# Effect of Different Ratios of Cow Manure and Chemical Fertilizers on Fruit Quality of Gala Apples
###### Abstract  
Nutrient patterns can significantly influence the growth and development of fruit trees, especially fruit quality. In order to clarify the appropriate ratio of inorganic and organic fertilizers, six treatments with different ratios of cow manure and chemical fertilizers were set up in this study to evaluate the effects of different treatments on fruit yield, appearance quality, intrinsic quality and volatile substances. The results showed that, after replacing some chemical fertilizers with cow manure, the content of sugar, tittatable acid, organic acid and aroma substance in the fruit increased, the fruit yield and colour did not change significantly, and the fruit weight per fruit decreased. Among the treatments of cow manure with chemical fertilizer, the fruits of 50% chemical fertilizer with 50% cow manure treatment had higher tittatable acid (0.4%), malic acid (4.15 mg/g), sorbitol (0.51%), glucose (1.30%), fructose (5.81%) content and total aroma substance content (1047.82 ug/g) than chemical fertilizer alone. Compared to the fertilizer treatment alone, the application of cow manure instead of 50% of the chemical fertilizer had a positive effect on fruit quality. apple; cow manure; fertilizer; fruit quality Article  
Effect of Different Ratios of Cow Manure and Chemical Fertilizers on Fruit Quality of Gala Apples  
1  
An Yang  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
China  
Yang Li  
1 Research Institute of Pomology, Chinese Academy of Agricultural Science, Xingcheng 125100, China  
Some authors had suggested that the application of organic fertilizer increased the weight per fruit as well as the number of fruits of apples [8;9]. A two-year experiment in southern Brazil by [PERSON] et al. (2008) [10] confirmed that the application of organic fertilizers resulted in a more yellow base colour and a higher percentage of red skin in apple fruit. In addition, [PERSON] et al. (2018) [11] reported soluble solids content increased with the amount of organic fertilizer applied, and although the differences between treatments were not significant, they were all higher than the control group. Meanwhile, the results of [PERSON] et al. (2013) [12] and [PERSON] et al. (2020) [13] confirmed that a higher soluble solids content and a lower titratable acid of apple were observed in the reasonable application of organic and inorganic fertilizer in the cultivation of apples that compared to the application of organic or inorganic fertilizers alone. Fruit flavour quality is relatively complex, and we perceive the flavour of the fruit through our senses of smell, taste, etc. It is an important component of the comprehensive quality of the fruit, which has an important guiding role for consumers to choose fruit. The flavour of the fruit is mainly influenced by the type and content of sugars, acids and aromatic substances in the fruit [14; 15; 16; 17; 18]. The organic sugar acids mainly include sucrose, fructose, sorbitol, glucose, malic acid, quintic acid and magniferic acid, while the fruit aroma substances mainly include esters, alcohols, aldehydes, ketones, ethers, terpenoids and alkanes. [PERSON] et al. (2019) [19] showed that bio-organic fertilizers applied in combination with chemical fertilizers could increase the content of reducing sugar fraction in jujube fruits.