Water-use and plant growth of Fraser photinia (Photinia × fraseri Dress) were studied under varying irrigation regimes during 2 different growing seasons, winter and summer. Rooted cuttings were transplanted into 7.57 1 (2 gal) plastic containers containing Metro-mix 500 and greenhouse-grown under 2 irrigation frequencies (3.5 or 7-day intervals) and 3 replacement amounts (100%, 75% or 50% replacement of actual water-use).
Increased irrigation frequency significantly reduced plant growth parameters of winter-grown plants, including shoot growth, leaf number, leaf area and shot dry weight. Decreased irrigation amount significantly increased root dry weight. Significant differences were not detected in growth measurements of summer-grown plants suggesting differences between experiments are seasonal in nature. Frequent irrigation resulted in poor plant pelformance under winter growing conditions of lower evapotranspiration (ET); however under summer growing conditions, frequent irrigation did not significantly affect plant growth.
Decreased irrigation frequency significantly increased total water-use for winter-grown plants due to increased plant performance. No significant differences in water-use due to frequency in summer-grown plants was found.
Texas Agricultural Experiment Station Journal Article no. 25373. We gratefully thank Hines Nurseries, Inc., Houston, TX for donation of plant materials.
2Extension horticulturist, Assistant professor, and Extension horticulturist, resp.