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Abstract Background: Weeds are unwanted and undesirable plants which deteriorate the quality of agricultural products and interfere with farming activities. Most of the weeds (indigenous and invasive) seeds get preserved in soil horizons as weed seed bank which ensure their survival leading to the spoilage of quantitative and qualitative functioning of agricultural farms. Objective: To keep weeds below threshold level, elimination of weeds seed before germination can be a viable and pro-ecological approach. To achieve this objective, weed seeds reserved in the soil which serve as an effective pool to ensure their survival necessitate weed-seed bank management. Thus the ultimate goal was to synthesize and analyze research findings on weed seed bank management leading to formulating the most effective strategy encompassing viable control of weeds in maize. Methods: This study reviewed and analyzed the characteristics which impart botanical superiority to weeds and impact of all prevalent weed control strategies on weed seed bank, weeds density and maize yield. The research findings pertaining to different agronomic practices and technological packages were critically analyzed to sort out the most effective and eco-friendly approach to control weed-seed bank and weeds density in maize crop. Results: The synthesis and critical evaluation of research findings pertaining to weed control methods revealed that manual and mechanical methods were eco-friendly but involved expensive labor, while the chemical approach involving the use of herbicides led to serious deterioration of agro-environmental resources. Two or more techniques used in coherence which encompassed deep tillage to burry weeds seed and prevented their germination through mulches of biotic and synthetic materials along with optimizing sowing method especially raised bed technique reduced weed seed bank and weeds density in maize. Conclusions: It is inferred that integrated approach entailing cultural, manual, mechanical and chemical control can be developed as a pro-environmental and farmer friendly approach for weed control by reducing weed seed reserves which can potentially lead to higher economic returns through higher maize yield.

Mixed micellization and surface properties of cationic and nonionic surfactants dimethyl decyl-, tetradecyl- and hexadecyl phosphineoxide mixtures are studied using conductivity and surface tension measurements. The models of Rubingh, Rosen, and Clint, are used to obtain the interaction parameter, minimum area per molecule, mixed micelle composition, free energies of mixing and activity coefficients. The micellar mole fractions were always higher than ideal values indicating high contributions of cationics in mixed micelles. Activity coefficients were less than unity indicating synergism in micelles. The negative free energies of mixing showed the stability of the surfactants in the mixed micelles.

En los sistemas tradicionales de cultivo intercalado de frijol caupí y sorgo en franjas y filas, el rendimiento de forraje del frijol caupí se reduce significativamente debido a la intensa competencia y al dominio del sorgo en la adquisición de recursos para el cultivo. Este estudio de campo evaluó novedosos sistemas de cultivo intercalado en franjas mixtas de frijol caupí forrajero y sorgo con diferente número de filas de cultivo en diferentes disposiciones espaciales. El frijol caupí se intercaló con el sorgo en franjas de 8, 12 y 16 filas con un espaciamiento de 30, 45 y 60 cm entre las filas. En cada franja se mantuvo igual número de filas de frijol caupí y sorgo. Para la ejecución de los ensayos de campo durante las temporadas de verano de 2013 y 2014 se utilizó un diseño factorial en bloques completos aleatorizados con tres repeticiones. Las franjas con 12 filas y un espaciamiento de 60 cm entre las filas afectaron positivamente a todas las variables agronómicas del frijol caupí que condujeron al máximo rendimiento forrajero (22.2 y 23.7 t/ha en 2013 y 2014, respectivamente) y de biomasa de materia seca (6.63 y 6.94 t/ha en 2013 y 2014, respectivamente). En cambio, las franjas de 8 filas con un espaciamiento de 30 cm superaron a otros sistemas de cultivo intercalado al obtener el rendimiento máximo de hierba y de biomasa de materia seca del sorgo. El sistema de cultivo intercalado compuesto por franjas de 12 filas con un espaciamiento de 60 cm entre las filas siguió siendo superior, al registrar el contenido máximo de proteína bruta, grasas y cenizas junto con el mínimo contenido de fibra de frijol caupí. Además, este sistema de cultivo intercalado bajo el resto de las disposiciones espaciales también permaneció incomparable, mientras que las franjas de 16 filas bajo todas las geometrías de siembra permanecieron inferiores a otros sistemas de cultivo intercalado. Por lo tanto, el cultivo intercalado de frijol caupí con sorgo en franjas de 12 filas con un espaciado de 60 cm ofrece una solución biológicamente viable para mejorar la biomasa y la calidad del forraje del caupí en cultivo intercalado con sorgo.