宮本早生의 과다착화를 방지하여 해거리를 해소하고자 화아분화 억제와 관련된 식물생장조절물질인 gibberellin(GA3)을 살포하여 낙엽률, 착화량, 과실크기 등 품질에 미치는 영향을 조사하였다. 낙엽률은 GA3 농도에 따른 처리 간에 차이를 볼 수 없었고, 착화량은 GA3 농도가 높아질수록 적어지는 경향이었으나 착과율은 GA3 농도가 높을수록 높아졌는데, 착화량이 많은 경우에는 착과율이 낮아지고 이와는 반대로 착화량이 적은 경우에는 착과율이 높아지는 경향을 나타내었다. 구엽 100 매당 신초수는 GA3 농도가 높아짐에 따라서 많아지는 경향이었다. 과실 크기는 GA3 농도가 높아질수록 커져 대과비율이 높아지고 반대로 GA3 농도가 낮아질수록 소과비율이 높아지는 경향이었다. 가용성 고형물 함량과 산 함량은 차이가 없었다.Gibberellin (GA3) treatment during winter to reduce flowering was evaluated as a means to alleviate the alternate bearing of satsuma mandarin (Citrus unshiu Marc. cv. Miyamotowase). GA3 at 0, 25, 50, 100mg텹-1, was sprayed on 9-year-old Miyamotowase satsuma mandarin trees on Dec. 30. 1997. A rate of leaf fall was not significantly different among the levels of GA3 concentration. GA3 treatment considerably decreased the number of flowers and increased the number of vegetative shoots. A rate of fruit set showed an increasing tendency as GA3 concentration level was increased. Fruit size was also affected by the levels of GA3 concentration. The percentage of large-sized fruit was increased at high level of GA3 concentration, while that of small-sized fruit was decreased at low level of GA3. The content of soluble solids and acid showed no significant differences among treatments.