POTENTIAL OF CHITOSAN IN REDUCING GA3 DOSES AND THEIR EFFECT ON GROWTH, YIELD, AND BULB QUALITY IN “GIZA RED” ONION

Tow field experiments were conducted during the seasons of 2020/2021 and 2021/2022 at experimental farm Etay El-Baroud research station to investigate effect foliar application with gibberellic acid (GA3) 50 100 ppm chitosan (CS) 200 ppm, in addition, control for each Giza Red onion. The results showed significant positive effects examined concentrations GA3 or CS on all studied characters except leaves number shape index, both seasons. Concerning interaction effect, enhanced significantly treatment combinations between levels. treatments (50 ppm) (200 ppm), (100 found give highest mean values characters, without differences among them. Also, revealed some kind synergistic where combined was be more effective onion plants performance thane single ones that gave ability reduce used doses by 50%, which, consequently, expected hazardous using gibberellins.