Emkhakheni wokuvikelwa kwezitshalo, izilawuli zokukhula kwezitshalo (PGRs) zisiza kakhulu ekulawuleni izinambuzane nezifo ngokulungisa ukukhula nokuthuthuka kwezitshalo kanye nokuthuthukisa ukubekezelela ingcindezi; bakha elinye lamathuluzi ezobuchwepheshe abalulekile ngaphakathi kohlaka "lwe-Green Plant Protection".

Izimo ezimbi ezivamile zasehlobo—njengamazinga okushisa aphakeme, ukukhanya kwelanga okunamandla, nesomiso—ngokuvamile kuholela ekukhuleni kwezitshalo ngokweqile (i-etiolation) kanye nokungasebenzi kahle komzimba ezitshalweni. Izilawuli zokukhula kwezitshalo zibhekana nalezi zinkinga ngokuguqula ibhalansi yamahomoni angapheli;

I-Mepiquat Chloride kuCotton: Lolu uhlelo lwayo olusakazeke kakhulu. Uma isetshenziswa ngesikhathi sokuhluma okukhulu kuya ezigabeni zokuqala zokuqhakaza, ilawula kahle ubude besitshalo, ivimbele ukunwebeka ngokweqile kwamagatsha athelayo, futhi inciphisa ukuchitheka kwebholl engxenyeni emaphakathi nephansi yesitshalo, okuholela ekwandeni kwesivuno ngo-10% kuya ku-20%.

Izilawuli zokukhula kwezitshalo ziyikilasi lezinto zamakhemikhali-ezihlanganiswe ngokuzenzela noma ezikhishwe ngokwemvelo-ezikwazi ukushintsha ukukhula nezinqubo zokuthuthuka kwezitshalo. Indlela yabo eyinhloko yokusebenza ilele ekulingiseni noma ekuphazamiseni ukudluliswa kwesignali kwamahomoni esitshalo angapheli (njengama-auxins, ama-cytokinins, nama-gibberellins)

njengesilawuli sokukhula kwesitshalo, i-Forchlorfenuron ivuselela ukuhlukaniswa kwamaseli kanye nokwanda kwegalikhi. Ukuhlolwa kwensimu kubonise ukuthi, uma kusetshenziswe ngendlela efanele, kungakhuphula ububanzi bamagabhu kagalikhi ngo-15-20% futhi kukhuphule isisindo sezitshalo ngazinye cishe ngama-30%.

I-Brassinolide i-endogenous steroidal plant hormone eyaqala ukuhlukaniswa ne-rapeseed pollen ngo-1979 futhi yaqashelwa umphakathi wesayensi ngo-1996 njengesigaba sesithupha esikhulu samahomoni ezitshalo. Ibonakala ngokusebenza kwayo okuphezulu, i-spectrum ebanzi yomsebenzi

I-Sodium Nitrophenolates isheshisa ukukhula kwezitshalo, inqamule i-dormancy, futhi ikhuthaze ukukhula okuphelele. Zivimbela ukuchithwa kwezimbali nezithelo, kanye nokuqhekeka kwezithelo nokushwabana; ngaphezu kwalokho, athuthukisa ikhwalithi yomkhiqizo, akhulise isivuno, futhi athuthukise ukumelana kwezitshalo ekucindezelekeni kwemvelo okuhlukahlukene—okuhlanganisa izifo, izinambuzane, isomiso, ukugcwala kwamanzi, amazinga okushisa abandayo, usawoti, i-alkalinity, nendawo yokuhlala.

I-Diethyl aminoethyl hexanoate (DA-6) iyisilawuli sokukhula kwezitshalo esibanzi. Ikhuthaza ukukhula kwezitshalo, ithuthukise ukumelana nokubanda nesithwathwa, ithuthukise ikhwalithi yezithelo, futhi ikhuphule ukusebenza kahle kokusetshenziswa komanyolo ngokwandisa umsebenzi wama-enzyme ezitshalo, ithuthukise i-photosynthesis, futhi yenze kube lula ukuhlukana kwamaseli nokulinganisela kwezakhi.

Lezi zinto zisebenza kakhulu "njengezilawuli zemizwa" ngaphakathi komzimba wesitshalo—ezikwazi ukuqhubekisela phambili ukukhula kokuqhuma kwezinye izimo, kuyilapho zikhuthaza ukulala okuzolile kwezinye. Isibonelo, i-Gibberellic Acid (GA3) ingabangela ukuthi izitshalo zikaphizi omncane zikhule zibe zinde, kanti i-Abscisic Acid ingabangela ukuchitheka kwezithelo ngaphambi kwesikhathi.