Effects of temperature on leaf growth in corn (Zea mays)

Abstract

Effects of temperature on certain leaf-growth characteristics are described for corn (Z. mays L.) hybrid A498 .times. CG10 grown at 62 nE [Einsteins] cm-2 s-1 irradiance (400-700 nm). The rate of leaf expansion declined from a maximum at the earliest measurement stage to zero sometime after the ligule was exserted. The number of visible leaves with actively growing laminae at any stage of ontogeny was constant over day/night temperatures of 15/10, 25/20, 30/25 and 35/30.degree. C but increased from 3 to 6 between the appearance of the 7th and 13th leaves. Rate of leaf appearance was increased by temperature, from 0.19 leaves/day at 15/10.degree. C to 0.58 leaves/day at 30/25.degree. C. Rate of leaf appearance only increased to 0.60 leaves/day at 35/30.degree. C. Areas of successive leaves increased to 842 cm-2 at (optimal) 25/20.degree. C and 772 cm-2 at 30/25.degree. C for leaf 11 and, then, decreased to leaf 15. Specific leaf weight (lamina weight/lamina area) increased throughout ontogeny and decreased with increasing temperature.