Bioagents and mix of cover plants affecting soybean / Bioagentes e mix de plantas de cobertura afetando a soja

The search for cultivation practices that provide productive, social and environmental benefits to the agroecosystem isof great importance for the sustainable intensification of agriculture. The objective of this study was to determine the effect of multifunctional microorganisms (MM) and mix of cover crops on gas exchange, production components and grain yield of soybean. In the field experiment, conducted by two growing seasons, the experimental design of randomized blocks in factorial scheme 8x2 was used, with four replications. The treatments were composed by the combination of eight vegetal cover and the use or not of MM. The vegetal cover were composed of: 1. Fallow, 2. Corn, 3. Mix 1 (white lupine, buckwheat, white oats, black oats, Crotalaria ochroleuca, C. juncea, turnip, coracana grass, white lupine), 4. Mix 2 (millet, C. ochroleuca, black oats, white oats, buckwheat, coracana grass), 5. Mix 3 (Millet, C. ochroleuca, black oats, white oats, buckwheat, coracana grass), 6. Mix 4 (C. spectabilis, buckwheat, millet and C. breviflora), 7. Mix 5 (oats, buckwheat, millet, piatã grass and C. Ocholeuca); and 8. Mix 6. (black oats, turnip forage, white lupine, coracana grass, buckwheat). The MM consortium used was Serratia marcenses(BRM 32114) + Bacillus sp.(BRM 63573). Soybean plants coinoculated with (BRM 32114) + (BRM 63573) showed an increase in photosynthetic rate (16.65%), stomatal conductance (37.50%), internal CO2concentration (10%), number of pods per plant (15%), mass of 100 grains (4.04%) and grain yield (14.83%). However, no differences were observed in soybean plants grown in succession to the mix of cover crops, except for the number of grains per pod. Therefore, in this study, the highlight was the consortium of multifunctional microorganisms, technology considered strategic for the sustainable intensification of agriculture.(AU)

A busca por práticas de cultivo que proporcionem benefícios produtivos, sociaiseambientaisao agroecossistemaé de grande importância para aintensificação sustentável da agricultura. O objetivo deste estudo foi determinar o efeito demicrorganismos multifuncionais (MM)emix de plantas decoberturasobre as trocas gasosas, componentes de produção e produtividadede grãosdasoja. Noexperimento de campo, conduzido por duas safras agrícolas,utilizou-se o delineamento experimental de blocos casualizados em esquema fatorial 8x2, com quatro repetições. Os tratamentos foram compostos pelacombinação de oito coberturas vegetaise do usoou não MM. As coberturasvegetais foram compostas de:1. Pousio; 2. Milho; 3. Mix 1 (Tremoço Branco, Trigo Mourisco, Aveia Branca, Aveia Preta, Crotalariaochroleuca, C.Juncea, Nabo Forrageiro, Capim coracana)4. Mix 2 (trigo Mourisco, C.spectabiliis, nabo forrageiro, aveia preta); 5. Mix 3 (Milheto, C. ochroleuca, aveia preta, aveia branca, trigo mourisco, Capim coracana); 6. Mix 4 (C. spectabilis, trigo mourisco, milheto e C.breviflora); 7. Mix 5 (Aveia, Trigo Mourisco, Milheto, Piatãe C.ocholeuca); e 8. Mix 6.(Aveia preta, Nabo Forrageiro, Tremoço Branco, Capim coracana, Trigo Mourisco). O consórciode MM utilizadofoi Serratiamarcenses(BRM 32114) + Bacillussp.(BRM63573). Plantas de soja coinoculadas com (BRM 32114) + (BRM63573)apresentaram aumento na taxa fotossintética (16,65%), condutância estomática (37,50%),concentração interna de CO2(10%), número de vagens por planta (15%),massa de 100 grãos (4,04%) e produtividade de grãos (14,83%). Contudo, não foram observadas diferenças nasplantas de soja cultivadasem sucessão aos mix de plantas de cobertura, com exceção do número de grãos por vagem.Portanto, nesse estudo, o destaque foi para o consórcio de microrganismos multifuncionais, tecnologiaconsideradaestratégica para a intensificação sustentável da agricultura.(AU)

Glyphosate in oat desiccation for haylage harvest at different wilting times

The objective was to evaluate the ruminal disappearance rate of dry matter and NDF of black oat haylage subjected to mechanical and chemical dehydration and six wilting periods in the field, as follows: 0, 3, 6, 9, 12 and 15 days. Forage haylageswere ensiled and stored in PVC mini-silos for 60 days until opening for in situ evaluations. The pre-set ruminal incubation times were: 0, 6, 12, 24, 36 and 48 hours. Regardless of the dehydration time, forage subjected to mechanical dehydration showed ruminal disappearance rates of dry matter and NDF, thus DISDM-48h and DISNDF-48h were superior for this method compared to the chemical method. There was a reduction in DISDM-48h and DISNDF-48h with advancing time of wilting in the field for haylage dehydrated by the chemical method. In general, the chemical dehydration method seems to be more related to better haylage making practices than nutritional factors, where the haylage obtained by mechanical dehydration is superior.(AU)

Optimal plot size in white oat with comparison of three methods / Tamanho ótimo de parcela em aveia branca com comparação de três métodos

The objective of this work was to compare three methods for estimating the optimal plot size to evaluate the fresh matter productivity of white oat (Avena sativa L.), IPR Suprema cultivar. Six uniformity trials (blank experiments) were carried out, three trials on the first sowing date (May 3, 2021) and three trials on the second sowing date (May 26, 2021). Fresh matter productivity was evaluated in 216 basic experimental units (BEU) of 1 m × 1 m (36 BEU per trial). The BEU was formed by five rows of 1.0 m in length, spaced 0.20 m apart, totaling 1.0 m2. The optimal plot size was determined using the methods of modified maximum curvature, linear response and plateau model and quadratic response and plateau model. The optimal plot size differs between the methods and decreases in the following order: quadratic response and plateau model (11.09 m2), linear response and plateau model (7.65 m2) and modified maximum curvature (4.00 m2). The optimal plot size to evaluate the fresh matter productivity of white oat is 7.65 m2 and the experimental precision stabilizes from this size on.

O objetivo deste trabalho foi comparar três métodos de estimação do tamanho ótimo de parcela para avaliar a produtividade de matéria fresca de aveia branca (Avena sativa L.), cultivar IPR Suprema. Foram conduzidos seis ensaios de uniformidade (experimentos em branco), sendo três na primeira data de semeadura (03 de maio de 2021) e três na segunda data de semeadura (26 de maio de 2021). Foi avaliada a produtividade de matéria fresca em 216 unidades experimentais básicas (UEB) de 1 m × 1 m (36 UEB por ensaio). A UEB foi formada por cinco fileiras de 1,0 m de comprimento, espaçadas 0,20 m entre fileiras, totalizando 1,0 m2. Foi determinado o tamanho ótimo de parcela por meio dos métodos da curvatura máxima modificado, do modelo linear de resposta com platô e do modelo quadrático de resposta com platô. O tamanho ótimo de parcela difere entre os métodos e decresce na seguinte ordem: modelo quadrático de resposta com platô (11,09 m2), modelo linear de resposta com platô (7,65 m2) e curvatura máxima modificado (4,00 m2). O tamanho ótimo de parcela para avaliar a produtividade de matéria fresca de aveia branca é 7,65 m2 e a precisão experimental estabiliza a partir desse tamanho.

Oat development in response to temperature / Desenvolvimento de aveia em resposta à temperatura

Temperature affects plant development therefore phyllochron has been used as a predictor for developmental events to define the time for agricultural managing practices. This study aims to evaluate changes in phyllochron and thermal sum required for flowering by oat genotypes developed at different decades at three temperature regimes; the effect of high temperature on phytomere development; and identify the development stage at the moment of meristem transition to reproductive stage. Three environments were obtained by sowing in the fall, in the spring, and under constant temperature (17ºC), always at inductive photoperiod. Despite changes in nominal values small differences were found among genotypes' phyllochron. Adding specific optimal and maximum temperatures into the growing degree days’ calculation demonstrated phyllochron stability among environments. Plant cycle length and thermal sum correlated with the number of developed phytomeres. UFRGS 078030-2 plants flowered earlier, had a small number of phytomeres, and greater tolerance to elevated temperatures than the other genotypes. More recent genotypes transit to reproductive stage at an earlier Haun stage than older ones.

A temperatura afeta o desenvolvimento das plantas, portanto o filocrono tem sido usado para prever eventos de desenvolvimento e estabelecer o momento adequado para práticas agrícolas. Esse estudo buscou avaliar mudanças em filocrono e soma térmica até o florescimento de genótipos de aveia desenvolvidos em diferentes décadas em três regimes térmicos; o efeito de altas temperaturas no desenvolvimento de fitômeros; e identificar o estágio de desenvolvimento em que ocorre a transição do meristema para a fase reprodutiva. Três ambientes foram estabelecidos pela semeadura no outono, na primavera e em temperatura constante (17ºC), em fotoperíodo indutor. Apesar da alteração dos valores numéricos, houve pouca diferença entre os filocronos dos genótipos. A adição das temperaturas ótima e máxima específicas no cálculo de graus dias demonstrou a estabilidade de filocrono entre ambientes. O ciclo e a soma térmica correlacionaram-se com o número de fitômeros. UFRGS 078030-2 floresceu mais cedo, teve menos fitômeros e maior tolerância a altas temperaturas do que os demais genótipos. Os genótipos mais recentes transitam para a fase reprodutiva em estágios mais precoces da escala Haun, em comparação com os genótipos mais antigos.

Oat development in response to temperature / Desenvolvimento de aveia em resposta à temperatura

Temperature affects plant development therefore phyllochron has been used as a predictor for developmental events to define the time for agricultural managing practices. This study aims to evaluate changes in phyllochron and thermal sum required for flowering by oat genotypes developed at different decades at three temperature regimes; the effect of high temperature on phytomere development; and identify the development stage at the moment of meristem transition to reproductive stage. Three environments were obtained by sowing in the fall, in the spring, and under constant temperature (17ºC), always at inductive photoperiod. Despite changes in nominal values small differences were found among genotypes' phyllochron. Adding specific optimal and maximum temperatures into the growing degree days calculation demonstrated phyllochron stability among environments. Plant cycle length and thermal sum correlated with the number of developed phytomeres. UFRGS 078030-2 plants flowered earlier, had a small number of phytomeres, and greater tolerance to elevated temperatures than the other genotypes. More recent genotypes transit to reproductive stage at an earlier Haun stage than older ones.(AU)

A temperatura afeta o desenvolvimento das plantas, portanto o filocrono tem sido usado para prever eventos de desenvolvimento e estabelecer o momento adequado para práticas agrícolas. Esse estudo buscou avaliar mudanças em filocrono e soma térmica até o florescimento de genótipos de aveia desenvolvidos em diferentes décadas em três regimes térmicos; o efeito de altas temperaturas no desenvolvimento de fitômeros; e identificar o estágio de desenvolvimento em que ocorre a transição do meristema para a fase reprodutiva. Três ambientes foram estabelecidos pela semeadura no outono, na primavera e em temperatura constante (17ºC), em fotoperíodo indutor. Apesar da alteração dos valores numéricos, houve pouca diferença entre os filocronos dos genótipos. A adição das temperaturas ótima e máxima específicas no cálculo de graus dias demonstrou a estabilidade de filocrono entre ambientes. O ciclo e a soma térmica correlacionaram-se com o número de fitômeros. UFRGS 078030-2 floresceu mais cedo, teve menos fitômeros e maior tolerância a altas temperaturas do que os demais genótipos. Os genótipos mais recentes transitam para a fase reprodutiva em estágios mais precoces da escala Haun, em comparação com os genótipos mais antigos.(AU)

Genome-wide association mapping for heading date in oats under subtropical environments

Selection for heading date has been a decisive factor to increase areas cropped with oats in Brazil. Although important to oat breeders, genomic regions controlling heading date have not been completely identified. The objective of this study was to identify genomic regions controlling oat heading date in subtropical environments. A set of 412 oat genotypes, developed from 1974 to 2015, was assessed for heading date in contrasting environments and genotyped using genotyping-by-sequencing (GBS). Phenotypic and genotypic data were used in single and multi-environment association models. Quantitative trait loci (QTL) associated to heading date were identified on oat consensus groups Mrg02, Mrg05, Mrg06, Mrg12, and Mrg21. Some of the findings confirmed the association of genomic regions with heading date, while others emerge as new candidate regions associated to the trait. The genomic regions identified on Mrg02 and Mrg12 were associated to Vernalization 3 (Vrn3), while the genomic region identified on Mrg21 is associated with Vernalization 1 (Vrn1). The Vrn1 region was detected in Londrina, an environment with reduced vernalization condition, and in the multi-environment model. The results reveal that some genotypes of the panel are responsive to vernalization, increasing the days to heading without this environmental stimulus. Our results provide important contribution for a better understanding of heading date in subtropical environments and a strong basis for marker-assisted selection in oats.

Screening of the hatching control of root-knot nematodes using extract concentrations from oat genotypes

Even though oats (Avena spp.) have the capacity to produce numerous compounds with the potential to act antagonistically against plant pathogens, studies on the genotypic effect of this crop focusing on their nematicidal activity are limited. The objective of this study was to verify the effect of the aqueous extracts prepared with the biomass of oat genotypes, on the hatching of second-stage juveniles of root-knot nematodes (Meloidogyne javanica and Meloidogyne incognita). The bioassays were carried out in a completely randomized design with four replications. Eighteen extracts were evaluated, consisting of a combination of six oat genotypes Agro Quaraí, Agro Esteio, Embrapa 139, AF 12202, UPFPS Farroupilha, and AF 1345 Ucraniana, and three extract concentrations (5 %, 10 %, and 20 % w/v). Three additional treatments were added to the study (distilled water, chemical nematicides abamectin, and imidacloprid + thiodicarb). The treatments and the suspension containing nematode eggs were placed in Petri dishes and incubated in a growth chamber for ten days. At the 5 % and 10 % w/v concentration levels, a genotype effect was observed in the hatching of juveniles for both nematode species. For the control of M. javanica the extracts of Embrapa 139 had a better performance, while the extracts of Agro Quaraí and AF1345 Ucraniana performed better when under the control of M. incognita. Thus, oat biomass formation might have the ability to suppress the nematode population in the soil, and could therefore, be used for the management of root-knot nematodes.

Doses and application times of trinexapac-ethyl on the industrial quality of white oat grains / Doses e épocas de aplicação de trinexapac-ethyl na qualidade industrial de grãos de aveia branca

The application of trinexapac-ethyl in white oats, in addition to controlling lodging, can modify the architecture of the plant, which can favor good growth and development and the production of well-formed, large and heavy grains, characteristics that are valued by the food industry oat processing. However, the responses of the white oat genotypes regarding the effect of doses and times of application of the growth reducer can be variable. The objective of this work was to evaluate the effect of different doses and application times of the growth regulator trinexapac-ethyl on the industrial quality of white oat grains. The experiment was carried out with the cultivar IPR Artemis, under a randomized block design with four replications, in a 4 x 3 factorial scheme, corresponding to four doses of trinexapac-ethyl (0, 50, 100 and 150 g ha-1) and three application times (E1: plants with the 1st noticeable node; E2: between the 1st visible node and the 2nd noticeable node and E3: plants with the 2nd visible node and 3rd noticeable node). The weight of one thousand grains, hectoliter weight, percentage of grains with thickness greater than two millimeters, husking index and industrial grain yield were evaluated. The application of trinexapac-ethyl regardless of the stages at doses of 0 and 50 g ha-1 does not interfere with the industrial quality of grains, but at doses of 100 and 150 g ha-1, at times E2 and E3, there is a reduction in industrial quality of grains (weight of a thousand grains, hectoliter weight, percentage of grains thicker than two millimeters, hulling and industrial grain yield) of the cultivar IPR Artemis.

A aplicação de trinexapac-ethyl em aveia branca, além de controlar o acamamento pode modificar a arquitetura da planta, o que pode favorecer o bom crescimento e desenvolvimento e a produção de grãos bem formados, grandes e pesados, características que são valorizadas pela indústria de processamento de aveia. No entanto, as respostas dos genótipos de aveia branca quanto ao efeito de doses e épocas de aplicação do redutor de crescimento podem ser variáveis. O objetivo deste trabalho foi avaliar o efeito de diferentes doses e épocas de aplicação do regulador de crescimento trinexapac-ethyl sob a qualidade industrial de grãos de aveia branca. O experimento foi conduzido com a cultivar IPR Artemis, em delineamento de blocos casualizados com quatro repetições, em esquema fatorial 4 x 3, correspondendo a quatro doses de trinexapac-ethyl (0, 50, 100 e 150 g ha-1) e três épocas de aplicação (E1: plantas com o 1º nó visível; E2: entre o 1º nó visível e o 2º nó perceptível e E3: plantas com o 2º nó visível e 3º nó perceptível). Foram avaliados o peso de mil grãos, peso hectolitro, porcentagem de grãos com espessura maior que dois milímetros, índice de descasque e rendimento industrial de grãos. A aplicação de trinexapac-ethyl independente dos estádios nas doses de 0 e 50 g ha-1 não interfere na qualidade industrial de grãos, porém nas doses de 100 e 150 g ha-1, nas épocas E2 e E3, ocorre redução da qualidade industrial dos grãos (peso de mil grãos, peso hectolitro, porcentagem de grãos com espessura superior a dois milímetros, descasque e produtividade industrial de grãos) da cultivar IPR Artemis.

Effects of ß-glucan from S. cerevisiae on the expression of Casp9, Ccna2 and Sod1 genes in MCF-7 cells

ß-Glucans (ßG) are polysaccharides widely distributed in nature with chemopreventive properties. The aim of this study was to investigate the effects of ßG and the combined treatment with doxorubicin (Dox) on cell viability and mRNA levels of genes involved in cell cycle, apoptosis and antioxidant response. ßG was not cytotoxic. The mRNA levels of CCNA2of cells exposed to ß-glucan was upregulated and the exposure to Dox decreased the expression, while the combination led to an upregulation. Modulation of mRNA levels of CASP9suggest that ßG could inhibit promotion and progression steps of carcinogenesis, eliminatingneoplastic cells. The upregulation of CCNA2gene in combined treatment could be occurred due to ability of ßG in restoring the cell cycle distribution pattern after treatment with Dox. The upregulation of SOD1suggests that ßG can enhance the intracellular antioxidant defense, reducing the levels of superoxide dismutase induced by Dox. This response could reduce oxidative damage and attenuate tissue damage during chemotherapeutic treatment. Our data suggest that the drug combination may be less effective in killing tumor cells than the treatment with Dox alone. Thus, future studies should carefully consider this effect on indication of ßG during chemotherapy.Keywords:caspase-9; cyclin A2; superoxide dismutase 1; cell cycle; antioxidant.Received on July 2, 2020.Accepted on February 7, 2022.IntroductionGlucans are polysaccharides widely distributed in nature and oftenstudied due to chemopreventive properties. They are constituent of the cell wall of plants (oats and barley), algae, bacteria and fungi. ß-glucans (ßG)have a common structure comprising a main chain of ß-(1,3) and/or ß-(1,4) D-glucopyranosyl unit and they differ in length and branching structures. ßG of Saccharomyces cerevisiaehave 1→6 side branches while those of bacteria have 1→4 side branches (Chan, Chan, & Sze, 2009). ßGcan prevent DNA damage induced by chemical and physical agents (Ghavami,Goliaei, Taghizadeh, & Nikoofar, 2014). Some authors showed its significant efficacy in preventing mutagenic effects caused by doxorubicin, cyclophosphamide and cisplatin (Tohamy, El-Ghor, El-Nahas, & Noshy, 2003), methyl methanesulfonate (Oliveira et al., 2007)and hydrogen peroxide (Slamenová, 2003). Moreover, some studies have related the antioxidant ability of ßGagainst reactive free radicals formed by endogenous metabolic processes or exogenous chemicals (Tsiapali et al., 2001; Slamenová,2003; Sener, Eksioglu-Demiralp, Cetiner, Ercan, & Yegen, 2006; Guerra Dore et al., 2007; Kofuji et al., 2012; Lei et al., 2015). Yeast-derived ßGhave modulating action of humoral and cellular immune responses (Vetvicka et al., 2007).This activity provides protection to the organism against infections and cancer development (Samuelsen, Schrezenmeir, & Knutsen, 2014; Roudbary, Daneshmand, Hajimorad, Roudbarmohammadip, & Hassan, 2015). Despite postulated modes of action by which ß-glucan works are lacking information about the molecular mechanisms involved in the chemopreventive activity of this polysaccharide. In addition, compounds with chemopreventive properties can contribute to reduce side effects and toxicity during the chemotherapeutic treatment. Therefore, the aim of this study was to investigate the effects of ßG and the combined treatment with doxorubicin (Dox) on the expression of genes related with apoptosis (CASP9), cell cycle control (CCNA2)and antioxidant defense (SOD1)in human breast cancer MCF-7 cells. Doxorubicin (Dox) was chosen because it is one of the most used chemotherapeutic agent for cancer treatment. The limitation on the use of Dox in cancer treatment is the lack of selectivity against cancer cells and, consequently, its toxicity to patients.(AU)

Crown rust on oat genotypes with different levels of resistance: damages and losses / Ferrugem da folha sobre genótipos de aveia com diferentes níveis de resistência: danos e perdas

The evolution in virulence of Puccinia coronata f. sp. avenae has challenged the genetic resistance to crown rust in oat genotypes. New resistance sources are constantly required for yield stabilization and costs reduction. This study aimed to characterize the crown rust resistance of oat genotypes and the disease´s productive and economic impact. Experiments were conducted in two environments, with and without chemical control. Resistance was measured by disease progress, apparent rate of infection, final severity and pustule size. Damages were based on reduction of yield, 1000 grain mass and hectoliter mass. UFRGS16Q6030-2 was immune. In both environments, UFRGS166091-2 and URS Brava exhibited the greatest level of resistance and the smallest grain yield reduction, while URS 22 was highly susceptible, reducing more than 70% of its grain yield. These results surpass the negative impacts of the disease previously reported in oats, particularly related to grain yield. The data presented in this paper highlighted the importance of genetic resistance, particularly partial resistance, for maintaining oat genetic yield potential, reducing environmental contamination with less fungicides, and increasing economic gains with oat cultivation.(AU)

A evolução da virulência de Puccinia coronata f. sp. avenae desafia a resistência genética de cultivares de aveia à ferrugem da folha. Novas fontes de resistência são constantemente necessárias para estabilizar a produção e reduzir custos. Os objetivos desse estudo foram caracterizar a resistência de seis genótipos de aveia à ferrugem da folha e avaliar o impacto produtivo e econômico causado pela doença. Foram conduzidos ensaios em dois ambientes com e sem o controle químico. A resistência foi medida via progresso da doença, taxa aparente de infecção, severidade final e tamanho da pústula. As perdas foram avaliadas em rendimento, massa de mil grãos e massa do hectolitro. UFRGS 16Q6030-2 foi imune. Em ambos os ambientes, UFRGS 166091-2 e URS Brava exibiram os maiores níveis de resistência e as menores reduções no rendimento de grãos, enquanto URS 22 teve a maior suscetibilidade, com redução superior a 70% no rendimento de grãos. Os resultados obtidos superam os impactos negativos da doença previamente relatados em aveia, particularmente em relação ao rendimento de grãos. Os dados apresentados neste trabalho ressaltam a importância da resistência genética, particularmente a parcial, na manutenção do potencial genético produtivo, na redução de contaminações ambientais pelo menor uso de fungicidas e na ampliação dos ganhos econômicos com a cultura da aveia.(AU)

Soil compaction and cover with black oat on soybean grain yield in lowland under no-tillage system / Compactação do solo e cobertura com aveia preta na produtividade de grãos de soja em várzea sob sistema de plantio direto

Brazil is the largest exporter and second largest producer of soybean grains. Most of this production is from plants grown under no-tillage system (NT). This research evaluated the effect of soil compaction, and different amounts of black oat residues on the soil surface on soybean growth and grain yield in lowland under NT. The experiment was conducted in a completely randomized design with seven treatments and four replications, in the 2016/2017 and 2017/2018 crop seasons. The treatments consisted of: 1) winter fallow without soil compaction (WF); 2) winter fallow with soil compaction (WF-C); 3) black oats and complete removal of surface residues, with soil compaction (0R-C); 4) black oats and removal half of surface residues, with soil compaction (0.5R-C); 5) black oats without surface residue removal, with soil compaction (1R-C); 6) black oats without surface residue removal, plus the residues from treatment 3, with soil compaction (2R-C); 7) black oats without surface residue removal, without soil compaction (1R). When the soybean plants were at the phenological stage R2, they were evaluated nodule, root and shoot dry matter, nitrogen contents, plant height, and grain yield. The soil physical properties were evaluated in the 0.0-0.05, 0.10-0.15 and 0.20-0.25 m layers. The soybean aerial dry matter is > 38% in non-compacted soil in year with soil water excess, regardless of the amount of surface oat straw. In year with small water deficit, soil with more surface oat straw produced > 5% shoot dry matter and > 4% of soybean grain, regardless of compaction. The plant growth and grain yield soybean in lowland varied according to the water conditions, and were affected by soil compaction and amounts of black oats residues on soil surface.

O Brasil se destaca na produção de soja, sendo o maior exportador e o segundo maior produtor do grão e a maior parte é cultivado em sistema plantio direto (SPD). Objetivou-se avaliar o efeito da compactação, cultivo e quantidades de palha de aveia preta na superfície do solo sobre o crescimento e o rendimento de grãos de soja em SPD em terras baixas. O delineamento experimental foi inteiramente casualizado com sete tratamentos e quatro repetições. Os tratamentos, nas safras 2016/17 e 2017/18, foram: 1) Pousio no inverno sem compactação (WF); 2) Pousio no inverno + compactação (WF-C); 3) Aveia preta e retirada da palha superficial + compactação (0R-C); 4) Aveia e retirada da metade da palha + compactação (0,5R-C); 5) Aveia + permanência da palhada + compactação (1R-C); 6) Aveia + a palha retirada do tratamento 3 (2 doses palha) + compactação (2R-C); 7) Aveia + permanência da palha, sem compactação (1R). No estádio fenológico R2 a soja foram avaliadas a massa seca de nódulos e de raízes, massa seca e nitrogênio da parte aérea, altura de plantas e produtividade de grãos. No solo foram avaliadas propriedades físicas nas camadas de 0,0-0,05; 0,10-0,15 e 0,20-0,25 m. A produção de massa seca da parte aérea de soja é > 38% em solo não compactado em ano com excesso hídrico independente da quantidade de palha de aveia na superfície. Em ano com pequeno déficit hídrico os tratamentos com mais palha produziram > 5% de massa seca da parte aérea e > 4% de grãos de soja, independente da compactação. O crescimento e o rendimento de grãos de soja em terras baixas oscilam de acordo com as condições hídricas, sendo influenciada pela compactação e quantidade de palha superficial.

Soil compaction and cover with black oat on soybean grain yield in lowland under no-tillage system / Compactação do solo e cobertura com aveia preta na produtividade de grãos de soja em várzea sob sistema de plantio direto

Brazil is the largest exporter and second largest producer of soybean grains. Most of this production is from plants grown under no-tillage system (NT). This research evaluated the effect of soil compaction, and different amounts of black oat residues on the soil surface on soybean growth and grain yield in lowland under NT. The experiment was conducted in a completely randomized design with seven treatments and four replications, in the 2016/2017 and 2017/2018 crop seasons. The treatments consisted of: 1) winter fallow without soil compaction (WF); 2) winter fallow with soil compaction (WF-C); 3) black oats and complete removal of surface residues, with soil compaction (0R-C); 4) black oats and removal half of surface residues, with soil compaction (0.5R-C); 5) black oats without surface residue removal, with soil compaction (1R-C); 6) black oats without surface residue removal, plus the residues from treatment 3, with soil compaction (2R-C); 7) black oats without surface residue removal, without soil compaction (1R). When the soybean plants were at the phenological stage R2, they were evaluated nodule, root and shoot dry matter, nitrogen contents, plant height, and grain yield. The soil physical properties were evaluated in the 0.0-0.05, 0.10-0.15 and 0.20-0.25 m layers. The soybean aerial dry matter is > 38% in non-compacted soil in year with soil water excess, regardless of the amount of surface oat straw. In year with small water deficit, soil with more surface oat straw produced > 5% shoot dry matter and > 4% of soybean grain, regardless of compaction. The plant growth and grain yield soybean in lowland varied according to the water conditions, and were affected by soil compaction and amounts of black oats residues on soil surface.(AU)

O Brasil se destaca na produção de soja, sendo o maior exportador e o segundo maior produtor do grão e a maior parte é cultivado em sistema plantio direto (SPD). Objetivou-se avaliar o efeito da compactação, cultivo e quantidades de palha de aveia preta na superfície do solo sobre o crescimento e o rendimento de grãos de soja em SPD em terras baixas. O delineamento experimental foi inteiramente casualizado com sete tratamentos e quatro repetições. Os tratamentos, nas safras 2016/17 e 2017/18, foram: 1) Pousio no inverno sem compactação (WF); 2) Pousio no inverno + compactação (WF-C); 3) Aveia preta e retirada da palha superficial + compactação (0R-C); 4) Aveia e retirada da metade da palha + compactação (0,5R-C); 5) Aveia + permanência da palhada + compactação (1R-C); 6) Aveia + a palha retirada do tratamento 3 (2 doses palha) + compactação (2R-C); 7) Aveia + permanência da palha, sem compactação (1R). No estádio fenológico R2 a soja foram avaliadas a massa seca de nódulos e de raízes, massa seca e nitrogênio da parte aérea, altura de plantas e produtividade de grãos. No solo foram avaliadas propriedades físicas nas camadas de 0,0-0,05; 0,10-0,15 e 0,20-0,25 m. A produção de massa seca da parte aérea de soja é > 38% em solo não compactado em ano com excesso hídrico independente da quantidade de palha de aveia na superfície. Em ano com pequeno déficit hídrico os tratamentos com mais palha produziram > 5% de massa seca da parte aérea e > 4% de grãos de soja, independente da compactação. O crescimento e o rendimento de grãos de soja em terras baixas oscilam de acordo com as condições hídricas, sendo influenciada pela compactação e quantidade de palha superficial.(AU)

Soil compaction and cover with black oat on soybean grain yield in lowland under no-tillage system / Compactação do solo e cobertura com aveia preta na produtividade de grãos de soja em várzea sob sistema de plantio direto

ABSTRACT: Brazil is the largest exporter and second largest producer of soybean grains. Most of this production is from plants grown under no-tillage system (NT). This research evaluated the effect of soil compaction, and different amounts of black oat residues on the soil surface on soybean growth and grain yield in lowland under NT. The experiment was conducted in a completely randomized design with seven treatments and four replications, in the 2016/2017 and 2017/2018 crop seasons. The treatments consisted of: 1) winter fallow without soil compaction (WF); 2) winter fallow with soil compaction (WF-C); 3) black oats and complete removal of surface residues, with soil compaction (0R-C); 4) black oats and removal half of surface residues, with soil compaction (0.5R-C); 5) black oats without surface residue removal, with soil compaction (1R-C); 6) black oats without surface residue removal, plus the residues from treatment 3, with soil compaction (2R-C); 7) black oats without surface residue removal, without soil compaction (1R). When the soybean plants were at the phenological stage R2, they were evaluated nodule, root and shoot dry matter, nitrogen contents, plant height, and grain yield. The soil physical properties were evaluated in the 0.0-0.05, 0.10-0.15 and 0.20-0.25 m layers. The soybean aerial dry matter is > 38% in non-compacted soil in year with soil water excess, regardless of the amount of surface oat straw. In year with small water deficit, soil with more surface oat straw produced > 5% shoot dry matter and > 4% of soybean grain, regardless of compaction. The plant growth and grain yield soybean in lowland varied according to the water conditions, and were affected by soil compaction and amounts of black oats residues on soil surface.

RESUMO: O Brasil se destaca na produção de soja, sendo o maior exportador e o segundo maior produtor do grão e a maior parte é cultivado em sistema plantio direto (SPD). Objetivou-se avaliar o efeito da compactação, cultivo e quantidades de palha de aveia preta na superfície do solo sobre o crescimento e o rendimento de grãos de soja em SPD em terras baixas. O delineamento experimental foi inteiramente casualizado com sete tratamentos e quatro repetições. Os tratamentos, nas safras 2016/17 e 2017/18, foram: 1) Pousio no inverno sem compactação (WF); 2) Pousio no inverno + compactação (WF-C); 3) Aveia preta e retirada da palha superficial + compactação (0R-C); 4) Aveia e retirada da metade da palha + compactação (0,5R-C); 5) Aveia + permanência da palhada + compactação (1R-C); 6) Aveia + a palha retirada do tratamento 3 (2 doses palha) + compactação (2R-C); 7) Aveia + permanência da palha, sem compactação (1R). No estádio fenológico R2 a soja foram avaliadas a massa seca de nódulos e de raízes, massa seca e nitrogênio da parte aérea, altura de plantas e produtividade de grãos. No solo foram avaliadas propriedades físicas nas camadas de 0,0-0,05; 0,10-0,15 e 0,20-0,25 m. A produção de massa seca da parte aérea de soja é > 38% em solo não compactado em ano com excesso hídrico independente da quantidade de palha de aveia na superfície. Em ano com pequeno déficit hídrico os tratamentos com mais palha produziram > 5% de massa seca da parte aérea e > 4% de grãos de soja, independente da compactação. O crescimento e o rendimento de grãos de soja em terras baixas oscilam de acordo com as condições hídricas, sendo influenciada pela compactação e quantidade de palha superficial.

Effects of sheep manure in agricultural soils on the behavior of Folsomia candida and initial growth and development of Avena sativa / Efeitos do esterco de ovelha em solos agrícolas no comportamento de Folsomia candida e no crescimento e desenvolvimento inicial de Avena sativa

The aim of this study was to evaluate the effects of sheep manure in agricultural soils on the behavior of Folsomia candida and initial growth and development of Avena sativa. For this, an Oxisol was submitted to different doses of sheep manure and was subsequently evaluated for Folsomia candida survival and avoidance behavior through standardized ecotoxicological assays, the initial performance of oats by germination test and the soil basal respiration rate by respirometry methodology. There was an increase in the basal respiration rate of the soil by the application of sheep manure and this was consistent with the increase of the doses. The survival rate and avoidance behavior of springtails were not altered and there was no change in the initial performance of oats, indicating that this manure can be used for organic fertilization of soils with low soil pollutant potential.(AU)

O objetivo deste estudo foi avaliar os efeitos do esterco de ovelha em solos agrícolas no comportamento de Folsomia candida e no crescimento e desenvolvimento inicial de Avena sativa. Para isso, um Latossolo foi submetido a diferentes doses de esterco de ovelha e posteriormente avaliado quanto ao comportamento de fuga e a sobrevivência de Folsomia candida por meio de ensaios ecotoxicológicos padronizados, desempenho inicial da aveia pelo teste de germinação e taxa respiratória basal do solo pela metodologia da respirometria. Houve um aumento na taxa de respiração basal do solo pela aplicação de esterco de ovelha e isso foi consistente com o aumento das doses. A taxa de sobrevivência e o comportamento de fuga dos colêmbolos não foram alterados e não houve alteração no desempenho inicial da aveia, indicando que esse esterco pode ser usado para fertilização orgânica de solos com baixo potencial poluente no solo.(AU)

Grazing height and nitrogen fertilization strategy in black oat/maize succession / Altura de pastejo e estratégia de adubação nitrogenada na sucessão aveia preta/milho

This study was developed to examine the effect of combining nitrogen (N) fertilization strategies and pasture management heights on animal and grain production in an Integrated Crop-Livestock System. The experiment was carried out in the municipality of Abelardo Luz - SC, Brazil, between April 2017 and April 2018. A randomized-block design was adopted, with the treatments arranged in a 2×2 factorial arrangement with three replicates. The first factor was the height of the pasture managed under continuous grazing: high (HH, 20 cm) or low (LH, 12 cm). The second factor corresponded to the N application times: in the winter, in the pasture (NP), and in the summer, in the grain crop (NG), in a single N rate of 200 kg ha-1 as topdressing. The forage species used during the pasture phase was black oat (Avena strigosa Schreb), and the pasture was grazed by Nellore × Charolais crossbred steers with an initial body weight of 260 kg. The summer crop was maize (Zea mays). Average daily gain (ADG) and herbage allowance were higher in HH than in LH, whereas animal load was higher in HH. Between the N application times, the animal load was higher in NP. Pasture management height and N fertilization strategy did not affect the variables of number of rows per ear, number of grains per row, thousand-grain weight, or total grain yield, which overall averaged 14,090 kg ha-1. In conclusion, the inversion of nitrogen fertilization between the periods of winter pasture production and grain crop and the management height of the black oat pasture do not compromise the production of maize grains in the summer, or animal production per area. However, steer performance is greater (higher ADG) when the pasture is managed at 20 cm, whereas a high grazing intensity significantly reduces straw on the soil.(AU)

O objetivo deste estudo foi avaliar o efeito da combinação de estratégias de adubação nitrogenada e de alturas de manejo da pastagem sobre a produção animal e de grãos em um Sistema Integrado de Produção Agropecuária. O experimento foi conduzido no município de Abelardo Luz-SC, entre abril de 2017 a abril de 2018. O delineamento experimental utilizado foi blocos ao acaso e os tratamentos dispostos em arranjo fatorial 2x2 com três repetições. O primeiro fator foi a altura do pasto manejado com lotação contínua: alta altura (AA) (20 cm) e baixa altura (BA) (12 cm). O segundo fator foram as épocas de aplicação do nitrogênio: na pastagem de inverno (NP), e na cultura de grãos, no verão (NG), em dose única de 200 kg N ha-1 em cobertura. A espécie forrageira utilizada durante a fase pastagem foi a aveia preta (Avena strigosa Schreb) e o pastejo foi realizado por novilhos cruza Nelore x Charolês com peso corporal inicial de 260 kg. A cultura de verão foi o milho (Zea mays). O ganho médio diário (GMD) e a oferta de forragem foram maiores em AA comparativamente à BA, enquanto a carga animal foi maior em BA. Para as épocas de aplicação do N, a carga animal foi maior em NP. As variáveis número de fileiras por espiga, número de grãos por fileira e peso de mil grãos não foram afetadas pelo manejo da altura do pasto e nem pela estratégia de adubação nitrogenada, bem como a produção total de grãos, que apresentou média geral de 14.090 kg ha-1. Concluiu-se que a inversão da adubação nitrogenada entre os períodos de produção de pasto de inverno e de cultivo de grãos, e a altura de manejo da pastagem de aveia preta não comprometem a produção de grãos de milho no verão e nem a produção animal por área. Entretanto, o desempenho dos novilhos é maior (maior GMD) quando o pasto é manejado a 20 cm, enquanto a alta intensidade de pastejo reduz significativamente a palhada sobre o solo.(AU)

Performance and milk quality of cows fed triticale silage or intercropped with oats or legumes

The use of intercropped grass legumes provides a source of sustainable animal production as these vegetables contribute to an increase in forage yield by area, and substitute inorganic nitrogen and other components. The objective of this study was to evaluate the nutritional characteristics of silages and the yield and milk quality of Holstein cows fed triticale silages in monoculture or intercropped with either oats or legumes. The crops for silage production were triticale (TS), triticale in consortium with forage pea (TSP), and triticale in consortium with oats, forage peas and vetches (TSOPV). The silages showed no differences in dry matter content. The highest crude protein (13.06 %) and ethereal extract content was observed in TSOPV, but in the case of the latter, there was little difference when compared with TS (2.35 and 2.16 %, respectively) although the ash contents of the TSOPV and TSP silages did present a difference compared to TS silage. The neutral and acid detergent fibers (NDF and ADF) and cellulose fractions of TS silage were higher (68.60, 41.46 and 38.19 %, respectively) than those in TSOPV and TSP silages, which also had higher levels of soluble nitrogen, ethanol and acetic acid. Dry matter intake was higher in both TSOPV and TSP, which also provided a higher milk yield (21.19 and 20.45 L cow d−1) compared to that of TS silage (18.74 L cow d−1). Cows fed TS also produced milk with a lower N-ureic content (15.15 mg dL−1). The inclusion of legumes with triticale provided good fermentative quality for silage and increased milk production of cows without altering their concentrations of fat and protein.

Performance and milk quality of cows fed triticale silage or intercropped with oats or legumes

The use of intercropped grass legumes provides a source of sustainable animal production as these vegetables contribute to an increase in forage yield by area, and substitute inorganic nitrogen and other components. The objective of this study was to evaluate the nutritional characteristics of silages and the yield and milk quality of Holstein cows fed triticale silages in monoculture or intercropped with either oats or legumes. The crops for silage production were triticale (TS), triticale in consortium with forage pea (TSP), and triticale in consortium with oats, forage peas and vetches (TSOPV). The silages showed no differences in dry matter content. The highest crude protein (13.06 %) and ethereal extract content was observed in TSOPV, but in the case of the latter, there was little difference when compared with TS (2.35 and 2.16 %, respectively) although the ash contents of the TSOPV and TSP silages did present a difference compared to TS silage. The neutral and acid detergent fibers (NDF and ADF) and cellulose fractions of TS silage were higher (68.60, 41.46 and 38.19 %, respectively) than those in TSOPV and TSP silages, which also had higher levels of soluble nitrogen, ethanol and acetic acid. Dry matter intake was higher in both TSOPV and TSP, which also provided a higher milk yield (21.19 and 20.45 L cow d−1) compared to that of TS silage (18.74 L cow d−1). Cows fed TS also produced milk with a lower N-ureic content (15.15 mg dL−1). The inclusion of legumes with triticale provided good fermentative quality for silage and increased milk production of cows without altering their concentrations of fat and protein.(AU)

Physiological quality of white oat seeds at different temperatures / Qualidade fisiológica de sementes de aveia branca em diferentes temperaturas

White oats are cereals that are grown in different regions of the globe because they have good adaptability and final destination. Thus, their cultivation has shown significant increases in order to meet demand, especially for forage production, grains, and animal and human consumption. High-quality seeds are necessary for crop cultivation and white oats are sown in winter when thermal fluctuations may occur. Therefore, the objective of this study was to evaluate the physiological changes in oat seeds exposed to different temperatures during the germination phase. The experiment was a completely randomized design with four replications in a 6 × 4 factorial design. Six cultivars were evaluated: Aphrodite, Altiva, Artemis, Brava, Corona, and Guará at temperatures of 15, 20, 25, and 30 °C, and the following measurements were taken: first germination count, germination, germination speed index (IVG), and seedling length and mass. The results were analyzed using analysis of variance (F test) and the means were compared using Tukey’s test. The cultivars were physiologically affected at the minimum and maximum temperatures. At 15 °C, normal seedlings did not form, whereas the highest germination values were recorded at 20 and 25 ºC, which showed that these temperatures were the most favorable temperatures for the germination process. Vigor declined at 30 °C and there was a greater number of abnormal seedlings and dead seeds.

A aveia branca é um cereal cultivado em diversas regiões do mundo, pois possui boa adaptabilidade e destino final, de modo que seu cultivo tem apresentado acréscimos significativos visando atender a demanda, com destaque para produção de forragem, grãos e alimentação animal e humana. O uso de sementes de alta qualidade é necessário para a formação da lavoura. O cultivo acontece no inverno e ocorrem oscilações térmicas durante a implantação da cultura, sendo assim, o objetivo do presente trabalho foi avaliar as alterações fisiológicas em sementes de aveia expostas a diferentes temperaturas durante a fase de germinação. O experimento foi disposto em delineamento inteiramente casualizado, com quatro repetições, em fatorial 6 × 4. Foram avaliadas seis cultivares, Afrodite, Altiva, Artemis, Brava, Corona e Guará nas temperaturas 15, 20, 25 e 30 °C por meio de testes de primeira contagem de germinação, germinação, índice de velocidade de germinação (IVG), comprimento e massa seca de plântulas. Os resultados foram submetidos à análise de variância (teste F) e as médias comparadas pelo teste Tukey. As cultivares foram afetadas fisiologicamente nas temperaturas mínima e máxima. A 15 °C não houve formação de plântulas normais. A 20 e 25 ºC foram obtidos os maiores valores de germinação, mostrando-se, portanto, como temperaturas mais propícias ao processo germinativo. A 30 °C, o vigor foi reduzido, apresentando ainda uma tendência de maior número de plântulas anormais e sementes mortas.

Physiological quality of white oat seeds at different temperatures / Qualidade fisiológica de sementes de aveia branca em diferentes temperaturas

White oats are cereals that are grown in different regions of the globe because they have good adaptability and final destination. Thus, their cultivation has shown significant increases in order to meet demand, especially for forage production, grains, and animal and human consumption. High-quality seeds are necessary for crop cultivation and white oats are sown in winter when thermal fluctuations may occur. Therefore, the objective of this study was to evaluate the physiological changes in oat seeds exposed to different temperatures during the germination phase. The experiment was a completely randomized design with four replications in a 6 × 4 factorial design. Six cultivars were evaluated: Aphrodite, Altiva, Artemis, Brava, Corona, and Guará at temperatures of 15, 20, 25, and 30 °C, and the following measurements were taken: first germination count, germination, germination speed index (IVG), and seedling length and mass. The results were analyzed using analysis of variance (F test) and the means were compared using Tukeys test. The cultivars were physiologically affected at the minimum and maximum temperatures. At 15 °C, normal seedlings did not form, whereas the highest germination values were recorded at 20 and 25 ºC, which showed that these temperatures were the most favorable temperatures for the germination process. Vigor declined at 30 °C and there was a greater number of abnormal seedlings and dead seeds.(AU)

A aveia branca é um cereal cultivado em diversas regiões do mundo, pois possui boa adaptabilidade e destino final, de modo que seu cultivo tem apresentado acréscimos significativos visando atender a demanda, com destaque para produção de forragem, grãos e alimentação animal e humana. O uso de sementes de alta qualidade é necessário para a formação da lavoura. O cultivo acontece no inverno e ocorrem oscilações térmicas durante a implantação da cultura, sendo assim, o objetivo do presente trabalho foi avaliar as alterações fisiológicas em sementes de aveia expostas a diferentes temperaturas durante a fase de germinação. O experimento foi disposto em delineamento inteiramente casualizado, com quatro repetições, em fatorial 6 × 4. Foram avaliadas seis cultivares, Afrodite, Altiva, Artemis, Brava, Corona e Guará nas temperaturas 15, 20, 25 e 30 °C por meio de testes de primeira contagem de germinação, germinação, índice de velocidade de germinação (IVG), comprimento e massa seca de plântulas. Os resultados foram submetidos à análise de variância (teste F) e as médias comparadas pelo teste Tukey. As cultivares foram afetadas fisiologicamente nas temperaturas mínima e máxima. A 15 °C não houve formação de plântulas normais. A 20 e 25 ºC foram obtidos os maiores valores de germinação, mostrando-se, portanto, como temperaturas mais propícias ao processo germinativo. A 30 °C, o vigor foi reduzido, apresentando ainda uma tendência de maior número de plântulas anormais e sementes mortas.(AU)

Degradabilidade e cinética ruminal de alimentos energéticos utilizados em dietas para ruminantes / Ruminal kinetics and degradability of energetic feedstuffs used in diets for ruminants

Objetivou-se neste trabalho avaliar alimentos energéticos quanto a composição química, degradabilidade ruminal in situ da matéria seca (DMS), cinética ruminal e taxa de desaparecimento ruminal da matéria seca. Foram avaliados sete alimentos (tratamentos): grão de milho moído, grão de aveia moído, grão de cevada moído, farelo de trigo, casca de soja, radícula de malte e gérmen de milho, num delineamento inteiramente casualizado com quatro repetições cada. Para a incubação dos materiais foram utilizados dois bovinos com cânula ruminal, e cada tratamento foi submetido a sete períodos de exposição ao rúmen (0, 3, 6, 9, 12, 18 e 24 horas). Dentre os alimentos avaliados, a casca de soja teve o maior teor de fibra em detergente neutro (68,91%) e apresentou a menor DMS em 24 h (64,91%). O grão de cevada moído e o grão de milho moído tiveram os menores níveis de fração solúvel (FS) (26,34% e 28,7%, respectivamente), porém o grão de cevada moído apresentou a maior DMS em 24 h (90,48%), que por conciliar estes parâmetros teve a maior taxa de desaparecimento ruminal (2,50%.h-¹), enquanto o grão de aveia moído teve a maior FS (47,75%) e a menor taxa de desaparecimento ruminal (1,09%.h-¹).

This study aimed to evaluate energetic feedstuffs regarding chemical composition, in situ ruminal degradability of dry matter (DMD), ruminal kinetics and ruminal disappearance rate of dry matter. Seven feedstuffs (treatments) were evaluated: ground corn, ground oat, ground barley, wheat bran, soybean hull, malt root and corn germ, in a completely randomized design of four repetitions each. Two bovines ruminally cannulated were used for incubation, wherein each treatment was subjected to seven periods of exposure to the rumen (0, 3, 6, 9, 12, 18 and 24 hours). Among the evaluated feedstuffs, soybean hull had the highest neutral detergent fiber (NDF) content (68.91%) and the lowest DMD at 24 h (64.91%). Ground barley and ground corn contained the lowest content of soluble fraction (SF) (26.34 and 28.7%, respectively), among which ground barley had the highest DMD at 24 h (90.48%) and therefore showed the highest rumen disappearance rate (2.50%.h-¹) by combining both parameters, while the ground oat presented the highest SF (47.75%) and the lowest rumen disappearance rate (1.09%.h-¹).