EPIDEMIOLOGY AND MANAGEMENT OF LATE BLIGHT OF TOMATO

Simple item page
dc.contributor.advisorKANSAL, SANDEEP
dc.contributor.authorKAUSHAL, SONIA
dc.date.accessioned2019-08-06T05:21:10Z
dc.date.available2019-08-06T05:21:10Z
dc.date.issued2019-04
dc.description.abstractABSTRACT Late blight caused by Phytophthora infestans (Mont.) de Bary has been recorded as one of the most destructive disease of tomato among various other diseases. It appeared in moderate to severe form in different tomato growing areas of Solan, Sirmaur, Shimla and Kullu districts of Himachal Pradesh. The different isolates of fungus collected from infected leaves and fruits of diseased plants revealed of white to creamish white, submerged to densely arial mycelium on OMA. Mycelium was coenocytic with sympodial branching of sporangiophores bearing ovoid to limoniformsporangia. The molecular identification revealed a PCR product of 900bp using ITS1 and ITS4 primers. Thus, based upon morphological, cultural characters and molecular characters the causative fungus was identified as Phytophthora infestans (Mont.) de Bary. The pathogenicity tests revealed peculiar symptoms on leaves as water soaked lesions which later enlarged rapidly and turned to black necrotic spots bearing mildew like downy growth covering most of leaf surface. Dark olivaceous greasy spots covering fruit surface were also observed. The variability study of different isolates of Phytophthora infestans (Mont.) de Bary collected from different tomato growing localities of H.P had manifested varied cultural, morphological, pathogenic and molecular characters. Epidemiological studies revealed that the temperature of 20ºC, relative humidity of 100%, leaf wetness period of 24 h and inoculum concentration of 5x104 sporangia/ml were optimum for the rapid progression of disease reflecting significant higher infection rate under artificial epiphytotic conditions. Under field conditions, disease was affected by variation in weather variables, as cool (16-20°C) and wet weather coupled with high relative humidity (>90%) favoured the progression of late blight disease. The screening of twenty seven genotypes using detach leaf and whole plant assay revealed Arka meghali, Solan Lalima, Him Sona, EC-526146 and BT-1012 as moderately susceptible against the disease. In vitro and in vivo evaluation of fungicides indicated Sectin 60 WG (fenamidone 10%+ mancozeb 50%) and Curzate M8 (cymoxanil8%+mancozeb64%)) as potent inhibitors of P.infestans while garlic and neem extracts were most promising amongst different botanicals. Trichoderma harzianum had proved the most efficacious antagonist. Field evaluation studies inferred the soil application of Trichoderma harzianum @ 2.5 Kg/50 FYM/ha in combination with six periodic spray of fungicides including fenamidone 10%+ mancozeb 50% @ 0.2% followed by copper oxychloride @ 0.3% and mancozeb @ 0.25% at ten days interval started with the initiation of disease to be most efficacious in limiting late blight of tomato and enhancing the fruit yield (532,75q/ha) with ICBR ratio of 1:16.50.en_US
dc.identifier.urihttp://krishikosh.egranth.ac.in/handle/1/5810119411
dc.keywordsLate blight, tomato, Phytophthora infestansen_US
dc.language.isoenen_US
dc.pages91+viien_US
dc.publisherUHF,NAUNIen_US
dc.subPlant Pathologyen_US
dc.subjectnullen_US
dc.themeLate blight, tomato, Phytophthora infestansen_US
dc.these.typePh.Den_US
dc.titleEPIDEMIOLOGY AND MANAGEMENT OF LATE BLIGHT OF TOMATOen_US
dc.typeThesisen_US
Files
Original bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
PDF Ph.D. Thesis Sonia Kaushal (2019) Plant Pathology.pdf
Size:
19.21 MB
Format:
Adobe Portable Document Format
Description:
PLANT PATHOLOGY
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Theses