Integraed Management of Tomato (Lycopersicon Esculentum Mill.) Wilt Caused by Fusarium Oxysporum F.sp.lycopersici (Sacc.) Snyder and Hansen

Abstract

Tomato (Lycopersicon escu/entum Mill.) is one of the important, world's largest cultivated vegetable crop. Among the fungal disease of tomato, Fusatium wilt is one of the most wide spread and destructive disease. The typical symptoms of the disease are characterized by appearance of deming of vein lets and chlorosis of the leaf, soon the petiole and leaves droop, wilt and die. The pathogen was isolated from naturally infected plant pa1is and the fungus was purified by single spore isolation technique. In the pathogenicity test, higher disease incidence per cent was obtained when the inoculum was mii{ed in pots fi.lled with sterilized soil seven days beiore sowing. The best suitable medium for growth found to be Potato dextrose agar followed by Richard's medium. The pathogen was fmmd to be grown in a wide temperature range from 1 0°C to 40°C and the best fi.mgal growth v-1as observed at 25°C. The best growch of the pathogen was obtained at 6.5 pH. Out of nine fungicides evaluated under laboratory conditions. carbendazim and thiophanate-methyl completely inhibited the growth of the pathogen. Efi:icacy of two antagonists was evaluated by dual culture method against F. oxysporum f.sp. lycopersici (Sacc.) in vitro and it was observed that T. hmzianum was more capable of suppressing the grovvth of the pathogen in comparison to Ps. jluorescens. The efficacy of antagonist (T. harzianum) was also evaluated by volatility test against F f.sp. lycopersici (Sacc.) and it was observed that T. harzianum produced some volatile compounds which inhibited the growth of the pathogen under in vitro conditions. The efficacy of the antagonist (T. harzianum) & (Ps. jluorescens) was evaluated as seedling and soil treatment in field condition. The disease was most effectively controlled by integrated mangement of chemical seedling treatement with carbendazim @ 2g/litre + soil application ofT. hmzianum @2.5 kglha + Ps. jluorescens @1.5 kg/ha with pressmud @ 5 tones/ha. Other treatments were also found effective in reducing disease incidence in an order as biological seedling treatment with (T. harzianum + Ps. f!uorescens ) + soil application of T. harzi.amum + Ps. jluorescens with Vermicompost and biological seedling treatment with (T. harzianum + Ps . .fluorescens) + soil application of (T. harzicmum + Ps. fluoi'escens) mixed with FYM. The efficacy of the biocontrol agents (T. harzianum + Ps. ;?uorescens) and fungicide (carbendazim) with integration on growth promotion of root, shoot length and number of leaves/plant was evaluated in pot experiment and it was observed that seed treated with carhendazim @ 2g/kg + soil application with T. harzianum @2.5 kg/ha + Ps. jluorescens @ 1.5 kg/ha mixed with pressmud @ 5 tones/ha showed highest growth promotion. Other treatments were also found effective in growth promotion in an order as biological seed treatment (T. harzianum + Ps. jluorescens) +soil application of (T. harzianum + Ps. fluorescens) with vermicompost and biological seed treatment (T. harzianum + Ps. jluorescens) + soil application of (T. harzianum + Ps. jluorescens) mixed with FYM. It is being concluded that the T .. harzianum as soil application+ carbendazim as seed treatment will reduce the disease incidence and enhance fruit yield.