Vishunavat, KarunaBhandari, Chandra Prabha2016-07-092016-07-092012-08http://krishikosh.egranth.ac.in/handle/1/68581Thesis-PhDFusarium Ear Rot of Maize caused by Fusarium moniliforme, commonly responsible for stalk and ear rot diseases in maize, causes significant qualitative and quantitative losses. Keeping in mind the importance of disease, present investigation was carried out on seed borne nature of pathogen, detection and location of infection in seed and other plant parts, transmission of pathogen from seed to seedling, losses in seed quality and Aflatoxin B1 production in storage, determination of disease severity, disease index, infection rate, area under disease progress curve and losses due to Fusarium Ear Rot incurred on artificial and natural field conditions. Suitable management strategies using different fungicides, bioagents and botanicals have been worked out with a view to formulate an effective management practice against the disease under field conditions. Deep freeze blotter was found to be the best for the maximum recovery of the pathogen from seeds. Histopathology of infected seed revealed location of the pathogen in the pericarp, endosperm and also in embryonal axis of the seed. The symptomatic kernels show the highest recovery of infection as compared to asymptomatic kernels. The pathogen was transmitted from seed to seedling and exhibited the symptoms of Fusarium infection in the form of white fluffy mycelial growth. Fusarium moniliforme, isolated from maize seed, when inoculated on other cereals, caused both pre emergence damping off and stunted seedlings in paddy and sorghum. The Czapex dox iprodione dichloran agar medium showed the highest selectivity to the mycelial growth of the fungus. The best carbon source favorable for the mycelial growth of Fusarium moniliforme is found to be Manitol while the best nitrogen source is Sodium nitrate and sulphur source is Magnesium sulphate. Culture filtrate of Fusarium moniliforme has been found with phytotoxic substances which may inhibit the growth of seedlings. In stored maize seed infected with Fusarium moniliforme revealed higher Aflatoxin B1 concentration than permissible Indian regulatory limit (30 μg kg l). Seed treatment with Polykote + Mancozeb + Dimethoate were found to be effective in which maximum seedling length, seed germination , vigour index and minimum un- germinated seed and seed rot was observed both in polythene and cloth bags at 10 th month of storage period. Polythene bags were found more suitable as compared to cloth bags for seed storage at different storage periods in most of the treatments. Tebuconazole completely inhibited the growth of the fungus at 50 ppm concentration followed by Bavistin at 100 ppm. At 50% concentration, plant extracts of Garlic, Turmeric, Ginger and Thuja reduced more than 65 % growth of Fusarium moniliforme. Trichoderma harzianum isolate Th 3 showed 73.33 % inhibition while Pseudomonas fluorescens isolate Pf6 gave 67.55 % inhibition of Fusarium moniliforme and were found to be the best among different isolates tested. Host cultivar response on artificial inoculation of Fusarium moniliforme was studied during 2010-11 and 2011-12. Among the methods tested for artificial inoculation, tooth prick method was observed to be the best and gave maximum disease severity, disease index, area under disease progress curve and minimum grain yield followed by pin prick and spray method in all the varieties. The rainfall is found directly proportional to both logarithmic and apparent infection rate of the disease. Variety Gaurav showed high degree of resistance to Fusarium Ear Rot under natural field condition. Among all the treatments, irrespective of chemicals, bioagents and botanicals Thiram (ST) @ 0.25% followed by two foliar spray of Folicur @ 0.1% at 15 days interval was found to be the best for both naturally infected cobs and cobs artificially inoculated with said fungus under field conditions for the management of disease. The minimum corn ear worm incidence was observed in treatment with Thiram (ST) followed by foliar spray of Folicur . However, There is no correlation between the methods of inoculation and incidence of corn ear worm but the corn ear worm is found to be directly related with the Fusarium Ear Rot severity.maize, rots, fungal diseases, Fusarium moniliforme, yield losses, stalks, plant pathogens, histopathology, damping offThesis