EFFECT OF DROUGHT HISTORY ON RECOVERY OF TRANSPIRATION, PHOTOSYNTHESIS, ANDLEAF AREA DEVELOPMENT IN MAIZE.

Authors: XIANSHI, GUO - DFI, GANSU, P.R. CHINA; Sinclair, Thomas; Ray, Jeffery - Jeff

Submitted to: Soil and Crop Science Society of Florida Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/25/1998
Publication Date: N/A
Citation: N/A

Interpretive Summary: Drought stress is the most serious problem limiting crop yields. While there have been a number of studies on crop behavior during the soil drying phase of drought, there have been very few studies on the response of the crop once there is rainfall or irrigation to relieve the drought. Since the recovery of the crop from the stress could have a critical influence on the final yield of the crop, this study by ARS scientists at Gainesville, FL, was undertaken to measure the response of corn to recovery from drought stresses of differing severity and duration in the vegetative phase of development. This study showed that, in fact, the corn plants were able to recover within two to four days after rewatering, even from the most severe stress of the longest duration. After only about four days, the corn plants were functionally equivalent to the plants that had never been stressed. Decreased plant weight that was a direct result of the stress itself, was the only lingering effect of the drought stress treatments. Consequently, no special attention seems to be needed in developing corn plants that are specially adapted to quick recovery from drought stress.

Technical Abstract: There have been many studies on the influence of drought stress on plants but surprisingly few studies have considered development and growth after rewatering. This research was undertaken to examine specifically the response of maize (Zea mays L.) plants during the recovery phase following water deficit periods of differing severity and duration. Two levels of severity and three durations of drought stress were imposed on greenhouse-grown maize plants during the vegetative development phase. Plant measurements during the recovery phase included plant transpiration rate, leaf photosynthetic rate, and leaf area. Transpiration and photosynthesis recovered quickly (within 2 to 4 d) after rewatering for all drought treatments. The area of individual leaves was permanently decreased for those leaves developing during the drought stress period, so that plant leaf area was initially decreased. However, plant leaf area became equivalent to the control following rewatering as a result of the senescence pattern of leaves on the plant. Overall, the recovery of the maize plants was such that by anthesis the stressed plants were nearly equivalent to the control plants in all traits except the dry weight of the plants.