Yellow (Maize)											Zulu
Kungani izitshalo ziphenduka umbala osaliphuzi ngezikhathi zonyaka ezinamanzi?
Imiyalo:
Folio strap: Ukwengeza ukubaluleka
Byline: NguLeon van Rensburg, uPhrofesa kwezoMumo woMhlaba, uMnyango weSayensi yezoMhlaba, eyeziTshalo nesiMo seZulu, eYunivesithi yaseFree State 
Photo: Umbala osaliphuzi/yellow
Caption: Izimo ezigcwele amanzi ziba nomthelela kwinqubo yokukhula kweningi lezitshalo.
Usomlando wakwelamaNgisi u-H.G. Willis, wake wathi umlando wesintu yingqayingqayi ephakathi kokufunda nenhlekelele. Maqondana nabakhiqizi bezitshalo ezindaweni ezithola imvula ehlobo eNingizimu Afrika, ikakhulukazi lezo ezisezingxenyeni ezinomhlaba othi awube ngowomile lo mjaho uyiqiniso lemihla ngemihla. 
Izinkambiso zokukhiqizwa kwezitshalo ezindaweni ezithi azibe ngezomile ziguquliwe ukuvimbela amahlalakhona engozi eyisomiso. Lokhu sikwenza ngokuguquguqula ukuminyana kwezitshalo, sisebenzisa ngendlela efanele izivundisi ezifakwayo ngokwezivuno ezitholakala sekwedlule isikhathi eside, izindlela zokulima ezilondoloza amanzi ikakhulukazi ukuze kwandiswe ukungena kancane kancane kwamanzi, kusetshenziswa izinsuku zokutshala ezilungele ukutshala kanye nokukhetha izinhlanganisela zezitshalo ezikwazi ukuzejwayeza isomiso, njll. Lezi zinhlanganisela zezitshalo zingena ngaphansi kweqoqo lezitshalo ezibizwa ngokuthi ngama-mesophyte, ezikhula kahle emihlabathini eswakeme kodwa enomoya. Izimpande zazo zikwejwayele kahle ukuthungatha amanzi nezondlazitshalo emhlabathini, ukwenza isibonelo, izimpande zommbila zizongena emhlabathini ngebanga elingama-24 mm ngosuku, zifike ekudepheni okungamamitha ama-2 kuye kwama-2,4, kwencike esimweni somhlabathi lowo.
Ukwakhekha kwezimpande kungakhinyabezeka kakhulu noma kunqanyulwe yizimvula ezine ngokwedlulele njengoba kwenzeka kulesi sikhathi sonyaka esikuso, lapho kutshalwe khona izitshalo ngoDisemba nangoJanuwari. Imvula eningi kakhulu emihlabathini ema amanzi izoba nomphumela wokugcwala kwamanzi emihlabathini afike emazingeni lapho ezothatha indawo yomoya okuyo. Inqubo yokuqala ebalulekile yokuphila kwendalo ezohlangabezana nomthelela omubi ukuphefumula kwezimpande; izitshalo zidinga amazinga athile okubonelelwa ngomoya (i-okhsijini) ezimpandeni zazo. Abacwaningi babonise ekuhlaziyeni kwabo ukuthi ngaphansi kwezimo ezingenamoya ngokuphelele, ukukhula kwezimpande kunganqamuka ngesikhathi esiyimizuzu. Kodwa-ke, izitshalo ziyehlukana ekubekezeleni izimo zokugcwala kwamanzi ndawo yinye. Ukwenza isibonelo izitshalo ezithanda amanzi ezingama-hydrophyte (irayisi) zikwejwayele ukuphila ezimweni ezingenamoya emhlabathini. Kodwa-ke lezi zitshalo zingafa emihlabathini enomoya owanele. Izimpande zezitshalo ezingazithandi impela izimo ezingenamoya, ezifana nemidumba (ubhontshisi owomile, isoya, njll.) ziyafa ngemuva kwezinsuku ezimbalwa zokungenelwa ngamanzi. Izimpawu zokuqala zomonakalo wokugcwala kwamanzi zisengaqhamuka ngemuva kwehora elilodwa noma amabili kuthi umonakalo ongasenakuguquka uvele ngemuva kwamahora angama-24, ikakhulukazi ezinsukwini ezifudumele ezinelanga.
Lapho ukuphefumula kwezimpande kuthikamezekile eminye imisebenzi yokuphila kwezitshalo efana nokukhula, ukumuncwa kwamanzi nezondlo nayo iyaphazamiseka. Nanxa emaningi amanzi, izitshalo azikwazi ukuwamunca amanzi nezondlo. Kuye kubonakale izimpawu ezithile zezitshalo, lokhu kwencike ebangeni lokukhula kwazo. Ukwenza isibonelo, lapho ukuphefumula kwezimpande kuncishisiwe ngesikhathi sokukhula kommbila, ukumunceka kwamanzi nakho kuya kuncipha ngokulinganayo okuzobe sekuba nomthelela ezimuncweni kwezondlo. Uphawu olubonakala kalula ukuphenduka umbala osaliphuzi kwamacembe (i-chlorosis) ngenxa yokwehla kobungako be-chlorophyll. Lokhu kwenziwa ukuntuleka kwe-nitrogen esitshalweni, yize i-phosphorus ne-potassium nezinye izondlo nazo zisuke ziyindlala. Kuleli banga isitshalo sithuthela i-nitrogen emacembeni asemasha siwasusa kulawo amadala ukuze kulondolozeke ukukhula kwaso. Ukugcwala kwamanzi okuqhubekayo kuzogcina kuholele ekukhuleni okuncishisiwe kwamahlumela esitshalo nasekulahlekelweni yisivuno.
