable acidity of the fruits were as compared to
healthy ones.
Six varieties of papaya were screened against fruit rot
pathogen. Among them the variety Washington was found resistant
whereas, Solo showed moderately resistant. However, Sunrise and
Taiwan Red Lady were found moderately susceptible . Madhubindu was
found susceptible and the desi/local cultivar was found highly
susceptible to fruit rot disease.
Out of six different wrapping materials were tested wrapping
fruits with news paper showed the least disease incidence (8.33 %)
followed by wrapping with butter paper, tissue paper, brown paper bag,
alluminium foil and polyethylene bag were found effective against fruit
rotting pathogens.
Studies on hot water dip treatment (HWT) against the disease
revealed that HWT at 500C for twenty minutes recorded significantly
lowest disease incidence (6.00 %) and delayed the fruit rot (72 hrs)
disease infection.
Six phytoextracts of different plant species were screened at
10 per cent concentrations. Among them, leaf extract of deshi babul
proved significantly more effective in checking the fruit rot (4.67 %) as
well as taken maximum time (72 hrs) for fruit rotting initiation .
Out of six oils tested, castor oil recorded minimum (10.33
PDI) with late symptoms initiation (72 hrs), followed by palm oil, cotton
oil, soyabean oil, mustard oil and ground nut oil.
Pre inoculated fruits were dipped in cell suspension of seven
different isolates of antagonists. Pseudomonas aeruginosa Pa R (Rambhas)
isolate recorded minimum PDI (15.67%) as well as maximum duration (72
hrs) for the initiation of symptoms followed by rest of the fungal and
bacterial antagonists tested.
Six different fungicides were tested in fie ld condition as pre -
harvest sprayings for their effectiveness against post-harvest rot (C.
gloeosporioides ) at three different locations viz., Navsari, Gandevi and
Nizar. Two sprays of combi-product of carbendazim (12%) + mancozeb
(63%) at 14 days interval on entire fruit column @ 1 g / l (11 .00 %) and
mancozeb @ 1 g / l (12.11 %) showed least PDI o f post harvest fruit rot
followed by carbendazim @ 1g / l which was at par with combination
product of Strobilurin + Metiram @ 1 g / l and hexaconazole @ 1 ml / l.
the highest per cent disease incidence of post harvest fruit rot was
observed in kresoxim methyl @ 1ml / l in field conditions.
 
Date 2016-05-03T11:06:01Z
2016-05-03T11:06:01Z
2013-05
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/65744
 
Language en
 
Format application/pdf
 
Publisher Navsari Agricultural University, Navsari