Effects of ozone on injury and dry matter partitioning in pepper plants

Abstract Pepper plants ( Capsicum annuum L.) grown in containers and exposed intermittently to 0.12 or 0.20 ppm ozone (O 3 ) for 106 days, increased in plant height and total number of leaves in spite of the formation of chlorotic leaves, when compared with plants similarly exposed to filtered air. On an absolute basis, root, stem and leaf dry weights were not significantly affected by O 3 , but fruit dry matter production fell by as much as 54%. However, on a relative basis, dry matter partitioning to fruit was not constant and a significant alteration of the expected dry matter distribution in the whole plant was observed in the O 3 treatment. O 3 also significantly enhanced the inverse relationship between crown fruit and leaf production. A conceptual model for whole plant response to O 3 was developed and discussed.