Optimizing Soybean Plant Population for a Short-Season Production System in the Southern USA

A high seed yield and associated attributes of dry matter production achieved by recent Japanese soybean cultivars

“…Achieving complete ground cover by the R1 stage or shortly thereafter is required to achieve maximum yield (Andrade et al, 2002;Ball et al, 2000;Board, 2000;Lee et al, 2008;Purcell et al, 2002). The light interception in our experiment reached 80% about 1 week after R1 in 2014 and around R1 in 2015, and reached 90% at 10 d after R1 in 2014 and 2-6 d after R1 in 2015 (Tables 1 and 3).…”

“…Hence, we developed the present study to focus on light interception and utilization by soybean plants because both are key constituents for dry matter accumulation. Ball et al (2000) argued that having a short duration before the full canopy cover is achieved (>90% light interception) may increase yield because it shortens the time required after emergence to begin linear biomass accumulation, which Goudriaan and Monteith (1990) is considered to be lost time. Lee et al (2008) showed that achieving complete ground cover by the R1 [stage in the classification of Fehr and Caviness (1977)] or shortly thereafter is required to achieve maximum yield.…”

“…This idea was supported by an examination of the effects of the distance between rows at a constant planting density (15 plants m −2 ); Andrade et al (2002) showed that seed yield at higher light intensity (about 90%) at R1 in narrowly spaced rows (.19 m) was about 10% greater than that at lower light intensity (about 73%) at R1 in widely spaced rows (.57 m). Equidistant plant spacing in narrow-row planting is beneficial because it minimizes competition between plants and increases light interception starting from the early growth stages (Ball et al, 2000;Egli, 1994;Nakano et al, 2001;Weber et al, 1966). Recently, narrow-row planting has been increasing in popularity in Japan due to the potential to improve yield and decrease labor (Furuhata et al, 2008;Uchikawa et al, 2009).…”

Sowing Dates and Soybean Cultivars Influence Seed Yield, Oil and Protein Contents in Subtropical Environment

“…Late sowings can reduce grain yield due to various factors, such as: (1) low temperatures during the grain filling which can reduce the pod set and the growth of formed grains (Thomas & Raper, 1978;Gibson & Mullen, 1996); (2) reduction of vegetative period due to high temperatures at initial plant development that can cause low plant growth and consequently lower number of leaves and viable nodes per area (Board & Harville, 1996;Ball et al,reproductive development, and when are long the flowering period, the pods formation period and the grain filling period (Bastidas et al, 2008). The amount of oil and proteins of soybean grains can also vary according to environment (Bianculli et al, 2016), and genotype (Jin et al, 2010;Rincker et al, 2014).…”

Populações de plantas na cultura da soja em cultivares convencionais e Roundup ReadyTM

“…Por meio dessa característica pode se ter a percepção de que existe uma faixa ampla de populações de plantas, em que a variação do número de plantas não afeta a produtividade de grãos. No entanto, em muitos trabalhos os resultados divergem dessa teoria (Ball et al, 2000;Peluzio et al, 2002;Rigsby & Board, 2003;Rezende et al, 2004;Heitholt et al, 2005;Ludwig et al, 2007). O tema densidade de semeadura e população de plantas na soja já vem sendo pesquisado desde o inicio do cultivo dessa espécie, dessa maneira inúmeros trabalhos já foram publicados sobre o assunto.…”