Effects of Exogenous 5-aminolevulinic Acid on the Growth and Fruit Quality of Kiwi

PurposeTo study the effects of exogenous 5-aminolevulinic acid (ALA) on the vegetative growth and fruit quality of kiwi, and to provide a support for kiwi fruit production and quality improvement.

MethodsUsing kiwi cultivar Cuiyu material, foliar spraying of exogenous ALA at the mass concentration of 10-50 mg/L every 20 days from the beginning of flowering to the fruit expansion period, three times in total, chlorophyll content (SPAD), net photosynthetic rate, leaf area, leaf thickness, stem thickness, vitamin C content, single fruit weight, soluble solid content, and titratable acid content were measured.

ResultsALA with the mass concentration of 10-40 mg/L could improve the indexes value of the growth and quality tested in kiwi at different degrees. Except leaf length, kiwi treated by 30 mg/L ALA obtained the best results for all other indexes. Compared with the control, chlorophyll content increased by 6.59% (fruit expansion period), net photosynthetic rate increased by 40.52%, vitamin C content increased by 25.00%, single fruit weight increased by 13.66%, soluble solid increased by 13.03%, and solid-acid ratio increased by 5.15%.

ConclusionFoliar spraying exogenous ALA with appropriate mass concentration at the beginning of flowering to the fruit expansion period can improve plant growth and fruit quality of kiwi.