Izindawo Ezibandayo Nezishisayo Zezitshalo

©Louise Brodie
Isitshalo sidinga izikhathi zokushisa nokubanda kwezinqubo ezithile ekujikelezeni kwayo. Lezi zikhathi zokushisa nokubandayo zikhonjiswe kumayunithi okushisa nama-chill units.

Yakha Izingxenye Zokushisa

Ukutshala izingxenye zokushisa (CHU) ziveza ithonya lokushisa ekukhuleni nasekuthuthukisweni kwezitshalo. Ukukhula kwesitshalo kuxhomeke ekutheni inani lokushisa elibhekene nalo ngesikhathi sokuphila kwalo, lithathwa njengezinsuku zezinsuku. Amazinga okushisa aphansi ahamba kancane futhi amazinga okushisa afudumele ashesha ukuvuthwa.
ENingizimu Afrika, sisebenzisa i-10°C, evumelekile ngommbila, isivuno sethu sokusanhlamvu okuyisisekelo, njengamazinga okushisa okuyisisekelo.
Ukushisa okuyisisekelo yizinga lokushisa elingezansi lapho lesi sitshalo sonakalisiwe, singakwazi ukukhula noma singenzi isivuno. Ukushisa okuyisisekelo kufana phakathi kwezitshalo ezahlukene.
Isibonelo, izinga lokushisa eliyisisekelo liyi-4°C ngamapayipi, isivuno sezulu esiphezulu, i-10°C ngommbila, isivuno se-okusanhlamvu sasehlobo, 13°C for citrus kanye noshukela kanye no-18ºC ngezintende zezandla.
Ezinye izici nazo zithonya ukukhula kwezitshalo; photoperiod (ubude bemini), ukuzala kwenhlabathi namanzi emhlabathini. Ukuvuthwa kungabambezeleka (okuqukethwe kwamanzi aphakeme) noma kuphuthumiswe okuqukethwe okuphansi kwamanzi emhlabathini.

Izinambuzane Nokushisa

©Olaf Leillinger
Ukutshala izinambuzane nakho kuthonywa ukushisa kanti futhi kunomqondo obuncane wokushisa kwamazinga okushisa. Ngakho-ke umqondo wukushisa / ucwaningo lwe-degree-day ungasetshenziselwa ukubikezela ukubukeka kwezinambuzane futhi uhlele uhlelo lwepiritikidi spray.
Isibonelo, izinga lokushisa eliyisisekelo lokubamba i-moth, inkathazo yama-citrus, i-peach, i-nectarine apula nokunye, yi-11ºC. Ukushisa okuyisisekelo kwe-cotton bollworm yi-14ºC, inkathazo ezitshalweni ezifana ne-peas, ubhontshisi, ukolweni, ukotini, ummbila, i-citrus, i-cucurbits, amazambane, utamatisi kanye ne-lucerne. Ngesikhathi se-moth isithelo se-oriental, inkathazo enkulu yamapayipi, i-7ºC kuphela.

Yiziphi Izingxenye Ezibandayo?

©Louise Brodie
Amayunithi e-Chill ngokuvamile abizwa ngokuthi 'ama-positive chill units' (ama-PCU). Ama-PCU ayaphambene namayunithi okushisa.
Ukubala okuyinkimbinkimbi kusetshenziselwa ukunquma inani eliphelele lamahora ngaphansi kwezinga lokushisa elinikeziwe isibonelo 4°C. E-USA, amazinga okushisa angu-4.4°C no-7.2°C asetshenziswa njengamazinga okushisa asezingeni eliphansi ekunqumeni amahora ashisa.

Izitshalo zidinga ukushisa okupholile ngezizathu ezahlukene. Izithelo ezinqunyiwe ziya esikhathini sokuphumula ngasekupheleni kwehlobo. Ukukhula kumile kuze kube yilapho isitshalo sesibhekene nesibalo esithile ebandayo ebusika. Isibonelo, ama-peaches adinga ukushisa okuphakathi kuka-2.5°C no-9°C ukuze kugcwaliswe ukuphela.
Uma izidingo ezincane ezibandayo zingakutholakali, kuholela ezinkingeni entwasahlobo, njengokuphuza ikhefu lokuphuza (ama-peach - isivuno sesikhathi esizayo njll) noma ukuntuleka kwephutha lembali (ama-apula - amancane, izithelo ezimbalwa njll). Lokhu kubangela ukunciphisa okukhulu ekuvuneni.
Izitshalo ezifana nama-peaches nama-apula, ngezinye izikhathi amakhemikhali asetshenziselwa ukwenza i-break break uma ama-PCU engakwanele ukuqinisekisa ukuphumula kwemvelo.
Esikhathini esinqunyiwe sezindawo zokukhiqiza izithelo ezithembekile ezisekelwe kwi-PCUs kungenziwa ukubikezela ikhefu lokuphumula, lihlume izinkinga kanye nezinsuku zokuvuna. Kungasetshenziselwa ukulibaziseka ukuqhakaza, ukuze kuvimbele ukulimala kweqhwa, noma ukucacisa ukuthi indawo iyakwazi yini ukukhula kwesitshalo esithile.

Ukolweni kudinga ukwelashwa okubandayo, okubizwa ngokuthi i-vernalization. I-Vernalization yilapho kudingeka khona amazinga okushisa aphansi ukuze kuvuselelwe ukukhiqiza kokutshala nokusanhlamvu.

©WRC

Translated by Nsika Khoza