Índice de área foliar e SPAD durante o ciclo da soja em função da densidade de plantas e sua relação com a produtividade de grãos

Yokoyama, Anderson Hideo; Balbinot, Alvadi Antônio; Zucareli, Claudemir; Ribeiro, Ricardo Henrique

doi:10.5965/223811711732018531

Cited by 16 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These data show that soybean growth was lower after wheat than black oat. Yokoyama et al (2018) also observed a lower vegetative growth of soybean plants sown after wheat, compared with corn, Crotalaria spectabilis Roth, and Urochloa ruziziensis (R.Germ. & C.M.Evrard) Morrone & Zuloaga; however, this effect was greatly influenced by the crop season.…”

Section: Resultsmentioning

confidence: 78%

See 1 more Smart Citation

Performance of soybean grown in succession to black oat and wheat

Balbinot

Santos

Debiasi

et al. 2020

Pesq. agropec. bras.

Self Cite

View full text Add to dashboard Cite

The objective of this work was to evaluate the influence of isolated or combined roots and straw of black oat and wheat, as previous crops in autumn/winter, on the performance of soybean in succession. The experiment was carried out in the 2017/2018 and 2018/2019 crop seasons in a randomized complete block design, with four replicates. The following seven treatments were applied in the autumn/winter of 2017 and 2018, before soybean planting: fallow; straw of black oat or wheat, distributed on plots kept under fallow during autumn/winter, without roots; plots only with roots of black oat or wheat, without straw; and plots with straw and roots of black oat or wheat. Soybean crop performance was estimated using the following variables: plant density, leaf area index, soil plant analysis development (SPAD) index, shoot dry matter, grain yield, and yield components. In comparison with fallow, the cultivation of black oat or wheat, as previous crops during the autumn/winter, increases soybean grain yield. The impact of the roots of black oat or wheat on soybean yield is similar to that of straw. Soybean agronomic performance is improved in the combined presence of roots and straw of black oat or wheat.

show abstract

Section: Resultsmentioning

confidence: 78%

“…In addition, the species can be easily desiccated for planting of the subsequent crops (Krenchinski et al, 2018). Another crop that can be used in the autumn/winter season is wheat (Triticum aestivum L.), which has positive effects on soybean growth, compared with corn (Zea mays L.) and fallow (Yokoyama et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Performance of soybean grown in succession to black oat and wheat

Balbinot

Santos

Debiasi

et al. 2020

Pesq. agropec. bras.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The decrease of chlorophyll content was quite expressive, with more than one unit of SPAD index reduced for every two-spotted spider mite per cm 2 ( Figure 2). Plants under damage score 4 (28.9 mites per cm 2 ) showed an average SPAD as low as 25.76, far below the level considered ideal for high-grain yield in soybean crops, which is around 40 during growing stages, and 50, during grain filling (Yokoyama et al, 2018). As to the variable grain yield, the regression model indicated a reduction of 0.35 g of grain yield per plant for every two-spotted spider mite per cm 2 (Figure 2).…”

Section: Resultsmentioning

confidence: 90%

Damage assessment and economic injury level of the two-spotted spider mite Tetranychus urticae in soybean

Padilha

Fiorin²,

Filho

et al. 2020

Pesq. agropec. bras.

View full text Add to dashboard Cite

The objective of this work was to quantify the reduction of soybean grain yield caused by Tetranychus urticae damage, and to propose an economic injury level (EIL) for this pest in the crop. The experimental design was set up in randomized complete blocks, with four replicates and a 4x2 factorial arrangement with four levels of mite infestation, with or without mite control. Chlorotic symptoms were evaluated using a damage scale of 1 to 4. Soybean grain yield, number of pods, number of grains, and 1,000-grain weight were quantified for each segment of plant canopy (lower, middle, and upper) and for the whole plants. The chlorophyll content in the leaves was evaluated using the SPAD index. The population density of one two-spotted spider mite per cm2 of leaf area caused the following reductions: one pod per plant, two grains per plant, 0.7 g of 1,000-grain weight, and 0.35 g of grain yield per plant or 42 kg ha-1. Based on the equation y = 4,369 - 41.99x, the EIL of one two-spotted spider mite per cm2 is determined by considering a control cost of US$ 20.00 ha-1 and a soybean crop value of US$ 350.00 Mg-1. As to chlorotic symptoms, the EIL is set between damage scores 1 (no apparent mite damage) and 2 (yellow mottling beginning to appear).

show abstract

“…Durante o ciclo da soja, nas 10 coletas realizadas, não houve efeito da interação entre os tratamentos de entressafra e a adubação nitrogenada na soja sobre os teores de nitrato e amônio no solo, apesar das culturas de entressafra produzirem quantidades distintas de palha, com diferentes características químicas (YOKOYAMA et al, 2018). Na média das cinco repetições o milho sem e com adubação nitrogenada produziu 2,5 e 2,8 t ha -1 de palha, enquanto o trigo, a braquiária e a crotalária produziram 4,7; 3,5 e 0,3 t ha -1 de palha, respectivamente.…”

Section: Resultsunclassified

“…Outra cultura usada na entressafra da soja é o trigo, especialmente em regiões subtropicais ou tropicais com altitudes superiores a 600 m. As culturas de cobertura do solo também são alternativas para o cultivo na entressafra, como as braquiárias (LOSS et al, 2011) e as crotalárias (CARVALHO et al, 2013), objetivando melhorar a qualidade do solo e reduzir problemas fitossanitários. Adicionalmente, em várias regiões do país há ausência de cultivo na entressafra da soja (pousio), provocando aumento da erosão, da degradação da qualidade do solo e da ocorrência de plantas daninhas de difícil controle (MORAES et al, 2013;YOKOYAMA et al, 2018).…”

Section: Introductionunclassified

Teores de nitrato e amônio no solo em função de culturas de entressafra da soja e adubação nitrogenada

Balbinot

Yokoyama²,

Ribeiro³

et al. 2019

COLLOQ AGRARIAE

Self Cite

View full text Add to dashboard Cite

ResumoO objetivo desse trabalho foi avaliar os teores de nitrato e amônio no solo na entressafra e na safra de soja em função de culturas de entressafra e fertilização com N mineral na soja. O delineamento experimental foi de blocos completos casualizados, com cinco repetições e em esquema de parcelas subdivididas. Nas parcelas foram alocados seis tratamentos de entressafra: pousio, milho segunda safra com 0 ou 80 kg de N ha -1 em cobertura, trigo, Urochloa ruziziensis e Crotalaria spectabilis. Nas subparcelas foram alocados duas adubações de N na implantação da soja (0 e 30 kg de N ha -1 ). De abril de 2016 a fevereiro de 2017 foram realizadas 26 coletas de solo na camada de 0,0-0,1 m, sendo avaliados os teores de nitrato e amônio nas amostras. Durante o período de entressafra da soja, os maiores teores de nitrato no solo foram observados no milho segunda safra adubado com 80 kg de N ha -1 , enquanto os teores de amônio variaram menos entre os tratamentos de entressafra. As culturas de entressafra não influenciaram os teores de nitrato e amônio no solo durante o ciclo da soja em sucessão. Na fase vegetativa da soja, os teores de nitrato no solo foram superiores quando a soja foi adubada com 30 kg de N ha -1 , em relação à ausência de adubação, mas nas fases de formação de vagens e de grãos essa diferença não ocorreu. Palavras-chave: culturas de cobertura; Glycine max L.; manejo do solo; nitrogênio inorgânico no solo; sistema plantio direto. Nitrate and ammonium content in the soil as a function of off-season crops and nitrogen fertilization in the soybean AbstractThe objective of this work was to evaluate the effect of off-season crops and fertilization with N mineral at soybean sowing on the nitrate and ammonium contents in the soil during the off-season and soybean development cycle. The experimental design was of randomized complete blocks, with five replications and in split plod scheme. Six off-season treatments were evaluated in the plots: fallow, maize with 0 or 80 kg of N ha 1 , wheat, Urochloa ruziziensis and Crotalaria spectabilis . In the subplots two levels of N were evaluated in the soybean sowing (0 and 30 kg N ha -1 ). From April 2016 to February 2017, 26 soil samples were collected in the 0.0-0.1 m layer, and the nitrate and ammonium contents in the samples were evaluated. During the off-season, the highest contents of nitrate were observed in maize fertilized with 80 kg de N ha -1 , while ammonium contents varied less among off-season crops. The off-season crops did not influence the soil nitrate and ammonium content during the soybean cycle. In the vegetative phase of soybean, nitrate contents were higher when the soybean received nitrogen fertilization in relation to the absence of fertilization, but in the pod and grain formation there was no effect of the nitrogen fertilization on the contents of inorganic N.

show abstract

Índice de área foliar e SPAD durante o ciclo da soja em função da densidade de plantas e sua relação com a produtividade de grãos

Abstract: Índice de área foliar e SPAD durante o ciclo da soja em função da densidade de plantas e sua relação com a produtividade de grãos Leaf area index and SPAD during the soybean development cycle at different plant densities and their relation to grain yield

Cited by 16 publications

References 18 publications

Performance of soybean grown in succession to black oat and wheat

Performance of soybean grown in succession to black oat and wheat

Damage assessment and economic injury level of the two-spotted spider mite Tetranychus urticae in soybean

Teores de nitrato e amônio no solo em função de culturas de entressafra da soja e adubação nitrogenada

Contact Info

Product

Resources

About