Tungsten deposits in the Sierra Nevada near Bishop, California

En la Sierra Nevada de Puebla, México, los huertos de durazno (Prunus persica L.) presentan problemas de producción relacionados con alta incidencia de plagas (incluye enfermedades), nutrición deficiente e inadecuado manejo de poda, que acentúan el problema de floración precoz en la mayoría de las variedades mejoradas.

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Transportation and the Environment

California History ◽

10.1525/ch.2017.94.3.37 ◽

2017 ◽

Vol 94 (3) ◽

pp. 37-61

Author(s):

Douglas R. Littlefield

Keyword(s):

Nineteenth Century ◽

San Francisco ◽

Sierra Nevada ◽

Mississippi River ◽

San Joaquin Valley ◽

Eastern United States ◽

Major Health ◽

San Joaquin River ◽

Natural Wetlands ◽

Prevailing View

Some histories of California describe nineteenth-century efforts to reclaim the extensive swamplands and shallow lakes in the southern part of California's San Joaquin Valley – then the largest natural wetlands habitat west of the Mississippi River – as a herculean venture to tame a boggy wilderness and turn the region into an agricultural paradise. Yet an 1850s proposition for draining those marshes and lakes primarily was a scheme to improve the state's transportation. Swampland reclamation was a secondary goal. Transport around the time of statehood in 1850 was severely lacking in California. Only a handful of steamboats plied a few of the state's larger rivers, and compared to the eastern United States, roads and railroads were nearly non-existent. Few of these modes of transportation reached into the isolated San Joaquin Valley. As a result, in 1857 the California legislature granted an exclusive franchise to the Tulare Canal and Land Company (sometimes known as the Montgomery franchise, after two of the firm's founders). The company's purpose was to connect navigable canals from the southern San Joaquin Valley to the San Joaquin River, which entered from the Sierra Nevada about half way up the valley. That stream, in turn, joined with San Francisco Bay, and thus the canals would open the entire San Joaquin Valley to world-wide commerce. In exchange for building the canals, the Montgomery franchise could collect tolls for twenty years and sell half the drained swamplands (the other half was to be sold by the state). Land sales were contingent upon the Montgomery franchise reclaiming the marshes. Wetlands in the mid-nineteenth century were not viewed as they are today as fragile wildlife habitats but instead as impediments to advancing American ideals and homesteads across the continent. Moreover, marshy areas were seen as major health menaces, with the prevailing view being that swampy regions’ air carried infectious diseases.

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Biología y daños de Conotrachelus crataegi (Coleoptera: Curculionidae) en tejocote (Crataegus spp.) en México

Revista Colombiana de Entomología ◽

10.25100/socolen.v43i2.5940 ◽

2017 ◽

Vol 43 (2) ◽

pp. 173

Author(s):

Martha Lilia Rosas-Alfaro ◽

Arturo Huerta-de La Peña ◽

Juan Morales-Jiménez ◽

Andrés Pérez-Magaña ◽

Luis Ricardo Hernández ◽

...

Keyword(s):

Sierra Nevada

Conotrachelus crataegi es un curculiónido plaga que barrena los frutos de tejocote en la zona de producciónen Puebla, México. Las hembras ovipositan en frutos pequeños en desarrollo, donde la larva barrena hasta llegar y destruir las semillas. En ausencia de trabajos de investigación sobre biología y daños de este insecto en la región productora de tejocote, se estudió la biología de este barrenador y los daños sobre los frutos. Se realizaron muestreos al follaje, frutos y suelo en tres localidades de la Sierra Nevada de Puebla, México del 30 de abril de 2014 al 27 de mayo de 2015. C. crataegi presentó alto traslape de estados de desarrollo; los huevos se observaron desde la tercera semana de abril, hasta la segunda de julio de 2014, con un período estimado de incubación de tres a cinco días. Las larvas se registraron durante todo el período de muestreo, desde la primera semana de julio de 2014, hasta la última de mayo de 2015. El estado de pupa ocurrió en marzo y abril de 2014, con una duración de 10 a 15 días. Los adultos se observaron de abril a septiembre de 2014; las mayores densidades poblacionales de los adultos se presentaron el 28 de mayo y el 11 de junio de 2014. Los resultados de esta investigación contribuyen al diseño de un programa de manejo sustentable de C. crataegi en México.

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