Original Articles

Effect of triadimefon on fruit set and seed development of ‘Starking Delicious’ apple

Published in: South African Journal of Plant and Soil
Volume 7, issue 2, 1990 , pages: 87–91
DOI: 10.1080/02571862.1990.10634544
Author(s): G. JacobsDepartment of Horticulture, Republic of South Africa, L. GouwsDepartment of Horticulture, Republic of South Africa, D.K. StrydomDepartment of Horticulture, Republic of South Africa

Abstract

Spray applications of triadimefon (TDF) (1–4 chlorophenoxy 3,3 dimethyl 1–1-H-1,2,4 triazol 1-yl-2 butanone) (5% W.P.) at 100 mg dm−3 active ingredient at full bloom and pre- and/or post-full bloom on ‘Starking Delicious’ apple trees (Malus domestica Borkh.) increased fruit set by reducing the November fruit drop. TDF increased the number of seeds per fruit, reduced the number of seedless fruits, altered seed distribution of seeds in the five loculi of individual fruits having 4–7 seeds and increased the number of loculi containing two seeds. Style removal reduced fruit set to the same extent in treated and control flowers. Dry weights of the pedicels and receptacles of treated flowers were significantly greater. The effective pollination period was not affected by TDF. Apparently TDF affects dry-matter allocation in favour of reproductive growth, which enhances the development of young embryos and fruit set.

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