Application Of Indolebutyric Acid Research Articles

Influência de ácido indolbutírico no enraizamento de estacas semilenhosas de Campomanesia aurea

Campomanesia aurea (O. Berg) is a species native to southern Brazil, naturally occurring from the state of São Paulo to Rio Grande do Sul, and presenting a great ornamental potential. The objective was to verify the rooting of semihardwood cuttings of Campomanesia aurea using indolebutyric acid (IBA) doses. The cuttings were collected in the municipality of Barão do Triunfo, Rio Grande do Sul State, in December 2014. The cutting base was immersed in concentrations of zero (control), 2,000, 4,000, 6,000 and 8,000 mg L-1 of IBA, subsequently established in a carbonized rice husk substrate and placed in a protected environment with an intermittent misting system. At 111 days after installation, dead and rooted cuttings, leaf retention, callus formation, root volume, root and shoot dry matter were evaluated. The experimental design was completely randomized with four replications with 20 cuttings. Data were submitted to analysis of variance and regression. No statistical differences were found for any of the evaluations. An average rooting was observed in 28% of cuttings and callus formation was observed in 48% of cuttings. Root average volume per cutting was 0.15 mL, root dry mass was 0.01 g, and shoot dry mass was 0.28 g. There was a negative correlation between leaf retention and mortality of cuttings. It is concluded that the production of C. aurea by cutting is viable, and that there was no positive response to the application of IBA with the conditions under which the experiment was developed.

Vegetative propagation of twelve fodder tree species indigenous to the Sahel, West Africa

In the Sahel region, many woody species are used as fodder because of their high nitrogen content, especially during the dry season, in contrast to grasses and crop residues. Unfortunately, this resource is being threatened by regular pruning, increasing livestock browsing and impeding their natural regeneration. Therefore, there is a need to find appropriate regeneration options to sustain fodder production. Thus, a series of vegetative propagation experiments were conducted to identify the most appropriate multiplication methods of some of the species used as fodder. This series included testing the effects of naphthalene acetic acid (NAA) and indole butyric acid (IBA) on rooting ability of stem cuttings of 12 species: Afzelia africana, Balanites aegyptiaca, Bauhinia rufescens, Commiphora africana, Faidherbia albida, Ficus gnaphalocarpa, Guiera senegalensis, Kigelia africana, Pterocarpus erinaceus, Pterocarpus lucens, Pterocarpus santalinoides and Terminalia avicennioides. The series also evaluated the impacts of the size (C. africana) and the age (P. erinaceus) of the cuttings on their rooting success. Pterocarpus santalinoides was revealed to be an easy-to-root species, showing a high percentage of rooted cuttings (up to 88±3%), followed by P. erinaceus, P. lucens and B. aegyptiaca (up to 37±4%, 31±5% and 26±6%, respectively), in contrast to A. africana, cuttings of which did not root at all. The application of NAA and IBA enhanced the number of roots and secondary roots per rooted cutting. Large-diameter cuttings (15–20 mm) of deeply planted C. africana gave the highest percentage of rooted cuttings (78.3±4.4%). Tree pruning improved the rooting capacity of cuttings collected from P. erinaceus with one-month resprouts giving the highest percentage of rooted cuttings (50.0±6.7%). These results indicate that P. santalinoides, C. africana, P. erinaceus, P. lucens and B. aegyptiaca are amenable to vegetative propagation as an alternative to sexual propagation.

Propagation of <i>Garcinia kola</i> (Heckel) by stem and root cuttings

The availability of appropriate propagation techniques is a major constraint to the domestication of the forest trees widely used by rural communities; such as (Heckel). This study tested the ability of root and stem cuttings to regenerate vegetatively when treated with indole-3-butyric acid (IBA), and set in non-mist poly-propagator within a shaded nursery. It found that is amenable to propagation by softwood stem cuttings. Attention was given to the effect of cutting age (softwood, semi hardwood) and IBA application with regard to the sprouting and rooting efficiency. Bud and leaf emergence time were also investigated, as was the coppicing ability of the stump. Results revealed that roots and branches from mature forest trees did not sprout under any culture conditions. The highest percentages of rooting (70–85%) were obtained with softwood cuttings set in non-mist poly-propagator, regardless of hormonal treatment. The mean numbers of buds (2.9 ± 0.4) and roots (2.6 ± 0.1) produced by softwood cuttings was significantly greater than those obtained in the Control. The best average emergence time of buds (25.1 days ± 9.3) and leaves (36.8days ± 8.4) was obtained with cuttings treated with IBA and set in non-mist poly-propagator against, 54.4 ± 12.5 and 72.6 ± 3.4 days respectively for the Control. In general, non-mist poly-propagator gave the best propagation results. When coppiced, the shoots emerging from stumps with one node were the most vigorous.Garcinia kola G. kola

Uso de regulador vegetal no enraizamento de estacas de glicínea japonesa

Wisteria floribunda , known as wisteria, is a woody climbing plant with inflorescence raceme type, stalky supported, which provides value for the cultivation towards ornamental purposes. Its propagation occurs via seeds or stem cuttings. The low rate of seed germination makes the vegetative propagation a more efficient method. The presented work verified the influence of synthetic auxin application, indole butyric acid (IBA), in different concentrations, such as its application way, talc or solution, in the rooting of wisteria cuttings. With branches of stock plants, collected in November 2012, were made cuttings of approximately 10 cm length, 0.5 cm diameter and with two leaves. After disinfection, the base of the cuttings were treated with: 0 mg L -1 ; 1000 mg L -1 and 2000 mg L -1 via IBA in solution and, 0 mg kg -1 ; 1000 mg kg -1 e 2000 mg kg -1 via IBA in talc. Vermiculite was the subtract used for all treatments. 63 days after the installation, the percentage of rooted cuttings was evaluated, live, with calluses and dead; the number of roots per cuttings and the length of the largest roots per cuttings. The best results were obtained with treated cuttings of 2000 mg kg -1 (78.75% and 73.75% of rooting) therefore both ways of application of IBA are efficient towards the rooting induction. The application in the form of talc is indicated for the induction of a greater number of roots per cutting.

Uso de regulador vegetal no enraizamento de estacas de glicínea japonesa

Wisteria floribunda , known as wisteria, is a woody climbing plant with inflorescence raceme type, stalky supported, which provides value for the cultivation towards ornamental purposes. Its propagation occurs via seeds or stem cuttings. The low rate of seed germination makes the vegetative propagation a more efficient method. The presented work verified the influence of synthetic auxin application, indole butyric acid (IBA), in different concentrations, such as its application way, talc or solution, in the rooting of wisteria cuttings. With branches of stock plants, collected in November 2012, were made cuttings of approximately 10 cm length, 0.5 cm diameter and with two leaves. After disinfection, the base of the cuttings were treated with: 0 mg L -1 ; 1000 mg L -1 and 2000 mg L -1 via IBA in solution and, 0 mg kg -1 ; 1000 mg kg -1 e 2000 mg kg -1 via IBA in talc. Vermiculite was the subtract used for all treatments. 63 days after the installation, the percentage of rooted cuttings was evaluated, live, with calluses and dead; the number of roots per cuttings and the length of the largest roots per cuttings. The best results were obtained with treated cuttings of 2000 mg kg -1 (78.75% and 73.75% of rooting) therefore both ways of application of IBA are efficient towards the rooting induction. The application in the form of talc is indicated for the induction of a greater number of roots per cutting.

Enraizamento de estacas de Tibouchina moricandiana var. vinacea em função da forma de aplicação e concentrações de AIB

Tibouchina moricandiana Baill. var. vinacea Handro is a woody shrub, native to Brazil with ornamental potential. The objective of this study was to evaluate the feasibility of cutting the vegetative propagation of the species according to the application form and different concentrations of indole butyric acid (IBA). Softwood cuttings were treated with 0, 1,000 and 2,000 mg kg-1/mg L-1 of IBA in powder and solution form. After 56 days the treatments were evaluated for rooting, cuttings with callus, survival, mortality, leaf retention, new shoots, number of roots per cutting and root length. The rooting of stem cuttings of T. moricandiana was negatively influenced by the concentrations of IBA or by way of application. The species has a high strike rate (90.8%), demonstrating a species with potential for vegetative propagation through cuttings. The form of application and concentration of IBA influenced other variables. The use of 2,000 mg kg-1 IBA applied by talc demonstrated a decrease in the number of roots and provided the greatest number of and unrooted live cuttings. The length of the three longest roots per cutting was higher with the use of 1,000 mg L-1 or mg kg-1 of IBA. The use of IBA for the rooting of cuttings can be dispensed with, but can be used at a concentration of 1,000 mg-1 or mg kg-1 to increase the length and number of roots.

Effects of exogenous indole-3-butyric acid and myo-inositol on in vitro rooting, vegetative growth and biochemical changes in leaves and roots in the sweet cherry rootstock MxM 14 using shoot tip explants

In the present study, the effects of indole-3-butyric acid (IBA) alone and in combination with myo-inositol under in vitro conditions on morphogenic and biochemical responses in the MxM 14 (Prunus avium × Prunus mahaleb) sweet cherry rootstock were investigated using shoot tips as explants. The best treatment that induced the better response for rooting in terms of root number per rooted explant (16.46), root length (23.12 mm), root fresh weight (0.372 g), root dry weight (0.037 g) and rooting percentage (100 %) was 9.84 μΜ IBA in the absence of myo-inositol. Thus, myo-inositol suppressed the positive effect of IBA on rooting. The simultaneous application of IBA and myo-inositol achieved the better response for shoots development regarding their length (22.5–25.6 mm) in relation to the control (15 mm). However, the optimum shoot biomass was obtained with 9.84 μΜ IBA resulting in a 4-fold increase in shoot fresh (0.455 g) and dry weight (0.045 g) compared to the control. Regarding biochemical parameters, it was shown that there is no evident relation between chlorophyll levels, endogenous leaf proline or carbohydrate content in both leaves and roots, and improvement of rooting and shoot biomass in the respective observed treatments. On the contrary, the enhancement of rooting and shoot biomass could be related to the elevated endogenous proline levels in roots. According to the results obtained, there may be a correlation between the augmented proline levels in both leaves and roots in the IBA + myo-inositol combination treatments and shoot growth of MxM 14 explants (i.e. microcuttings height). The survival percentage of the ex vitro MxM 14 plantlets was 93 %. An efficient protocol of in vitro rooting and vegetative growth for the cherry rootstock MxM 14 was established using IBA and myo-inositol which constitutes a very useful tool for future genetic transformation.

ORIGEM DE BROTAÇÕES EPICÓRMICAS E APLICAÇÃO DE ÁCIDO INDOLILBUTÍRICO NO ENRAIZAMENTO DE ESTACAS DE <i>Vochysia bifalcata</i> Warm.

http://dx.doi.org/10.5902/1980509818457A guaricica (Vochysia bifalcata) é uma espécie nativa da região litorânea do Estado do Paraná, Santa Catarina, São Paulo, Rio de Janeiro e Minas Gerais, com grande importância ecológica, devido à sua capacidade para regenerar áreas degradadas. No entanto, existem poucas informações sobre a sua propagação, seja sexuada ou assexuada. Uma das causas do baixo enraizamento adventício de estacas caulinares é a maturação dos tecidos coletados para tal fim. Desta forma, o presente trabalho objetivou avaliar diferentes origens de brotações epicórmicas associadas à aplicação de ácido indolilbutírico (AIB) na propagação vegetativa de estacas semilenhosas de Vochysia bifalcata. Foram utilizados dois tipos de estacas (provenientes de brotação de decepa e envergadura de caule) nas quais foram aplicadas duas concentrações de AIB (0 e 1000 mg L-1). Após o plantio em tubetes com vermiculita de granulometria média e casca de arroz carbonizada, as estacas foram mantidas em casa de vegetação climatizada por 60 dias. Análises anatômicas da base de cada tipo de estaca demonstraram que a presença de fibras na região cortical do caule de estacas de decepa não constituiu uma barreira anatômica para a emissão radicial, pois estas apresentaram maior capacidade de enraizamento (81%), maior número de raízes por estaca (8,0) e maior comprimento das raízes (2,0 cm) em relação àquelas de envergadura de caule, que apresentaram resultados inferiores como porcentagem de enraizamento (31%), número de raízes por estaca (3,3) e comprimento das raízes (0,7 cm). Conclui-se, assim, que o uso de brotações epicórmicas induzidas por decepa de caule proporciona melhor enraizamento adventício do que de envergadura de caule, não necessitando da aplicação de AIB como indutor do enraizamento neste tipo de material.

Propagación asexual de Pinus leiophylla Schiede ex Schltdl. et Cham.

The effect of substrate, type of cutting and indole 3-butyric acid (IBA) concentration on the rooting of Pinus leiophylla cuttings was evaluated with the goal of multiplying progenies of half-sib families of this species, which have showed superior growth and positive response against Toumeyella pinicola attack. Two types of substrates (100 % perlite vs. a mix of peat, perlite, vermiculite at a ratio of 1:1:1), two types of cuttings (apical vs. basal) and two concentrations of IBA (0 vs. 10,000 ppm) were used. Probability and percentage of rooting, growth of cuttings and characteristics of the roots were evaluated. Results indicate that using basal cuttings is 3.5 times more likely to induce rooting of P. leiophylla than using apical cuttings. The treatment consisting of the mixture of peat-perlite-vermiculite, a basal cutting and 10,000 ppm of IBA produced 45.3 % rooting (highest percentage), while the control only yielded 8.6 % rooting (perlite, basal cutting and without IBA). Interactions with the type of substrate showed significant differences (P ≤ 0.05) in the growth of the cuttings. The use of perlite and application of IBA promoted a greater number of roots, particularly in the basal cuttings of P. leiophylla.

Enraizamento de estacas de lichieira tratadas com ácido indolbutírico e substratos

The seedling production of lychee (Litchi chinensis Soon.) by cuttings, is a promising alternative because it allows the reduction of the period of juvenility and maintenance of the desirable characteristics of the stock plant. The aim of this study was to evaluate the rooting of semihard cuttings of litchi cv. Bengal treated with indole butyric acid (IBA) on different substrates. The experimental design was completely randomized arranged in a factorial 3 x 2 (three substrates: rice hulls, coconut fiber and vermiculite, and two IBA concentrations: 0 and 1,000 mg L-1), with five replicates of 10 cuttings per plot. It was found that there was no influence of the substrate and the concentration of IBA on the survival of cuttings. The rooted cuttings on coconut fiber showed higher leaf retention. The application of IBA on cuttings in carbonized rice husk and vermiculite resulted in the best average of rooting. For the dry mass of roots, the highest average has observed with vermiculite and IBA application. The use of rice hulls and vermiculite as substrates and the application of 1,000 mg L-1 IBA is the most appropriate for rooting of litchi ‘Bengal’ cuttings.

Effect of indole-3-butyric acid and Trichoderma harzianum Rifai on asexual cape gooseberry propagation (Physalis peruviana L.)

The growth and development of cape gooseberry plants obtained from cuttings is affected by microorganisms in the substrate and by the concentration of plant growth regulators applied during planting. Using a factorial design, the effect of four concentrations of indole-3-butyric acid (IBA) (0, 800, 1,200, and 1,600 mg L-1) and four suspensions of Trichoderma harzianum (0, 2·106, 3·106, and 4·106 cfu/mL) on the growth of cape gooseberry cuttings was evaluated. Apical cuttings were used, 20 cm long, from 20-month-old plants of the Colombian ecotype, which were planted in pots (2 L) using peat moss with burned rice husks as the substrate at a 3:1 ratio (v/v). The 800 mg L-1 of IBA application showed the highest accumulation of total dry mass (DM) and root DM. Moreover, 800 mg L-1 of IBA resulted in the highest leaf chlorophyll content, showing significant differences from 1,600 mg L-1, which had the lowest value. The 3·106 cfu/mL suspension of T. harzianum caused a greater accumulation of root DM and total DM and a higher leaf area in the plants. The most favorable interaction between the factors, which favors the growth of cape gooseberry plants obtained from cuttings, was observed with the application of 800 mg L-1 of IBA and 3·106 cfu/mL of T. harzianum.

EFFECT OF DELAYED IBA TREATMENTS ON ROOTING OF PROTEA CULTIVARS 'NIOBE', 'LADY DI', 'PINITA', 'SUSARA' AND 'PINK ICE'

Successful clonal propagation is essential for commercial production of Proteaceae. The standard protocol developed for rooting Proteaceae cuttings has not been successful with all protea cultivars. The purpose of this study was to evaluate delayed application of indole-3-butyric acid (IBA) to improve the propagation of protea cultivars known to have low rooting success. Cuttings were either stored in the dark for 0 to 10 days before treating with IBA or incubated in a rooting environment under natural light without IBA for conditioning periods of 0 to 28 days before application of IBA. Cultivars Protea F2 hybrid ‘Niobe’, P. magnifica × P. compacta ‘Lady Di’, P. magnifica × P. longifolia ‘Pinita’, P. magnifica × P. Susannae ‘Susara’ and P. compacta × P. susannae ‘Pink Ice’ were used. More than 80% rooting was achieved with ‘Pink Ice’ and ‘Susara’ and these may be described as “easy-to-root”. The first approach did not increase rooting percentage of the more “difficult-to-root” cultivars, ‘Lady Di’, ‘Niobe’ and ‘Pinita’. ‘Niobe’ cuttings rooted significantly better with no cold storage period. Although some trends were detected that indicated improved rooting success with delayed IBA treatment after incubation in the rooting house, there was no significant improvement in the number of transplantable cuttings. In both approaches, ‘Pinita’ had a high percentage of cuttings with no root formation, but without decay or leaf drop.

Enraizamento de estacas de pinheira (Annona squamosa L.) com ácido indolbutírico

A pinheira (Annona squamosa L.) apresenta boas perspectivas econômicas para a fruticultura brasileira, e sua propagação tem sido realizada comumente de forma seminífera; todavia, a propagação vegetativa de plantas selecionadas é o método mais indicado para a formação de pomares uniformes e produtivos. A estaquia apresenta vantagens que incluem a facilidade da técnica e seu baixo custo. A aplicação de auxinas sintéticas, como o ácido indolbutírico (AIB) na base da estaca, garante o suprimento exógeno, auxiliando no processo do enraizamento. Este trabalho objetivou estabelecer a concentração e o método de aplicação do AIB, visando ao estímulo ao enraizamento em estacas de pinheira, e estudar os tecidos que as formaram. Independentemente da concentração, a aplicação do AIB via pó foi significativamente mais eficiente para a formação das raízes do que na forma líquida. Os estudos anatômicos revelam que as raízes surgem de forma indireta, a partir do tecido caloso, formado na base das estacas.

Acclimatization of micropropagated Musa cavendischii cultivar roatan plants submitted to doses of fertigation and auxin

Micropropagation of banana is suggested to produce great number of healthy plants but the success depends on the ability to transfer plants from in vitro conditions to greenhouse or field environment, at low cost and with high survival rates. In this study, the effects of the fertilization and indolebutyric acid (IBA) applied in the nutritive solution on growth of Musa cavendischii plantlets were evaluated during acclimatization process in greenhouse. First, in vitro plantlets of M. cavendischii were transplanted to pots of 150 cm3 containing perlite and transferred to greenhouse for their acclimatization during 11 weeks. The experiment was established according to a completely randomized design with 5 treatments and 20 replications per treatment. The experimental unit was one plant transplanted in each pot, resulting from the combinations of daily applications of 10 ml of the Steiner’s nutritive solution at 10, 25, 50, 75 and 100%, respectively (Factor A), without and with 1 mgL-1 of the auxin IBA (Factor B). After 11 weeks of acclimatization, the results shows that, the higher plants with respect to plant fresh, dry weight and height, and leaf width corresponded to the treatments from 75 to 100% of the Steiner’s solution. The IBA application had no significant effects on the growth of the M. cavendischii plants. There was no significant interaction between fertigation and IBA applications. The plants fertigated at 100% of nutriments concentration had 27.7 cm of height, 259.9 cm2 of foliar area, and 1.01 mg of chlorophyll g-1 of foliar fresh weight. Key words: Acclimatization, fertilizer, micropropagation, indolebutyric acid, plant nutrition.

<b>Use of phytoregulators in overcoming macaw palm seed dormancy</b> - doi: 10.4025/actasciagron.v35i4.16385

The macaw palm is a tropical palm with significant potential for biofuel production; however, seed dormancy is a major factor limiting its agro-industrial use. The present study evaluated the effects of phytoregulators in overcoming macaw palm seed dormancy. We evaluated the effects of immersion in solutions of gibberellic acid (GA3) (0, 2000 and 5000 mg L-1) during two exposure times (24 and 48 hours), associated with the removal or maintenance of the opercular tegument, as well as the effects of the associations between GA3 (2000 mg L-1), indole-3-butyric acid (IBA) and benzylaminopurine (BAP) and the effects of repeated applications (one, two or five) of combinations of these phytoregulators. The seeds were sown in vermiculite and incubated in a humid growth chamber at 95 ± 5% relative humidity and 30°C for 18 weeks in all experiments. GA3 application and removal of the opercular tegument had positive effects on germination, but no significant differences were observed in immersion times for this phytoregulator. The application of IBA and BAP did not influence germination. The application of GA3 on five separate occasions gave the best results, with 41% germination at the end of the experiment.

Effects of exogenous l-arginine on in vitro rooting, chlorophyll, carbohydrate, and proline concentrations in the sweet cherry rootstock M × M 14 (Prunus avium L. × Prunus mahaleb L.)

The effects of indole-3-butyric acid (IBA) alone and in combination with l-arginine on the morphogenic and biochemical responses in shoot tip explants of the cherry rootstock M × M 14 (Prunus avium × Prunus mahaleb) were examined. The maximum root number per rooted explant (16), root fresh (FW) and dry (DW) weights, as well as the rooting percentage (100 %) were recorded when 2 mg l−1 IBA (alone) were applied. Including the lowest IBA concentration (0.5 mg l−1) with the lowest and highest l-arginine concentrations (0.5 and 2 mg l−1, respectively) resulted in the greatest root length. The maximum leaf chlorophyll concentration and shoot length of the initial explant were recorded when 0.5 mg l−1 IBA plus 2 mg l−1l-arginine were applied. In addition, l-arginine in combination with IBA (1 and 2 mg l−1) was found to suppress shoot FW and DW. On the other hand, l-arginine enhanced the promoting effect of IBA on both root length and leaf chlorophyll concentration. The carbohydrate and proline concentrations in leaves were not significantly altered with the application of IBA alone or in combination with l-arginine. On the other hand, the carbohydrate and proline concentrations in roots were decreased with the application of 1 and 2 mg l−1 IBA with l-arginine, resulting in the suppression of the promoting effects of IBA. It is clear from the findings that l-arginine has a direct effect on the in vitro rooting of M × M 14 explants, is involved in the function of the photosythetic apparatus, influences leaf chlorophyll content, participates in carbohydrate biosynthesis and metabolism, and is involved in proline accumulation both in leaves and roots.

Indole-3-butyric acid and myo-inositol impacts on in vitro rooting of the cherry rootstocks CAB-6P and Gisela 6

The present study investigates the effects of indole-3-butyric acid (IBA) alone and in combination with myo-inositol on in vitro rooting and biochemical responses in the cherry rootstocks CAB-6P (Prunus cerasus L.) and Gisela 6 (Prunus cerasus × Prunus canescens). For the CAB-6P rootstock, the best results for root number (6.31), fresh mass (FM), dry mass (DM), and rooting percentage (100 %) were obtained on Murashige and Skoog (MS) medium with 2 mg dm-3 IBA and maximum root length (30.57 mm) was obtained at 1 mg dm-3 IBA. Myo-inositol suppressed the positive effects of IBA on root length. In the Gisela 6 explants, the inclusion of 2 mg dm-3 IBA together with 0.5 mg dm-3 of myo-inositol in the culture medium significantly enhanced root number (9.91) and root FM and DM. The root length was maximum in the combination of the lowest IBA and myo-inositol concentrations (0.5 mg dm-3). The rooting percentage was the greatest (100 %) with the application of 1 mg dm-3 IBA alone. In both explants, the application of IBA alone or in combination with myo-inositol resulted in a lower leaf proline content in comparison with the control (without growth regulators). The maximum leaf chlorophyll content was at 1 mg dm-3 IBA in the CAB-6P whereas at 2 mg dm-3 IBA and 1 mg dm-3 myo-inositol in Gisela 6. Addition of myo-inositol mostly increased sugar content in comparison with control or IBA alone in both rootstocks.

The influence of indolebutyric acid, sampling-dates and juvenility on the rooting of filbert (Corylus sp.) cuttings

Propagation of filberts (= hazelnuts) by cuttings taken from long shoots (adult cuttings) and offshoots (juvenile cuttings) was attempted. The influence of sampling-dates, source of cuttings and of application of indolebutyric acid (IBA) was investigated. The best results were obtained when cuttings were taken in June and treated with IBA (50 mg/l<sup>-1</sup> for 18 h). Juvenile cuttings, obtained from offshoots rooted better than those from long shoots of the crown. The rootability of cuttings varied in the investigated filbert cultivars. The results suggest the possibility of propagating filbert by cuttings.

Substratos no enraizamento de estacas herbáceas de amora-preta Xavante

A amora-preta (Rubus spp.) destaca-se entre as espécies que apresentam boas perspectivas de cultivo em áreas de agricultura familiar. Visando a otimizar a multiplicação de mudas dessa espécie, o objetivo deste trabalho foi avaliar o uso de substratos e concentrações do ácido indolbutírico (AIB) no enraizamento de estacas de amora-preta Xavante. O delineamento experimental foi o inteiramente casualizado em arranjo fatorial 3x2 (três tipos de substratos e duas concentrações de AIB), com cinco repetições de sete estacas, sendo adotados os fatores: tipos de substratos (casca de arroz carbonizada, vermiculita grânulos médios e fibra de coco) e tratadas ou não com AIB (0 e 1000mg L-1). Após 80 dias, foram avaliadas as variáveis: sobrevivência das estacas; retenção foliar; estacas enraizadas; número de raízes por estaca; comprimento da maior raiz; massa seca das raízes por estaca; e pH; condutividade elétrica; densidade e capacidade de retenção de água dos substratos. Não houve influência dos substratos e da aplicação de AIB sobre a porcentagem de estacas enraizadas, verificando-se alta eficiência no enraizamento das estacas de amora-preta Xavante (86,2%). Para a porcentagem de sobrevivência das estacas, o melhor resultado foi obtido sem a aplicação de AIB. Conclui-se que a amora-preta Xavante pode ser propagada por estaquia herbácea com eficiência, sem o uso de AIB, utilizando-se preferencialmente o substrato casca de arroz carbonizada como opção de baixo custo.

Growth Promotion of Yunnan Pine Early Seedlings in Response to Foliar Application of IAA and IBA

A field experiment was conducted using a 3 × 3 orthogonal regression design to explore the growth promotion of one-year-old Yunnan pine seedlings (Pinus yunnanensis Franch.) in response to foliar application of IAA (indole-3-acetic acid) at rates of 0, 200 and 400 mg·L−1 and IBA (indole-3-butyric acid) at rates of 0, 200 and 400 mg·L−1 in order to promote the growth during the seedlings’ early stage. The experiment was conducted at the Lufeng Village Forest Farm of Yiliang County in Kunming, Yunnan, China. The results showed that IAA and IBA were effective in growth promotion of Yunnan pine seedlings. The response of both growth increment and biomass accumulation to the concentration of IAA and IBA can be modeled using a bivariate surface response, and each growth index had a peak value. Growth indexes increased with the increase of the dosage of photohormones before reaching a peak value, and then decreased. The different growth indexes had various responses to the concentrations and ratio of IAA and IBA. The foliar application of IAA in combination with IBA showed the largest improvement on the biomass of the needles, followed by stems and roots. The higher ratio of IAA promoted stem diameter growth, root system development and biomass accumulation in the needles, while a higher ratio of IBA contributed to height growth and biomass accumulation in the stem. Based on the auxin effect equations on the different growth indexes and surface response, the optimum concentrations and the (IAA:IBA) ratios can be obtained. The optimum concentrations of IAA and IBA were 167 and 186, 310 and 217, 193 and 159, 191 and 221, and 206 and 186 mg·L−1, with corresponding ratios of 1:1.11, 1:0.70, 1:0.82, 1:1.15 and 1:0.90, respectively, at the maximum seedling height and collar diameter growth as well as biomass accumulation at the root, stem and needle. The above growth indexes were 22.00%, 79.80%, 48.65%, 82.20% and 107.00% higher than the control treatment.