Pineapple (Ananas comosus var. comosus) (Coppens d'Eeckenbrugge and Leal, 2003) is an important fruiting monocot and produces the only edible fruit in plants of the family Bromeliaceae. A major limitation that afflicts pineapple growers is the phenomenon of natural flowering, which results in unscheduled fruiting. The percentage of natural induction is highly unpredictable and the incidence may vary from 0% to 100% in any given year (Kuan et al., 2005), which causes serious scheduling problems for growers and, in particular, fresh market growers. Fruits produced by natural induction may not find a market, are costly to harvest because a relatively small percentage of these fruits mature at any given time in a field, and sometimes the fruits are too small to be marketable. These factors ultimately increase the cost of cultivation and reduce profits.
Being a tropical fruit, pineapple is highly susceptible to frost and is commonly planted within 30°N and S latitude. Natural flower induction in subtropical latitudes mainly occurs in cooler winter months, and in N latitudes typically occurs from late November through at least February, when temperatures are cooler and winter daylengths are shorter (Bartholomew et al., 2003). Van Overbreek and Cruzado (1948) provided the first evidence that low night temperature could enhance the induction of reproductive development in pineapple. However, the duration of the period of natural induction in a field of pineapples is determined by a variety of factors, including cultivar sensitivity, plant size, and the prevailing weather conditions, particularly temperature (Kuan et al., 2005; Lin et al., 2005).
Forcing (induction of flowering by external application of ethylene or related compounds) of pineapple is a well-established commercial practice whereby pineapple can be induced to flower at any time of a particular year (almost irrespective of the temperature) and the fruits can be made available through nearly all of the year. Forcing efficiency will be high when forcing is done during the period when natural induction normally occurs. Forcing of pineapple is commonly done with ethylene, ethylene-releasing compounds such as ethephon, and CaC2, or acetylene when the plants are of sufficient size so as to yield fruits of marketable value (Bartholomew et al., 2003). Forcing also synchronizes flowering and produces a sharp ripening peak. In Taiwan (latitude 22° to 26°N), natural induction begins in late November as a result of sudden drops in temperature that coincide with passing cold fronts. Hence, most forcing is done during September and October and the fruits are harvested from March to May of the next year. If forcing of fully developed plants is delayed beyond October, they are highly prone to natural induction in the following months (Kuan et al., 2005).
Management of flowering of pineapple can be controlled to some extent by cultural practices that reduce plant stresses and promote vegetative growth (Bartholomew et al., 2003). Alternatively, growers can inhibit natural induction during susceptible periods by spraying a plant growth regulator and flowering can later be forced by spraying ethylene or ethephon. A number of plant growth regulators will inhibit flowering of pineapple under field conditions. Gowing and Leeper (1960) reported that low concentrations of certain phenoxyacetic acids forced pineapple, whereas higher concentrations inhibited it. Others (Martinez et al., 1997, 2000; Scott, 1993) found that foliar sprays of 2-(3-chlorophenoxy)-propionic acid (CPA) reduced the percentage of natural induction of pineapple. Cunha et al. (2003) tested the effect of many growth regulators on natural flowering of pineapple and found that CPA and paclobutrazole inhibited natural flowering of pineapple at concentrations of 90 and 240 mg·L−1, respectively. Kuan et al. (2005) reported that aviglycine (AVG) prevented natural flowering in ‘Tainon 18’ pineapple under field conditions. AVG is an inhibitor of ethylene biosynthesis that is registered in the United States to improve fruit retention of apples and pears. Recently, Martinez et al. (2005) reported that Fruitone CPA (20 mg·L−1 of a.i.) produced more than 90% inhibition of natural flowering in the pineapple hybrid 73–114, which is also widely known as MD-2 (Chan et al., 2003), with four to six applications at weekly intervals starting from the last week of October or first week of November.
Although growth regulators can inhibit natural induction of pineapple, their practical application in pineapple fields has been limited by availability, cost, or both. The potential of AVG to control flowering in pineapple (Kuan et al., 2005) accompanied with the recent availability of large quantities of a commercial formulation of AVG has made it an attractive candidate for the control of a long-term problem in pineapple cultivation. Although Kuan et al. (2005) demonstrated that AVG will control pineapple flowering, the potential of AVG was not fully explored. The present study reports a more detailed investigation on the potential use of AVG for flowering control so that the grower can determine the date of initiation of reproductive development rather than depend on weather factors for this purpose.
BartholomewD.P.MalezieuxE.SanewskiG.M.SinclairE.2003Inflorescence, and fruit development and yield167202BartholomewD.P.PaullR.E.RohrbachK.G.The pineapple: Botany production and usesCABI PublishingWallingford, U.K
ChanY.K.Coppens d'EeckenbruggeG.SanewskiG.M.2003Breeding and variety improvement3355BartholomewD.P.PaullR.E.RohrbachK.G.The pineapple: Botany production and usesCABI PublishingWallingford, U.K
Coppens d'EeckenbruggeG.LealF.2003Morphology, anatomy and taxonomy1332BartholomewD.P.PaullR.E.RohrbachK.G.The pineapple: Botany production and usesCABI PublishingWallingford, UK
GowingD.P.LeeperR.W.1960Studies on the relation of chemical structure to plant growth- regulator activity in the pineapple plant. I. Substituted phenyl and phenoxyalkylcarboxylic acidsBot. Gaz.121143151
KuanC.S.YuC.W.LinM.L.HsuH.T.BartholomewD.P.LinC.H.2005Foliar application of aviglycine reduces natural flowering in pineappleHortScience40123126
LinC.H.KuanC.S.HsuY.M.BartholomewD.P.2005Delaying Natural Flowering in Pineapple8AnonProceedings of the 5th ISHS International Pineapple SymposiumPort Alfred, South Africa
MalezieuxE.ZhangJ.SinclairE.BartholomewD.P.1994Predicting pineapple harvest date in different environments, using a computer simulation modelAgron. J.86609617
MartinezA.R.AvilaD.U.GutierrezL.A.1997Inhibicion de la floracion de la pina con diferentes dosis de Fruitone CPA en dos densidades de siembra (flowering inhibition in pineapple with different rates of CPA on two planting densities)Acta Hort.425347354
MartinezA.R.AvilaD.U.MartinezL.R.2000Rates of fruitone CPA in different applications number during day versus night to flowering inhibition in pineappleActa Hort.529185190
MartinezA.R.MartinezL.R.AvilaD.U.PerezA.D.A.2005Inhibition of the flowering pineapple MD-2 cv. using fruitone CPA at different rates and application dates9AnonProceedings of the 5th ISHS International Pineapple SymposiumPort Alfred, South Africa