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Subject: Plant Pathology × Author: Bagaria, Pravin Kumar × End date: 2012 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Integrated management of root rot of sesame (sesamum indicum L.) caused by macrophomina phaseolina (Tassi) goid
    (CCSHAU, 2012) Bagaria, Pravin Kumar; Sharma, S. K.
    Root-rot/charcoal-rot caused by Macrophomina phaseolina (Tassi) Goid. is one of the most important soil-borne disease in south-western parts of Haryana. Efforts were made to manage the disease with application of various methods. Root-rot incidence (seedling and maturity stage) and intensity (at maturity) was observed maximum in sandy soil and decreased with increase in clay content. The minimum disease incidence (pre-emergence, post-emergence damping-off, total seedling mortality) and intensity of charcoal rot was observed when optimum irrigation was applied at daily and after every 3rd day as compared when the pots were irrigated after every 7th and every 10th day. Carbendazim (50, 100, 200, 500 ppm), propiconazole (100, 200, 500 ppm) and hexaconazole (200, 500 ppm) exhibited complete (100%) mycelial growth inhibition of M. phaseolina in vitro conditions. The evaluation of 11 plant extracts at 5, 10, 20 and 40 per cent concentrations revealed that aqueous extract of garlic clove was proved to be most effective inhibitor of M. phaseolina in vitro. Onion bulb extract ranked as the next most effective in inhibiting mycelial growth of pathogen followed by extracts of bougainvillea, clerodendron and datura leaves. All antagonists viz., Trichoderma harzianum, T. viride and Pseudomonas fluorescens significantly reduced mycelial growth of M. phaseolina in vitro. However, T. viride and T. harzianum were proved the best with 70.27 and 67.5 per cent mycelial growth inhibition of M. phaseolina, respectively. Neem leaves (50 g/kg soil) was the most effective in reducing root-rot incidence/intensity under screenhouse conditions followed by clerodendron and bougainvillea leaves amendments. Neem seed powder and neem cake each @ 20 g/kg soil applied as organic amendment showed significant reduction in root-rot incidence/intensity as compared to control followed by jamun seed powder and castor cake. Dry seed dressing (1 g/kg seed) and soil application (5 g/kg soil) of bioagent, Trichoderma viride at various intervals produce lesser pre-emergence, post-emergence damping-off and charcoal rot incidence/intensity at maturity compared to control. Seed treatment as well as spray @ 100 ppm with either Isonicotinic acid (INA) or Salicylic acid (SA) was also found effective in reducing disease incidence/intensity under screenhouse conditions. Seed treatment with carbendazim (0.25%) showed the lowest disease incidence and intensity as compared to other treatments in the screenhouse and field conditions. In artificially inoculated conditions also (inoculated at pith region), seed treatment with carbendazim (0.25%) and soil application of neem cake (0.5 kg/m2) were the most effective. IDM (Integrated Disease Management) modules developed revealed that, soil application of neem cake (0.5 kg/m2) + Trichoderma viride (0.2 kg/m2) followed by seed treatment with carbendazim (0.25%) showed the lowest charcoal-rot incidence and intensity under field conditions.