EFFECT OF PACLOBUTRAZOL (PP333) ON APPLE SHOOT GROWTH

J.D. Quinlan, P.J. Richardson
Paclobutrazol, coded PP333, {(2RS, 3RS)-1-(4-chlorophenyl)-4, 4-dimethyl-2-(1H-1,2,4-triazol-1-yl) pentan-3-ol} is an experimental growth retardant which gives long-lasting control of tree growth with little or no adverse effect on fruit yield or quality.

When PP333 is applied to apple shoots, the effect on shoot elongation is influenced by the treatment site; application to the shoot stem and/or shoot tip causes a greater reduction in shoot growth than application of the chemical to unrolled leaves or to the woody stem.

In comparison with post-harvest and summer foliar sprays, soil application of PP333 is generally ineffective on apple in the U.K. Summer foliar treatments give the best control of tree growth particularly when applied sequentially during early summer.

Quinlan, J.D. and Richardson, P.J. (1984). EFFECT OF PACLOBUTRAZOL (PP333) ON APPLE SHOOT GROWTH. Acta Hortic. 146, 105-112
DOI: 10.17660/ActaHortic.1984.146.10
https://doi.org/10.17660/ActaHortic.1984.146.10

Acta Horticulturae