' Adv. Hort. Sci., 5 ( 199 1 ): 77-80 The reflowering of prickly pear Opuntia ficus-indica ( L. ) Mi ller: influence of removal time and cladode load on yield and fru it ripening. G. Barbera*, F. Ca ri mi*, P. Inglese· '* • lstitUio di Coltivazioni Arboree. Universita di Palermo, 90128 Pale rmo, /i(l/y H lsli WIO di Colture Leg nose Agrarie e Foreswli. Universitil di Reggio Calabria. 8906 / R eggio Calabria, ftaly K£•y wo rds: cladode load, yield. rcOowering. time . ri peni ng ti me Abstrac t: In prickly indlca ( L.) Miller - tile co mp let e of the s pr ing Oush ( flowe rs :llld cl:t- dodes) ;a furth er no,\c ri n ,g. Thc reflowcring bchrn·io ur of the two m:tin culti,:trs o f the indus try. wns iu, ·csti- g:tlcd in Sicil )'· hod n j:;.rc:ater apt itu de fo r reflowcring. : lh:m «l{oss: :m which : tl so showtd an b <::tri ng h:tbil. S pri ng fl ush r(•ll)Ol'tLI W<) I1U) 1C:d furl hCr nowcring depending on the St:lgC of the flowers :l( the time of lr (":l lmcnl. The prc- bi OOill trcnhnc:nt rc- .sull ed in the hights t rcnowering whi l s-t rCniO\· ing t he : spri ng flush a fter 1 >t tal she ddjng reduced reno- wcri ng by Th(' second fl ush load of Ntth cJ: uiO<I e was rc l:lfc:d to th: Jt of the firs t b)' :t regression. Tr c:thnc: nt.S: :1 ffec::tcd H1e ti me SJI:Ul of rc fl owc rin t;, fruit de\·clopm<: nt :l nd E arl y fruils (pr<"bloomin g) ht td the shortest frui t de,·e- lopm('nt ill'riod and re:1 c.hed h;1 nest m: •tur ity 40 earlier tlmn the late ones ( llOStbloomiug). f ru it s it e :tnd weight ;:tr<'i tftr the l:lt<: r the fruits ri t )CII C d. U•t<" fruits SI10 n<Cd the lowt .sl seed/core r:tt io. 1. Introdu ct ion An o fT -season reflowe ring ca n be arti fi ci ally ind uced in some rruit trees. In lemon-Ci1rus lemon Burm. - ( Ba r bera et a/., 1988) a pro longed water stress pro· moLe s a h eavy su mmer flowering and a crop of sum- me r rruits ca lled verdelli. Sc hup p and Fe rr ee (1987) re- ported th at deblosso ming is able to sti mulate a seco nd bloo m in 'Golde n de licious' a pp le whil e cteroliatio n is co mmo nl y pr acti ced to indu ce bud burst u nde r trop i- ca l co ndit ions (P ieni aze k, 198 1 ). Er ez obta ined an season peach floweri ng and pr oduc ti o n us in g the res/ avoid ance te ch niq ue (Erez, 1987); a bian nu al peac h prod uction al so has been repon ed in Au stra lia (George eta! ., 1988). In mango (Mangifera indica L.) a second, ofT -season, fl owering can be in du ced by means or de- budding (Singh et a/., 1974), a nd by deblossoming and early dcr ru iting (Kulkarni and Rame shawar , 1989). T he in te nsive p ri ck ly pea r indus try in Sicily is based on the production of late ripe ni ng fr ui ts ob tained by ful ly remov ing flowers and cladodes of the spr ing fl ush at bloom (Barbera et a/ ., 1 988a). The prac ti ce, known as scoz=olmura (Coppoler, 1827), results in a furth er s pro uting a nd a crop to be harvested in October- Novembe r. La te ri pe ning rru1ts have a bigger size, a hi gher flesh perce nt and a lower seed/ fl esh ratio than t he fruits produced by the spr ing fl ush, wh ich ri pe n at the end or August (Barbera et a/ .. /.c.). Neve rtheless very li ll ie information is ava ilable co ncern ing the bio- Recehcd fot publ ica ti on 29 1 991 logica l a nd fie ld aspects involved in the phenomenon of rellowering in prickly pe ar (Barbe ra et a/ ., 1988b). T he experime nt repo ned herein was des ig ned to as- ce rtain t he cu ltiva r aptitude to re fl owering, the rela- tions hi p bet ween removaJ time, re fl owering rat e, ripen- in g time and fruit qual it y together with the quan tita- tive relationship between the sp ring fl ush and the in- duced late one at Cll1 dode level. 2. l\hte rials and Me thods T he tr ials were carr i ed out over two bear in g cyc les (1988-89) in a co mmercial, nine-year-old g ro ve at S. Margher it a Belice (T rapani) 37" 44' La t N, under Me- diterranean climatic co nditio ns with a dry pe,·iod last- ing from Jun e to Sept ember. Five 'Gialla' and ·Rossa' trees, spaced 7 x 5 m per t real mcnt were chosen as single tree replicates in a ran do mized blo ck de sign. Tr eatments co nsisted or ru ll y re mov ing the year's spring flush (fl owers and cladodes) a ccord ing to the fl o we r's p he nological stage de f ined as follows: A = prebloo mi ng (I 00% closed flowers): B = ru ll blo om (50% ope n fl owers); C = pos tb oo m {100% dr y petal s) . An i nterva l o f abo ut two weeks differe nt iated each stage rrom the n ex t (23.5, 7. 6, 24.6). T he ti me spans of rcspro uting, reflowering and ri- pe ni ng were r eco rded week iy o n ten cladodes per tree: live bear in g less tha n five fl owers and five with more than I0 fl owers in the I st fl ush . The total fl owers (F), re nil e cladodes (FC) an d c urr ent year cladodes (YC) were co un ted on e ach plant at removal time and at the e nd of reflowering. 77