IMPACT OF SURFACTANTS ON FRUIT QUALITY OF ‘SCHATTENMORELLE’ SOUR CHERRIES AND ‘GOLDEN DELICIOUS’ APPLES

Surfactants often applied with herbicides, fungicides or insecticides as emulsifying, dispersing and spreading agents may cause distinct stress symptoms and considerable leaf damage as observed in experiments with ‘cowpeas’ (Vigna unguiculata). Ethylene production was used as a quantitative indicator for surfactant-induced stress.
Phytotoxicity and intensity of stress was shown to be dependent on the type and concentration of surfactant.

Spray treatment of sour cherry (cv. ‘Schattenmorelle’) and apple trees (cv. ‘Golden Delicious’) at different times of development (full bloom, fruit-set and 10 weeks after full bloom) with 0.1, 1.0 and 2.0 % Citowett and Tween 20, respectively, induced flower and fruit abscission, leaf necrosis and changes in photosynthetic and transpirational behaviour.
Fruit growth and development as well as quality were also affected.
In cherries, fruit cracking was enhanced, tendency to russeting was significantly increased in ‘Golden Delicious’ apples especially with the higher surfactant concentrations.
Since in apple a positive correlation between surfactant dosage and fruit abscission was established, the use of surface active components for chemical fruit thinning in practice can be considered.

V International Symposium on Growth Regulators in Fruit Production

G.J. Noga, M.J. Bukovac

https://doi.org/10.17660/ActaHortic.1986.179.130