Browsing by Author "GAUTAM, HARENDER RAJ"
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ThesisItem Open Access DEVELOPMENT OF BIO-FORMULATION BASED ON BOTANICALS AND YEASTS AGAINST Alternaria spp. CAUSING LEAF SPOTS IN CAULIFLOWER(UHF,NAUNI, 2021-09) PARWAN, SONALI; GAUTAM, HARENDER RAJABSTRACT The present study on Alternaria leaf spot of cauliflower (Alternaria brassicicola (Schwein.) Wiltshire) were undertaken in relation to prevalence during 2019 and 2020 crop seasons. Characteristic symptoms of the disease were characterized by the presence of yellow, dark brown to black circular leaf spots with target like concentric rings. Under warm and humid weather conditions, centers of the lesions may fall out, giving the leaf spots a shot-hole appearance. Individual spots coalesce into large necrotic areas and leaf drop can occur. The pure culture of the pathogen was isolated over PDA. While studying the morphology of the test pathogen it was found that the mycelia (2.5-6.02 μm) were brown or olivaceous brown, septate and profusely branched in old cultures whereas pathogen produced conidiophores of 35- 45×5-8 m on which dark conidia were formed which ranged from 44-55×11-16 m in size and had 5-8 transverse and 0-5 longitudinal septa and are muriform with no beak formation. On the basis of morphological characters, the associated pathogen was identified as Alternaria brassicicola (Schwein.) Wiltshire. Pathogenicity of Alternaria brassicicola was proved following Koch’s postulates on cauliflower cv. “Pusa Snowball K1”. The pathogen exhibited initial symptoms after 120.30 h and 62.10 h of inoculation on potted plants and detached leaves, respectively. For disease management, botanicals, yeasts and their combinations were evaluated against test pathogen both under in vitro and in vivo conditions. Among botanicals, Karvaya (Roylea elegans) (52.64 per cent) recorded maximum mycelial inhibition while in case of yeasts, BK5 and BK7 was most effective and significantly superior to all other treatments with 59.72 and 55.56 per cent inhibition in mycelial growth, respectively. Out of botanicals, yeasts and well known fungicides, Yeast BK5 @ 5 per cent was found superior with 94.07 per cent mycelial growth inhibition which was comparable with Mancozeb @ 0.25 per cent. Microbial count of the yeast based foliar sprays was determined to find out the microbial strength of the treatments. Butter milk had more (log10 (CFU/cm2) = 11.26) microbial count followed by Field formulation 2 + Yeast BK5 (10.77) as compared to other bio-formulations. Field evaluation studies referred the application of five foliar sprays of Field formulation 2 + Yeast BK5 @ 5 per cent at 10 day interval started with the inhibition of disease as most efficacious in limiting the Alternaria leaf spot of cauliflower (8 per cent) and enhancing the yield (176.67 q/haThesisItem Open Access POTENTIAL OF ANTAGONISTIC YEASTS, BOTANICALS AND GRAS CHEMICALS AGAINST POST-HARVEST ROT CAUSED BY Penicillium digitatum Sacc. IN KINNOW MANDARIN(UHF,NAUNI, 2022-10) ARAVINTHKUMAR A; GAUTAM, HARENDER RAJABSTRACT The present investigation titled “Potential of antagonistic yeasts, botanicals and GRAS chemicals against post-harvest rot caused by Penicillium digitatum Sacc. in Kinnow mandarin” was conducted in the laboratories of the Department of Plant Pathology, Dr. YS Parmar University of Horticulture and Forestry, Nauni-Solan. During the survey in different Kinnow growing areas of North India (2021-2022), disease incidence of the post-harvest green mould rot ranged between 14 and 27.5 per cent. Maximum severity (23%) of disease was recorded in Kinnow wholesale market of Abohar. Seven yeast isolates isolated from different sources, nine locally available botanicals and six different GRAS chemicals were evaluated against Penicillium digitatum under in vitro conditions. Among yeasts, Saccharomyces cerevisiae strains viz., R, BK 4 and BK 6 were found to inhibit the mycelial growth of the pathogen by 66.66, 53.50 and 48.14 per cent, respectively. Among botanicals, aqueous extracts of Ashy Roylea (84.81%), Curry leaf (78.70%) and Peppermint (76.47%) were found to be effective in inhibiting the mycelial growth of the pathogen. In GRAS chemicals, Salicylic acid (2500 ppm), Sodium bicarbonate (5000 ppm) and Potassium sorbate (7500 ppm) resulted in cent per cent inhibition of mycelial growth of the pathogen. Yeasts, botanicals (10%) and GRAS chemicals (2500 ppm) which were found effective under in vitro conditions were further evaluated as fruit protectants under in vivo condition to observe their efficacy against Penicillium digitatum at injured site of Kinnow fruits. Fruits treated at injured site with Saccharomyces cerevisiae BK 6, Ashy Roylea and Salicylic acid resulted in 50, 33.33 and 66.7 per cent reduction in disease incidence, respectively. Similarly, Saccharomyces cerevisiae BK 6, Ashy Roylea and Salicylic acid also reduced the disease severity by 63.3, 33.3 and 78.0 per cent, respectively. Yeasts, GRAS chemicals (2500 ppm) and botanicals (10%) which were found effective under in vitro conditions were further evaluated as fruit dip treatments. Fruits dipped with Saccharomyces cerevisiae R, Salicylic acid and Ashy Roylea resulted in 83.33, 100 and 50 per cent reduction in disease incidence, respectively. Simultaneously, Saccharomyces cerevisiae R, Salicylic acid and Ashy Roylea also reduced the disease severity by 98.67, 100 and 80 per cent, respectively. Saccharomyces cerevisiae treated fruits were found significantly superior over botanicals and GRAS chemicals in improving the quality of Kinnow fruits viz., Titratable acidity (1.01%), TSS (14.6°Brix) and reducing sugars (6.99%). It was also found that the increased content of nitrogen (24.37%), phosphorus (40%), magnesium (66.67%), iron (4.52%), copper (-39.72%), zinc (25.14%) and manganese (80.02%) have positive correlation, whereas potassium (7.32%) and calcium (61.22%) have negative correlation with disease incidence in the treated Kinnow fruits.ThesisItem Open Access STUDIES ON PHYLLOSTICTA LEAF SPOT OF PEAR(DEPARTMENT OF MYCOLOGY AND PLANT PATHOLOGY DR. YASHWATN SINGH PARMAR UNIVERSITY OF HORTICULTURE AND FORESTRY, SOLAN, 1987) GAUTAM, HARENDER RAJ; GUPTA, V. K