International Water & Irrigation

44 irrigation volume. Responses were seen to be influenced by the main effect of N rate, irrigation frequency, or the interaction between N rate and container type. Leaf area was also affected by the interaction between N rate and container type, not by irrigation frequency, sharing similar trend with PGI and dry weights (Table One) . Regardless of container type, higher N rates from 10 to 20 mM resulted in greater leaf area than did 0 and 5 mM N. Flowering performance. Flower number per plant was affected by the interactions between irrigation frequency and N rate (P = 0.0153) (Figure. 2A) and that between irrigation frequency and container type (P = 0.0179) (Fig. 2B) . Generally, no N treatment resulted in fewer than five flowers per plant throughout the growing season, with flower number per plant increasing to 13.2 (one irrigation per day) and 11.6 Table Two. Tissue nitrogen (N) concentration and N content of Azalea ‘Chiffon’ plants. N Rate Container N Concentration (%) N Concentration (Mg) Leaf Stem Root Ave Leaf Stem Root Total 0 Biocontainer 0.83 0.45 0.39 0.47 3.63 6.10 6.90 16.60 Plastic 0.75 0.45 0.36 0.47 5.01 7.40 5.60 18.00 5 Biocontainer 0.89 0.89 0.58 0.92 20.50 12.80 12.70 46.00 Plastic 0.89 0.89 0.60 1.01 26.80 15.90 13.70 56.40 10 Biocontainer 1.00 0.59 0.43 0.60 64.50 26.40 29.40 122.30 Plastic 1.05 0.71 0.47 0.61 50.60 28.90 21.90 101.40 15 Biocontainer 1.09 0.67 0.51 0.68 102.00 44.00 43.30 189.20 Plastic 1.29 0.83 0.59 0.75 70.60 39.30 25.20 135.10 20 Biocontainer 1.33 0.82 0.52 0.77 132.00 61.40 43.80 237.20 Plastic 1.44 0.96 0.59 0.93 60.00 40.10 20.50 120.60 Irrigation Effect P value 0.530 0.184 0.171 0.678 0.160 0.880 0.0087 0.1324 Azalea ‘Chiffon’ plants were fertilized with 0, 5, 10, 15, or 20 mM N from ammonium nitrate, grown in plastic containers or paper biocontainers, and irrigated once or twice per day with the same total daily irrigation volume. Responses were affected by the interaction between the N rate and container type and the main effect of irrigation frequency on root N content. yAverage N concentration in a plant was determined by dividing total N content by total plant dry weight in a given plant. Total plant N content was estimated by summing N content in leaf, stem, and root of a given plant. Figure.Two: Flower number per plant affected by the interaction between Nitrogen (N) rate and irrigation frequency (A), as was the last interaction between container type and irrigation frequency.( B) Azalea ‘Chiffon’ plants ,grown in plastic containers or paper biocontainers, were irrigated either once or twice per day with the same total daily water volume