Effect of Flower and Fruit Thinning on Yield and Quality of Loquat in Northern Margin of Loquat Distribution Area in China

In China, loquat (Eriobotrya japonica Lindl.) is mainly grown in the south of Yangtze River including provinces such as Fujian, Jiangsu, Zhejiang and Sichuan. The area in the south of Qinling Mountains, Shanxi province, is the north marginal zone of loquat growth. Ankang, where the present study was carried out, is located in the south of Qinling Mountains with a cool sub-tropical climate. The average annual temperature is 15.5 degrees C. A study was conducted to determine the effect of flower and fruit thinning, fruit bagging, and twig and bud thinning on the growth and quality of 'Changqi Zaosheng' loquat. The trees 5 to 8 years old were selected as test materials. Flower thinning effectively reduced nutrition consumption and increased fruit-set by 49.1%. Compared to the unthinned check, retaining 3 to 5 young fruits per panicle significantly increased single fruit weight and rate of marketable fruit and reduced the number of rusty and cracking fruit. It was also demonstrated that thinning twigs and buds can increase single fruit weight and the yield to some degree. Bagging after fruit thinning completely prevented sunburn and reduced rusty fruit from 47.2 to 0.9%, and commodity fruits increased from 31.3 to 95.2%. Bagging also increased fruit flesh recovery and total acids but soluble solids content was slightly lower.