Effects of Controlled Release Fertilizer on Apple Development and Fruit Quality

The objective of the study is to investigate the response mechanism of controlled release fertilizer(CRF) on apple fruit growth and fruit quality for the utilization of CFR on fruit.Different nutrient content treatments were designed with Red Fuji and fruit special CFR as the materials,and the effect of CRFs on the mineral elements and chlorophyll of apple leaves,new shoot length and fruit quality were analyzed.The results showed that compared with applied common compounds fertilizer,the application of CFR increased contents of N,P,K,Ca and Mg in leaves by 4.4%,26.5%,27.2%,4.2% and 6.5% respectively,and also decreased the content of Zn in leaves by 70.2%,but the contents of Fe,Cu and Mn were different in different treatments.Application of CRFs also increased new shoot length,chlorophyll content.The fruit quality,contents of soluble sugar and vitamin C were increased by 10.4%,11.5% and 73.3% respectively.The single fruit mass and titratable acidity were reduced by CRFs application,but there was no significant difference in fruit shape index.Most indexes of different CRF treatments were significant different.The study suggested that the application of CRFs increased the apple growth and improved the fruit quality.