THE EFFECT OF AVIGLYCINE APPLICATION RATE AND FREQUENCY ON THE INHIBITION OF NATURAL FLOWERING OF ‘QUEEN’ PINEAPPLE IN SOUTH AFRICA

Natural differentiation of flowering is a severe problem in the production of ‘Queen’ pineapples destined for the fresh market in South Africa.
Natural flowering is mainly induced by short days/long nights and low temperatures, but total radiation and extremes in water supply can also play a role.
In Northern Kwazulu Natal, natural flowering occurs during the winter months (May, June), yielding an over-production of fruit in December/January with consequently lower market prices.
Chemical control of natural flowering with [2-(m-chlorophenoxy), propionic acid] (Swelpine^®) had the adverse effect of stunting the plants and reducing sucker growth, therefore affecting available planting material.
Trials were also done with aviglycine, an ethylene biosynthesis inhibitor.
In a 2008 study aviglycine at 100 mg L^-1, applied every two weeks from May to the end of July (6 applications), reduced natural flowering from 33.5% in the control to 1.5%. When aviglycine was applied before and after a predicted cold front (3-4 applications), natural flowering was reduced to 2.2%. Two more trials were done in 2009 with 60 and 100 mg L^-1, sprayed at 7 and 14 day intervals.
Sprays of 100 mg L^-1 at 7-day intervals in two trials resulted in 0.5 and 0% natural flowering, while 100 mg L^-1 sprays at 14-day intervals reduced natural flowering to 2% (control = 45 and 14%). These application rates are thought very costly and therefore more cost effective application rates were evaluated in further trials.

VII International Pineapple Symposium

E.C. Rabie, B.W. Mbatha, H.A. Tustin

natural flower induction, ‘Queen’ pineapples, ReTain^®, Northern KwaZulu Natal

https://doi.org/10.17660/ActaHortic.2011.902.31