Rooting of juvenile cuttings of Bertholletia excelsa under different concentrations of indolebutyric acid. Iracema M. Recalcitrant behavior and slow and irregular germination are limiting factors for the production of Bertholletia excelsa seedling production, through the conventional process. The objective of this study was to evaluate the rooting of juvenile cuttings of B. The experimental design was completely random with a factorial arrangement of 3x3x2 of treatments: three doses 0, and mg L -1 of IBA as growth regulator; three types of cuttings apical, middle, basal ; and two immersion times 1 s and 60 s. At d the number and mean length of roots, percentage of rooting, presence of callus, and survival of the cuttings were evaluated.
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Rooting of juvenile cuttings of Bertholletia excelsa under different concentrations of indolebutyric acid. Iracema M. Recalcitrant behavior and slow and irregular germination are limiting factors for the production of Bertholletia excelsa seedling production, through the conventional process. The objective of this study was to evaluate the rooting of juvenile cuttings of B.
The experimental design was completely random with a factorial arrangement of 3x3x2 of treatments: three doses 0, and mg L -1 of IBA as growth regulator; three types of cuttings apical, middle, basal ; and two immersion times 1 s and 60 s. At d the number and mean length of roots, percentage of rooting, presence of callus, and survival of the cuttings were evaluated.
The results show that the middle and basal cuttings immersed for 1 s in mg L -1 of IBA had the highest percentages of rooting, The cuttings only presented, in average, the formation of a single root. The highest average root lengths were obtained with middle cuttings submerged for 1 s in mg L -1 of IBA 7.
Thus, the IBA concentrations stimulate the surge of roots in different types of B. Brazil nut Bertholletia excelsa H. This species is key for the conservation and development of the Amazon region, due to its multiple uses by the communities that exploit it, is a source of employment and income for rural and urban workers in this region, and because of the use of its wood Tonini, In northern Brazil, B.
Seed propagation in B. In addition, its fruits are susceptible to attacks by predators before their maturation Figueiredo and Carvalho, To obtain a quick germination, it is necessary to remove the tegument, and in most cases mechanical damage is produced on the seed. Given these limitations, vegetative propagation through cuttings and the application of growth regulators, especially the synthetic auxin indolebutyric acid IBA , is a promising technique for most species.
IBA is a photostable substance, non-toxic, of localized action, and less sensitive to biological degradation Husen, Its use is recommended to stimulate rooting in a large number of plants Bortoline, , and low and high concentrations are used, as are types and sizes of cuttings Vernier and Cardoso, According to Xavier et al.
For some trees like Eucalyptus , the technique for propagation with cuttings is well-established, with dominion in the production of seedlings of high quality and low cost. Studies by Pinheiro and Moraes et al. Therefore, the objective of this study was to evaluate the rooting of juvenile cuttings of B. For the plant production, the seeds of B. When the plants reached 45 cm of height, they were selected in cuttings 10 cm long, cut obliquely at the base, containing at least two buds and two pairs of leaves reduced to half of their original size, with the goal of avoiding excessive transpiration.
The cuts were separated into three groups: apical, middle and basal position. With the aim of maintaining the vigor and turgidity of the plant material, immediately after the collection, the cuttings were washed with water and placed in a thermal box with water. For the rooting of the cuttings, they were placed for six months in a subirrigation type chamber propagator, with a metallic structure wrapped in polyethylene plastic that made it waterproof.
The base was covered with four beds: 1 sand cm ; 2 gravel cm ; 3 rocks 5 cm ; and 4 substrate 5 cm , made up of sterile sand, according to the Leakey et al. During the period of permanence of the cuttings in the propagator, phytosanitary control was performed through a spray of Benomyl 1 g L -1 every 15 d. The experimental design was completely random with a factorial arrangement 3x3x2 of treatments: IBA 0, and mg L -1 , types of cuttings apical, middle and basal and immersion times 1 s and 1 min.
Each treatment had three experimental units of 12 cuttings. The measurements were performed in intervals of 30 d during d, and the variables were a percentage of the cuttings rooted, the number and length of the roots, the presence of calluses and the percentage of mortality.
The Keuls method is relatively easy to apply and considers the total number of treatments used in the experiment, and is a multiple amplitude test that evaluates the significance of a set of differences, making a balance between Errors of Type I and II. The positive interaction with the same factors was verified by Dias et al. According to Santos et al. These results highlight that the rooting of cuttings presented differentiated behavior and that for the start of rooting, intrinsic factors related to the plant itself influenced as well as extrinsic ones linked to environmental conditions Hartmann et al.
The low percentage of root formation is explained because the cuttings responded differently to the action of the hormone; some need to remain in contact with the growth regulating solution for longer and others root sporadically or they do not root. This difference is due to the physiological variations between cuttings from the same plant, although they may be juvenile; in addition, the process can be inhibited based on the concentration of the growth regulator.
These results suggest that juvenile plant material is not always favorable for the rooting process of woody species from seeds, as found with B. Fachinello et al. The use of IBA increased the number of roots per cutting, and promotes a greater percentage of rooting according to Endres et al. The same was observed by Gratieri-Sossella et al. The presence of calluses in the sections of cuttings occurred independently from the presence of the growth regulator or position of the cut.
The natural auxin produced in the leaves and buds moves towards the inferior part of the cuttings stimulating the rooting activity and accumulating in the base of the cutting, together with sugars and other nutrients Janick, , acting as inhibiting substances in the initiation of the preformed adventitious roots and potentiating the formation of calluses at the base of the cuttings Hartmann and Kester, Iritani et al.
The formation of calluses must be due to the presence of equilibrium of the auxin applied IBA in the presence of an endogenous cytokinin and, according to Hartmann and Kester , this equilibrium can also occur when cytokinin is applied with the endogenous auxin. Thus, the presence of calluses in B. However, the roots that arise from differentiation of callus cells rarely have vascular connections with the cuttings, so propagation from these is not recommended George et al.
With regard to mortality, the cuttings in the basal position, immersed 1 s with mg L -1 of IBA presented higher percentage Among treatments, only the apical cuttings in absence of IBA did not present mortality Table 1. Bastos et al. The cuttings presented, in average, the formation of only one root Figure 2. The treatment that caused a higher number of roots was the one with concentration of mg L -1 of IBA Table 1.
The middle cuttings submerged 1 s at mg L -1 of IBA showed a higher percentage of rooting However, the latter did not differ from the middle and basal cuttings, immersed 1 min in mg L -1 of IBA. In absence of IBA, for the three types of cuttings used, there was no root formation, as well as in the apical cuts submerged for 1 s in a concentration of mg L -1 of IBA and immersed for 1 min at mg L -1 of IBA Table 1.
In the regression equation, the total number of roots obtained through direct morphogenesis tended towards a linear increase in the number of roots produced by cuttings, as the concentration of the growth regulator increases Figure 3. Within each IBA concentration, the cuttings in the apical position had the lower percentage of rooting Table 1. In this sense, Dias et al. The greater mean root lengths were obtained in treatments with cuttings in the middle position, submerged for 1 s at mg L -1 of IBA 7.
The smallest mean root length 1. The linear regression showed a growing trend with an increase in the concentration of IBA, indicating that it would eventually have better results in higher concentrations. However, per cutting there was broad variation in the root length. This fact could be due to genetic factors, since each cutting presented unique characteristics and, therefore, the requirements for propagation also tended to be unique Figure 4. These results are similar to those found by Xavier et al.
According to the observations performed, after six months, the surviving cuttings were green and strengthened, suggesting a later initiation and elongation of adventitious roots. However, the success of this technique depends on the type of plant material, the species and its nutritional conditions, the type of growth regulator, the concentrations used and the immersion time. Due to the low percentage of rooting and time for rooting, it is necessary to make adjustments for the technique to be viable and to become an alternative for the production of seedlings throughout the year, especially in situations where the seed is a limiting input.
The use of IBA stimulated the growth of roots in different types of cuttings of Bertholletia excelsa ; the concentration of mg L -1 stood out as the most appropriate to increase the percentage of rooting, submerging the base of the cutting in the IBA solution for one second and using the middle segment to obtain the cuttings.
The technique of cuttings may be adopted for the mass vegetative propagation of the species. However, the low rooting suggests that this process depends on multiple factors which must be considered to stimulate and optimize the later production of seedlings. Bastos, D. Martins, E. Scaloppi Junior, I. Sarzi, e J. Bortolini, M. Fanti, L. A Biasi, M. Quoirin, H. Koehler, K. Zuffella Toribas. Enraizamento de estacas de Ficus benjamina L.
Scientia Agraria 4: Brondani, G. Araujo, I. Wendling, e D. Enraizamento de miniestacas de erva-mate sob diferentes ambientes. Caldwell, J. Coston, e K. Hortscience Dias, P. Oliveira, A. Xavier, e I. Xavier, L. Oliveira, H. Endres, L. Marroquim, C. Santos, e N.
Considering the great potential of agro-industrial exploration of Spondias mombin L. Regulador de crescimento. Cuttings were taken from adult plants, healthy nine years old clone cup Lagoa Redonda grafted onto the rootstock of Spondias tuberosa. The experimental design was completely randomized in factorial scheme 3x2, with the following factors: types of cuttings apical, median and basal and IBA 0 and mg. L-1 , with five replicates of eight cuttings each, total cuttings. After the treatments, the cuttings were placed for rooting in polyethylene plastic bags containing as substrate a mixture of soil hydromorphic, cattle manure and quartz sand in proportion Evaluations were performed days after planting, being rated the number of dead cuttings, of dormant cuttings, of buds cuttings active, of cuttings with dormant buds, of cuttings with callus, of cuttings rooted, the number of active buds, of dormant buds, of leaves and leaflets, the leaf dry mass and root, and also, those suitable for planting.
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Sistema OJS3 - Metabiblioteca. Inicio Archivos Vol. Publicado May 2, Pigatto, G. Las estacas de tallos se vieron afectadas por las concentraciones de IBA. Referencias Abdullateef, R. Effects of stem cutting types, position and hormonal factors on rooting in Stevia rebaudiana Bertoni.