Physiology

Research of the physiology section was centered on identifying the characters associated with high root yields and quality in cassava under stress conditions. Plant reaction to water stress was studied, specifically regarding growth and yields of var. M Mex 59 and M Col 22 with a period of artificial rain exclusion. Observations were made throughout the stress period and subsequent recovery. Water stress reduced LAI notably although M Mex 59 maintained a LAI approx. twice that of M Col 22 during the stress period. LAI for both var. increased during recuperation and by final harvest (10 mo.) they were similar in both control and stressed plants. DM and starch contents increased during the stress period but decreased during recuperation. (CIAT)||El enfasis de las investigaciones de la seccion de fisiologia se centro en la identificacion de los caracteres asociados con un alto rendimiento y calidad de las raices en condiciones de estres. Se estudiaron las reacciones de la planta a la sequia, especificamente el desarrollo y los rendimientos de las var. M Mex 59 y M Col 22 en un periodo de sequia artificial. Las observaciones se realizaron durante los periodos de sequia y de recuperacion posterior. La sequia redujo notablemente el IAF, aunque M Mex 59 mantuvo un IAF aprox 2 veces mayor que M Col 22 durante el periodo de estres. Durante el periodo de recuperacion los IAF aumentaron para ambas var.; en el momento de la cosecha (10 meses), los IAF fueron similares con los de las plantas testigo. Los contenidos de MS y de almidon se incrementaron durante el periodo de sequia pero disminuyeron en el periodo de recuperacion. (CIAT)