Growth-stage dependent crop yield response to ozone exposure

Area of Science:

• Agricultural Science
• Environmental Science
• Plant Physiology

Background:

• Ozone exposure is a significant abiotic stressor impacting crop productivity.
• Traditional methods of assessing ozone impact may not accurately reflect crop sensitivity across different growth stages.

Purpose of the Study:

• To evaluate the effectiveness of phenological weighting functions in assessing ozone's impact on crop yield.
• To identify critical growth stages of specific crops sensitive to ozone exposure.

Main Methods:

• Field trials were conducted on alfalfa, dry bean, and tomato crops under varying ambient ozone levels.
• Crop growing seasons were divided into quarters, with ozone exposure calculated for each period.
• Phenological weighting functions (reciprocal residual mean square and TOP100) were applied to ozone exposure data.
• Ozone exposure statistics were regressed against final crop yield.

Main Results:

• The third quarter of the growing season showed the highest ozone sensitivity for alfalfa and dry bean yields.
• The second quarter was identified as the most sensitive period for fresh market and processing tomatoes.
• Ozone exposure during critical physiological events like flowering, fruit set, and pod development most significantly influenced yield.

Conclusions:

• Growth-stage-dependent phenological weighting provides a more accurate prediction of ozone-induced crop yield reductions.
• Understanding crop-specific phenological sensitivity to ozone is crucial for effective agricultural management and policy development.