Creación de un jardín botánico y de árbol madre de arbustivas forrajeras nativas del estado de Sonora

ABSTRACT The Mexican state of Sonora has a great diversity of floristic plant species with great fodder value that are currently in danger of disappearing or diminishing their populations, due to the bad handling of the rangelands, and the change of land use (urbanization, agriculture, aquaculture, mining industry and cement etc.), causing serious problems to the natural ecosystems. Our work was done to establish a botanical garden and mother tree of forage shrubs of the state of Sonora. An area of 2 hectares was conditioned and a drip irrigation system was installed. The involved species were 10 shrubs and 10 trees with an average age of 2 years. The transplant survival of the shrub species was 70 to 90% and the trees presented from 60 to 100%. The bush trees reached 6.20 to 20.76 cm2 of stem diameter, a crown diameter from 0.63 to 2.11 m2 and a height from 0.45 to 1.62m. The growth rate of the stem diameter was from 22.3 to 43.2, its crown from 28.8 to 67.4 and the heights from 17.0 to 48.6%. On the other hand, the trees stem diameters reached from 0.85 to 31.93 cm2, the crown diameters from 0.62 to 2.82 m2, and heights of 0.47 to 1.97 meters. Their growth rate for the stem diameter was from 15.2 to 77.0%, the crowns 12.9 to 61.5% and heights from 7.7 to 82.5%. With the irrigation systems, some species presented flowering from 3 to 4 times during the year.RESUMEN El estado Mexicano de Sonora cuenta con una gran diversidad florística, de gran valor forrajero que actualmente se encuentran en peligro de desaparecer o disminuir sus poblaciones, debido al mal manejo de los agostaderos y el cambio de uso de suelo (ur banización, agrícola, acuícola, industria minera y cementera, etc.), provocando serios problemas a los ecosistemas naturales. El objetivo de nuestro trabajo fue crear un jardín y de árbol madre de arbustivas forrajeras del estado de Sonora. Se acondicionó una área de 2 ha y se le instaló un sistema de riego por goteo. Las especies involucradas fueron 10 arbustivas y 10 árboles, con edad promedio de dos años. La sobrevivencia al trasplante, de las especies arbustivas fue de 70 al 90% y los árboles presentaron del 60 al 100%. Las arbustivas presentaron diámetros de tallos de 6,20 a 20,76 cm2, diámetros de copas de 0,63 a 2,11m2, alturas de 0,45 a 1,62 metros y el índice de crecimiento de los diámetros de tallos fue de 22,3 a 43,2%, coberturas de copas fue 28,8 a 67,4% con alturas de 17,0 hasta 48,6%. Los árboles tuvieron diámetros de tallos de 0,85 a 31,93 crrf, diámetros de copas de 0,62 a 2,82m2, alturas de 0,47 a 1,97 metros y el índice de crecimiento para los diámetros de tallos fue desde 15,2 a 77.0%, con coberturas de copas 12,9 a 61,5% y alturas 7,7 a 82,5%. Con la aplicación de los riegos, algunas especies presentaron floración de 3 a 4 veces al año

RESPUESTA DE CUATRO ESPECIES DE CEREALES A LA DENSIDAD DE PLANTAS EN SIEMBRA DE SURCOS

Las diferencias en el rendimiento de los cereales en respuesta a cambios en la densidad de plantas (DP) son debidas a las diferencias en el área foliar (capacidad fotosintética) que puede ser estimada por medio de variables cuantitativas durante el ciclo de crecimiento. Para probar esta hipótesis, ocho experimentos en serie fueron establecidos con cuatro cultivos de cereal: avena (Avena sativa L.), cebada (Hordeum vulgare L.), trigo harinero (Triticum aestivum L.) y trigo duro (Triticum durum Desf.), usando dos variedades de cada cereal y sembrados en un sistema en surcos bajo riego. Cada experimento consistió de ocho densidades de población: 30, 60, 90, 120, 150, 180, 210 y 800 mil plantas por hectárea (MPPH). Los resultados indicaron que las funciones de producción fueron similares entre variedades de cada cultivo, pero diferentes entre cultivos. La densidad de plantas óptima para el máximo rendimiento de grano fue de 150 MPPH para avena, de 180 MPPH para cebada y de 210 MPPH para trigo harinero y trigo duro. La importancia de las variables para predecir la DP y rendimiento de grano fue como sigue: altura de planta, número de hijuelos por planta, número de espigas por metro cuadrado, rendimiento de grano y peso hectolítrico. Debido a su capacidad predictiva y a su fácil manejo, la altura de planta fue utilizada como la mejor variable dependiente para predecir la DP óptima para la obtención del máximo rendimiento de grano

Effect of population density and variety on irrigated wheat yield and components when grown on beds in Northwest Mexico

Wheat (Triticum aestivum L.) population density (PD) could be used to improve the wheat production technology in Northwestern Mexico. Tillering capacity is a characteristic of the variety. Theoretically, the recommended PD should not be modified by the variety. The objective of this study was to determine the effects of the variety (V) and PD on wheat yield and other components. A field study was carried out at the Yaqui Valley Agricultural Experimental Station, in Sonora, Mexico. It consisted of a complete factorial of five wheat varieties: Aconchi C89, Tepoca T89, Oasis F86, Altar C85, and Rayon F89, and seven PD treatments: 20, 40, 80, 160, 240, 320 and 800 thousand plants per hectare (TPPH)) in a split plot design with varieties as main plots and the PD as subplots in a complete randomized block design with five replications. For all the evaluated variables, the response to PD was different according to the variety, mainly in treatments with low PD, and as this was increased, the response turned asymptotic, with optimum PD being different for each variety. The maximum yield and the other wheat components were reached with the optimum PD, around 160 TPPH. The number of tillers per plant (TPP) always decreased with increased PD, while the harvest index (HI) was not affected by the studied factors

Irrigated wheat response to population density and number of rows per bed in Northwest Mexico

Under the use of the new irrigated wheat production method on raised beds in NW Mexico, it is necessary to re-define the components of the traditional production technology, focused on population density (PD) and number of rows per bed (RPB). At the Yaqui Valley Agricultural Experiment Station an experiment was carried out during fall-winter 1991–1992, which consisted of a complete factorial of three plant arrangements: one, two, and three rows per raised bed (RPB), and seven population densities (PD): 20, 40, 80, 160, 240, 320 and 800 thousand plants per hectare (TPPH), in a randomized complete block design with four replications. Results indicated that average wheat grain yields were 730 and 250 kg ha −1 higher when seeded at two RPB compared with one and three RPB, and PD had no significant effect. At PD higher than 80 TPPH, yields increased consistently. The response to PD was consistent up to around 240 TPPH. Differences in optimum PD were not so large and it is not necessary to change the recommendations when the plant pattern arrangement (RPB) is modified

Irrigated wheat response to population density and planting date in bed planting in Northwest Mexico

Irrigated wheat response to different population densities and planting dates when it is planted on raised beds is not well defined. A field study was carried out at the Yaqui Valley Agricultural Experimental Station in Sonora, Mexico during fall-winter 1992–1993, in a split plot design with three planting dates: Nov 10, Dec 10 and Jan 10; and six population densities: 50, 100, 150 200, 250 and 800 thousand plants per hectare (TPPH), in a complete randomized block design, with four replications. The fertilization used was 150-40-0 kg ha −1 of N-P 2 O 5 -K 2 O; the wheat variety used was Altar C85. Results indicated that wheat response to population density (PD) was different at different planting dates. At an early date, the plants grew taller and more vigorous and the field area could be covered with a small number of plants. The optimal PD was around 150 TPPH (15 plants m −2 ) when planted on Nov 10, which represents less than 10 kg ha-1 of seed. After this date, it was required to increase the PD as the planting date was delayed through Jan 10. The wheat capacity to produce tillers can explain its response to PD, and the different response to the planting date was explained by an increased grain density, which also is function of the size of the plant canopy