Scientia Agropecuaria

Potencial fisiológico de sementes de milho híbrido tratadas com inseticidas e armazenadas em duas condições de ambiente

O tratamento de sementes é uma prática largamente difundida nas áreas agrícolas brasileiras, a qual, associada às demais práticas culturais, tem contribuído para o incremento na produtividade, redução de custos, melhoria da qualidade do produto final, redução de danos ao ambiente e oferta uma boa proteção às sementes, tanto em nível de campo quanto no armazenamento. O trabalho teve como objetivo verificar o efeito do tratamento inseticida sobre a germinação e o vigor das sementes de milho híbrido, armazenadas em duas condições de ambiente. As sementes foram tratadas com três inseticidas, identificados como: Inseticida 1 (Thiametoxan); Inseticida 2 (Neonicotinóide) e Inseticida 3 [Neonicotinóide+(Imidaclopride+Thiodicarbe)]. Após tratadas as sementes foram armazenadas por um período de 270 dias, em dois ambientes, sendo um com controle de temperatura (10ºC) e umidade relativa (60%) e outro em condições normais de armazenamento. Durante este período realizou-se avaliações a cada 45 dias, através dos testes de germinação e vigor. Além dos testes de germinação e teste de frio foi realizada a emergência de plântulas após as sementes permanecerem armazenadas por um período de 30 dias em ambientes sem controle e com controle das condições do ar. Os resultados obtidos permitem concluir que a qualidade das sementes armazenadas de milho híbrido, tratadas com inseticidas é influenciada pelo produto químico empregado no tratamento das mesmas, dependente do híbrido e das condições do ambiente de armazenamento e que a redução na viabilidade e no vigor de sementes tratadas com thiametoxan, intensifica-se com o prolongamento do período de armazenamento.

Seed treatment is a widely disseminated practice in Brazilian cultural areas, which linked to other cultural practices, has contributed to the increase in productivity, cost reduction, final product improvement, environmental damage reduction as well as good seed protection in the field level and storage. The work had the objective to check the insecticide effect on the germination and vigor of the hybrid maize seeds, stored in two environmental conditions. The seeds were treated with three insecticides, identified as: Insecticide one (Thiametoxan); Insecticide two (Neonicotinoide) and Insecticide three [Neonicotinoide + (Imidaclopride+thiodicarbe)]. After being treated, the seeds were stored for a period of 270 days, in two different places, one with (10ºC) temperature and relative humidity (60%) and another under normal condition of storage. During this period evaluations were accomplished every 45 days, through germination and vigor tests. In addition to germination and cooling tests, sanitation analysis, seedling emergency and seed inoculation were carried out. After that the seeds were stored for a period of 30 days in environmental places with and without control of air condition. The results obtained allow to conclude that the maintenance of seed quality of hybrid maize, treated with insecticides, depends on the hybrid and chemical product used in their treatment and that the reduction in feasibility and vigor of seeds treated with thiametoxan is intensified due to the storage period extension.

Maize responds to Azotobacter sp and Burkholderia sp inoculation at reduced dose of nitrogen fertilizer

La respuesta positiva del maíz a la inoculación con bacterias promotoras de crecimiento vegetal (BPCV) como los géneros bacterianos: Azotobacter sp. y Burkholderia sp. endofita es una alternativa para la reducción y optimización de la dosis del fertilizante nitrogenado (FN) como el nitrato de amonio (NH4NO3), recomendado para esta gramínea, sin afectar negativamente su crecimiento. El objetivo de este trabajo fue analizar la respuesta del maíz a la inoculación con Azotobacter sp. y Burkholderia sp. a la dosis 50% del FN. El experimento se realizó bajo un diseño experimental de bloques al azar, mediante las variables respuesta para analizar el efecto de BPCV en el maíz: porcentaje de germinación (%); la fenotípia aérea y radical; y la biomasa: peso fresco aéreo (PFA) y radical (PFR); el peso seco aéreo (PSA) y radical (PSR). Los resultados indicaron un efecto positivo de ambos géneros de BPCV en el maíz desde su germinación, a nivel de plántula y en floración. En el maíz coinoculado se registró un PSR de 7,03 g, valor estadísticamente significativo comparado con los 2,60 g de PSR del maíz sin inocular, alimentado con la dosis de FN recomendado, empleado como control relativo. Lo anterior sugiere una interacción sinérgica de Azotobacter sp. y Burkhoderia sp. en la síntesis de sustancias promotoras de crecimiento vegetal (SPCV) en maíz para optimizar la dosis reducida del FN y permitir su sano crecimiento.

The positive maize response to inoculation with plant growth promoting bacteria (PGPB) as Azotobacter sp and Burkholderia sp an endophytic type, are an alternative to reduced and optimize nitrogen fertilizer (NF) dose, recommended for this plant, without adversely affect its growth. The aim of this study was to analyze maize respond to inoculation with Azotobacter sp and Burkholderia sp at the dose 50% of FN. Used an experimental design of randomized blocks. By response variables: percent germination (%), the shoot and root phenology: plant height (PH), root length (RL) and biomass: shoot fresh weight (SFW) and root fresh weight (RFW), the shoot dry weight (SDW) and root dry weight (RDW). The results indicated a positive maize respond to PGPB inoculation at germination, seedling and flowering level, reached a RDW of 7.03 g, statistically significant value compared with 2.60 g of RDW non inoculated maize feed with NF dose recommended regard as relative control (RC). This suggests a synergistic interaction among these PGPB in synthesis of plant growth promoting substances (PGPS) on maize, to optimize the reduced NF dose.

An efficient method for in vitro callus induction in Myrciaria dubia (Kunth) Mc Vaugh "Camu Camu"

Debido a la alta variabilidad en la producción de vitamina C en Myrciaria dubia "camu camu", es necesario establecer procedimientos biotecnológicos para la propagación clonal masiva de genotipos promisorios de esta especie. El objetivo fue establecer un método eficiente para inducir la formación de callos in vitro a partir de explantes de M. dubia. Los explantes de hojas y nudos se obtuvieron de ramas cultivadas en el laboratorio y la pulpa a partir de frutos colectados en el campo. Estos fueron desinfectados y sembrados en medio Murashige-Skoog (1962) suplementado con ácido 2,4-diclorofenoxiacético (2,4-D), bencilaminopurina (BAP) y kinetina (Kin). Los cultivos fueron mantenidos a 25±2°C, en oscuridad por 2 semanas y posteriormente con un fotoperiodo de 16 horas luz y 8 horas de oscuridad por 6 semanas. El tratamiento con 2 mg/L de 2,4-D y 0,1 mg/L de BAP estimuló mayor callogénesis en los tres tipos de explantes. Los callos se generaron a partir de la primera semana (nudos), cuarta semana (hojas) y sexta semana (pulpa) y estos fueron friables (hojas y nudos) y no friables (pulpa). En conclusión, el método descrito es eficiente para inducir callos in vitro en hojas, nudos y pulpa de M. dubia, siendo los explantes de hojas y nudos los más idóneos para la obtención de callos.

Due to the high variability in vitamin C production in Myrciaria dubia "camu camu", biotechnological procedures are necessary for mass clonal propagation of promising genotypes of this species. The aim was to establish an efficient method for in vitro callus induction from explants of M. dubia. Leaf and knot sex plants were obtained from branches grown in the laboratory and from fruit pulp collected in the field. These were desinfected and sown on Murashige-Skoog (1962) medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), benzylaminopurine (BAP) and kinetin(Kin). The cultures were maintained at 25±2°C in darkness for 2 weeks and subsequently with a photoperiod of 16 hours in light and 8 hours in dark for 6 weeks. Treatment with 2 mg/L 2,4-D and 0.1 mg/L BAP allowed major callus formation in the three types of explants. Calluswere generated from the first week (knots), fourth week (leaves) and sixth week (pulp) and these were friable (leaves and nodes) and non-friable (pulp). In conclusion, the described method is efficient for in vitro callus induction in leaves, knots and pulp of M. dubia, been leaves and knots explants more suitable for callus obtention.

The anti-senescence effect of resveratrol reduces postharvest softening rate in cherimoya fruit

El fruto de chirimoya (Annona cherimola Mill.) es muy susceptible al deterioro poscosecha debido a su naturaleza climatérica. Con el fin de observar el efecto antisenescente del resveratrol (RVS), éste bioregulador vegetal se aplicó en frutos de Fino de Jete y Bronceada a 1,6; 0,16; 0,016 y 0 mM a los 0, 8 y 15 días antes de la cosecha (DAC). A los 1, 7 y 15 días después de la cosecha (DDC) se analizaron variables bioquímicas y biofísicas. Al termino de 15 días de almacenamiento a temperatura ambiente, en relación al control, 1,6 mM RVS, aplicado 15 DAC, disminuyó el ablandamiento del fruto 78% para chirimoya Fino de Jete y 54% para Bronceada. A los 15 DDC se realizó la evaluación sensorial a frutos tratados 8 y 15 DAC, los resultados mostraron que los frutos de mayor aceptación fueron los tratados con 1,6 mM RVS ya sea a los 8 y 15 DAC, al ser calificados como de mejor aspecto, aroma y sabor.

Due to its climateric behavior, the cherimoya fruit (Annona cherimola Mill.) is a very perishable commodity. Present research aimed to observe the anti-senescence effect of resveratrol (RVS); this plant bioregulator was applied at 1.6, 0.16, 0.016 and 0 mM at 0, 8 and 15 days before harvest (DBH). At 1, 7 and 15 days of postharvest life, several physical and biochemical determinations were performed on the cherimoya fruit. After 15 days under room temperature conditions, in relation to control fruit, those fruit with 1.6 mM RVS applied 15 DBH reduced skin softening rate 78% and 54% for Fino de Jete and Bronceada, respectively. Similarly, after 15 days of storage, a non-trained group of tasters preferred those fruit treated with 1.6 mM RVS 15 DBH; they qualified the fruit as better than the control fruit in presentation, aroma and taste.

Obtaining a filter irish lace marigold (Tagetes filifolia Lag.) sweetened with stevia leaves (Stevia rebaudiana Bertoni)

El presente trabajo de investigación se realizó para determinar el segmento de la planta de anís de monte y formulación apropiada de anís de monte y hojas de estevia en la elaboración de un filtrante edulcorado; para lo cual se emplearon plantas de anís de monte y hojas de estevia, las cuales fueron lavadas, desinfectadas, secadas a 65°C, molidas, tamizadas y envasadas; posteriormente se realizaron las formulaciones del filtrante con anís de monte y hojas de estevia (90:10; 85:15; 80:20 y 75:25), empleando un gramo por muestra envasadas en papel termosellable; los resultados del color, tiempo de infusión y pH; asimismo, las evaluaciones organolépticas de olor, sabor, dulzor y aspecto general se procesaron empleando el paquete estadístico SAS (Statistical Analysis System) for Window V8. Los resultados mostraron que empleando 80 a 85% hojas + flores de anís de monte y 15 a 20% de hojas de estevia se obtiene un filtrante edulcorado con adecuadas características organolépticas.

The present investigation was conducted to determine the segment of the irish lace marigold and appropriate formulation of irish lace marigold and leaves of stevia in the development of a filter sweetened, for which plants were used irish lace marigold and leaves stevia, which were washed, disinfected, dried at 65 °C, ground, sieved and packed; later formulations were made with irish lace marigold and stevia leaves (90:10, 85:15, 80:20 and 75:25), using a gram per sample packed in sealable paper, the results of the color, infusion time and pH, also the organoleptic evaluations smell, taste, sweetness and overall appearance were processed using the SAS statistical package (Statistical Analysis System ) for Window V8. The results showed that using 80 to 85 % leaves + flowers irish lace marigold and 15 to 20% stevia leaf with a sweetened organoleptically suitable filter is obtained.

Porcentagem de sacarose aparente e potencial produtivo de açúcar em cultivares de cana

A porcentagem de sacarose aparente POL consiste em importante variável para a determinação da produção açucareira, sendo que o seu valor é distinto em diferentes cultivares, partes da planta e épocas de crescimento. O trabalho teve como objetivo comparar os valores da POL e estimar o potencial produtivo de açúcar do caldo extraído de nós e entrenós de cultivares de cana-de-açúcar ao longo do ano agrícola 2010/2011. Utilizou-se o delineamento experimental de blocos ao acaso, em esquema fatorial 3x2x6, com quatro repetições. Os tratamentos principais foram os cultivares de cana-de-açúcar, os tratamentos secundários as duas partes do colmo de cana e o terceiro as épocas de análises distribuídas ao longo da safra. Os cultivares SP81-3250 e RB72454 apresentaram os maiores valores de POL. De modo contrário, o RB867515 obteve resultados menos satisfatórios, apresentando menor valor da POL durante todo o período estudado, e nas duas partes do colmo. O entrenó obteve maior POL, e apresentou maior potencial de produção de açúcar quando comparado à parte do colmo representada pelo nó. Os valores de POL e o potencial produtivo de açúcar, obtidos por ambas as partes do colmo, foram crescentes ao longo da safra, e coincidiram com a época de colheita recomendada para estes cultivares. Entretanto, foi neste período que ocorreu a maior diferença entre as partes do colmo, indicando a necessidade de um melhor aproveitamento do entrenó.

The percentage of saccharose apparent "POL" is an important variable for the determination of sugar production, and its value differs among the cultivars, plant parts and growth seasons. The study aimed to compare values of POL and estimate productive potential of sugar in juice extracted from nodes and internodes of the sugarcane cultivars sugar during the 2010/2011 crop season. We used the experimental design of randomized blocks in factorial scheme 3x2x6, with four replications. The main treatments were cultivars of sugarcane, the secondary treatments two parts of the stalks of sugarcane, and third the seasons of analysis distributed over the harvest. The cultivars RB72454 and SP81-3250 showed the highest values POL. Conversely, the RB867515 obtained less satisfactory results, showing lower value of POL throughout the study period, and the two parts of the stalk. The internode was greater than POL, and showed greater potential for sugar production when compared to the stalk portion represented by the node. The values of POL and the productive potential of sugar, obtained by both sides of the stalk were growing throughout the season, and coincided with the harvest season recommended for these cultivars. However, there was this period that the biggest difference between the parts of the stalk, indicating the need for a better use of the internode

Estimation of repeatability and genetic selection of aromatic cacao trees with genetic material from EE-INIA-San Martin and UC Lebuaf in Peru

El cultivo de cacao, es una de las actividades más importantes en la Amazonía Peruana. Su base genética está sustentada en la introducción de clones mejorados, por lo que el potencial genético local que están en los bancos de germoplasma no está siendo bien utilizados debido al limitado estudio en mejoramiento genético. Este trabajo tuvo por objetivo estimar la repetibilidad para la selección genética de árboles con alto rendimiento de granos de cacao aromático. El análisis de selección genética fue ejecutado con el software SELEGEN REML/BLUP, en una data de 3 años de evaluación de rendimiento de granos kg/árbol, peso promedio de granos (g) y peso promedio de mazorcas (kg) en el banco de Germoplasma de INIA-San Martin y Unidad de Conservación de Lebuaf SAC. La repetibilidad individual para rendimiento de granos/árbol y peso promedio de granos fue moderada con (0,52) y (0,30) respectivamente, lo que no ocurrió con el peso promedio de la mazorca que fue baja con (0,24). La variable con mayor estabilidad fue el rendimiento de granos/árbol, quien arrojo en 3 cosechas 0,77, propiciando una exactitud selectiva de 0,88. Genotipos superiores pueden ser seleccionados con precisión con 4 a 5 cosechas. La selección y clonación de los 20 mejores genotipos o árboles selectos deberán propiciar una ganancia genética de 112%, elevando la productividad media anual de granos por árbol de 1,24 kg/árbol a 1,54kg/árbol.

Cocoa farming is one of the most important activities in the Peruvian Amazon. Its genetic basis is supported by the introduction of improved clones, so that the local genetic potential are in germplasm bank is not well used due to limited breeding study. This study aimed to estimate the repeatability for the genetic selection of high-yield trees with aromatic cocoa beans. Genetic selection analysis was executed with the SOFTWARE SELEGEN REML / BLUP in a 3-year data for assessing grain yield kg / tree, average grain weight (g) and average weight of cobs (kg) in the bank germplasm INIA-San Martin and Lebuaf Conservation Unit SAC (Plantation Maria). The individual repeatability grain yield / tree and average grain weight was moderate (0.52) and (0.30) respectively, which did not happen for the repeatability of the variable average cob weight was low with (0.24). The variable was more stable grain yield / tree, who threw an average of 3 harvest repeatability was 0.77, favoring selective accuracy of 0.88. Superior genotypes can be accurately selected with 4 to 5 harvests. The selection and cloning of the 20 best genotypes or selected trees should facilitate a genetic gain of 112%, raising the annual average productivity of 1.24 grains per tree kg / tree to 1.54 kg / tree.