VIEW ARTICLE

Importance of Phytophthora spp. and Aeration in Root Rot and Growth Inhibition of Orange Seedlings. L. J. Klotz, Department of Plant Pathology, University of California, Riverside 92502; L. H. Stolzy(2), C. K. Labanauskas(3), and T. A. DeWolfe(4). (2)(3)(4)Soil Science and Agricultural Engineering; and Plant Sciences, University of California, Riverside 92502. Phytopathology 61:1342-1346. Accepted for publication 4 June 1971. DOI: 10.1094/Phyto-61-1342.

Infection of sweet orange seedling roots by Phytophthora spp. greatly increased the rate of decay of roots and depressed the rate of production of healthy roots, stems, and leaves, the rate of increase in height of stems, and rate of water use. Reduced aeration of root environment significantly decreased rate of roots produced, height of stem, and water use, but did not affect rate of root decay or rate of increase in weight of stem and leaves. The effects of Phytophthora parasitism on the vegetative growth of the seedlings and on root decay were greater than those of aeration.