Growth stage and ensiling: impact on chemical composition, conservation quality and in situ ruminal degradability of whole-crop oat.

BACKGROUND: The effects of growth stage (GS) and ensiling were assessed on whole-crop oat's (Avena sativa L. cv. Cantara) chemical composition, silage fermentation quality and in situ ruminal degradability. Oat was harvested and ensiled at six GS: boot, heading, water ripe, early milk, early dough and grain ripe (144, 151, 178, 234, 362 and 512 g kg-1 of dry matter (DM) of whole-crop forage, respectively). RESULTS: GS influenced chemical composition, silage fermentation quality and ruminal degradability of whole-crop oat. Lower DM and higher water-soluble carbohydrates (WSC) contents lead to adequate forage compaction and fermentation at early GS; however, effluent was produced until the dough stage (L and Q; P ≤ 0.003). Advancing in maturity increased (P < 0.001) crop yield (4.5 to 9.4 t DM ha-1 ), DM (144 to 512 g kg-1 ), neutral detergent fibre (NDF; 537 to 571 g kg-1 DM), lignin (44.6 to 71.3 g kg-1 DM) and starch contents (26.4 to 201 g kg-1 DM), and reduced (P < 0.001) crude protein (107 to 60 g kg-1 DM) and WSC (115 to 17.5 g kg-1 DM). DM and NDF ruminal degradability declined with maturity for fresh and ensiled forages (L and Q; P < 0.05). Density and buffering capacity decreased with GS (L and Q; P < 0.001), whereas pH and soluble protein increased (L and Q; P ≤ 0.004). CONCLUSION: The growth stage of oat influenced the nutritive value and ruminal degradation to a greater extent than ensiling, and thus it can play a paramount role in whole-crop oat silage quality. © 2021 Society of Chemical Industry.

Herbicide performance in the control of Conyza spp. where three plant heights

Intensive use of the herbicide glyphosate has led to herbicide resistant Conyza spp. populations. Thus, there is a need to indicate alternative herbicides and the appropriate developmental stage for controlling these populations. This study identifies alternatives for controlling glyphosate-resistant horseweed, with treatment applications at different plant heights. For this purpose, field experiments were conducted in the 2016/17 and 2017/18 crop years. The evaluated treatments were: glyphosate (540 g ae ha-1), glyphosate (1080 g ae ha-1), glyphosate (2160 g ae ha-1), glyphosate (3240 g ae ha-1), glyphosate + 2.4-D (1080 + 1005 g ae ha-1), glyphosate + saflufenacil (1080 + 49 g ae/ai ha-1), paraquat (400 g ai ha-1), diquat (400 g ai ha-1), ammonium glufosinate (600 g ai ha-1), and control (without application). These treatments were applied to plants with a maximum of 5 cm; plants between 6 and 15 cm; and plants between 16 and 25 cm. The results showed that glyphosate did not control weeds, regardless of rate. With the exception of 2,4-D, which needs complementation with sequential application of another contact herbicide, all alternatives were viable for the control of Conyza spp. plants with a maximum height of 5 cm.

Salmonella enterica Optimizes Metabolism After Addition of Acyl-Homoserine Lactone Under Anaerobic Conditions.

Acyl-homoserine lactones (AHLs) are quorum sensing (QS) signaling molecules that mediate cell-to-cell communication in Gram-negative bacteria. Salmonella does not produce AHL, however, it can recognize AHLs produced by other species through SdiA protein modulating important cellular functions. In this work, the influence of the N-dodecanoyl-DL-homoserine lactone (C12-HSL) on glucose consumption, metabolic profile, and gene expression of Salmonella throughout the cultivation time in Tryptic Soy Broth (TSB) under anaerobic conditions was evaluated. Analysis of the supernatant culture in high-performance liquid chromatography (HPLC) revealed lower glucose uptake after 4 and 6 h of the addition of C12-HSL. Gas chromatography-mass spectrometry (GC-MS) based analysis of the intracellular metabolites revealed C12-HSL perturbation in the abundance levels of metabolites related to the metabolic pathways of glycerolipids, purines, amino acids, and aminoacyl-tRNA biosynthesis. The real-time quantitative PCR (RT-qPCR) indicated that Salmonella increase expression of genes associated with nucleoside degradation and quantification of metabolites supported the induction of pentose phosphate pathway to ensure growth under lower glucose consumption. The obtained data suggest an important role of C12-HSL in the optimization of metabolism at a situation of high population densities.

Is the chemical control of glyphosate-resistant hairy fleabane more efficient during pre-flowering or re-growth? / Controle químico de buva resistente a glyphosate é mais eficaz no pré-florescimento ou no rebrote?

To test the efficacy of alternative herbicides for controlling of glyphosate-resistant Conyza bonariensis under different growth stages, we carried out an experiment in an apple orchard, in a factorial arrangement 2x5, consisting of: (i) two growth stages pre-flowering and re-growth; and (ii) five herbicides glyphosate, glufosinate, bentazon, diquat, and glyphosate+saflufenacil. Basagran, diquat, and glyphosate+saflufenacil were not efficient to control C. bonariensis in pre-flowering. Glufosinate, diquat, bentazon, and glyphosate+saflufenacil controlled C. bonariensis in re-growth. Just glufosinate showed efficient control (>90%) of C. bonariensis in both pre-flowering and re-growth. In general, control of C. bonariensis is more efficient in re-growth.(AU)

Para testar a eficácia de herbicidas alternativos no controle de Conyza bonariensis resistente a glyphosate em diferentes estádios de crescimento, conduziu-se um experimento em pomar de maçã, em esquema fatorial 2x5, sendo: (i) dois estádios pré-florescimento e rebrote; e (ii) cinco herbicidas glyphosate, glufosinate, bentazon, diquat e glyphosate+saflufenacil. Basagran, diquat e glyphosate+saflufenacil não foram eficazes no controle de C. bonariensis em pré-florescimento. Glufosinate, diquat, bentazon e glyphosate+saflufenacil controlaram plantas de C. bonariensis em rebrote. Somente glufosinate apresentou controle eficaz (>90%) de C. bonariensis em pré-florescimento e em rebrote. Em geral, o controle de C. bonariensis é mais eficaz no rebrote.(AU)

Is the chemical control of glyphosate-resistant hairy fleabane more efficient during pre-flowering or re-growth? / Controle químico de buva resistente a glyphosate é mais eficaz no pré-florescimento ou no rebrote?

To test the efficacy of alternative herbicides for controlling of glyphosate-resistant Conyza bonariensis under different growth stages, we carried out an experiment in an apple orchard, in a factorial arrangement 2x5, consisting of: (i) two growth stages pre-flowering and re-growth; and (ii) five herbicides glyphosate, glufosinate, bentazon, diquat, and glyphosate+saflufenacil. Basagran, diquat, and glyphosate+saflufenacil were not efficient to control C. bonariensis in pre-flowering. Glufosinate, diquat, bentazon, and glyphosate+saflufenacil controlled C. bonariensis in re-growth. Just glufosinate showed efficient control (>90%) of C. bonariensis in both pre-flowering and re-growth. In general, control of C. bonariensis is more efficient in re-growth.

Para testar a eficácia de herbicidas alternativos no controle de Conyza bonariensis resistente a glyphosate em diferentes estádios de crescimento, conduziu-se um experimento em pomar de maçã, em esquema fatorial 2x5, sendo: (i) dois estádios pré-florescimento e rebrote; e (ii) cinco herbicidas glyphosate, glufosinate, bentazon, diquat e glyphosate+saflufenacil. Basagran, diquat e glyphosate+saflufenacil não foram eficazes no controle de C. bonariensis em pré-florescimento. Glufosinate, diquat, bentazon e glyphosate+saflufenacil controlaram plantas de C. bonariensis em rebrote. Somente glufosinate apresentou controle eficaz (>90%) de C. bonariensis em pré-florescimento e em rebrote. Em geral, o controle de C. bonariensis é mais eficaz no rebrote.

Glyphosate associado a outros herbicidas no controle de Commelina benghalensis e Spermacoce latifolia / Glyphosate associated with other herbicides for control of Commelina benghalensis and Spermacoce latifoli

A liberação da soja transgênica possibilitou o uso do glyphosate para o controle das plantas daninhas em pós-emergência, facilitando o manejo e diminuindo os custos. No entanto, o controle de algumas espécies tolerantes ao glyphosate pode ser otimizado com associações com outros herbicidas. O trabalho teve como objetivo verificar o efeito da associação de diferentes herbicidas com glyphosate para o controle de Commelina benghalensis e Spermacoce latifolia após aplicação dos herbicidas em dois estádios de desenvolvimento (1-3 e 4-6 folhas). Para isso, foram realizados quatro experimentos em casa de vegetação, aplicando-se glyphosate nas doses de 480 e 960 g ha-1, isolado ou combinado com os latifolicidas cloransulam-methyl (30,24 g ha-1), chlorimuron-ethyl (12,5 g ha-1), imazethapyr (80 g ha-1), fomesafen (62,5 g ha-1), lactofen (72 g ha-1), flumiclorac-pentyl (30 g ha-1) e bentazon (480 g ha-1), além de uma testemunha sem herbicida. Foram realizadas avaliações de porcentagem de controle aos 3, 7, 14, 21, 28 e 35 dias após aplicação (DAA) e massa seca da parte aérea (35 DAA). Para o controle de C. benghalensis, quando a aplicação é realizada no estádio de 1-3 folhas todos os tratamentos apresentaram controle satisfatório. Para S. latifolia, as maiores eficiências foram obtidas para as aplicações realizadas no estádio de 4-6 folhas, nas quais mesmo o glyphosate isolado na menor dose testada (480 g ha-1), proporcionou excelente controle. De modo geral, o uso de misturas melhorou o controle de ambas as espécies quando se usa glyphosate a 480 g ha-1 em estádios mais precoces do desenvolvimento das plantas daninhas

The widespread cultivation of Roundup Ready soybeans enabled the use of glyphosate for post-emergence weed control in, turning weed handling into an easier and less costly operation. Despite such improvements, controlling glyphosate tolerant species can still be improved by associations with other herbicides. The aimed at evaluating the effect of the association of different herbicides with glyphosate in relation to Commelina benghalensis and Spermacoce latifolia control, after spraying plants in two different growth stages (1-3 and 4-6 leaves). For that, four experiments were carried out under greenhouse conditions, where glyphosate was applies at rates of 480 and 960 g a.e. ha-1, isolated or combined in tank mixtures with cloransulam-methyl (30,24 g ha-1), chlorimuron-ethyl (12,5 g ha-1), imazethapyr (80 g ha-1), fomesafen (62,5 g ha-1), lactofen (72 g ha-1), flumiclorac-pentyl (30 g ha-1) and bentazon (480 g ha-1), besides a no-herbicide check. We evaluated the percentage of control at 3, 7, 14, 21, 28 and 35 days after application (DAA) and shoot dry mass (35 DAA). For C. benghalensis control, when herbicides were applied at 1-3 leaves stage, all treatments performed satisfactorily in weed control. For S. latifolia, the highest levels of weed control when applications were made at 4-6 leaves stage, when even glyphosate alone at lowest rate (480 g a.e. ha-1), provided excellent weed control. Overall, the use of tank mixtures improved weed control of both species when the rate of 480 g a.e. ha-1 of glyphosate was applied at earlier stages of weed development.

Essential oil composition and variability in Hyptis fruticosa

The composition of six samples of essential oil (EO) extracted from leaves, flowers and seeds of several plants of Hyptis fruticosa Salzm. ex Benth., Lamiaceae, was investigated by GC/MS and GC/FID. 1,8-Cineole, spathulenol, α-pinene, β-pinene were the major constituents. Ten constituents that have not been previously described in the composition of the oil of H. fruticosa were identified. Hydrocarbons sesquiterpenes represented the main group, followed by hydrocarbons monoterpenes. The results were submitted to Cluster Analysis which allowed three groups of EO to be distinguished with respect to the content of α-pinene/β-pinene, 1,8-cineole and spathulenol. Growth stages of the plants and geographical parameters seem to be important factors determining the variability of the oil. Sesquiterpenes were mainly produced in the seeds.

Glyphosate associado a outros herbicidas no controle de Commelina benghalensis and Spermacoce latifolia / Glyphosate associated with other herbicides for control of Commelina benghalensis and Spermacoce latifolia

A liberação da soja transgênica possibilitou o uso do glyphosate para o controle das plantas daninhas em pós-emergência, facilitando o manejo e diminuindo os custos. No entanto, o controle de algumas espécies tolerantes ao glyphosate pode ser otimizado com associações com outros herbicidas. O trabalho teve como objetivo verificar o efeito da associação de diferentes herbicidas com glyphosate para o controle de Commelina benghalensis e Spermacoce latifolia após aplicação dos herbicidas em dois estádios de desenvolvimento (1-3 e 4-6 folhas). Para isso, foram realizados quatro experimentos em casa de vegetação, aplicando-se glyphosate nas doses de 480 e 960 g ha-1, isolado ou combinado com os latifolicidas cloransulam-methyl (30,24 g ha-1), chlorimuron-ethyl (12,5 g ha-1), imazethapyr (80 g ha-1), fomesafen (62,5 g ha-1), lactofen (72 g ha-1), flumiclorac-pentyl (30 g ha-1) e bentazon (480 g ha-1), além de uma testemunha sem herbicida. Foram realizadas avaliações de porcentagem de controle aos 3, 7, 14, 21, 28 e 35 dias após aplicação (DAA) e massa seca da parte aérea (35 DAA). Para o controle de C. benghalensis, quando a aplicação é realizada no estádio de 1-3 folhas todos os tratamentos apresentaram controle satisfatório. Para S. latifolia, as maiores eficiências foram obtidas para as aplicações realizadas no estádio de 4-6 folhas, nas quais mesmo o glyphosate isolado na menor d

The widespread cultivation of Roundup Ready soybeans enabled the use of glyphosate for post-emergence weed control in, turning weed handling into an easier and less costly operation. Despite such improvements, controlling glyphosate tolerant species can still be improved by associations with other herbicides. The aimed at evaluating the effect of the association of different herbicides with glyphosate in relation to Commelina benghalensis and Spermacoce latifolia control, after spraying plants in two different growth stages (1-3 and 4-6 leaves). For that, four experiments were carried out under greenhouse conditions, where glyphosate was applies at rates of 480 and 960 g a.e. ha-1, isolated or combined in tank mixtures with cloransulam-methyl (30,24 g ha-1), chlorimuron-ethyl (12,5 g ha-1), imazethapyr (80 g ha-1), fomesafen (62,5 g ha-1), lactofen (72 g ha-1), flumiclorac-pentyl (30 g ha-1) and bentazon (480 g ha-1), besides a no-herbicide check. We evaluated the percentage of control at 3, 7, 14, 21, 28 and 35 days after application (DAA) and shoot dry mass (35 DAA). For C. benghalensis control, when herbicides were applied at 1-3 leaves stage, all treatments performed satisfactorily in weed control. For S. latifolia, the highest levels of weed control when applications were made at 4-6 leaves stage, when even glyphosate alone at lowest rate (480 g a.e. ha-1), provided excell