REDUCTION OF THE TREE PRODUCTION CYCLE OF IN VITRO

Transcription

1 REDUCTION OF THE TREE PRODUCTION CYCLE OF IN VITRO PROPAGATED STANLEY PLUM CULTIVAR AND THE TREE BEHAVIOUR IN AN ORCHARD. 2. REPRODUCTIVE BEHAVIOR STANLEY PLŪMJU PAVAIROŠANAS CIKLA SAĪSINĀŠANA, IZMANTOJOT PAVAIROŠANU IN VITRO UN KOKU IZVĒRTĒJUMS DĀRZĀ: 2.REPRODUKTĪVIE PARAMETRI Popov S.K. Fruitgrowing Institute, Ostromil 12, Plovdiv, Bulgri. Kopsvilkums Viengdīgi un divgdīgi mikroklonāli pviroti plūmju šėirnes `Stnley` stādi tik slīdzināti r trdicionāli pvirotiem stādiem, kuri coti uz potcelm Jnk 4 (Prunus cersifer Ehrh.). Mērėis - novērtēt ržu un ekonomisko efektivitāti dārzā. Tik izvērtēti sekojoši prmetri: ržošns sākums, rž un ržs efektivitāte izteikt kā ržs un stumr šėērsgriezum lukum ttiecī, kā rī ržs un ving projekcijs lukum ttiecī. Sīsinātā stādu udzēšns ciklā iegūtie mikropvirotie stādi sāk ržot otrjā gdā, tāpt kā cotie, et tiem ij mzāk ugĝu un pirmjā ržs gdā ziedpumpuri ij izvietoti zru glos. PtskĦu kokiem ij zemāk rž, slīdzinot r cotjiem. Ržs efektivitāte ugstāk ij mikropvirotjiem stādiem. Astrct The study ws crried out on the reproductive ehviour of own-rooted micropropgted trees of Stnley plum cultivr grown for only yer in nursery. Trditionlly produced trees grfted on the seedling rootstock Jnk 4 (Prunus cersifer Ehrh.) s well s in vitro propgted trees of the sme cultivr, ut grown in the nursery for two vegettion periods, were plnted for comprison. The im of the study ws to estlish the reproductive nd economic qulities of the micropropgted ownrooted plnting mteril produced y reducing the cycle nd to evlute the possiility of estlishing fruit orchrds from these plnts. The following chrcteristics were oserved: eginning of fruiting, yield, iometric indices nd fruit production efficiency expressed s yield to trunk cross-section re nd to crown projection re rtios. The trees otined y reducing the production cycle egn to er fruits during the second vegettion like grfted trees. They hd less fruit uds per tree compred to the grfted ones nd the uds were locted in the picl prts of the shoots. Such juvenile ehviour ws oserved only for the first yer fter the eginning of fruiting. The own-rooted trees were less fertile in comprison to the grfted ones. However, there were no differences in fruit qulity nd in the iometric indices. The efficient productivity clculted on the sis of the trunk cross-section re nd the crown projection re ws higher thn tht of the trditionlly produced trees. Keywords: micropropgtion, own-root, fruit tree, yield, plum, ehvior. Introduction The efficiency of plnttion is determined y the production vlue nd the price of the plnting mteril, s well s y the economic results depending on the reproductive ehviour of the trees used. The in vitro method is modern pproch in the propgtion of rootstocks nd own-rooted cultivrs of species for which the trditionl methods proved to e difficult to pply or inpplicle t ll. Reducing the nursery production cycle of micropropgted own-rooted trees of Stnley cultivr is fct nd the ppliction of this technology in prctice enled the estlishment of orchrds using such plnting mteril. Its ehvior in orchrd ws unknown. Therefore necessity of the studies in this question ws defined. In the results of some investigtions delyed eginning of fruiting ws reported (Сoinchi et l., 1988). The lower yields resulting from the poorer growth were underlined s the prolem of using micropropgted own-rooted trees. Becuse of the poorer growth of tht type of trees their productivity ws higher in comprison with the grfted ones (Сoinchi et l., 1993; Snsvini et l., 1990). Fer et l. (2002) reported tht the productivity of the trditionlly produced trees of Stnley cultivr ws higher. The differences in the reported results s well s the use of plnting mteril 119

2 produced y the reduced cycle gve us the theoreticl se for crrying out the presented study. Its im ws to show the effect of reducing the production cycle y yer on the reproductive ehvior of own-rooted micropropgted trees in comprison with the trees grown in the nursery for two yers nd the trditionlly otined trees y grfting on the seedling rootstocks. Mterils nd Methods The study ws crried out in the fields of the Fruit Growing Institute Plovdiv in the period The oject of the experiment ws the plum cv. Stnley. Own-rooted micropropgted trees (produced without grfting), grown in nursery for only one vegettion period, were studied. Trees grown in nursery for two yers nd trees grfted on the seedling rootstock Jnk 4 (Prunus cersifer Ehrh.) otined y the trditionl technology for grfted fruit tree plnting mteril, were produced nd plnted on the experimentl plot for control. The explnts nd the cuttings for grfting were collected from the sme trees plnted nd grown for tht purpose. The trees were plnted t 6 m distnce etween the rows nd 4 m distnce within the rows. The experimentl plot ws grown under irrigtion conditions, the spce etween the rows ws periodiclly tilled in ccordnce with the technologicl requirements for fruit production. Pruning ws very slight only in the first yers for trining of free growing crown. Stem thickening, the crown size nd height were mesured during vegettion. The following indices were reported: eginning of fruiting, yield per tree nd totl yield for the period, productivity on the sis of the trunk cross-section re nd the crown projection re, s well s fruit qulity expressed y fruit nd stone iometry. The morphologicl chrcteristics were visully oserved for detecting ny eventul chnges resulting from the method of propgtion. Dt were sttisticlly processed y pplying Anov single fctor nd the Duncn test. Results nd Discussion First flowering ws reported during the second vegettion fter plnting in the spring of All the three vrints hd flower uds. In the micropropgted vrints the flowering trees were % for those produced for one nd those produced for two yers, respectively, while 93.3 % of ll the grfted trees hd flowers. The own-rooted trees formed 4 to 5 times less flower uds thn those grfted on the seedling rootstock Jnk 4 (Pr. cersifer Ehrh). At the end of the vegettion single fruits were lso reported in 60 % of the grfted trees nd in 13.3 nd 25 % of the own-rooted in vitro propgted trees, grown in nursery for one nd for two yers, respectively. kg 2 yers old 1 yer old on Pr. cersifer ,0 70,0 60,0 50,0 40,0 30,0 20,0 10,0 0,0 Figure1. Fruit yield of micropropgted own-rooted trees of cv. Stnley produced y reducing the nursery cycle 120

3 The own-rooted trees hd flowers locted in the picl prt of the shoots, fct typicl of the juvenile seedling plnts. Tht ws oserved only in the first yer of flowering. By the fertility index the ownrooted micropropgted trees of oth vrints fell ehind the trditionlly produced ones. The igger numer of flowers in the first yers fter the eginning of fruiting rought the higher yields per tree in the vrint with grfted trees. The tendency ws mintined until the end of the study period. The trees produced y reducing the nursery cycle were slightly more fertile thn the own-rooted ones grown for two yers in the nursery with the exception of the yer Mximl yields per tree were otined kg, 67.8 kg nd 61.4 kg, respectively, from the grfted trees, the own-rooted trees grown for one nd for two yers in nursery (Fig. 1). The totl yield per tree for the period of investigtion ws the highest for the trditionlly produced kg versus kg nd kg for the trees produced y reducing the nursery cycle nd for those grown for two yers in the nursery, respectively. The yields clculted s rtio to the trunk cross-section re (Fig. 2) nd to the crown projection re (Fig. 3) showed tht the trditionlly produced trees hd higher vlues of production efficiency t the end of the period. The differences were sttisticlly insignificnt. kg/cm -2 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0, verge 2 yers old 1 yer old on Pr. cersifer Figure 2. Productivity ccording to trunk cross-section re, kg сm -2 kg/m yers old 1 yer old on Pr. cersifer Figure 3. Productivity ccording to crown projection re, kg m

4 The verge fruit mss for three yers vried insignificntly etween 2.99 to 32.6 g (Fig. 4). The fruits of the micropropgted trees were slightly igger in comprison to the trditionlly produced, proly due to the smller numer of fruits per tree nd, respectively, to the lower yield. The fruit size expressed in grms correlted to the stone weight. No ig differences mong the three vrints were detected in the sizes of the fruits nd stones. They were sttisticlly insignificnt. It confirmes the lck of ny pomologicl chnges resulting from the propgtion method nd the ppliction of the originl technology developed t the Fruit Growing Institute Plovdiv. Vritions of the fruit nd stone sizes incresed with tree ging, the vlue of the vrition coefficient out the length of the fruit peduncle eing lmost twice higher t the end of the period. g 100,0 10,0 Fruit weight Stone weight 2 yers old 1 yer old on Pr. cersifer 1,0 2 yers old 1 yer old on Pr. cersifer Figure 4. Averge weight of fruits nd stones of micropropgted own-rooted trees of cv. Stnley plum produced y reducing the nursery cycle. It should e mentioned tht our results definitely confirmed the opinion of Snsvini еt l. (1990) out the fct tht fruit qulity ws not ffected y the method of propgtion nd production of the plnting mteril. The visul oservtions on the morphologicl chrcteristics of leves, shoots, flowers, period of flowering, fruit ripening nd the seprte phenophses during vegettion lso did not show ny differences etween the trees produced y different methods. The technology of reducing the production cycle of the own-rooted micropropgted trees cn e pplied in prctice due to the lower product cost nd lower price of the plnting mteril. However, t the estlishing of orchrds it should e tken into ccount tht the yields nd productivity re slightly lower. Conclusions The micropropgted own-rooted trees grown for yer in nursery, egn to fruit in the second vegettion fter plnting in the orchrd, similr to the trees grown in the nursery for two yers nd the trees grfted on seedling rootstocks. The totl yield per tree for the period of study ws the highest for the trditionlly produced trees of Stnley cultivr. The own-rooted plnts produced y reducing the nursery cycle were slightly more fertile thn the trees of the other vrint with micropropgted trees. In the period of full fruiting pomologicl chnges s result of the micropropgtion were not oserved concerning the fruits nd stones, which ws lso confirmed y the comprtively slight differences in the iometric sizes. The estlishment of fruit orchrds with plnting mteril produced in vitro nd further grown in nursery for only yer is possile nd not risky t ll. It should e kept in mind tht the lower yield in oth vrints with own-rooted trees is fct nd it should not e neglected when mking the finl decision. References 1. Coinchi D., de Sldor F. R., Fedi W., Insero O., Liverni A., Rivlt I., Minguzzi A. nd Mrni M. (1988) Preliminry field oservtions on in vitro propgted trees. Act Horticulture, 227,

5 2. Coinchi D., de Slvdor R., Fedi W., Insero O., Liverni A., Mltoni M. L., Minguzzi A. nd Rivlt L. (1993) Comportmento in cmpo di mterile vrietle propgto in vitro L informtore Agrrio, Veron, XLIX (23), Fer T., Lech W., Mlodory M. nd Dziedzic E. (2002) Assessment of growth nd cropping of the plum trees growing on Wgenheim prune rootstock nd originted in vitro, Act Horticulture, 577, Snsvini S., Buscroli C., Mrtelli S. nd Plr U., (1990) Osservzioni sul comportmento di susini micropropgti e innestti. Rivist di Fritticoltur e di Ortofloricoltur, 52, 6,