Effects of some periods of variable daily exposure to temperatures of 5 and 20 degrees C on photosynthesis and water relations in maize seedlings

acide gras air temperature cold contenido de humedad fatty acids feuille frio froid hojas leaf area leaves moisture content necrose necrosis osmotic pressure photosynthese photosynthesis plantule pression osmotique seedlings superficie foliar surface foliaire temperatura del aire teneur en eau zea mays