EFFECT OF GIBBERELLINS AND ANTI-GIBBERELLINS ON THE VEGETATIVE GROWTH OF 'HAYWARD' KIWIFRUIT (ACTINIDIA DELICIOSA)

N.M.R. Vattiprolu, D.J. Woolley, B.M. van Hooijdonk
Kiwifruit vines typically exhibit excessive vegetative vigour that can decrease harvest index and fruit quality. At present, there are no suitable size-controlling rootstocks for use in commercial kiwifruit production, and the hormonal mechanisms regulating shoot vigour of kiwifruit vines are poorly understood. In order to understand the role gibberellins (GAs) may have in stimulating shoot vigour, we treated lateral shoots of Actinida deliciosa ‘Hayward’ (green kiwifruit) with five concentrations (0, 500, 1000, 2000 and 4000 mg/L) of GA3 + GA4+7 applied as foliar sprays. The first application of GA3 + GA4+7 began at spring bud break (13 October 2009), with subsequent applications occurring every 14 days until the end of the growing season. To investigate whether inhibition of gibberellin biosynthesis could decrease shoot vigour, we also applied foliar sprays of paclobutrazol (PBZ) and prohexadione-calcium (Ca-Pro) at three different concentrations (0, 400, 600 and 0, 250, 350 mg/L for PBZ and Ca-Pro, respectively) three times at 14-day intervals beginning on 13 October 2009. GA sprayed at 500 and 1000 mg/L increased the length and node number of lateral shoots, whilst 2000 and 4000 mg/L caused shoot tips to wither, but promoted internode elongation, and increased the formation of axillary shoots. Laterals treated with 250 mg/L Ca-Pro were 38% shorter than the controls by growth cessation. These results will be discussed in the light of the role of gibberellins in vegetative vigour and the steps at which gibberellin biosynthesis could be inhibited to reduce vigour of kiwifruit vines.
Vattiprolu, N.M.R., Woolley, D.J. and van Hooijdonk, B.M. (2011). EFFECT OF GIBBERELLINS AND ANTI-GIBBERELLINS ON THE VEGETATIVE GROWTH OF 'HAYWARD' KIWIFRUIT (ACTINIDIA DELICIOSA). Acta Hortic. 913, 433-439
DOI: 10.17660/ActaHortic.2011.913.58
https://doi.org/10.17660/ActaHortic.2011.913.58
paclobutrazol, prohexodione-calcium, dose response curve, shoot vigour
English

Acta Horticulturae