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73 resultados, página 4 de 8

Domesticación de papaya: implicaciones en la tolerancia al cambio climático

AMARANTA GIRON RAMIREZ ARIANNA CHRISTINE CHAN LEON YESSICA BAUTISTA BAUTISTA ERICK ARROYO ALVAREZ Humberto José Estrella Maldonado Gabriela Fuentes Ortiz Jorge Manuel Santamaría Fernández (2023, [Artículo])

Mucho se ha hablado de que el proceso de domesticación de las especies comerciales trajo consigo una reducción en la talla de las plantas, un aumento en el tamaño de los frutos, cambios en el tipo sexual de las flores en algunos casos, etc. Sin embargo, poco se ha discutido la posibilidad de que, en algunas especies como en la papaya, el proceso de domesticación pudo haber traído consigo una pérdida de la tolerancia a sequía y posiblemente a otros factores climáticos, tolerancia que aún es posible encontrar en las poblaciones silvestres de esta importante especie.

CARICA PAPAYA PLANTAS SILVESTRES RESERVORIO GENETICO SEQUIA BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL

Análisis de sequías en el marco del Tratado sobre Aguas Internacionales de 1944

Felipe Arreguin Mario Lopez Perez (2013, [Artículo])

Se presenta el análisis de sequías en las cuencas de los ríos Colorado y Bravo, mediante el Índice de Escurrimientos Estandarizados. En el río Colorado se registraron tres años con sequía extrema (1934, 1977 y 2002) en la cuenca total y en la región alta de la misma, y cuatro años (1928, 1929, 1935 y 1936) en la cuenca baja. Aplicando este mismo criterio, en el caso del río Bravo se registró una sequía extrema para el periodo k3 (octubre-junio) en el año agrícola 1901-1902. El Índice de Precipitación Estandarizada sólo se aplicó en la cuenca del río Colorado, y se encontró una coincidencia de sequía extrema entre la cuenca baja y total en los años 1950, 1956 y 1989; además, en este último año, también hubo sequía extrema en la cuenca alta. Tales resultados son importantes para el manejo conjunto del agua entre México y Estados Unidos en ambas cuencas, para satisfacer las demandas de sus habitantes, cumplir compromisos establecidos en el Tratado sobre Aguas Internacionales de 1944, y tomar las medidas necesarias ante el impacto del cambio climático sobre el ciclo hidrológico en la región.

Sequía Disponibilidad de agua Indicadores de sequía Río Bravo Río Colorado INGENIERÍA Y TECNOLOGÍA

Training Manual for Two-wheel tractor and ancillary equipment for operators, service providers, extension experts and workshop owners

Rabe Yahaya (2022, [Libro])

Mechanization is a term used to describe tools, implements and machinery applied to improve the productivity of farm land and labour force, including crop processing after harvest. Mechanization covers broadly the entire process of on and off farm operations and mechanization may use either human, animal or motorized power, or a combination of these. In practice, therefore, it involves the provision and use of all forms of power sources and mechanical assistance to agriculture, from simple hand tools to draught animal power and to motorized power technologies. In Ethiopia, smallholder farming experiences high drudgery at all stages of crop husbandry and post-harvest processing. Field operations are performed using human and animal power (Mrema et al., 2008). Smallholder farmers without animal power use a lot of human power on crop husbandry and harvesting operations (Daum et al., 2020). Postharvest threshing and shelling are performed using human power but, in some countries like Ethiopia, farmers use livestock (cattle, donkeys and horses) for wheat, barley and teff threshing (Mohammed and Tadesse, 2018). The use of tractor power is low in Ethiopia and the government aims to increase farm power available to Ethiopian farmers 10 folds (from the current 0.1 Kw ha-1 to 1 kW ha-1 ) by 2025, with at least half of this power is derived from fossil fuel and electric engines. The government of Ethiopia aims to increase farm power using two-wheel tractors on smallholder farms in addition to four-wheel tractors that are already in use. Two-wheel tractors are sources of power designed to perform most field operations. Due to the size of two-wheel tractors, they have become an economic alternative for smallholder farming. In addition, twowheel tractors are also more productive than animal traction and they require less time for attendance and preparation, giving the individual farmer more independence and contact with modern technology. Also, due to their simple design, local manufacturing of two-wheel tractors has been implemented in several countries successfully, increasing employment opportunities in the process.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA FARM EQUIPMENT TRACTORS TRAINING SMALLHOLDERS

Risk aversion, impatience, and adoption of conservation agriculture practices among smallholders in Zambia

Hambulo Ngoma João Vasco Silva Frédéric Baudron Isaiah Nyagumbo Christian Thierfelder (2024, [Artículo])

Sustainable agricultural practices such as conservation agriculture have been promoted in southern Africa for nearly three decades, but their adoption remains low. It is of policy interest to unpack behavioural drivers of adoption to understand why adoption remains lower than anticipated. This paper assesses the effects of risk aversion and impatience on the extent and intensity of the adoption of conservation agriculture using panel data collected from 646 households in 2021 and 2022 in Zambia. We find that 12% and 18% of the smallholders were impatient and risk averse, respectively. There are two main empirical findings based on panel data Probit and Tobit models. First, on the extensive margin, being impatient is correlated with a decreased likelihood of adopting combined minimum-tillage (MT) and rotation by 2.9 percentage points and being risk averse is associated with a decreased propensity of adopting combined minimum tillage (MT) and mulching by 3.2 percentage points. Being risk averse is correlated with a decreased chance of adopting basins by 2.8 percentage points. Second, on the intensive margin, impatience and risk aversion are significantly correlated with reduced adoption intensity of basins, ripping, minimum tillage (MT), and combined MT and rotation by 0.02–0.22 ha. These findings imply a need to embed risk management (e.g., through crop yield insurance) in the scaling of sustainable agricultural practices to incentivise adoption. This can help to nudge initial adoption and to protect farmers from yield penalties that are common in experimentation stages.

Risk and Time Preferences CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA TECHNOLOGY ADOPTION RISK SUSTAINABLE INTENSIFICATION SMALLHOLDERS