Effects of growth regulants on defoliation, flowering, and fruit maturity of the low chill peach cultivar Flordaprince in subtropical Australia

The growth regulants paclobutrazol, hydrogen cyanamide (Dormex 500 g a.i./L), and potassium nitrate were tested for their effectiveness in promoting earlier and more even budbreak, flowering, and fruit maturity of the low chill peach cultivar Flordaprince in subtropical Australia. Paclobutrazol advanced harvest by about 10 days. Hydrogen cyanamide was effective in advancing fruit maturity by about 19 days, but even at the lowest concentration used (5 mL/L), it severely reduced fruit set by > 40 %. In contrast, 1-3 sequentially autumn-applied potassium nitrate sprays advanced flowering by about 10 days; > 3 applications caused significant (P < 0.05) yield reductions (29%).