Effects of postharvest topping, autumn cincturing, and paclobutrazol on growth, yield, and fruit quality of the low chill nectarine cv. Sundowner in subtropical Australia.
George, A. P.; Nissen, R. J.; Rassmussen, T.;
Australian Journal of Experimental Agriculture Year: 1993 Vol: 33 Issue: 3 Pages: 353-362 Ref: 35 ref.
1993
บทคัดย่อ
Paclobutrazol, alone or in combination with postharvest topping and/or autumn cincturing, was used to control the size of nectarine cv. Sundowner trees in subtropical Australia. Compared with controls over 3 seasons, paclobutrazol used alone reduced tree size by 34-52%, with further reductions of 5-25 and 58-71% when combined with light (removal of 20% of extension shoot growth) and severe (removal of 40% of extension shoot growth) postharvest topping, respectively. Yield efficiency (yield per unit canopy volume) was significantly improved by paclobutrazol and was doubled by paclobutrazol + severe postharvest topping. Although this combination reduced time associated with pruning, thinning and harvesting, it also delayed flowering, and therefore fruit maturity, in the subsequent harvest season. Light postharvest topping or autumn cincturing used with paclobutrazol had little effect on yield efficiency, fruit quality, or harvest period. The seasonal pattern of starch reserves for twigs was similar for all treatments, with starch levels falling to a minimum during the early harvest period. At harvest increments (fruit DW as a percentage of total tree DW) <10% there was little or no depletion of starch from the twigs and leaves, but as harvest increments increased (in the range 10-40%), starch depletion in the roots, trunks and branches (in that order) increased.