Physiological Effects of Ultra-High Temperatures on Corn

Abstract

Twelve-day-old corn seedlings (Zea mays L. ‘Funk's G-83’) were exposed to thermal conditions (482 C for 125 msec) approximating those used for flame weed control. Tissue dehydration was evident within 1 min after flame application. One hour after flame exposure, the water content of shoot tissues was 6% less than in nonflamed shoots. Transpirational water loss 16 hr after flame application was reduced by 68% when compared to that of nonflamed seedlings. Assimilation of 14CO2 by flamed seedlings, while substantially decreased when compared with that of nonflamed seedlings, continued on a limited basis even in the most severely injured leaf tips.