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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 Dyanamics of inoculum affecting occurrence of karnal bunt epidemic in wheat(Department of Plant Pathology College of Agriculture, 2001) Kaur, Sarbjeet; Chahal, S. SThesisItem 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 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.ThesisItem Open Access RESPONSE OF COTTON GENOTYPES TO RELATION TO INDUCTION OF RESISTANCE AGAINST COTTON LEAF CURL DISEASE(PAU Ludhiana, 2013) Ritu Raj; P S, SekhonThe present study was conducted to check the response of different American cotton cultivars namely RS 921, LH 2076, PIL 8, Ankur 3028 BGII and a desi cotton variety LD 694 to Jasmonic acid (JA) and Salicylic acid (SA) in induction of resistance against cotton leaf curl disease (CLCuD). Different cotton cultivars were grown in pots under screen cages. At four to six leaf stage potted plants of different cotton cultivars were treated with different concentration of JA and SA i.e. 50 μM, 100 μM, 150 μM, 200 μM respectively and water sprayed plants of corresponding genotypes served as control. Quantification of proteins was done using spectrophotometric method from the leaf samples collected at 24, 48, 72, 96 hrs and a week after treatment with JA and SA. Application of JA and SA resulted in the induction of proteins 24 hrs after treatment. After a week interval at 150 μM concentration of JA maximum protein induction of 19.9 mg/g fr. wt., 16.7 mg/g fr. wt., 19.6 mg/g fr. wt., 15.0 mg/g fr. wt. and 14.4 mg/g fr. wt. was recorded in RS 921, LH 2076, PIL 8, Ankur 3028 BGII and LD 694 respectively whereas, in case of SA 200 μM concentration showed maximum protein induction i.e 10.6 mg/g fr. wt., 9.3 mg/g fr. wt., 9.9 mg/g fr. wt., 9.0 mg/g fr. wt., 8.1 mg/g fr. wt. in RS 921, LH 2076, PIL 8, Ankur 3028 BGII and LD 694 respectively. In the induction of proteins JA was found to be more effective than SA. Electrophoretic study of cotton cultivars treated with 150 μM of JA and 200 μM of SA revealed the induction of Pathogenesis-related (PR) proteins ranging from 15-45 kDa along with some other proteins as well. JA and SA applied at different concentrations affected the CLCuD incidence and severity when inoculated with viruliferous whiteflies (Bemesia tabaci) in screen cages. Lower disease incidence as well as disease index was observed with JA when applied @ 150 μM and SA @ 200 μM. Disease incidence was 37%, 30%, 30% and disease index was 48%, 40%, 40% in RS 921, LH 2076, Ankur 3028 BGII at 150 μM concentration of JA whereas, at 200 μM SA disease incidence was 48%, 36%, 34% and disease index was 57%, 50%, 50% respectively in above mentioned cultivars and in their respective control values for disease incidence and disease severity were quite high. So, JA at 150 μM and SA at 200 μM concentration was found to be most effective in lowering the disease. Latent carry over detection of symptomless plants treated with 150 μM of JA and 200 μM of SA through PCR amplification using DNA specific primers confirmed the presence of virus in all the tested cotton cultivars except LD 694 which signified that PR proteins does not eliminate virus. JA and SA application resulted in imparting tolerance with the induction of PR proteins but does not lead to complete resistance against the disease.
