[Behaviour of venture wheats varieties and the temporalera M-87 variety under drought at Mixteca alta, Oaxaca]

Inglés. Four wheat varieties (venture wheats) from the Mixteca Alta region at Oaxaca state, and the Temporalera M-87 variety, were studied under residue humidity in that region. The experiment was stablished on October 19th, 1990. There was 40 mm of rain fall at the begining of their growing cycles. The venture wheats were under severe dry conditions since their growing stage and temporalera variety since its reproductive stage, the last one showed earlier growing cycle, more wax content, higher transpiration rate, more production and plant hight that venture wheats, which showed lower transpiration rate and higer stomatal resistance. It means that venture wheats have more capacity to save water, representing important conditioning to survive under drought. The venture wheats can showed their drought resistance capacity, if there is certain soil moisture, enough to let the development of the root system and the area structure

Español; castellano. Cuatro variedades de trigo en la Mixteca Alta Oaxaquena, conocidas como trigos ventureros y la variedad Temporalera M-87, se estudiaron en dicha region bajo el sistema de humedad residual. El experimento se establecio el 19 de Octubre de 1990. Se registraron 40 mm de precipitacion que ocurrieron al principio del ciclo. Los trigos ventureros estuvieron bajo severa sequia desde la etapa vegetativa, y Temporalera M-87, a partir de la reproductiva. Temporalera M-87 fue mas precoz, alcanzo mayor altura, mayor rendimiento y acumulo cera; los trigos ventureros a pesar de que bajo otras condiciones pueden crecer mas que Temporalera M-87, mostraron menor produccion, menor altura de planta, asimismo bajas tasas transpiratorias y altas resistencias estomatales, lo que indica su capacidad para ahorrar agua, representando acondicionamientos importantes para la sobrevivencia bajo sequia. Los trigos ventureros pueden mostrar su potencial de resistencia a sequia siempre y cuando tengan un minimo de humedad que les permita desarrollar sus estructuras aereas y subterraneas.