Analysis of the chemical and biological characteristics and their relationship with the yield of radish (Raphanus sativus L.) nourished with compost based on plant residues.

The increase in fertilizer prices was 20% after the pandemic, which increased the cost of crop production in Peru. For this reason, research was conducted on the analysis of the chemical and biological characteristics and their relationship with the yield of radish nourished with compost based on plant residues. The objective was to analyze the chemical and biological characteristics and their relationship with the yield of radish nourished with vegetable waste-based compost. It is based on the methodology applied with an experimental approach; therefore, the statistical model of the Completely Randomized Block Design was used, which consisted of 3 blocks and 5 treatments that were T1 with 0, T2 with 4, T3 with 6, T4 with 8 and T5 with 10 t/ha of compost based on vegetable residues, and the doses were applied 14 days after sowing. Physical characteristics (total plant length, plant weight, bulb equatorial diameter and marketable yield), nutrient concentrations (nitrogen, potassium, phosphorus, calcium, magnesium, sulfur, molybdenum, iron, manganese, copper, zinc, boron, chlorides and sodium) in leaves and stomata density were evaluated. The results determined that T5 stood out in total plant length with 28.07 cm, plant weight with 75 g, bulb equatorial diameter with 4.52 cm and commercial yield with 22.53 t/ha. In the total contribution of nitrogen in relation to yield with 300.44 kg/ha. Profitability with 186.8%. Quantification of stomata per treatment with 598 stomata/mm2 and concentration of nutrients in leaves at T3 with nitrogen, potassium, phosphorus and magnesium. It concludes that T5, which has an adequate concentration of nutrients in leaves such as magnesium, manganese, zinc and stomata density of 598 stomata/mm2 influenced optimal biochemical reactions that resulted in the highest yield with 22.53 t/ha, differing by 31.38% in relation to T1.

Biological and chemical characterization in relation to the yield of radish (Raphanus sativus L.) nourished with humus from plant residues.

The increase in prices of fertilizers, energy and other materials necessary for the industry triggered a global economic crisis. Reason that was investigated on the biological and chemical characteristics in relation to the yield of radish nourished with humus from plant residue. The objective was to determine the appropriate dose of humus to obtain greater yield and its relationship with the chemical and biological characteristics of the radish. It is based on applied methodology with an experimental approach; Therefore, the Completely Random Block Design model was used, which consisted of 3 blocks and 5 treatments that were T1 with 0, T2 with 4, T3 with 6, T4 with 8 and T5 with 10 t/ha of humus and They applied 15 days after sowing. The physical characteristics of the radish were evaluated and processed using analysis of variance and Duncan. Concentration of elements in leaves and stomatal density were also analyzed. It was determined that T5 stood out in total plant length with 28.95 cm, plant weight with 76.87 g, equatorial diameter with 4,404 cm and commercial yield with 20,296 t/ha. Nitrogen consumption in relation to yield with 247.44 kg/ha. Stomatal density 459 stomata/mm2 and profitability with 150% and nutrient concentration in leaves highlighted T4 with N, K, Ca, Mg, Mo and Zn. It concludes that T5 stood out with 20,296 t/ha, which differed by 26.04% in relation to the control (T1) with 15,011 t/ha. Therefore, this dose added nutrients to the soil that improved the availability for plant absorption and this influenced the concentration of nutrients in leaves such as N, P and Fe and stomatal density with 459 stomata/mm2, which had a response in good development, strengthening against environmental stress and therefore greater performance.

Do organic fertilization and azospirillum brasilense influence radish cultivation? / A adubação orgânica e o azospirillum brasilense influenciam o cultivo do rabanete?

The association of conventional fertilizers with fertilizers of organic origin is a well-known practice in agriculture for achieving high productivity and also with the adoption of inoculants, composed of bacteria for promoting better plant development of crops. Thus, the objective of the work was to investigate the growth and productivity of radish with organic fertilization and the influence of the use of nitrogen fixing bacteria of the genus Azospirillum spp.radish (Raphanus sativus L.) Hybrid Margaret Queen. The treatments were the use of different doses of organic fertilizer and the application of Azospirillum brasilense, besides the control. At the end of the cycle, plant height, tuber diameter, tuber fresh mass, tuber dry mass, and total tuber fresh mass were evaluated. With and without application of A. brasilense,increases of 16.5% and 6.40% in tuber diameter were obtained, respectively. Without application of A. brasilense, there was an increase of 0.37% in leaf dry mass when the maximum concentration of 8 kg m² of organic fertilizer was used. For root fresh mass and root dry mass, with foliar application of A. brasilense, there was an increase of 9.57% and 0.67%, while without A. brasilensethere was an increase of 2.43% and 0.22%. There were increases of 12.83% for total fresh mass with the management of A. brasilenseand 3.4% without A. brasilense, using the maximum concentration of 8 kg m² of organic fertilizer. For height, there was an increase of 5.12% without A. brasilense.It was concluded that organic fertilization alone or combined with A. brasilenseis an alternative in radish production.(AU)

A associação de fertilizantes convencionais com fertilizantes de origem orgânica é uma prática bastante conhecida na agricultura por alcançar alta produtividade e também com a adoção de inoculantes, compostos por bactérias por promoverem melhor desenvolvimento vegetal das lavouras. Assim, o objetivo do trabalho foi investigar o crescimento e a produtividade do rabanete com adubação orgânica e a influência do uso de bactérias fixadoras de nitrogênio do gênero Azospirillum spp. rabanete (Raphanus sativus L.) Híbrido Margaret Queen. Os tratamentos foram o uso de diferentes doses de adubo orgânico e a aplicação de Azospirillum brasilense, além da testemunha. Ao final do ciclo, foram avaliados altura da planta, diâmetro do tubérculo, massa fresca do tubérculo, massa seca do tubérculo e massa fresca total do tubérculo. Com e sem aplicação de A. brasilense, foram obtidos aumentos de 16,5% e 6,40% no diâmetro do tubérculo, respectivamente. Sem aplicação de A. brasilense, houve aumento de 0,37% na massa seca foliar quando utilizada a concentração máxima de 8 kg m² de adubo orgânico. Para massa fresca de raiz e massa seca de raiz, com aplicação foliar de A. brasilense, houve aumento de 9,57% e 0,67%, enquanto sem A.brasilense houve aumento de 2,43% e 0,22%. Houve incrementos de 12,83% para massa fresca total com manejo de A. brasilense e de 3,4% sem A. brasilense, com a utilização da concentração máxima de 8 kg m² de adubo orgânico. Para altura, houve aumento de 5,12% sem A. brasilense. Concluiu-se que a adubação orgânica isolada ou combinada com A. brasilense é uma alternativa na produção de rabanete.(AU)

Selectivity and efficacy of herbicides applied to the wheat crop / Seletividade e eficácia de herbicidas aplicados à cultura do trigo

When not controlled efficiently, weeds in wheat crop stands may affect both the grain quality and yield production. This work aimed to assess the selectivity and efficacy of herbicides applied to control weeds in the wheat cultivar TBIO Sinuelo. Two experiments were set upto assess the selectivity and the efficacy of herbicides applied to wheatin randomized blocks designwith four replications. Treatments tested were: iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, clodinafop-propargyl, [bentazon + imazamox], saflufenacil, bentazon, carfentrazone-ethyl, imazamox, pendimethalin, [sulfentrazone + diuron], plus two control treatments, one weeded and the other infested. The greatest damages to wheat were caused by imazamox and the commercial mixture [bentazon + imazamox] with phytotoxicity of approximately 50%. On the other hand, applyingthe commercial mixture [sulfentrazone + diuron] allowed the highest wheat grain yield. The use of clodinafop-propargyl and pyroxsulam promoted the best control of Lolium multiflorum, with 100 and 98.25% at 21 days after treatment application, respectively. The control above 90% of Raphanus raphanistrumwas reported with iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, [bentazon + imazamox], saflufenacil, bentazon, and carfentrazone. Clodinafop-propargyl was the most efficient on ryegrass, and iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, saflufenacil, and carfentrazone performed best on the turnip. Pyroxsulam was the treatment that showed, in both experiments, the best results for all-grain yield components, especially for grain yield.(AU)

As plantas daninhas ocasionam efeitos negativos na produtividade e na qualidade dos grãos da cultura do trigo quando não controladas de modo eficiente. Assim sendo, objetivou-se com os trabalhos avaliar a seletividadee a eficácia deherbicidas aplicados para o manejo de plantas daninhas infestante da cultivar de trigo TBIO Sinuelo. Foram instalados dois experimentos, um para avaliar a seletividade e outro a eficácia de herbicidas aplicados em trigo, em blocos casualizados, com quatrorepetições. Os tratamentos testados foram: iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, clodinafope-propargil, [bentazon + imazamox], saflufenacil, bentazon, carfentrazone-ethyl, imazamox, pendimethalin, [sulfentrazone + diuron], mais duas testemunhas uma capinada e outra infestada. Os herbicidas que ocasionaram as maiores injúrias ao trigo foram o imazamox e a mistura comercial de [bentazon + imazamox] com fitotoxicidade próxima a 50%. A aplicação da mistura comercial de [sulfentrazone + diuron] demonstrou a maior produtividade de grãos do trigo. O uso de clodinafope-propargil e pyroxsulam apresentaram os melhores controles de Lolium multiflorum, com100 e 98,25%, aos 21 dias após a aplicação dos tratamentos, respectivamente. Ocorreu controle acimade 90% de Raphanus raphanistrumcom uso de iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, [bentazon + imazamox], saflufenacil, bentazon e carfentrazone. O clodinafope-propargil demonstra o maior controle para o azevém e o iodosulfuron-ethyl, pyroxsulam, metsulfurom-metílico, 2,4-D, saflufenacil e carfentrazone para o nabo. O pyroxsulam foi o tratamento que demonstrou, nos dois experimentos, os melhores resultados para os componentes da produção, especialmente para a produtividade da cultura.(AU)

Agro-economic efficiency dynamics in vegetable cowpea and radish cultivar combinations in strip-intercropping systems / Dinâmica de eficiência agroeconômica em combinações de cultivares de feijão-caupi e rabanete em sistemas consorciados em faixas

This work aimed to evaluate the dynamics of agro-economic efficiency in combinations of vegetable cowpea and radish cultivars in strip-intercropping systems through agronomic, economic and competition indices tested by the Hsu test in a semi-arid environment. The experimental design was a completely randomised block with eight treatments and four replications. The treatments consisted of combinations of four cowpea cultivars, BRS Tumucumaque, BRS Cauamé, BRS Guariba, and BRS Itaim, with two radish cultivars, Crimson Gigante and Zapp. In each block, individual plots of these cultivars in single cultivation were planted as additional treatments to obtain the system indices. The indices of agronomic and economic efficiency and of competition evaluated were land equivalent ratio (LER), actual yield loss (AYL), land use efficiency (LUE%), score of the canonical variable (Z), gross income (GI), net income (NI), rate of return (RR), corrected monetary advantage (CMA), competitive ratio (CR) and the aggressivity of radish over cowpea (Ar) and cowpea over radish (Avc). The cowpea cultivar BRS Tumucumaque, when combined with the radish cultivar Zapp, provided the highest agro-economic efficiency of the intercropped system in a semi-arid environment. The complementarity and sustainability of the intercropping systems of cowpea and radish were observed in the results of the Hsu test applied to the indices of agro-economic efficiency and of competition. Radish was the dominant crop.(AU)

Este trabalho teve como objetivo avaliar a dinâmica de eficiência agroeconômica de combinações de cultivares de caupi-hortaliça e de rabanete em consórcio através de índices agronômicos, econômicos e de competição testados pelo teste de Hsu em ambiente semiárido. O delineamento experimental foi o de blocos casualizados completos, com oito tratamentos e quatro repetições. Os tratamentos consistiram de combinações de quatro cultivares de caupi-hortaliça, BRS Tumucumaque, BRS Cauamé, BRS Guariba e BRS Itaim, com duas cultivares de rabanete, Crimson Gigante e Zapp. Em cada bloco, parcelas individuais dessas cultivares em monocultivo foram plantadas como tratamentos adicionais para obtenção dos índices do sistema. Os índices de eficiência agronômica, econômica e de competição avaliados foram: relação equivalente da terra (RET), perda real de rendimento (PRR), indice de eficiência de uso da terra (EUT), escore da variável canônica (Z), renda bruta (RB), renda líquida (RL), taxa de retorno (TR), vantagem monetária corrigida (VMC), taxa de competição (TC) e o índice de superação do rabanete sobre o caupi-hortaliça (ISr) e do caupi-hortaliça sobre rabanete (ISch). A cultivar de caupi-hortaliça BRS Tumucumaque quando combinada com a cultivar de rabanete Zapp proporcionou a maior eficiência agroeconômica do sistema consorciado em ambiente semiárido. A complementaridade e a sustentabilidade dos sistemas consorciados de caupi e rabanete foram registradas nos resultados do teste de Hsu aplicado aos indices de eficiência agroeconômica e de competição. O rabanete foi à cultura dominante.(AU)

Agro-economic efficiency dynamics in vegetable cowpea and radish cultivar combinations in strip-intercropping systems / Dinâmica de eficiência agroeconômica em combinações de cultivares de feijão-caupi e rabanete em sistemas consorciados em faixas

This work aimed to evaluate the dynamics of agro-economic efficiency in combinations of vegetable cowpea and radish cultivars in strip-intercropping systems through agronomic, economic and competition indices tested by the Hsu test in a semi-arid environment. The experimental design was a completely randomised block with eight treatments and four replications. The treatments consisted of combinations of four cowpea cultivars, BRS Tumucumaque, BRS Cauamé, BRS Guariba, and BRS Itaim, with two radish cultivars, Crimson Gigante and Zapp. In each block, individual plots of these cultivars in single cultivation were planted as additional treatments to obtain the system indices. The indices of agronomic and economic efficiency and of competition evaluated were land equivalent ratio (LER), actual yield loss (AYL), land use efficiency (LUE%), score of the canonical variable (Z), gross income (GI), net income (NI), rate of return (RR), corrected monetary advantage (CMA), competitive ratio (CR) and the aggressivity of radish over cowpea (Ar) and cowpea over radish (Avc). The cowpea cultivar BRS Tumucumaque, when combined with the radish cultivar Zapp, provided the highest agro-economic efficiency of the intercropped system in a semi-arid environment. The complementarity and sustainability of the intercropping systems of cowpea and radish were observed in the results of the Hsu test applied to the indices of agro-economic efficiency and of competition. Radish was the dominant crop.

Este trabalho teve como objetivo avaliar a dinâmica de eficiência agroeconômica de combinações de cultivares de caupi-hortaliça e de rabanete em consórcio através de índices agronômicos, econômicos e de competição testados pelo teste de Hsu em ambiente semiárido. O delineamento experimental foi o de blocos casualizados completos, com oito tratamentos e quatro repetições. Os tratamentos consistiram de combinações de quatro cultivares de caupi-hortaliça, BRS Tumucumaque, BRS Cauamé, BRS Guariba e BRS Itaim, com duas cultivares de rabanete, Crimson Gigante e Zapp. Em cada bloco, parcelas individuais dessas cultivares em monocultivo foram plantadas como tratamentos adicionais para obtenção dos índices do sistema. Os índices de eficiência agronômica, econômica e de competição avaliados foram: relação equivalente da terra (RET), perda real de rendimento (PRR), indice de eficiência de uso da terra (EUT), escore da variável canônica (Z), renda bruta (RB), renda líquida (RL), taxa de retorno (TR), vantagem monetária corrigida (VMC), taxa de competição (TC) e o índice de superação do rabanete sobre o caupi-hortaliça (ISr) e do caupi-hortaliça sobre rabanete (ISch). A cultivar de caupi-hortaliça BRS Tumucumaque quando combinada com a cultivar de rabanete Zapp proporcionou a maior eficiência agroeconômica do sistema consorciado em ambiente semiárido. A complementaridade e a sustentabilidade dos sistemas consorciados de caupi e rabanete foram registradas nos resultados do teste de Hsu aplicado aos indices de eficiência agroeconômica e de competição. O rabanete foi à cultura dominante.

Selectivity and efficacy of herbicides applied to the wheat crop / Seletividade e eficácia de herbicidas aplicados à cultura do trigo

When not controlled efficiently, weeds in wheat crop stands may affect both the grain quality and yield production. This work aimed to assess the selectivity and efficacy of herbicides applied to control weeds in the wheat cultivar TBIO Sinuelo. Two experiments were set upto assess the selectivity and the efficacy of herbicides applied to wheatin randomized blocks designwith four replications. Treatments tested were: iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, clodinafop-propargyl, [bentazon + imazamox], saflufenacil, bentazon, carfentrazone-ethyl, imazamox, pendimethalin, [sulfentrazone + diuron], plus two control treatments, one weeded and the other infested. The greatest damages to wheat were caused by imazamox and the commercial mixture [bentazon + imazamox] with phytotoxicity of approximately 50%. On the other hand, applyingthe commercial mixture [sulfentrazone + diuron] allowed the highest wheat grain yield. The use of clodinafop-propargyl and pyroxsulam promoted the best control of Lolium multiflorum, with 100 and 98.25% at 21 days after treatment application, respectively. The control above 90% of Raphanus raphanistrumwas reported with iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, [bentazon + imazamox], saflufenacil, bentazon, and carfentrazone. Clodinafop-propargyl was the most efficient on ryegrass, and iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, saflufenacil, and carfentrazone performed best on the turnip. Pyroxsulam was the treatment that showed, in both experiments, the best results for all-grain yield components, especially for grain yield.

As plantas daninhas ocasionam efeitos negativos na produtividade e na qualidade dos grãos da cultura do trigo quando não controladas de modo eficiente. Assim sendo, objetivou-se com os trabalhos avaliar a seletividadee a eficácia deherbicidas aplicados para o manejo de plantas daninhas infestante da cultivar de trigo TBIO Sinuelo. Foram instalados dois experimentos, um para avaliar a seletividade e outro a eficácia de herbicidas aplicados em trigo, em blocos casualizados, com quatrorepetições. Os tratamentos testados foram: iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, clodinafope-propargil, [bentazon + imazamox], saflufenacil, bentazon, carfentrazone-ethyl, imazamox, pendimethalin, [sulfentrazone + diuron], mais duas testemunhas uma capinada e outra infestada. Os herbicidas que ocasionaram as maiores injúrias ao trigo foram o imazamox e a mistura comercial de [bentazon + imazamox] com fitotoxicidade próxima a 50%. A aplicação da mistura comercial de [sulfentrazone + diuron] demonstrou a maior produtividade de grãos do trigo. O uso de clodinafope-propargil e pyroxsulam apresentaram os melhores controles de Lolium multiflorum, com100 e 98,25%, aos 21 dias após a aplicação dos tratamentos, respectivamente. Ocorreu controle acimade 90% de Raphanus raphanistrumcom uso de iodosulfuron, pyroxsulam, metsulfuron-methyl, 2,4-D, [bentazon + imazamox], saflufenacil, bentazon e carfentrazone. O clodinafope-propargil demonstra o maior controle para o azevém e o iodosulfuron-ethyl, pyroxsulam, metsulfurom-metílico, 2,4-D, saflufenacil e carfentrazone para o nabo. O pyroxsulam foi o tratamento que demonstrou, nos dois experimentos, os melhores resultados para os componentes da produção, especialmente para a produtividade da cultura.

Physiological role of silicon in radish seedlings under ammonium toxicity.

BACKGROUND: High concentrations of ammonium as the sole nitrogen source may result in physiological and nutritional disorders that can lead to reduced plant growth and toxicity. In this study, we hypothesized that ammonium toxicity in radish seedlings (Raphanus sativus L.) might be mitigated by the incorporation of silicon (Si) into applied nutrient solution. To examine this possibility, we conducted a hydroponic experiment to evaluate the effects of five concentrations of ammonium (1, 7.5, 15, 22.5, and 30 mmol L-1 ) on the photosynthesis, green color index, stomatal conductance, transpiration, instantaneous water-use efficiency, and biomass production of radish in the absence and presence (2 mmol L-1 ) of Si. The experimental design was a randomized block design based on a 2 × 5 factorial scheme with four replicates. RESULTS: The highest concentration of applied ammonium (30 mmol L-1 ) was found to reduce the photosynthesis, transpiration and total dry biomass of radish seedlings, independent of the presence of Si in the nutrient solution. However, at lower ammonium concentrations, the application of Si counteracted these detrimental effects, and facilitated the production of seedlings with increased photosynthesis, greater instantaneous water-use efficiency, and higher total dry biomass compared with the untreated plants (without Si). Transpiration and stomatal conductance were affected to lesser extents by the presence of Si. CONCLUSION: These findings indicate that the addition of Si to nutrient solutions could provide an effective means of alleviating the unfavorable effects induced by ammonium toxicity at concentrations of less than 30 mmol L-1 . © 2020 Society of Chemical Industry.

Phytostimulant properties of highly stable silver nanoparticles obtained with saponin extract from Chenopodium quinoa.

BACKGROUND: Quinoa (Chenopodium quinoa Willd) is an Andean original pseudocereal with high nutritional value. During quinoa processing, large amounts of saponin-rich husks byproducts are obtained. Quinoa saponins, which are biologically active, could be used for various agriculture purposes. Silver nanoparticles have increasingly attracted attention for the management of crop diseases in agriculture. In this work, silver nanoparticles are synthesized by a sustainable and green method, using quinoa husk saponin extract (QE) to evaluate their potential for application in agriculture as biostimulants. RESULTS: Quinoa extract was obtained and characterized by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Sixteen saponin congeners were successfully identified and quantified. The QE obtained was used as a reducing agent for silver ions to synthesize silver nanoparticles (QEAgNPs) under mild conditions. The morphology, particle size, and stability of Ag nanoparticles were investigated by transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-visible), energy-dispersive X-ray (EDS), zeta potential, and Fourier transform infrared spectroscopy with attenuated total reflection (FTIR-ATR). Ultraviolet-visible spectroscopy measurements confirmed the formation of silver nanoparticles in the presence of QE, with estimated particle sizes in a range between 5 and 50 nm. According to the zeta potential values, highly stable nanoparticles were formed. The QE and QEAgNPs (200-1000 µg/mL) were also tested in radish seed bioassay to evaluate their phytotoxicity. The seed germination assays revealed that QEAgNPs possessed a phytostimulant effect on radish seeds in a dose-dependent manner, and no phytotoxicity was observed for both QE and QEAgNPs. CONCLUSION: Silver nanoparticles obtained by a so-called 'green' method could be considered as good candidates for application in the agricultural sector for seed treatment, or as foliar sprays and plant-growth-promoters. © 2020 Society of Chemical Industry.

Phytotoxicity of secondary metabolites isolated from Flourensia oolepis S.F.Blake.

The aim of this study was to isolate the active principles of Flourensia oolepis S.F.Blake (Asteraceae), which completely inhibited the germination of Raphanus sativus seeds at 10 mg/ml. Flavanone pinocembrin and sesquiterpene ilicol, were isolated by bioassay-guided fractionation. They were active both against monocot and dicot seeds. Pinocembrin was the most active compound, with an IC50 (germination) value of 0.24, 3.40, 3.28, and 3.55 mM against Panicum miliaceum, Avena sativa, Lactuca sativa, and R. sativus, respectively; ilicol, however, exhibited IC50 (germination) values of 0.67, 2.73, 5.25, and 9.66 mM for the same species, respectively. Pinocembrin and ilicol inhibited root growth and showed IC50 (root growth) values of 0.199, 14.68, 8.05, 7.69 mM, and 1.22, 2.90, 7.35, 8.07 mM, against P. miliaceum, A. sativa, L. sativa, and R. sativus, respectively. Pinocembrin and ilicol reduced Allium cepa cell division without chromosome aberrations.

N,O6-partially acetylated chitosan nanoparticles hydrophobically-modified for controlled release of steroids and vitamin E.

Diosgenin, two synthetic analogs of brassinosteroids, testosterone and dl-α-tocopherol were covalently linked to synthetic water-soluble N,O6-partially acetylated chitosan, for their controlled release. Drug linking was confirmed by FTIR spectroscopy and proton NMR. Conjugates were also characterized by differential scanning calorimetry and wide-angle X-ray diffraction. These conjugates formed self-assembled nanoparticles in aqueous solution with particle sizes ranging from 197 to 358 nm and drug contents between 11.8 and 56.4% (w/w). Spherical 30-60 nm nanoparticles were observed by scanning electron microscopy and transmission electron microscopy upon drying. In vitro release studies performed at acid pH indicated a drug release dependence on substitution degree and particle sizes. Almost constant release rates were observed during the first 6-8h. Brassinosteroids-modified nanoparticles showed good agrochemical activity in radish seeds bioassay at 10(-1) to 10(-4) mg mL(-1). Tocopheryl-modified nanoparticles exhibited radical scavenging activity in DPPH test.

Efeito alelopático de Salix spp. sobre a germinação de sementes e desenvolvimento de plântulas de Raphanus sativus L / Allelopathic effect of Salix spp. on seeds germination and seedling delvelopment of Raphanus sativus L

O objetivo do trabalho foi o de avaliar o efeito alelopático de folhas verdes e cascas frescas trituradas de três espécies de vimeiro sobre a germinação de sementes e desenvolvimento de plântulas de rabanete (Raphanus sativus L.). O experimento foi conduzido no Laboratório de Sementes da Universidade do Estado de Santa Catarina - UDESC, Centro de Ciências Agroveterinárias - CAV no ano de 2009. O delineamento foi inteiramente casualizado com quatro repetições. Os tratamentos foram constituídos por pedaços de folhas verdes e cascas frescas de Salix x rubens, Salix viminalis e Salix smithiana, distribuídas separadamente sobre sementes de rabanete em caixas de Gerbox. A testemunha foi constituída por sementes de rabanete e água destilada. As caixas com os respectivos tratamentos foram transferidas para câmara de germinação 25ºC e UR 70%. Em intervalos de 24 horas, a partir do segundo dia após o início do experimento até o décimo dia foram avaliados o número de sementes germinadas, a velocidade de germinação, o comprimento e a massa fresca e seca de radículas. Os dados foram submetidos à análise de variância, teste de comparação de médias e análise de contrastes lineares. Das variáveis analisadas, o comprimento de radícula foi o único que diferiu estatisticamente entre os tratamentos. A análise de contraste entre os tratamentos folhas verdes e cascas frescas de S. viminalis e S. smithiana mostrou signifi cância estatística no comprimento de radícula e massa fresca de raízes, mostrando efeito alelopático negativo sobre o crescimento e desenvolvimento de raízes de rabanete. Folhas verdes e cascas frescas de Salix rubens, S. smithiana e S. viminalis não exercem efeito alelopático negativo sobre a massa fresca, massa seca, percentual de germinação e velocidade de germinação em rabanete. As cascas de S. rubens podem reduzir o crescimento de radículas de rabanete enquanto que folhas de S. viminalis podem estimular o crescimento das radículas.

The objective of this study was to evaluate the allelopathic effect of green fresh leaves and crushed fresh barks of three willow species on the seed germination and seed development of radish (Raphanus sativus). The experiment was conducted at the Seed Laboratory of the State University of Santa Catarina - UDESC, Centro de Ciências Agroveterinárias - CAV in 2009. Bioassays were carried out in a complete randomized design with four replications. The treatments consisted of pieces of green fresh leaves and bark of Salix x rubens, Salix viminalis and Salix Smithiana, separately distributed on radish seeds in Gerbox boxes. The control treatment consisted of radish seeds and distilled water. The boxes containing the treatments were transferred into a germinator chamber maintained at constant temperature (25°C) and Relative Humidity (70%). At 24-hour intervals, from the second day after the bioassay start, until the tenth day the number of germinated seeds, speed of germination, length, fresh and dry mass of rootlets were evaluated. Data was subjected to variance analysis, mean comparison and analysis of linear contrasts. The radicle length was the only parameter which differed between the treatments. The contrast analyses between the treatments with green leaves and fresh barks of S. viminalis and S. smithiana showed statistical signifi cance in the radicle length and the roots fresh weight, showing negative allelopathic effects on the growth and development of radish roots. Green leaves and fresh bark of Salix rubens, S. Smithiana and S. viminalis do not present a negative allelopathic effects on fresh mass, dry mass, germination percentage and speed of germination in radish. The S. rubens fresh bark can reduce the growth of radish radicle whereas the fresh S. viminalis leaves can stimulate the radicle growth.

Efeito alelopático de Salix spp. sobre a germinação de sementes e desenvolvimento de plântulas de Raphanus sativus L / Allelopathic effect of Salix spp. on seeds germination and seedling delvelopment of Raphanus sativus L.

O objetivo do trabalho foi o de avaliar o efeito alelopático de folhas verdes e cascas frescas trituradas de três espécies de vimeiro sobre a germinação de sementes e desenvolvimento de plântulas de rabanete (Raphanus sativus L.). O experimento foi conduzido no Laboratório de Sementes da Universidade do Estado de Santa Catarina - UDESC, Centro de Ciências Agroveterinárias - CAV no ano de 2009. O delineamento foi inteiramente casualizado com quatro repetições. Os tratamentos foram constituídos por pedaços de folhas verdes e cascas frescas de Salix x rubens, Salix viminalis e Salix smithiana, distribuídas separadamente sobre sementes de rabanete em caixas de Gerbox. A testemunha foi constituída por sementes de rabanete e água destilada. As caixas com os respectivos tratamentos foram transferidas para câmara de germinação 25ºC e UR 70%. Em intervalos de 24 horas, a partir do segundo dia após o início do experimento até o décimo dia foram avaliados o número de sementes germinadas, a velocidade de germinação, o comprimento e a massa fresca e seca de radículas. Os dados foram submetidos à análise de variância, teste de comparação de médias e análise de contrastes lineares. Das variáveis analisadas, o comprimento de radícula foi o único que diferiu estatisticamente entre os tratamentos. A análise de contraste entre os tratamentos folhas verdes e cascas frescas de S. viminalis e S. smithiana mostrou signifi cância estatística no comprimento de radícula e massa fresca de raízes, mostrando efeito alelopático negativo sobre o crescimento e desenvolvimento de raízes de rabanete. Folhas verdes e cascas frescas de Salix rubens, S. smithiana e S. viminalis não exercem efeito alelopático negativo sobre a massa fresca, massa seca, percentual de germinação e velocidade de germinação em rabanete. As cascas de S. rubens podem reduzir o crescimento de radículas de rabanete enquanto que folhas de S. viminalis podem estimular o crescimento das radículas.(AU)

The objective of this study was to evaluate the allelopathic effect of green fresh leaves and crushed fresh barks of three willow species on the seed germination and seed development of radish (Raphanus sativus). The experiment was conducted at the Seed Laboratory of the State University of Santa Catarina - UDESC, Centro de Ciências Agroveterinárias - CAV in 2009. Bioassays were carried out in a complete randomized design with four replications. The treatments consisted of pieces of green fresh leaves and bark of Salix x rubens, Salix viminalis and Salix Smithiana, separately distributed on radish seeds in Gerbox boxes. The control treatment consisted of radish seeds and distilled water. The boxes containing the treatments were transferred into a germinator chamber maintained at constant temperature (25°C) and Relative Humidity (70%). At 24-hour intervals, from the second day after the bioassay start, until the tenth day the number of germinated seeds, speed of germination, length, fresh and dry mass of rootlets were evaluated. Data was subjected to variance analysis, mean comparison and analysis of linear contrasts. The radicle length was the only parameter which differed between the treatments. The contrast analyses between the treatments with green leaves and fresh barks of S. viminalis and S. smithiana showed statistical signifi cance in the radicle length and the roots fresh weight, showing negative allelopathic effects on the growth and development of radish roots. Green leaves and fresh bark of Salix rubens, S. Smithiana and S. viminalis do not present a negative allelopathic effects on fresh mass, dry mass, germination percentage and speed of germination in radish. The S. rubens fresh bark can reduce the growth of radish radicle whereas the fresh S. viminalis leaves can stimulate the radicle growth.(AU)

Efeito alelopático de folhas de bamburral [Hyptis suaveolens (L. ) Poit] sobre a germinação de sementes de sorgo (Sorghum vulgare Pers. ), rabanete (Raphanus sativus L. ) e alface (Lactuca sativa L. ) / Allelopathic effects of leaves of "bamburral" [Hyptis suaveolens (L. ) Poit] on the germination of seeds of sorghum (Sorghum vulgare Pers. ), radish (Raphanus sativus L. ) and lettuce (Lactuca sativa L. )

O objetivo do presente trabalho foi à verificação do efeito alelopático de Hyptis. suaveolens na germinação de sorgo, alface e rabanete, bem como, a comprovação da existência de compostos com potencial alelopático. Sementes de sorgo, alface e rabanete foram semeadas em substrato constituído de areia, terra e adubo orgânico contendo folhas de H. suaveolens. As análises da germinação foram feitas considerando a protrusão da radícula para o término do evento germinativo. Foi calculado o IVG (índice de velocidade de germinação) e %G (porcentagem de germinação). Os resultados mostraram que sorgo e a alface foram mais susceptíveis ao potencial alelopático de H. suaveolens, sendo que para o rabanete foi observado um efeito benéfico. Entre os tratamentos, o substrato esterilizado e não esterilizado mostraram diferenças entre si. A análise cromatográfica do óleo essencial presente nas folhas de H. suaveolens revelou a presença de compostos com potencial alelopático. Portanto, H. suaveolens, pode apresentar efeito alelopático positivo no IVG de sementes de rabanete e a presença de microorganismos pode ser necessária para que esse efeito alelopático aconteça.

The aim of this study was to verify the allelopathic effect of H. suaveolens on the germination of sorghum, lettuce and radish, as well as to prove the existence of compounds with allelopathic potential. Seeds of sorghum, lettuce and radish were sown in substrate consisting of sand, soil and organic fertilizer containing leaves of H. suaveolens. The germination tests were performed considering the protrusion of the radicle for the conclusion of the germinative event. GSI (germination speed index) and G% (percentage of germination) were calculated. The results showed that sorghum and lettuce were more susceptible to the allelopathic potential of H. suaveolens, while for radishes a beneficial effect was observed. Between treatments, the sterilized and unsterilized substrate showed differences. The chromatographic analysis of essential oil present in the leaves of H. suaveolens revealed the presence of compounds with allelopathic potential. Therefore, H. suaveolens may have positive allelopathic effect on the GSI of radish seeds, and the presence of microorganisms may be necessary for such an allelopathic effect to occur.

Phytotoxic activities of Mediterranean essential oils.

Twelve essential oils from Mediterranean aromatic plants were tested for their phytotoxic activity, at different doses, against the germination and the initial radicle growth of seeds of Raphanus sativus, Lactuca sativa and Lepidium sativum. The essential oils were obtained from Hyssopus officinalis, Lavandula angustifolia, Majorana hortensis, Melissa officinalis, Ocimum basilicum, Origanum vulgare, Salvia officinalis and Thymus vulgaris (Lamiaceae), Verbena officinalis (Verbenaceae), Pimpinella anisum, Foeniculum vulgare and Carum carvi (Apiaceae). The germination and radicle growth of tested seeds were affected in different ways by the oils. Thyme, balm, vervain and caraway essential oils were more active against both germination and radicle elongation.

La inoculación de plantas con Pantoea sp., bacteria solubilizadora de fosfatos, incrementa la concentracion de P en los tejidos foliares / Plant inoculation with Pantoea sp., phosphate solubilising-bacteria increases P concentration in leaf tissues

El fósforo (P) es un macronutriente mineral esencial para las plantas. Aunque puede encontrarse en los suelos en diferentes formas minerales, la baja solubilidad de estos disminuye su disponibilidad para las plantas, y el nutriente debe aplicarse como fertilizante a los cultivos. Las reservas mundiales de P son limitadas y tendrán una reducción considerable en los próximos años. Usar microorganismos solubilizadores de fosfatos como inoculante para los cultivos es una alternativa biotecnologica para incrementar la disponibilidad del nutriente. Pantoea sp. (cepa 9C) es una bacteria endofitica fijadora de nitrogeno, aislada del interior de tallos de la caña de azucar (Loiret et al., 2004); este microorganismo produjo halos de solubilizacion con tamaños de hasta 6 mm en medio sólido NBRI-P en 7 dias a 30 grados centigrados, y en ese tiempo y condiciones solubilizo Ca3(PO4)2 en el medio líquido hasta acumular 1128 μg P mL-1. La bacteria sobrevivio durante 35 días en un sustrato preparado con mezcla de Vermiculita y suelo ferralítico rojo (Cambisol Ferrálico, ródico), alcanzando poblaciones de 3,2 x 1015 células g-1. Plantas de rábano (Raphanus sativus, L. var. Scarlet Globe), de alta demanda de P y crecimiento rápido, usadas como modelo y cultivadas en suelos inoculados con el microorganismo, absorbieron mas P que las plantas no inoculadas, alcanzando en los tejidos foliares concentraciones ≥ 3500 ppm P base seca.

Nutrient status and plant growth effects of forest soils in the Basin of Mexico.

The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols.