Integrated Disease Management of Stem Rot of Rice

Abstract

R1ce IS a majOr food constltuent of human dret, for ITI()(e than tw'IO th rd populaton of our country The drmatic conditions are favorable for the production of export quahty basmaU nee IntenSive culllva!Jon of nee has brought about a sMtm pest and drseases as reftected rn the predomnance of sheath blight. and blast and stem rot1n recent years Among these diseases, stem rot or nee occul'l rn most nee growing regrons of the world and IS the most prevalent and rmportant drsease of nee Stem rot drsease Is caused by SclerotiUm oryzae. the drsease Is sorl borne and rema1ns. marnly conf1ned to stem but 11 also attacks all the aenal plant pan Presently, the attempts for the management of nee stem rot have been drrected towards the use of res1stant culbvars. chen11cals and cultural practices Eight rsolates of Trichoderma wera collected and used n this study among these four Isolates are Trichoderma harvanum and 4 isolates are o: Trichoderma viride were collected from different sources Trichoderma Wide sJo..., grow"~ wtli e ISOlates of Trtchoderma harz~anum were fast growtng S oryzae grew over arange of pH (4 5-9 0) where as the radral growth S oryzae was best at pH 7 0 (90 00 mm) followed by 6 5 (83 58 mm). and 7.5 (79 51 mm), The mn1mum mycelial growth was observed tn 9 0 pH (58 28 mm) The pathogen (S oryzae) grew well at the temperature range 15 to 35 "C With redial growth (26.68 to 85 83 mm) The maXImum mhibttlon was recorded rn propconozale (79.96%) rollowed by carbendaz•m (77.69%) and manoozeb (75 27%) Two 1nsect1cides. Malathron and Endosulphan, were tested against S oryzae Malathion 1nh1bited highest rad1al growth of S oryzae (74 78%) The leaf extract of Gart1c (AII1um satJvum) inhll:~~ted maXImum mycelial growth of S oryzae at aD throe tested concentrations V1Z: 5%, 7 5% and 1 O% foiiOiied by Neem. (Az.adractlta Indica) G1nger (Zingiber offJCmale}, Under glass house condrtion, folrar spray was found elfedrve 10 reduong d1sease incidence whereas seedl1ng root dtp found effecbve 1n enhancing plant herght Folrar spray reduced max1mum d1sease rnadence (64 03%) followed by carbendazlm (59 39%), mancozeb (56.65%) In Khanf 2010 aU rntegrated treatments and fu11g1odes, significantly Increased plant heJght over con1rOI Folrar spray With T hafZianum Increased rn mruumum plant hetght (36 51%), followed by T viridae (34 80%). The field expenrnents conducted dunng two oonsecunve years Kharif 2010 and 2011 and obsef\'abons mdiC8ted that fohar sprays of propconazole gave maXJITIIm reduction rn disease modence followed rolulf sprays With carbendaZJm which reduced (56 68%), and mancozeb (50 79%). The maXImum plant height (28 45%) 11\0'8858 was recorded 1n treatment of roliar spray With T. harztanum followed by foliar spray wtth T.vmdae and seedling root drp with T. hamanum in 10 gm mcreased 25.31% and 23 10% respectively The maxrmum increase (27 37%) tn 1000-grarn weight was recorded In treatment of fol1ar spray With proproonazole followed by catbendazrm (26 0%), mancozeb (25 70%) T hafZIBnum (25 55%), and T Wide (23 59%) All methods of app11catron of btoagents significantly reduced dtsease 1nddence and 1ncrease plant hetght 1000 grarn wetght and overall gram yteld as CO!lllSred to control