Effect Of Different Agents On Bud Thinning And Flower Thinning Of Kiwifruit

Bud and flower thinning is an important operation for high yield and high quality cultivation of kiwifruit.At present,orchards in China rely on manual thinning of bud and flower,which has a good effect but the cost is higher.Chemical fruit and flower thinning has high efficiency,saving labor cost,easy to produce and apply.The technology of chemical bud and flower thinning of kiwifruit will play a positive role in alleviating the contradiction of manual shortage in bud and flowering stage and reducing production cost.The effects of different chemical bud and flower thinning agents on kiwifruit were studied,Two kinds of bud thinning agents CPPU and Kuoshi were selected to explore the effects of different times,periods and concentrations of bud thinning on the lateral bud thinning effect and fruit quality of ‘Nongdajinmi’ and ‘Xuxiang’.Urea,naphthylacetic acid(NAA)and calcium formate(CFA)were selected as flower thinning agents to study the effects of different flower thinning agents on the lateral flower thinning effect and fruit quality of ‘Nongdajinmi’ and ‘Xuxiang’.Explore the most suitable bud thinning and flower thinning agents for ‘Nongdajinmi’ and ‘Xuxiang’.The main results were as follows:1.The experiment on bud thinning of ‘Nongdajinmi’ showed that Kuoshi 1.67 ml/L had good bud thinning effect.Compared with the water control,Kuoshi 1.67 ml/L had no effect on fruit setting of central buds,but the thinning rate of lateral buds could reach68.61%,which could increase the VC content of fruit after soft ripening and had no adverse effect on other fruit qualities.During the 0-2 mm period of lateral buds,Kuoshi 1.67 ml/L was sprayed continuously for 3 times,and the effect of thinning lateral buds was the best when each time interval was 24 hours.CPPU treatment had a good thinning effect,but the abnormal fruit rate of all CPPU treatments was too high compared with that of the water control,so it was not suitable to be used as bud thinning agent in ‘Nongdajinmi’.2.The experiment on flower thinning of ‘Nongdajinmi’ showed that Urea 3 g/L,NAA 15 mg/L and CFA 2.5 g/L had good flower thinning effect.Compared with the water control,Urea 3 g/L,NAA 15 mg/L and CFA 2.5 g/L had no effect on the fruit setting rate of central flowers,but the thinning rates of lateral flowers could reach 38.95%,61.12% and49.6% respectively,which have no adverse effects on fruit quality.Urea 3 g/L and NAA 15mg/L were suitable for the first spraying when the lateral flowers bloomed by 30%-40%and the second spraying when the lateral flowers bloomed by 90%.CFA 2.5 g/L was suitable for the first spraying when the lateral flowers bloomed 20%-30%,the second spraying when the lateral flowers bloomed 50%-60%,and the third spraying when the lateral flowers bloomed 80%-90%.3.The experiment on bud thinning of ‘Xuxiang’ showed that Kuoshi 1.67 ml/L had good bud thinning effect.Compared with the water control,Kuoshi 1.67 ml/L had no effect on fruit setting of central buds,but the thinning rate of lateral buds could reach 18.11%.In the period of lateral bud 0-1 mm,Kuoshi 1.67 ml/L was sprayed continuously for 3 times,and the effect was the best when the interval was 24 hours.CPPU treatment had a good thinning effect,but the abnormal fruit rate of all CPPU treatments was too high compared with that of the water control,so it was not suitable to be used as bud thinning agent in‘Xuxiang’.4.The experiment on flower thinning of ‘Xuxiang’ showed that Urea 3 g/L,NAA 15mg/L and CFA 4 g/L had good bud thinning effect.Compared with the clean water control,Urea 3 g/L,NAA 15 mg/L and CFA 4 g/L had no effect on the fruit setting rate of central flowers,but the thinning rates of lateral flowers could reach 15.12%,29.8% and 22.12%respectively,which have no adverse effects on fruit quality.NAA 15 mg/L was suitable for the first spraying when the lateral flowers bloomed at 30%-40% and the second spraying when the lateral flowers bloomed at 90%.CFA 4 g/L and Urea 3 g/L were suitable for the first spraying when the lateral flowers bloomed 20%-30%,the second spraying when the lateral flowers bloomed 50%-60%,and the third spraying when the lateral flowers bloomed80%-90%.5.The comprehensive effects of different kinds of bud thinning and flower thinning agents on ‘Nongdajinmi’ and ‘Xuxiang’ showed that the effect of bud thinning agent was better than the effect of flower thinning agent.Moreover,the thinning effect of bud thinning and flower thinning agents in‘Nongdajinmi’ is better than that in ‘Xuxiang’.