Seed rot, Rootcollar rot, Crown rotandStem Rot
Agents
Pythiumspp, Fusariummoniliforme, F. Subglutians, F.proliferatum, F. Avenaceum, F. Graminearum, Diplodiamaydis, Macrophominaphaseolina, Rhizoctoniasolani, R. Zeae
Symptoms
As a general disease, thediseaseproducessymptoms of palenessandblightthatprecipitate on seedlings. Whenpaleseedlingsarewithdrawnfromthesoil, theplantedpartwill not remain. Whentheseedbed is examined in thepartswherenoexitoccurs; Seedsthatarecoveredwithmiscellawithoutgerminationorthathavebeenweaklygerminatedanddried in differentdegrees of rootorgrasspipeareencountered.
Inrootcollar rot andstem rot; Typically, torsionsoccuraroundthestemaxis in plants. Thediseasedseedling is knockedoverthesoilsurface. Supportrootsareformed in theparts of theplantsthatcomeintocontactwiththesoil. Stem rot appearsbetweenthefreshknucklebeforethecornpeaksareremoved.
Stem rotandseed rot areseen in the form of rot in theplant’sknuckle, betweentheknuckle, thestubseatandstubstems. Decay is mainlybrown-blackoilystain. A pink-whitemicellecover is formed on thisstain.
Stem rot(Diplodiamaydis), usuallyappearsaftergermination of theseed. Afterfadinganddrying, theknucklebetweenthegroundturnsfromstrawyellowtobrown.
- phoseolinacausessymptoms of rootcollarandstem rot duringtherapidgrowthperiods of corn. Black microscleroles of theplantareseen in thetransmissionbundles of theplant.
DiseaseCycleandEpidemiology
Thisdiseaseoccurs in heavytexturedsoilswithpoordrainageandinsufficientoxygen in theearlyperiod. Lateperiodrot facilitates thepassage of thedisease in the form of stem rot.
Diplodiamaydisspendsthewinter in conical form in myceliumandpycnide in plantresidues, and in conidandmycelium in theseed. At theend of summer, conidiesarereleasedfromthecirrhi, which is formed in pycnide in hot, humidweather.
Sclerots of M, phaseolinaaregerminated in themostsuitabledrysoiland at temperatures of 37-38C. Fungusproducesseedlings of infectionsthatinfesttheroots of seedlings, youngandmatureplants. Hifsthenprogressfromcortialtissuestothestems.
Inthestudiesconducted, it has beennotedthattherelationship of someredspiderswiththeirhighpopulationsincreasesthelevelandseverity of stem rot. It is reportedthatthefactthatthesoil’stemperature is lowandsoil’smoisture ishighpreventsthedevelopment of coal rot disease.
Fighting
Shouldcultivatedurablevarieties,
Fieldsoilshould be leveledproperly,
Pestsshould be dealtwithtimelyandappropriately,
Excessiveirrigationshould be avoidedanddrainageshould be done,
Croprotationshould be applied,
Hoeingandmiddlebreakingshould be done properly.
