POSSIBILITY OF N-PROPYL DIHYDROJASMONATE APPLICATION FOR THINNING FRUIT, DEFOLIATING AND PROMOTING THE FRUIT MATURATION AS A CULTURAL TECHNIQUE

To yield large sized and good colored fruit in ‘Fuji’ apple production, the application of n-propyl dihydrojasmonate (PDJ), jasmonic acid derivative, was carried out in thinning side fruits on a cluster and promoting leave abscission around fruits.
As results, PDJ spray at concentration of 500 mg/l to each cluster 17 days before the anthesis caused alternatively the side flower and/or fruitlet drop.
The effect tended toward a diminution when applied close to the full bloom.
And the leaf removal was induced by the application of PDJ at the same concentration to the bearing branch 45 days before harvest, resulting in fruit with a high ratio of red-blushed area due to an exposure to the sun light as well.
Unlike the leaves attached to each cluster, PDJ did not affect the abscission of other leaves; sensitivity difference of the leaves accounts for it presumably.

At maturation of ‘Fuyu’ persimmon fruit, PDJ promoted coloring and softening and increased the sugar content by spraying 50 or 100 mg/l on the trees approximately 30 days before harvest.
Endogenous ABA and ethylene levels increased with time after the PDJ application.

We focus and discuss that PDJ application can be considered as a cultural technique replacing the hand manipulation in apple production and PDJ can involve in the fruit maturation by influencing ABA and/or ethylene biosynthesis.

XXV International Horticultural Congress, Part 6: Culture Techniques with Special Emphasis on Environmental Implications Physiological Processes in Plants

H. Gemma

apple, defoliation, flower thinning, fruit maturation, jasmonic acid, n-proryl dihydorojasmonate, persimmon

https://doi.org/10.17660/ActaHortic.2000.516.6