Redalyc.Efeito Do Tipo De Crescimento No Desenvolvimento De Cultivares
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Bragantia ISSN: 0006-8705 [email protected] Secretaria de Agricultura e Abastecimento do Estado de São Paulo Brasil Junior Zanon, Alencar; Streck, Nereu Augusto; Schmitz Marques da Rocha, Thiago; Maus Alberto, Cleber; Cristiano Bartz, Alex; Moiano de Paula, Gizelli; Tomiozzo, Regina; Camargo da Costa, Liege; Fensterseife, Cesar Augusto; Lago Tagliapietra, Eduardo; Paz Cardoso, Ânthony; Scolari Weber, Patric; Pribs Bexaira, Kelin Efeito do tipo de crescimento no desenvolvimento de cultivares modernas de soja após o início do florescimento no Rio Grande do Sul Bragantia, vol. 75, núm. 4, octubre-diciembre, 2016, pp. 446-458 Secretaria de Agricultura e Abastecimento do Estado de São Paulo Campinas, Brasil Available in: http://www.redalyc.org/articulo.oa?id=90848169009 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative DOI: http://dx.doi.org/10.1590/1678-4499.535 A.J. Zanon et al. CROP PRODUCTION AND MANAGEMent - Article Growth habit effect on development of modern soybean cultivars after beginning of bloom in Rio Grande do Sul Alencar Junior Zanon1, Nereu Augusto Streck1*, Thiago Schmitz Marques da Rocha1, Cleber Maus Alberto2, Alex Cristiano Bartz2, Gizelli Moiano de Paula3, Regina Tomiozzo3, Liege Camargo da Costa4, Cesar Augusto Fensterseifer1, Eduardo Lago Tagliapietra1, Ânthony Paz Cardoso1, Patric Scolari Weber1, Kelin Pribs Bexaira1 1. Universidade Federal de Santa Maria - Departamento de Fitotecnia - Centro de Ciências Rurais - Santa Maria (RS), Brazil. 2. Universidade Federal do Pampa - Departamento de Agronomia - Itaqui (RS), Brazil. 3. Universidade Federal de Santa Maria - Frederico Westphalen (RS), Brazil. 4. Fundação Estadual de Pesquisa Agropecuária - Júlio de Castilhos (RS), Brazil. ABSTRACT: There was a change in the genetics of soybeans grown Tupanciretã and Água Santa. Overlap determination (in days) of in southern Brazil from the 2000s, which requires investment in vegetative and reproductive phases, difference in the number basic and detailed studies about growth and development. The of nodes and height in R8 and R1 were estimated. The cultivars with purpose in this paper was to characterize the overlap period of indeterminate growth had higher overlap period of vegetative and vegetative and reproductive phases, growth in height and the reproductive phases, height growth and emission of nodes after the emission of nodes after the beginning of flowering in determinate beginning of flowering in comparison with the determinate cultivars. and indeterminate cultivars in different sowing dates and soybean The magnitude of the overlap values of vegetative and reproductive regions in Rio Grande do Sul. Field experiments were conducted phases and of the increase in height and number of nodes after R1 during the growing seasons of 2012/2013 and 2013/2014, in Santa ranged with the type of growth, maturity group, location, and sowing Maria, Itaqui, Frederico Westphalen, Capão do Leão, Júlio de date. Castilhos and in 3 commercial soybean crops in Restinga Sêca, Key words: Glycine max, determinate, indeterminate, maturity group. *Corresponding author: [email protected] Received: Nov. 6, 2015 – Accepted: Mar. 28, 2016 446 Bragantia, Campinas, v. 75, n. 4, p.446-458, 2016 Soybean growth habit INTRODUCTION et al. 1971; Bernard 1972; Bernard et al. 1998; Ashlock and Purcell 2000). However, new soybean cultivars are In southern Brazil, the use of soybean cultivars with released annually, and farmers in southern Brazil are indeterminate growth habit and maturity group (MG) currently using cultivars with indeterminate growth habit between 4.5 and 6.5 has increased since 2000 (Zanon and MG less than 6.5 in different production systems. et al. 2015b). In Rio Grande do Sul (RS) State, this new Therefore, it is worthy to resume studies to characterize group of cultivars represented more than 90% of the area the duration of the overlapping period node appearance, cultivated with soybeans in the last 5 growing seasons and stem height growth after R1. This information can and allowed many farmers to anticipate (September and assist agronomists and farmers in choosing the most early October) or delay (January and early February) the appropriate sowing date, cultivars (MG), row spacing, sowing date (EMATER 2015). These changes in soybean seeding density and other management practices to genetics and sowing date demand investment in basic exploit the genetic potential of each cultivar. and detailed studies on growth and development so that The objective of this study is to determine the management practices can be adapted to the new cultivars. duration of the overlapping period between vegetative The overlap of vegetative and reproductive and reproductive phases, the growth in plant height and developmental phases in soybean is an important variable the node appearance after the beginning bloom stage since a longer overlapping period means more competition in determinate and indeterminate soybean cultivars in for photoassimilates between vegetative (leaves and stems) different sowing dates and locations across the RS State. and reproductive (pods and seeds) structures (Setiyono et al. 2011). The overlapping period is influenced by temperature and photoperiod and is associated with MATERIAL AND METHODS soybean growth habit, which is defined as the time of termination of the main stem growth after the beginning Field experiments were conducted during 2 growing bloom (R1) developmental stage (Bernard 1972). seasons (2012/2013 and 2013/2014) in 8 locations where Bernard et al. (1998) accessed the soybean germplasm soybean is predominantly grown in RS (Figure 1). The bank of the United States Department of Agriculture experimental sites were located at the Universidade (USDA) and classified the cultivars from “1” (very Federal de Santa Maria (Santa Maria and Frederico determinate) to “5” (very indeterminate) according to the Westphalen), Universidade Federal de Pelotas (Capão do period after which the plants cease to grow vegetatively, after the R1 stage. Cultivars with values lower than 2.0 Rio Grande do Sul – Brazil 27S were classified as determinate, i.e. they showed none or a Frederico Westphalen slight growth in stem height after the R1 stage. Cultivars 28S with values between 2.0 and 2.5 were classified as semi- Água Santa Tupanciretã 29S Itaqui determinate and those with values ≥ 2.5 were classified Júlio de Castilhos as indeterminate since the stem elongation and node Santa Maria 30S Restinga Sêca appearance continue after the R1 stage until nearly the grain filling stage. However, when soybean cultivars Latitude 31S are sown before or after the recommended period, the 32S Capão do Leão duration of the overlapping period varies with weather conditions during the development cycle, which may 33S change the growth habits (Bernard 1972; Heatherly and 34S Smith 2004). 58W 57W 56W 55W 54W 53W 52W 51W 50W 49W A limited number of environments and genotypes were Longitude studied by comparing different growth habits, and most Figure 1. Map of the State of Rio Grande do Sul, Brazil. Solid circles of the observations resulted from experiments conducted indicate experimental sites, during the 2012/2013 and 2013/2014 outside Brazil during the 1970s, 1980s and 1990s (Fehr growing seasons. Bragantia, Campinas, v. 75, n. 4, p.446-458, 2016 447 A.J. Zanon et al. Leão), Universidade Federal do Pampa (Itaqui), Fundação of seeds with fungicides and insecticides, as well as Estadual de Pesquisa Agropecuária - FEPAGRO Sementes control of weeds, pests and diseases were performed (Júlio de Castilhos), and 3 commercial soybean fields according to the technical recommendations for the located at the counties of Restinga Sêca, Tupanciretã, and crop. In Santa Maria, the experiments were irrigated Água Santa. The climate in RS is subtropical humid with so that the plants developed without water deficit. In hot summers and no dry season. Five types of soils were the other areas, the experiments were conducted under observed in the experimental sites, from very deep, over rainfed conditions, which represent most soybean farms 2.50 m, up to shallow, less than 1.0 m. In southern and in RS. Experiments in Santa Maria, Itaqui, Capão do western RS, the experiments were conducted in areas Leão and Frederico Westphalen were conducted in a traditionally cultivated with rice (lowlands), where most completely randomized blocks design, with 4 replications. soils have low water storage capacity and low hydraulic Each block had 17 rows, with 2 border rows on each conductivity, compared with those of the highlands in side. Each 3-m-long row contained 1 cultivar. In Júlio northern RS (Streck et al. 2008). de Castilhos, the experiment had 3 replications, and The soybean cultivars were selected due to the different the plots had four 5-m-long rows of each cultivar. In the growth habits, and the range of relative maturity represent commercial soybean fields (Restinga Sêca, Tupanciretã, all the MGs currently cultivated in RS (Table 1). In Santa and Água Santa), the experiments were conducted as Maria, sowings were conducted before (September), during demonstrative plots (without repetition), and each plot (November) and after (February), the recommended consisted of four 3-m-long rows of each cultivar. In all soybean sowing date in RS. In Itaqui, sowings occurred experiments, the row spacing used was 0.45 m, with before (October and November) and during (December) 30 plants∙m−2, which represents the row spacing and the recommended period; in all other places, sowings density used in most soybean farms in RS (EMATER 2015). were conducted during the recommended period, totaling The emergence was defined when the cotyledons of 50% 12 sowing dates (Table 2). The fertilization, inoculation of the plants were above the soil surface. Shortly after the of seeds with Bradyrhizobium japonicum, treatment appearance of the first pair of unifoliate leaves, the plants used to assess the number of nodes (NN), phenology, and Table 1.