Izilawuli zokukhula kwezityalo ziquka iindidi ezininzi, nganye inendima yayo ekhethekileyo kunye nobubanzi bokusetyenziswa. Oku kulandelayo ngabalawuli bokukhula kweZityalo kunye neempawu zabo ezibonwa ngokubanzi njengento elula ukuyisebenzisa kwaye esebenzayo:

Izilawuli zokukhula kwezityalo (PGRs) ziikhompawundi zekhemikhali ezenziwe ngobuchule ezineempembelelo ezifanayo zomzimba kunye nezakhiwo zeekhemikhali ezifanayo njengeehomoni zezityalo ezingapheliyo. Ukulawula ukukhula kwezityalo kuluhlu olubanzi lwezitshabalalisi kwaye ludidi lwezitshabalalisi ezilawula ukukhula kwezityalo kunye nophuhliso, kubandakanywa iikhompawundi zokwenziwa ezifana neehomoni zezityalo zendalo kunye namahomoni akhutshwe ngokuthe ngqo kwizinto eziphilayo.

I-Auxin i-indole-3-acetic acid, kunye ne-molecular formula C10H9NO2. Yeyona hormone yokuqala efunyenweyo ukukhuthaza ukukhula kwezityalo. Igama lesiNgesi livela kwigama lesiGrike elithi auxein (ukukhula). Imveliso ecocekileyo ye-indole-3-acetic acid i-crystal emhlophe kwaye ayinyibiliki emanzini. Inyibilika ngokulula kwizinyibilikisi eziphilayo ezifana ne-ethanol kunye ne-ether. I-oxidized ngokulula kwaye ijike ibe bomvu i-rose phantsi kokukhanya, kwaye umsebenzi wayo we-physiological nawo uyancipha. I-Indole-3-acetic acid kwizityalo ingaba kwindawo ekhululekile okanye kwindawo eboshiweyo (eboshwe).

Umahluko kumsebenzi: 24-epibrassinolide i-97% esebenzayo, ngelixa i-28-homobrassinolide i-87% esebenzayo. Oku kubonisa ukuba i-24-epibrassinolide inomsebenzi ophezulu phakathi kwe-brassinolides eyenziwe ngamakhemikhali.