UMary Hausbeck, uMnyango Wezitshalo Nomhlaba kanye Nesayensi Yezinto Ezincane, Michigan State University-Julayi 23, 2014
Isifunda saseMichigan siqinisekise i-downy mildew ku-anyanisi.E-Michigan, lesi sifo sivela njalo eminyakeni emithathu kuya kwemine.Lesi isifo esiyingozi kakhulu ngoba uma singelashwa, singanda ngokushesha futhi sisakazeke kuyo yonke indawo ekhulayo.
I-Downy mildew ibangelwa ukubhujiswa kwe-pathogen Peronospora, engakwazi ukubola izitshalo ngaphambi kwesikhathi.Iqala ukuthelela amaqabunga angaphambili futhi ivele ekuseni kakhulu ngenkathi engekho.Ingase ikhule njengokukhula okumpunga-nsomi okufiphele namachashaza azacile afiphele.Amaqabunga angenwe yileli gciwane aphenduka abe luhlaza ngokukhanyayo bese ephuzi, futhi angagoqwa futhi asongwe.Isilonda singaba nsomi-nsomi.Amaqabunga athintekile aphenduka abe luhlaza ngokukhanyayo kuqala, bese ephuzi, futhi angagoqa futhi agoqe.Izimpawu zesifo zibonakala kangcono lapho kuvela amazolo ekuseni.
Ukufa ngaphambi kwesikhathi kwamaqabunga ka-anyanisi kuzonciphisa usayizi we-bulb.Ukutheleleka kungenzeka ngohlelo, futhi ama-bulb agciniwe athambile, ashwabene, abe namanzi kanye nenhlaka.Ama-asymptomatic bulbs azohluma ngaphambi kwesikhathi futhi akhe amaqabunga aluhlaza okhanyayo.Isibani singangenwa amagciwane esibili ebhaktheriya, abangele ukubola.
Amagciwane e-Downy mildew aqala ukungenwa emazingeni okushisa apholile, ngaphansi kuka-72 degrees Fahrenheit, nasezindaweni ezinomswakama.Kungase kube nemijikelezo eminingi yokutheleleka ngesizini.Ama-spores akhiqizwa ebusuku futhi angashaya kalula ibanga elide emoyeni oswakeme.Uma izinga lokushisa lingama-50 kuya ku-54 F, lingahluma ku-anyanisi yezicubu ngehora elilodwa nesigamu kuya kwayisikhombisa.Izinga lokushisa eliphezulu emini kanye nomswakama omfishane noma wezikhawu ebusuku kuzovimbela ukwakheka kwezinhlamvu.
Izinhlamvu ze-overwintering, ezibizwa ngokuthi ama-oospores, zingakheka ezicutshini zezitshalo ezifayo futhi zingatholakala ku-anyanisi wokuzithandela, izinqwaba zokuqopha u-anyanisi, kanye nama-bulb agcinwe amagciwane.Izinhlamvu zinezindonga eziwugqinsi kanye nokudla okwakhelwe ngaphakathi, ngakho zingakwazi ukumelana namazinga okushisa asebusika angalungile futhi ziphile emhlabathini iminyaka emihlanu.
I-Purpura ibangelwa ukhunta i-Alternaria alternata, isifo esivamile seqabunga lika-anyanisi eMichigan.Iqala ibonakale njengesilonda esincane esifakwe emanzini futhi ikhula ngokushesha ibe isikhungo esimhlophe.Njengoba sikhula, isilonda sizoshintsha sibe nsundu sibe nsomi, sizungezwe izindawo eziphuzi.Izilonda zizohlangana, ziqinise amaqabunga, futhi zenze ukuthi ichopho lihlehle.Ngezinye izikhathi i-bulb ye-bulb itheleleka entanyeni noma enxebeni.
Ngaphansi komjikelezo womswakama ophansi nophezulu, ama-spores esilonda angakheka ngokuphindaphindiwe.Uma kunamanzi amahhala, izinhlamvu zingamila phakathi kwemizuzu engama-45-60 ku-82-97 F. Izinhlamvu zingakheka ngemva kwamahora angu-15 lapho umswakama ohlobene ungaphezu noma ulingana no-90%, futhi ungasakazwa ngumoya, imvula, kanye ukuchelela.Izinga lokushisa liyi-43-93 F, futhi izinga lokushisa eliphezulu liyi-77 F, elihambisana nokukhula kwesikhunta.Amaqabunga amadala namancane alinyazwa ama-thrips ka-anyanisi asengozini yokuthola izifo.
Izimpawu zizovela ngosuku olulodwa kuya kwezine ngemva kokutheleleka, futhi ama-spores amasha azovela ngosuku lwesihlanu.Amachashaza ansomi angenza izitshalo zika-anyanisi zibe namaqabunga ngaphambi kwesikhathi, wonakalise ikhwalithi ye-bulb, futhi angase aholele ekuboleni okubangelwa amagciwane esibili amagciwane.I-pathogen yamachashazi onsomi ingaphila ebusika phezu kwentambo yokukhunta (mycelium) ezingcezu zika-anyanisi.
Uma ukhetha i-biocide, sicela ushintshe phakathi kwemikhiqizo enezindlela ezahlukahlukene zokwenza (ikhodi ye-FRAC).Ithebula elilandelayo libala imikhiqizo enelebuli ye-downy mildew namabala ansomi ku-anyanisi e-Michigan.Isandiso saseMichigan State University sithi kufanele sikhumbule ukuthi amalebula emithi yokubulala izinambuzane ayimibhalo esemthethweni mayelana nokusetshenziswa kwezibulala-zinambuzane.Funda amalebula, njengoba eshintsha njalo, futhi ulandele yonke imiyalelo ngqo.
*Ithusi: ibheji SC, umkhiqizo ongumpetha, inani lethusi le-N, umkhiqizo we-Kocide, i-Nu-Cop 3L, i-Cuprofix hyperdispersant
*Akuyona yonke le mikhiqizo ephawulwe ngesikhutha namachashaza ansomi;I-DM inconywa ikakhulukazi ukulawula isikhutha, i-PB inconywa kakhulu ukulawula izindawo ezinsomi