I-Potato cyst nematode iyinkathazo eyingozi. Lezi zikelemu ezincane zihlala emhlabathini, zingena ezimpandeni zezitshalo zamazambane ezisencane futhi zehlise isivuno ngo-70%. Kunzima futhi ukuqeda: amaqanda avikelwe ngaphakathi komzimba wesifazane, ophenduka i-cyst ngemva kokufa, angaqhubeka emhlabathini iminyaka.
Ucwaningo lwakamuva lubonise ukuthi isikhwama sephepha esilula esenziwe ngemicu kabhanana sivimbela ama-cyst nematode ekuchanyuselwe nasekutholeni izimpande zamazambane. Indlela entsha yandise isivuno ngokuphindwe kahlanu ezivivinyweni zamapulazi amancane eKenya.
“Lena yingxenye ebalulekile yomsebenzi,” kusho uGraeme Thiele, umqondisi wocwaningo e-International Potato Center. Kodwa “usemningi umsebenzi okufanele wenziwe ukuze lokhu kususwe ekutholeni okuhle kube yisixazululo sangempela kubalimi baseMpumalanga Afrika,” uyaxwayisa.
I-Soil nematodes iyinkinga ezinhlotsheni eziningi zezitshalo. Kumazambane, i-golden nematode (Globodera rostochiensis) iyingozi emhlabeni wonke. Izitshalo ezinezimpande ezinegciwane, ezilimele zinamaqabunga aphuzi, abuna. Lawa mazambane mancane futhi avame ukonakala kakhulu, okwenza ukuthi angakwazi ukudayiswa. Emazweni apholile, i-nematode ingalawuleka ngokushintshanisa amazambane nezinye izitshalo, ukufafaza umhlabathi ngezibulala-zinambuzane, nokutshala izinhlobo ezimelana nezifo.
Lezi zindlela azikasebenzi emazweni amaningi asathuthuka, ngokwengxenye ngenxa yokuthi izibulala-zinambuzane ziyabiza futhi izinhlobo zamazambane amelana azitholakali ezindaweni ezishisayo. Ukwengeza, abalimi abancane, abangakwazi ukwenza imali enhle ngokuthengisa amazambane, bavame ukungabaza ukushintshanisa amazambane okutshala ngezitshalo ezingabalulekile kangako.
EKenya, i-potato cyst nematode iye yandisa ububanzi bayo futhi iyachuma. "Ukuminyana kwe-nematode kuphezulu ngendlela emangalisayo," kusho uDanny Coyne, uchwepheshe we-nematode e-International Institute of Tropical Agriculture. Lokhu kuholela enkingeni eyengeziwe yokulahleka kwezinhlobonhlobo zezinto eziphilayo, lapho abalimi bamazambane begawula amahlathi ukuze bakhe amasimu amasha angenayo i-nematode.
Umbono wokuthi iphepha likabhanana lingasiza abalimi ukukhipha ama-nematodes emhlabathini wabo waqala eminyakeni engaphezu kweyi-10. Abacwaningi baseNorth Carolina State University bebefuna indlela yokusiza abalimi emazweni asathuthuka ukuthi balethe imithamo emincane yezibulala-zinambuzane ngokuphepha. Bahlola izinto ezihlukahlukene futhi bathola ukuthi iphepha elenziwe ngobhanana lisebenza kangcono kakhulu. Imicu yayo eshubhu, enezimbotshana idedela izibulala-zinambuzane emhlabathini amasonto ambalwa ngaphambi kokuphuka. Ngaleso sikhathi, lesi sitshalo sesikhule ngokwanele kangangokuthi ngisho noma singenwa igciwane, sizobe sesivele sinezimpande ezinempilo.
Ezivivinyweni zasensimini, abacwaningi banezela ephepheni i-abamectin, isibulala-zinambuzane esibulala ama-nematode. Baphinde batshala amazambane ephepheni likabhanana ngaphandle kwe-abamectin njengendlela yokulawula. Okwabamangalisayo ukuthi lezi zitshalo zenza kahle njengezitshalo ephepheni elifakwe izibulala-zinambuzane. U-Coyne wabelane ngalo mphumela odidayo nozakwabo, usokhemisi wemvelo ogama lakhe lingu-Baldwin Torto, ocwaninga ngokusebenzelana kwezitshalo nezinambuzane e-International Center for Insect Physiology and Ecology.
Ekanye noJuliet Ochola, manje osengumfundi oneziqu eNyuvesi Yesifundazwe yaseNorth Carolina, uTorto wenze izivivinyo ukuze athole ukuthi kwenzekani. Bathola ukuthi iphepha likabhanana linezithako eziyinhloko eziphuma ezimpandeni zezitshalo zamazambane ezisencane, ezinye zazo eziheha amagciwane azuzisa isitshalo. I-Nematode nayo ifunde ukuqaphela lezi zinhlanganisela. Ezinye, njenge-alpha-chaconin, ziwuphawu lokuthi amaqanda e-nematode achanyuselwe. “Uma eziningi zichanyuselwa ngesikhathi esisodwa, zizokwazi ukuvula ama-cyst,” kusho u-Ochola. Ngemva kokuchanyuselwa, ama-nematode amancane ezwa ukuxhumana futhi ayisebenzise ukuthola izimpande zamazambane ezithambile.
Imicu kabhanana imunca u-94% wezinhlanganisela, i-Ochola nozakwabo abatholakele. Lapho eveza amaqanda e-nematode ukuze akhishwe ngephepha, izinga lokuchanyuselwa lehle ngo-85% uma liqhathaniswa nezilawuli, ithimba libika kujenali ye-Nature Sustainability. Okunye ukuhlola kubonise ukuthi ama-nematode achanyuselwe mancane kakhulu amathuba okuthi athole izimpande zamazambane ezimbozwe ngephepha.
Emasimini agcwele ama-nematode eKenya, uCoyne nozakwabo babonise ukuthi ukutshala amazambane asongwe ngephepha likabhanana elingenalutho kuphindwe kathathu isivuno uma kuqhathaniswa nokutshala ngaphandle kwephepha. Umthamo omncane we-abamectin ephepheni—izingxenye eziyizinkulungwane ezinhlanu kuphela zalokho okuvame ukufuthwa emhlabathini—ukhulise isivuno ngomunye u-50%. Ngokunokwenzeka, noma iyiphi i-nematodes ehlala phezu kwamazambane ibulawa i-abamectin.
Manje abacwaningi bacabanga ukuthi bangalithola kanjani iphepha lokugoqa nokutshala amazambane kubalimi baseMpumalanga Afrika. Amasimu kabhanana eKenya nasemazweni aseduze angahlinzeka ngemicu, manje esilahlwa njengemfucuza. Abakhi bamaphepha base bengenza izikhwama. Ngokusho kukaCoyne, inselelo enkulu kuzoba wukukholisa abalimi ukuthi bazithengele iphepha.
Uma abalimi sebezama izikhwama, abacwaningi bathi bazothola ukuthi kulula ukuzisebenzisa. “Vele ugoqe bese utshala,” kusho u-Ochola.
Kepha ukupakisha amazambane amaningi kusazosebenza kanzima, kuphawula u-Isabelle Conceicao, uchwepheshe we-nematode e-University of Coimbra. Uma kwenziwa umshini wokugoqa amazambane, uthe, mhlawumbe le ndlela ingasetshenziswa emapulazini amakhulu kusetshenziswa imishini yokutshala.