Issuing Body

Mississippi State University


Harkess, Richard L.

Committee Member

Bi, Guihong.

Committee Member

Broderick, Shaun.

Committee Member

Cox, Michael S.

Date of Degree


Document Type

Graduate Thesis - Open Access


Department of Plant and Soil Sciences


Pelargonium peltatum, ivy geranium, experiences foliar bleaching at temperatures exceeding 30° C. Contessa™ Red (heat tolerant) and Temprano™ Lavender (heat susceptible) were compared. Established plants underwent temperature treatments of 15/20° C or 25/30° C night/day with moisture treatments of 80% or 30% substrate volumetric water content (VWC). Photosynthesis, leaf greenness and growth data were collected at days 0, 7 and 11. No differences in photosynthetic rate nor a decrease in greenness in developed leaves occured in either cultivar due to high temperature or drought. Contessa™ Red had overall greater growth and leaf greenness than Temprano™ Lavender. Greenness and growth increased similarly for both cultivars at 80% VWC. Any decrease in foliar bleaching due to drought was likely due to a decrease in growth. A second study using Temprano™ Lavender indicated foliar bleaching occurs in newly emerging, developing leaves.