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  • ThesisItemRestricted
    Biocontrol of Phomopsis Blight of Brinjal
    (Department of Plant Pathology College of Agriculture, 2002) Bala, Anju
  • ThesisItemRestricted
    Epidemiology and management of anthraconose of mango (Mangifera India L.)
    (Department of Plant Pathology College of Agriculture, 2003) Sharma, Abhishek; Verma, K. S
  • ThesisItemOpen Access
    Veterinary and Mamagement of colletotrichum capsiei (syd.) Butler and bisby on Chillies
    (Department of Plant Pathology College of Agriculture, 2002) Bhawana; Mohan, Chander
  • ThesisItemOpen Access
    Studies on factors affecting development of kernel smut of rice
    (Department of Plant Pathology College of Agriculture, 2000) Anita; Chahal, S. S
  • ThesisItemRestricted
    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. S
  • ThesisItemOpen Access
    Induction of resistance in potato against phytophthora infestans (mont.) De bary
    (Punjab Agricultural University, Ludhiana, 2009) Sudhir Kumar; Thind, T.S
    Late 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.
  • ThesisItemOpen 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.