Effect of Different Fertilization Methods on Yield and Quality of Kiwifruit

Fertilization is one of the main factors affecting yield and quality of kiwifruit. There is little information on fertilization methods effect on qualitative and quantitative characteristics of kiwifruit. Therefore, this research was conducted with the objective of evaluating different fertilization methods -including broadcast application (as control), drill hole fertilization, and fertigation alone or in combination with foliar application- on yield and nutrient content in kiwifruit, at Iran Citrus Research Institute of Ramsar. Results showed that fertilization methods had a significant effect on yield and fruit weight, and the highest amounts were observed in fertigation combined with foliar application. Furthermore, foliar application increased tree yield 157 percent at all treatments. Firmness and total dissolved solid (TSS) decreased by foliar application at all treatments, except for the broadcast that caused an increase. Mineral concentration in fruit was significantly affected by the fertilization methods e.g., foliar application had significant effect on the concentration of potassium (K), calcium (Ca), and nitrogen (N). In addition, the mineral concentration in fruit decreased in the order of K> N> Ca, regardless of fertilization method. The correlation results showed that fruit firmness had significant relation with Ca and negative relations with K/Ca, N/Ca, and (K)/Ca. In addition, TSS showed significant regressions with K and N. Since all kiwifruit orchards in the North of Iran are equipped with micro jet irrigation system, fertigation and foliar application not only can save time and money but can also cause an increase in yield and improve fruit quality.