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ThesisItem Restricted Biocontrol of Phomopsis Blight of Brinjal(Department of Plant Pathology College of Agriculture, 2002) Bala, AnjuThesisItem Restricted Epidemiology and management of anthraconose of mango (Mangifera India L.)(Department of Plant Pathology College of Agriculture, 2003) Sharma, Abhishek; Verma, K. SThesisItem Open Access Veterinary and Mamagement of colletotrichum capsiei (syd.) Butler and bisby on Chillies(Department of Plant Pathology College of Agriculture, 2002) Bhawana; Mohan, ChanderThesisItem Open Access Studies on factors affecting development of kernel smut of rice(Department of Plant Pathology College of Agriculture, 2000) Anita; Chahal, S. SThesisItem Restricted Management of white rot of gobhi sarson incited by sclerotinia sclerotiorum (Lib.) de bary through botanicals and biocontrol agents(Department of Plant Pathology College of Agriculture, 2000) Srivinasan, A; Kang, I. SThesisItem Open Access Gene scouting for rust(s) resistance in wheat germplasm(Punjab Agricultural University, Ludhiana, 2018) Sandeep Singh; Jaspal KaurDuring the Rabi crop season of the year 2016-17, six hundred and seven (607) wheat germplasm lines were evaluated in the field and found sixty six lines resistant to stripe rust, three hundred thirty six lines resistant to leaf rust and thirty four lines resistant to both stripe rust and leaf rust. In the second year (2017-18), the wheat germplasm was evaluated against different pathotypes of Puccinia striiformis tritici (Pst) (238S119, 110S119, 46S119 and 78S84) and P. triticina (Pt) (77-5 and 77-9) at seedling stage. From seedling reaction test it was observed that fifty six (56) lines and one hundred and ten lines (110) possess resistance against all the pathotypes of Pst and Pt tested respectively. All the test wheat lines were categorized into different clusters based on final rust severity (FRS), area under disease progress curve (AUDPC), relative area under disease progress curve (rAUDPC) and coefficient of infection (CI). Fifty two (52) lines were highly resistant to stripe rust and one hundred seventy one (171) lines were highly resistant to leaf rust and remaining lines showed different reaction based on the particular range of slow rusting parameters. Genotypes which showed resistance either to stripe rust or to leaf rust were further evaluated against mixture of Pst pathotypes (238S119, 110S119, 46S119 and 78S84) and individually against 110S119 and 46S119. For leaf rust evaluation was done by using mixture of Pt pathotypes (77-5, 77-9, 104-2 and 12-2) and 77-5 and 77-9 in isolation. NILs carrying known APR genes and susceptible checks for also used for comparison purpose under the field conditions. The results of the present study revealed that fifty two lines has resistance against most prevalent pathotypes of stripe rust in Punjab (238S119, 110S119, 46S119 and 78S84) and one hundred seventy one (171) lines have resistance to mixture (77-5, 77-9, 104-2 and 12-2) pathotypes of Pt. Reaction on NILs showed that Yr1, Yr5, Yr10, Yr15, Yr24, Yr26, Yrsp, Yr31, Yr51, Yr47, Yr57, Yr63 are effective against most prevalent pathotypes of stripe rust in Punjab and Lr2a, Lr2b, Lr8, Lr19, Lr22a, Lr23, Lr(27+31), Lr45, Lr51, Lr53, Lr57, Lr58, Lr76 are effective against leaf rust pathotypes. For deployment of resistance sources, total 40 crosses were made. Eleven lines resistant to stripe rust were crossed with PBW621 and twenty nine lines resistant to leaf rust were crossed with HD3086. F1 and F2 plants obtained were tested separately against stripe rust and leaf rust. From the disease reaction of majority of F1 and F2 populations it was concluded that resistance in these lines is controlled by single dominant gene against both stripe and leaf rust.ThesisItem Restricted Epidemiology and management of Stemphylium blight of garlic(Punjab Agricultural University, Ludhiana, 2018) Salaria, Pooja; Amarjit SinghStemphylium blight of garlic caused by Stemphylium vesicarium (Wallr.) Simmons is commonly found in garlic growing areas of Punjab. The lesions colonized by S. vesicarium was round to elliptical. The most effective media for growth and sporulation of S. vesicarium was V8 juice agar media. Maximum disease severity was recorded in Moga district whereas minimum in Ludhiana. Leaf wetness duration of minimum 8 hrs is necessary for the infection but maximum disease developed at 24 hrs of leaf wetness duration. The optimum temperature for the disease development was 25ºC whereas it was nil at 15ºC. The disease severity increases with the increase in age of the plant and it was found maximum on 105 days old plants. The garlic plants sown on 6-16 November exhibited minimum disease severity. No genotype exhibited resistance to disease under natural and artificial epiphytotic conditions. The performance of PG-17 and PG-18 was better in comparison to other genotypes tested against Stemphylium blight under artificial epiphytotic conditions. Neem oil and Neem extract can be used as an alternative to Mancozeb 75% WP for eco-friendly management of the disease. These can be useful in devising integrated management strategy for Stemphylium blight of garlic.ThesisItem Open Access Induction of resistance in potato against phytophthora infestans (mont.) De bary(Punjab Agricultural University, Ludhiana, 2009) Sudhir Kumar; Thind, T.SLate blight of potato caused by Phytophthora infestans is a serious disease of potato and is generally managed by the application of fungicides. Induced resistance in plants offers viable alternative to fungicidal control of diseases. Attempt was made to induce resistance in potato against P. infestans through application of inducer chemicals and bioagents. Seven inducer chemicals viz. salicylic acid, benzothiodiazol, fosetyl-Al, calcium chloride, ethylene, hydrogen peroxide and potassium phosphate along with bio-agents Pseudomonas fluorescens, Trichoderma viride and Trichoderma harzianum at different doses were used for inducing resistance in potato cvs. Kufri Chanramukhi and Kufri Badshah against late blight. The treatments included tuber treatment, foliar application and both tuber treatment and foliar application. Maximum resistance was induced by salicylic acid and benzothiadiazol @ 50 and 100 µg/ml, respectively, when tuber treatment was combined with foliar application. Under field conditions, maximum control of the disease was obtained in treatment with salicylic acid @100µg/ml followed by benzothiadiazol @100µg/ml. Treatment with fosetyl-Al was next in inducing resistance where considerable resistance was induced at 500 and 1000 µg/ml. Other treatments were found less effective. The bio-agents used in the present study failed to induce much resistance as evident from higher disease severity in these treatments. All treatments with inducers stimulated phenolics and enzymatic activities. The highest activity was obtained in plants treated with salicylic acid and benzothiodiazol @50 and 100 µg/ml, respectively. The inducers used also increased chitinase, peroxidase and phenylalanine ammonia lyase activity as compared with untreated control plants. The observation indicated that induced resistance in potato plants is promising for commercial application as a new approach for controlling late blight of potato.ThesisItem Open Access Etiology and management of foliar blight of barley(Punjab Agricultural University, Ludhiana, 2007) Girish Kumar; Sharma, Vineet K.The foliar blight of barley appeared to be a mixed infection of spot blotch and net blotch. However, majority of symptoms were of spot blotch. The isolated fungus was identified as Bipolaris sorokiniana. Eight single spore isolates of pathogen were obtained from infected leaves. All eight isolates sporulate on PDA medium. Pathogenic behaviour of selected isolates on four barley cultivars viz., PL426, PL419, PL172 and VJM201, wheat cultivars viz., HD2329 and PBW343 and Phalaris minor revealed that isolate I1 was more pathogenic on all barley cultivars but none of them produce disease on wheat cultivars and Phalaris minor. Early sowing increased the disease and it decreased significantly with each succeeding date of sowing. Increase in doses of fertilizers (N :P :K) increased the disease severity. The disease severity was found to be more in zero than conventional tillage. In the laboratory the results revealed that Tilt was most effective checked the fungal growth followed by Folicur/Raxil, Amistar and Vitavax. Score and Contaf were found to be least effective. Results of the field experiments were similar to those obtained in laboratory. In seed treatment, Vitavax + Thiram @ 3g each/kg seed controlled disease to maximum extent, followed by Vitavax + Thiram @ 1.5g each/kg seed, Amistar @ 2ml/kg seed. Raxil and bio-control agents were least effective. In foliar spray, Tilt was most effective, followed by Folicur and Amistar in controlling disease. Contaf and bio-control agents were least effective. In seed treatment & foliar spray, Vitavax + Thiram @ 3g each & Tilt @ 0.1% spray were most effective. Bio-control agents were least effective as seed treatment and foliar spray in controlling disease. Calcium chloride (0.3%) was most effective in inducing resistance.
