Rooting Products and Cutting Timing on Sage (Salvia officinalis L.) Propagation

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1 Rooting Products and Cutting Timing on Sage (Salvia officinalis L.) Propagation S. Nicola, E. Fontana, J. Hoeberechts and D. Saglietti Dipartimento di Agronomia, Selvicoltura e Gestione del Territorio Università di Torino Via Leonardo da Vinci, Grugliasco (TO) Italy Keywords: root length, root number, organic farming, auxins, medicinal and aromatic plant Abstract Propagation success represents one of the most important goals for plant producers. Vegetative propagation is used when seed germinability is very low and in Medicinal and Aromatic Plant (MAP) it is sometimes less than 50%. Beside, plant producers complain about the lack of seed selection programs and also of detailed information on cultural techniques of these species. The aim of the research was to study the cutting techniques on sage testing natural rooting hormones for organic farming and synthetic auxins with different application procedures to increase rooting. The experiment started on June 2001 and ended on October 2001, leading to 11 cuttings, which were performed every two weeks. Plastic trays (104 cells each) were filled with a cutting specific medium, well pressed and wetted with water until saturation. Portions of stem were cut from stock plants and planted in the substrate. considered were seven commercial rooting products, plus an untreated control. Trays were located on a bench provided of mist irrigation system. Starting three weeks after each cutting, four weekly samplings took place to evaluate rooting degree: four cuttings for each treatment for each cutting period were taken, and roots were carefully washed in water to eliminate the growing medium. The longest root length was measured and root number was counted. The experimental design consisted of a complete randomized design with rooting products as a factor (8 levels plus control) with four repetitions. According to the results, sage was earlier than other tested aromatic species on root production; the use of rooting products had a positive effect on root system development, both in terms of root number and longest root length. auxin rooting products positively affected measured parameters more than rooting products for organic farming. INTRODUCTION The expansion of the Medicinal and Aromatic Plant (MAP) sector and the lack of detailed information on cultural techniques require professionalism and studies to rationalize MAP cultivation. The success of propagation represents one of the most important goals for plant producers. The vegetative propagation is widely preferred to seeding propagation because the germinability of MAP seeds is sometimes lower than 50%, and the seed selection programs are lacking. Cutting is one of the most important means of plant propagation. Cutting propagation is fast, simple and does not require the special techniques which are mandatory in grafting, budding, or micropropagation. Many new plants can become available in a limited space from a few stock plants. The vegetative propagation leads to a great uniformity of the plant material with virtually no genetic change with the parent plants (Hartmann et al., 1997). The vegetative propagation is used when seed viability is very low. Increasing demand for organic farming techniques also requires further research to match the needs for organic nursery material. The aims of the present research were to study the cutting techniques on sage (Salvia officinalis L.), testing rooting products Proc. WOCMAP III, Vol 2: Conservation Cultivation & Sustainable Use of MAPs Eds.: A. Jatisatienr, T. Paratasilpin, S. Elliott, V. Anusarnsunthorn, D. Wedge, L.E. Craker and Z.E. Gardner Acta Hort. 676, ISHS

2 registered for organic farming and rooting products of synthetic to increase rooting, and to evaluate the difference on rooting among the tested products. MATERIALS AND METHODS Trials were carried out in a greenhouse at the Experimental Center of the Faculty of Agriculture of the University of Turin, where cuttings were produced every 2 weeks. The experiment started on 15 th May 2001 and ended on 30 th October 2001, leading to 11 cutting periods (Table 1). At each experiment 104-cell plastic trays were filled with a cutting specific medium ( Steckmedium, Klasmann-Deilmann GmbH, Geeste-Groβ Hesepe, Germany), a mix of peat moss and perlite, with ph ranging from 5 to 6, composed, in dry matter percent, by 30% organic Carbon of biological, 0,4% organic Nitrogen, and 50% organic matter. The medium was well pressed in the cells and wetted with water until saturation. Portions of stem about 8-cm long with lateral buds were cut from diseasefree stock plants. About one third of the leaf surface of each cutting was removed to limit the transpiration. Cuttings were treated and immediately planted into holes punched into the medium. considered were 7 commercial rooting products (Rooting Products Registered for Organic Farming, rprof, and Rooting Products of Origin, rpso), plus an untreated control (Table 2). According to the different application procedures, cuttings were either soaked in the solution for the requested time (Naftal and Cytokin ), or sprayed with the solution until medium saturation (Cytokin, Stimolante 66f, Kendal, Radifarm and Radix ), or dusted in the powder product (Germon ). One product (Cytokin ) was applied in two ways, leading to 8 product treatments. An outline of each product is reported in Table 2. Trays were located on a bench provided of mist irrigation system; irrigation management varied throughout the year according to cutting needs. Four weekly samplings (22, 29, 36 and 43 days after cutting, DAC) were carried out to evaluate rooting degree starting three weeks after each cutting. The roots of 4 young cuttings for each treatment and cutting period were carefully washed in water to eliminate the growing medium. The length of the longest root and the root number were assessed. Fifty days after cutting the plants were pricked in pots (120 mm diameter). The treatments were arranged according to a complete randomized design with rooting products as a factor (9 levels: 8 products plus control) with 4 replications. Data were submitted to the analysis of variance and to preplaned orthogonal contrasts according to Table 3. RESULTS AND DISCUSSION Rooting of sage cuttings was significantly affected by treatments at each sampling in terms of the longest root length except at the last one (P<0.001, 1 st, 2 nd and 3 rd samplings; P=0.146, ), and in terms of root number (P=0.001, 1 st and 2 nd samplings; P<0.001, ; P=0.003, ), hence orthogonal contrasts were considered for each sampling throughout the cutting periods. The root system of sage develops independently of application of rooting products and faster in comparison to other MAPs (Nicola et al., 2003, 2002). However, the analysis of orthogonal contrasts comparing the control vs. rooting products indicated that the production of adventitious roots was favoured by the rooting products. The treated cuttings produced always longer roots and a greater number of roots respect to plants not treated (Tables 4 and 5). At (), the differences in length of the longest root and in root number between control and treated cuttings were already sensible, even if not significant (P=0.111), and were respectively of 13.9 and 20.0 mm and of 1.4 and 2.7 roots. At the 2 nd () and 3 rd () samplings the differences increased and became highly significant (Tables 4 and 5). At the,, rooting of sage was statistically not affected by rooting product application (Tables 4 and 5). However, plants could have been considered already for transplanting at, 136

3 when the rooting products had already enhanced the root length and number. The orthogonal contrast indicated that the effect of rpso vs. rooting rprof was not significant for the length of the longest root (Table 6): either rpso or rprof can be used to enhance rooting with the same final effect. Consequently, the use of the last ones is preferable to the first ones because of their environmental respect; furthermore, rprof were competitive with respect to the rpso, thus they represent a useful tool in organic farming. The contrast for root number was significant at the 1 st and s (Table 7). The cuttings treated with rpso produced a greater root number than cuttings treated with rprof (: 3.1 vs. 2.2; : 4.2 vs. 3.3) (Table 7). Later on, root number was not statistically influenced by rooting application, and the difference of growth between rpso and rprof decreased (Table 7). These results indicated that the rprof effect on sage cutting rooting was slower than rpso one. Between the rprofs, the difference of rooting observed between the two tested products, Cytokin and Radix, was statistically significant from to for the length of the longest root and only (at ) for the root number (Tables 8 and 9). The length of the longest root in cuttings treated with Radix was greater than in cuttings treated with Cytokin from 1 st to, while it levelled off at the (about 34 mm) (Table 8). These results indicated that Radix affected the rooting of sage cutting earlier than Cytokin. The contrast between products based on NAA (Stimolante 66f, Germon and Naftal ) vs. products based on fertilizer (Kendal and Radifarm ) was significant at 3 rd sampling for the length of the longest root and at the last two samplings for root number (Tables 10 and 11). The cuttings treated by the former products produced roots longer and more numerous than cuttings treated by the latter products, indicating that also fertilizers like Radifarm and Kendal can be used for rooting of sage. The results of the present research indicated that sage is a species prone to rooting by cutting, although rooting was favoured and anticipated by rooting product application. Good results were obtained with rpso at the first samplings; later on the difference of rooting between rpso and rprof decreased. The choice of using rpso rather than rprof is linked to the farm organization and commercial period, because duration requested to obtain a rooting system strong enough to assure cutting development and growth are different according to rooting products applied. Cutting rooting of sage was good from spring to the end of autumn, later on stock plants were in vegetative rest so that it was not possible to use the cutting technique for this species. ACKNOWLEDGEMENTS Thanks to Riccardo Rizzo for his MSc work and Giuseppe Piovano, Mario Gilardi, Gabriele Gariglio, Mauro Gilli and Paolo Gastaldi for their field work. The Authors have equally contributed to the research and to the manuscript. Literature Cited Hartmann, H.T., Kester, D.E., Davies, F.T. and Geneve, R.L Plant Propagation: principles and practices. Prentice Hall, Inc., New Jersey. Nicola, S., Fontana, E. and Hoeberechts, J Impiego di radicanti ecocompatibili e scelta dell epoca di taleaggio: importanti fattori tecnici per la propagazione del rosmarino (Rosmarinus officinalis L.). Proc. VI Giornate Scientifiche SOI Spoleto, April p Nicola, S., Fontana, E. and Hoeberechts, J Effects of rooting products on medicinal and aromatic plant cuttings. Acta Hort. 614:

4 Tables Table 1. Experimental timetable. CUTTING DATE SEASON 1 st 15 May, 2001 Spring 2 nd 29 May, 2001 Spring 3 rd 12 June, 2001 Spring 4 th 26 June, 2001 Summer 5 th 31 July, 2001 Summer 6 th 21 August, 2001 Summer 7 th 4 September, 2001 Summer 8 th 18 September, 2001 Summer 9 th 2 October, 2001 Autumn 10 th 16 October 2001 Autumn 11 th 30 October, 2001 Autumn Table 2. List of rooting products used in the experiments. Rooting products Stimolante 66f Germon Naftal Kendal Radifarm Cytokin Radix Product class Registered for organic farming Registered for organic farming Active principle/s Manufacturer Dose Application (ml L -1 ) NAA Gobbi 0.3 Sprayed NAA Gobbi - Powder NAA Aifar Agricola 0.1 Soaked for 12 h Liquid fertilizer Valagro 2.0 Sprayed Liquid fertilizer with aminoacids, polysaccharides and betaines, specific for rooting Cytokins Gliocladium spp. Trichoderma spp. Pseudomonas spp. Streptomyces spp. Valagro 2.5 Sprayed Miller 8.0 Sprayed Chemical & 0.3 Soaked for F.C. 5 minutes Biochem 5.0 Sprayed 138

5 Table 3. Preplaned orthogonal contrasts considered for the longest root length and root number analyses. Orthogonal contrasts 1 Rooting products vs. control 2 Rooting products of synthetic (rpso) vs. rooting products registered for organic farming (rprof) 3 Cytokin vs. Radix 4 Products based on NAA vs. Products based on fertilizers Table 4. Longest root length in cuttings treated with rooting products or untreated in 4 samplings (22, 29, 36 and 43 days after cutting, DAC), and P values. Control Rooting products Significance (P=) < Table 5. in cuttings treated with rooting products or untreated in 4 samplings (22, 29, 36 and 43 days after cutting, DAC), and P values. Control Rooting products Significance (P=) <

6 Table 6. Length of the longest root in cuttings treated with rooting products registered for organic farming (Cytokin and Radix ) and rooting products of synthetic (Stimolante 66f, Germon, Naftal, Kendal and Radifarm ) in 4 samplings (22, 29, 36 and ), and P values. rprof rpso Significance (P=) Table 7. in cuttings treated with rooting products registered for organic farming (rprof) (Cytokin and Radix ) and rooting products of synthetic (rpso) (Stimolante 66f, Germon, Naftal, Kendal and Radifarm ) in 4 samplings (22, 29, 36 and ), and P values. rprof rpso Significance (P=) Table 8. Length of the longest root in cuttings treated with two different rooting products registered for organic farming, Radix and Cytokin, in 4 samplings (22, 29, 36 and ), and P values. Cytokin Radix Significance (P=)

7 Table 9. in cuttings treated with two different rooting products registered for organic farming, Radix and Cytokin, in 4 samplings (22, 29, 36 and ), and P values. Cytokin Radix Significance (P=) Table 10. Length of the longest root in cuttings treated with rooting products based on NAA (Stimolante 66f, Germon and Naftal ) and with rooting products based on fertilizers (Radifarm and Kendal ) in 4 samplings (22, 29, 36 and ), and P values. Rooting products based on NAA Rooting products based on fertilizers Significance (P=) Table 11. in cuttings treated with rooting products based on NAA (Stimolante 66f, Germon and Naftal ) and with rooting products based on fertilizers (Radifarm and Kendal ) in 4 samplings (22, 29, 36 and ), and P values. Rooting products based on NAA Rooting products based on fertilizers Significance (P=)