To meet the demands of several cultivar evaluation projects, a plot planting system utilizing a rear‐engine tractor was developed. Important design criteria were that it be adaptable to several different row spacings and row numbers, that it use only one seed packet per plot, and that it be easily transported. The equipment developed uses a 20 kw rear‐engine power unit equipped with a three point bitch behind the front axle. Seed is metered through a cone to a spinning divider which can be fitted with interchangeable heads to divide the seed into two to nine rows. Interchangeable tool bars, one equipped with double disc drill openers, the other with unit‐planters permit planting, as many as, nine 18‐cm rows, or as few as, two 95‐cm rows. The planting system has been used successfully for several crop evaluation trials, population and row width studies.

The growing season in the semi-arid region of West Africa is drought prone and of irregular duration. Two experiments were conducted in 1986 and 1987 to test the effects of flat cultivation and tied ridge cultivation (TRC) on the yields of maize and the component crops of a maize and cowpea relay cropping system. The two research sites, with slopes of 0.05% and 3%, were near Sapu, The Gambia, on an Aridic Kandiustalf in the 700 mm rainfall zone.Both growing seasons had above average rainfall. In both years, maize on level sites showed no response to tillage practices. On the sloped site in 1987, soil moisture 10 and 15 days after the last rain was greater with TRC than with flat cultivation and yields of sole cowpea and maize were 25% and 18% greater, respectively. On the level site, TRC had no effect on residual soil moisture or grain yield. When rainfall was well distributed, tied ridging did not appear to be a viable tillage alternative for maize-based systems on flat land in central Gambia but with modest slopes, tied ridges markedly increased soil water reserves in the 0.15 to 0.60 m depth after maize harvest.El efecto del cullivo transversal en laderas respecto del rendimiento de maizy un reemplazo de maiz/caupien Gambia RESUMEN La temporada de crecimiento en la region semiarida de Africa Occidental es propensa a la sequia y tiene una duration irregular. Se Uevaron a cabo dos experimentos en 1986 y 1987 para comprobar los efectos del cultivo llano y el cultivo transversal en laderas respecto de los rendimientos del maiz y las cosechas componentes de un sistema de cultivo de reemplazo de maiz y caupi. Las dos areas de investigation, con pendientes de 0,05% y 5%, estaban cerca de Sapu, Gambia, en un 'Aridic Kandiustalf en la zona de 700 mm de precipitaciones.Ambas temporadas de crecimiento tuvieron precipitaciones por encima del promedio. En ambos afios, el maiz en los emplazamientos llanos no mostro respuesta alguna a las practicas de cultivo. En los emplazamientos con pendiente, en 1987 la humedad del suelo 10 y 15 dias despiies de la ultima lluvia fur mayor con el sistema transversal que con el sistema de cultivo llano, y los rendimientos del caupi solo y el maiz solo fueron un 25% y un 18% superiores, respectivamente. En al area liana, el sistema transversal no tuvo ningun efecto sobre la humedad residual del suelo ni sobre el redimiento del grano. Cuando las precipitaciones estuvieron bien distribuidas, el sistema transversal no parecio ser una alternativa de labranza viable para los sistemas a base de maiz en las llanuras del centro de Gambia, pero con pequenas pendientes, el sistema transversal incremento en gran medida las reservas de agua en el suelo en la profundidad de 0,15 a 0,60 m, luego de la cosecha del maiz.Present addresses: fUSAID/FEWS, 01 BP 35, Ouagadougou, Burkina Faso, and ^University of Wisconsin-Madison,

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The US Centers for Disease Control and Prevention, with funding from the US President’s Plan for Emergency Relief, implements a virtual model for clinical mentorship, Project Extension for Community Healthcare Outcomes (ECHO), worldwide to connect multidisciplinary teams of healthcare workers (HCWs) with specialists to build capacity to respond to the HIV epidemic. The emergence of and quick evolution of the COVID-19 pandemic created the need and opportunity for the use of the Project ECHO model to help address the knowledge requirements of HCW responding to COVID-19 while maintaining HCW safety through social distancing. We describe the implementation experiences of Project ECHO in 5 Centers for Disease Control and Prevention programs as part of their COVID-19 response, in which existing platforms were used to rapidly disseminate relevant, up-to-date COVID-19–related clinical information to a large, multidisciplinary audience of stakeholders within their healthcare systems.