Indawo Ezitshisayo ze Sivuno
I-Crop Heat Units (CHU) ibonakalisa indawo yobushushu ekukhuleni kwesivuno nokuphuhla kwaso. Ukukhula kwesityalo kuxhomekeke kwinani elipheleleyo lobushushu edibana nabo ngexesha lokukhula kwaso, idityaniswa njenge ntsuku ezishiyanayo. Ubushushu obuphantsi behlisa ukukhula, obushushu obuphezulu buncedisa kwaye bukhawulezisa ukukhula.E-Mzantsi Afrika, sisebenzisa u 10℃, kumbona, isivuno sengqolowa etyiwayo, njenge simo sobushushu. Isimo sobushushu bubushushu obusezantsi apho isityalo sithi sonakale khona, asikwazi ukukhula okanye asivelisi sivuno. Isimo sobushushu siyohluka phakathi kwezivuno ezahlukileyo. Umzekelo, isimo sobushushu ngu 4℃ kwi peas zona kesisivuno esithanda isimo sezulu esipholileyo. 10℃ kumbona, wona sisivuno sengqolowa sasehlotyeni, 13℃ kwi citrus kunye nomobo weswekile kunye no 18℃ kwi date palms.
Ezinye izinto ezichaphazela ukukhula kwesivuno; ixesha lobude bokukhanya base mini, ukuchuma komhlaba kunye namanzi emhlabeni. Ukuvuthwa kunga cothiswa (lzinga lamanzi eliphezulu) okanye likhawuleziswe lzinga lamanzi elise zantsi emhlabeni.
Iinkumbi ze Zivuno kunye Nobushushu
Umzekelo, ubushushu obuqhelekileyo becodling moth, inkumbi ekwi ziqhamo ezifana ne orenji, ipesika, inectarine neapile njalo njalo, ngu 11℃. Ubushushu obuqhelekileyo be coton bollworm ngu 14℃, inkumbi ekwisivuno esifana ne peas, imbotyi, ingqolowa, cotton, umbona, citrus, cucurbits, amazambane, itomata kunye ne lucerne. Logama kwi oriental fruit moth, inkumbi enkulu kwipesika ubushushu obufunekayo ingu 7℃ kuphela.
Zintoni ii ‘Chill Units’?
Izivuno zidinga indawo epholileyo ngezizathu ezahlukileyo. Iziqhamo ezivuthuluka ziyeziphumle pha ekupheleni kwehlobo. Ukukhula kuyama de isityalo nomlinganiselo othile wengqele ngexesha lasebusika. Umzekelo, iipesika zidinga ubushushu obuqikelelwa ku 2.5°C ukuya ku 9℃ ukuze kugqibeke ixesha lokuphumla.
Xa amazinga okubanda afunekayo ingawa fumenanga, oku kuye kwenza ingxaki entwashlobo, ezifana nokulibaziseko bokudubula kwesityalo (kwi pesika- isivuno sokugqiela njalo njalo) okanye ukungadubuli kwesityalo (ama-apile-amancinci, iziqhamo ezimbalwa njalo njalo). Ezi zenza ubungakanani besivuno behle.
Izivuno ezifana nepesika nama apile, iikhemilkhali ngamanye amaxesha bezisetyenziswa ukwenza isityalo sidubule xa iPCUs zingonelanga ukuqinisekisa ukudubula kwendalo.
Kwindawo yemveliso yeziqhamo ziqinikelela ngokwe PCUs zingenziwa zikwazi ukuchaza xa isityalo sidubulile, umngcipheko woku khenkcesizwa kwentloko yesityalo kunye nentsusku zokuvuna. Ingasetyenziswa ukulibazisa ukudubula, ukuthintela ukutshatyalaliswa ngumkhence, oknaye ukuqonda okokuba indawo ikulungele na ukukhulisa isityalo esithile.
Ingqolowa idinga indawo ebandayo, ebiza okokuba yi vernalization. I-Vernalization kuxa amazinga obushushu esezantsi adingeka ukukhuthaza intyatyambo kunye nemveliso yengqolowa.
Translated by Zikhona Plaatjie