Abstract:
Foot rot disease of betelvine is a serious fungal disease caused by Sclerotium rolfsii. Eight cultivars of betelvine were identified on survey period and found the highest and the lowest disease incidence in cultivars Bangla and Sanchi. Among the places, Mohanpur areas of Rajshahi district showed the highest disease infected areas than that of other places in different districts. The disease incidence also varied from place to place and year to year. During survey period, loamy soil planted borojes showed the highest disease incidence and sandy loamy soil borojes showed the lowest disease incidence. Flood systems irrigated borojes showed the highest and drip system irrigated borojes showed the lowest disease incidence of betelvine. Positive correlation existed between the disease incidence and the weather factors like rainfall, number of rainy days and relative humidities. The morphological variation was observed among ten isolates of S. rolfsii and isolates-5 showed the highest virulence. The highest per cent mycelial growth was observed in cellulose containing carbon sources medium and in sodium nitrate, nitrozen sources medium. Phytohormone 2, 4 D inhibited hundred per cent mycelial growth of the fungus. Clove and Cinnamum oil inhibited hundred per cent mycelial growth of the fungus at all concentrations at PDA medium. Urea fertilizer inhibited hundred percent mycelial growth of the fungus. Neem cake at 3% concentration inhibited hundred percent mycelial growth of the fungus. Cow dung and cow urine also had inhibitory effect on mycelial growth of the fungus. Nicotinic acid showed inhibitory effect of the fungus. At all concentrations NaHCO3 and NH4HCO3 showed complete inhibition mycelial growth of the fungus. Complete inhibition of mycelial growth of S. rolfsii was observed with treatment after A. sativum and Lawsonia inermis plant extracts. Hundred per cent mycelial growth inhibition was observed in Allium sativum and Lawsonia inermis, extracts at all concentrations in dried plant extracts. Hundred per cent mycelial growth inhibition was observed in Allium sativum ethanolic extracts. Complete inhibition of mycelial growth was observed in folicure and score fungicides. Herbicides Logran and 2, 4-D inhibited hundred per cent mycelial growth at all concentrations. Insecticides Desis and Moventa at all concentrations showed the same results. The highest per cent mycelial growth inhibition was observed in Trichoderma isolates-3 and the lowest in Trichoderma isolates-14. Among the ten Trichoderma isolates culture filtrates, isolates-3 had shown maximum per cent mycelial growth inhibition. The highest per cent disease incidence observed in 03 months old betelvine plantation. The lowest viability of sclerotia was observed at 5 cm depth with black plastic mulching. The lowest per cent disease incidences were recorded after treatment with 60 days solar heating. Maximum reduction in sclerotial germination was observed in soil amended with neem cake. No viability of the fungus was recorded upto 30 minutes hot water treatment at 52C and above. The lowest disease incidences were recorded after treatment hot water 0.5 Lit/kg cultural practices. The lowest disease incidence was recorded after treatment with neem cake, A. sativum, Score, Trichoderma iso-3, N200P100K100 respectively in field. The effect of crop rotation by sugarcane cultivation found the lowest disease incidence. Out of eight cultivars, only one cultivar, namely, sanchi showed moderately resistance reaction. In case of IDM effect, the lowest disease incidence was recorded in treatment T9 by (sanitation + neem cake 6t/h + application A. sativum extract 5% + application T. harzianum + score 1.0% drenching (neem cake, A. sativum and Trichoderma at quarterly intervals and score at monthly intervals) and increasing production number of leaves in lakh/hac/year.
Description:
This thesis is Submitted to the Institute of Biological Sciences (IBSc), University of Rajshahi, Rajshahi, Bangladesh for The Degree of Doctor of Philosophy (PhD)