Culture and physiological variability in Rhizoctonia solani, responsible for foliar and lesions on aerial part of soybean

Foliar blight of soybean is one of the major fungal diseases. Rhizoctonia solani isolated from soybean growing in tarai regions of Uttarakhand. Six isolates of R. solani has been characterized on the basis of cultural and physiological nature such as colony diameter, growth, colour and sclerotia formation were recorded. Potato Dextrose Agar (PDA) was found best for growth and development. Two isolates (Lakhimpur and Pantnagar) covered the whole plates (90 mm) in 48 hrs. However, maximum number of sclerotia and weight was recorded on Czapek Dox agar medium. Overall radial growth supporting is recorded Corn Meal Agar Medium. Varied range of temperatures i.e. 10, 15, 25, 30, 35 and 400C was tested and found better growth of different isolates of R. solani at 10 - 400C, with an optimum growth temperature at 300C. Isolates were grown on five broth media (Asthana & Hawkers, Potato Dextrose Agar, Czapek’s Dox Agar, Corn Meal Agar and Richards Agar) for fresh, dry weight and oat meal broth culture filtrates of all isolates was used in phytotoxic effects. It recorded that maximum fresh and dry weight was observed on corn meal agar medium. The maximum reduction in radical and plumule length of germinating seeds were recorded in Haldichaur isolate

A study on fungicides potential and incidence of sheath rot of rice caused by Sarocladium oryzae (Sawada)

Sheath rot, Sarocdadium oryzae (Sawada) Gams. and Hawksw., has recently become a serious disease of rice when climatic conditions are unfavorable during flag sheath development. In this study systemic and nonsystemic fungicides were tested against S. oryzae. Maximum inhibition of radial growth (76.53%) was recorded at 10.0ppm of tebuconazole fungicides. In non-systemic fungicides, maximum inhibition of radial growth (78.86%) was recorded at 200.0ppm. Comparative efficacy of fungicides on sheath rot was tested during Kharif 2008-2009. Foliar spray of tebuconazole was found superior overall other treatments giving reduction in disease severity (59.01-64.33%), which was followed by followed by carbendazim (48.70-55.28%), and also increased grain yield per plant (45.06-65.84%), grain yield per plot (45.57-65.85%), 1000-grains weight (10.80-52.58%) and reduction in chaffiness (48.07-53.80%). Among non-systemic fungicides chorothalonil was found best in managing sheath rot, giving reduction in disease severity (35.68-38.85%), and also increased grain yield per plant (24.78-44.74%), grain yield per plot (24.52-44.57%), 1000-grains weight (4.25-35.47%) and reduction in chaffiness (15.74-45.96%) as compared to check. Another field experiment was conducted during Kharif 2009-10 to observe sheath rot incidence on rice cultivars in Tarai region. The incidence was recorded in thirty three varieties; only varieties (Type-3 and Basmati-370) were recorded as free from disease symptoms

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Not AvailablePlant growth-promoting rhizobacteria (PGPR) have multifarious beneficial activities for plant growth promotion; act as source of metabolites, enzymes, nutrient mobilization, biological control of pests, induction of disease resistance vis-a-vis bioremediation potentials by phytoextraction and detoxification of heavy metals, pollutants and pesticides. Agrochemicals and synthetic pesticides are currently being utilized widely in all major field crops, thereby adversely affecting human and animal health, and posing serious threats to the environments. Beneficial microorganisms like PGPR could potentially substitute and supplement the toxic chemicals and pesticides with promising application in organic farming leading to sustainable agriculture practices and bioremediation of heavy metal contaminated sites. Among field crops limited bio-formulations have been prepared till now by utilization of PGPR strains having plant growth promotion, metabolites, enzymes, nutrient mobilization and biocontrol activities. The present review contributes comprehensive description of PGPR applications in field crops including commercial, oilseeds, leguminous and cereal crops to further extend the utilization of these potent groups of beneficial microorganisms so that even higher level of crop productivity and quality produce of field crops could be achieved. PGPR and bacteria based commercialized bio-formulations available worldwide for its application in the field crops have been compiled in this review which can be a substitute for the harmful synthetic chemicals. The current knowledge gap and potential target areas for future research have also been projected.Not Availabl