Abstract
Chemical root pruning studies were carried out on greenhouse grown Photinia x fraseti commonly known as red-tip photinia. Thirty plants were grown in containers coated on interior surfaces with 100 g Cu(OH)2/liter and thirty were grown in non-treated containers. The effects of chemical root pruning on water relations and root morphology were studied. A model was developed to predict transpiration in greenhouse grown photinia. A separate experiment was conducted to test accuracy of stem gauges. Chemically root pruned plants had a higher plant water uptake (10-15 % more than non-pruned plants). This was due to the apparent increase in fibrosity of the root system. Root surface area was found to be uniformly distributed in treated containers. Consequently, the treated plants were morphologically better developed. Leaf water potential, stomatal conductance, and stomatal aperture measurements were not found to be significantly different in treatment and control. A problem of excessively high flow rates was observed due to very small or negative values of dT in the stem gauges. The data was reconstructed accurately using a newly developed computer program. A regression model was developed to predict transpiration for greenhouse grown photinia in response to greenhouse weather parameters. R 2was found to be 0.79. It may be increased by incorporating in the model an additional term of accurately measured amount of water applied.
Vartak, Diptish Ramesh (1993). Chemical root pruning and its effects on water relations and root morphology of photinia. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -1993 -THESIS -V326.