Water Relations of Lagerstroemia indica Grown in Amended Media Under Drought Stress

by F.T. Davies and Y. Castro-Jimenez

To determine the role of selected media treatments on water relations and growth of crape myrtle (Lagerstroemia indica L. cultivar ‘ Natches’ ), liners were planted in a container medium containing one of two hydrogels (polyethylene oxide or starch polymer ), a synthetic mulch covering (wax-impregnated cardboard ), a media drenched with the fungicide triadimefon (2- (4-chlorophenoxy )-3, 3-dimethyl-1-(1H-1,2,4-triazol-1-y1)-2-butanone ) or no amendments. Plants were initially established under optimum irrigation and then subjected to drought stress cycles. Water-stressed plants had lower shoot and root dry weight than nonstressed conditions. The starch hydrogel increased shoot dry weight of stressed and nonstressed plants. The organic hydrogel (polyethylene oxide ) increased shoot and root dry weight under nonstressed conditions. Under water-stress conditions, neither the synthetic mulch covering nor application of triadimefon had any effect on plant growth or water relations. Drought stress resulted in a reduction of shoot water potential (more negative ) and reduce turgor.

Scientia Horticulturae, 41 (1989) 97-104.