Research On The Flower And Fruit Thinning On Apple In Dryland

Apples are easily to over-fruiting under natural conditions resulting in poor fruit quality.Chemical thinning and fruit thinning achieve a suitable load by thinning out excess flowers and fruits,thereby improving fruit quality and increasing benefits and maintaining orchard consistency.However,labor costs have risen sharply in recent years due to labor shortages.Labor-saving fruit-thinning has been an urgent problem in apple industry.In this study,in order to screening for the most suitable chemical flower and fruit thinning agents for Luochuan,we used cross-sectional and longitudinal comparison methods to compare the thinning effect of nine different chemical flower and fruit thinning agents.At the same time,we also determine the appropriate loadings for different types of orchards and discuss the relationship between loadings and fruit quality and benefits.In addition,wer also noted that the naphthalene acetic acid(NAA)has an negative effect on the growth of ‘Fuji’ apples.candidate genes that may be related to it were screened out by transcriptome sequencing.The main findings are as follows:1.Spray flower thinning agent when 75% of ‘Fuji’ apple center flowers are in full bloom,and spray fruit thinning agent 15 days after full bloom period.There were9 treatment groups and 1 control group.The results showed that calcium formate,Zhi Shu You Hua,stone sulfur mixture,ceverine and 6-BA had a certain increase in the fruit setting rate and single fruit ratio of Fuji apple,and had a good effect on Fuji apple.Among the flowerphobic agents,calcium formate and Zhishuyou flowers had the best effect.In the fruit-thinning agent,cardantin had the best effect.2.We set 4 concentration gradients and 3 spraying times to explore the effect of different concentrations and spraying times of flower thinning agent,the results show that: 50 times Zhi Shu You Hua,10g/L calcium formate,2°Be lime sulfur could improve the inflorescence thinning rate,central flower fruit setting rate and single fruit ratio;50 times Zhi Shu You Hua and 10g/L calcium formate had a certain improvement on fruit single fruit weight,soluble sugar,sugar-acid ratio and fruit coloring.The optimal number of sprays of Zhi Shu You Hua and calcium formate is 2times.3.Exploring the optimal concentration and spraying time of carbamide and 6-BA,the results show that: 2000mg/L carbamide treatment can significantly improve the fruit setting rate of fruit inflorescence center flowers,0.3g/L 6-BA treatment resulted the highest fruit setting rate which was 57.05%.The fruit quality can be improved by spraying carbaryl 10 d after the full bloom period and 6-BA spraying 15 d after the full bloom period.4.The effects of different loading on tree development and fruit benefit were studied in 3m×4m,20 year old ’Fuji’/suichuzi cultivated orchard,1.5m×4m,7 year old’changfu 2’ /M26 dwarfing self-rootstock orchard,1.5m×4m,7 year old ’changfu 2’/M26 dwarfing interstock orchard.For the cultivated orchards,with the increase of load,leaf area,chlorophyll content,leaf net photosynthetic rate increased,new shoot length and diameter,fruit weight per fruit,soluble sugar content in fruit,large fruit proportion and yield decreased,and the optimal load was 320 / plant.Dwarfed interstocks for dwarf the root anvil and orchard,as load increases,leaf area,chlorophyll content increased after decreased first,fruit weight,soluble sugar content in fruit,fruit quality,yields are low,the increase in the number of small fruit of contrast concluded that dwarfed the most suitable for the growth of the tree since root stock fruit capacity up to 120 / plant;The optimal load of dwarfing interstock fruit trees was 150 trees per plant.5.Set up water spraying control group and NAA spraying treatment group,collect the fruits of four fruit development stages named as D1,D2,D3,D4(60d,90 d,120d,150 d after flowering)respectively,and use high-throughput Illumina Hiseq sequencing technology Transcriptome comparative analysis was performed on fruit samples.The results suggest that NAA may reduce the extensibility of the cell wall by down-regulating the expression levels of XTH family genes which we found as XTH23 and XTH30.NAA may hinder the development of fruit by the delaying rapid expansion of cells.