Figures (0)  Tables (9)
    • Cultivar Plant heightz (cm) Crown diameter (cm) Leaf SPAD
      'Carlton' 38.11 a 42.54 a 66.05 a
      'Chun Mei' 22.06 bc 33.75 b 47.13 d
      'Nabai Spring' 12.98 c 31.78 c 56.38 b
      'QD2-Express' 26.59 b 41.84 a 28.61 e
      'Win Win Choi' 26.25 b 41.43 a 52.19 c
      p-Value
      Cultivar < 0.0001 < 0.0001 < 0.0001
      Biostimulant 0.41 0.20 0.34
      Interaction 0.32 0.13 0.56
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD test at a p < 0.05.

      Table 1. 

      Plant height, crown diameter, and leaf SPAD varied among five Asian green cultivars were not affected by biostimulant application when grown in a high tunnel production system.

    • Cultivar Substrate
      temperaturez (°C)      		 Leaf temperature
      (°C)      		 Substrate
      moisture (%)
      'Carlton' 15.58 ab 16.05 a 14.0 abc
      'Chun Mei' 15.74 a 15.03 b 15.2 ab
      'Nabai Spring' 15.68 a 15.72 ab 15.9 a
      'QD2-Express' 15.19 bc 15.32 ab 13.9 bc
      'Win Win Choi' 14.95 c 15.33 ab 13.0 c
      p-Value
      Cultivar < 0.0001 0.021 0.0005
      Biostimulant 0.80 0.011 0.39
      Interaction 0.70 0.27 0.54
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD test at a p < 0.05.

      Table 2. 

      Substrate temperature, leaf temperature, and substrate moisture varied among five Asian green cultivars grown in a high tunnel production system.

    • Biostimulant Leaf
      temperaturez (°C)      		 PhiPS2y Electron transport
      rate (µmol·m−2·s−1)
      Control 14.96 b 0.620 ab 198.1 ab
      Dune 15.49 ab 0.654 a 171.6 b
      Kelpak Maxx 15.95 a 0.607 b 214.8 a
      Continuum 15.56 ab 0.637 ab 183.4 b
      p-Value
      Cultivar 0.021 < 0.0001 0.11
      Biostimulant 0.011 0.023 0.002
      Interaction 0.27 0.93 0.061
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD test at a p < 0.05. y PhiPS2 stands for PSII actual photochemical quantum yield.

      Table 3. 

      Leaf temperature, quantum efficiency, and electron transport rate of five Asian green cultivars grown in a high tunnel as affected by the application of three biostimulants.

    • Cultivar Stomatal conductancez (mol·m−2·s−1) Transpiration (mmol·m−2·s−1) PhiPS2y Electron transport rate (µmol·m−2·s−1)
      'Carlton' 0.343 b 3.891 bc 0.637 ab 188.6
      'Chun Mei' 0.492 a 4.845 ab 0.657 a 209.9
      'Nabai Spring' 0.485 a 5.043 a 0.590 b 199.5
      'QD2-Express' 0.306 b 3.660 c 0.659 a 184.5
      'Win Win Choi' 0.478 a 4.721 ab 0.605 b 177.3
      p-Value
      Cultivar < 0. 0001 0.001 < 0. 0001 0.11
      Biostimulant 0.67 0.13 0.023 0.002
      Interaction 0.43 0.68 0.93 0.061
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD test at a p < 0.05. y PhiPS2 stands for PSII actual photochemical quantum yield.

      Table 4. 

      Stomatal conductance, transpiration, and quantum efficiency of photosystem 2 varied among five Asian green cultivars grown in a high tunnel production system.

    • Cultivar Lz a* b*
      'Carlton' 33.58 d −7.395 a 8.479 e
      'Chun Mei' 40.42 b −11.97 d 17.02 b
      'Nabai Spring' 34.26 d −9.995 b 13.55 d
      'QD2-Express' 47.23 a −15.29 e 27.66 a
      'Win Win Choi' 39.24 c −10.97 c 15.14 c
      p-Value
      Cultivar < 0.0001 < 0.0001 < 0.0001
      Biostimulant 0.096 0.89 0.86
      Interaction 0.70 0.34 0.23
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD test at a p < 0.05.

      Table 5. 

      Leaf coloration varied among five Asian green cultivars and was not affected by biostimulant treatment when grown in a high tunnel production system.

    • Cultivar Marketable yieldz (kg·m−2) Number of
      marketable plant
      (per plot)      		 Fresh shoot weight
      (g·plant−1)      		 Dry shoot weight
      (g·plant−1)
      'Carlton' 0.79 d 9.94 a 302.4 d 43.49 b
      'Chun Mei' 1.22 c 9.75 ab 442.6 c 40.46 c
      'Nabai Spring' 0.93 d 9.38 b 410.1 c 39.64 c
      'QD2-Express' 1.52 b 9.75 ab 600.5 b 46.58 a
      'Win Win Choi' 1.84 a 10 a 669.1 a 43.91 b
      p-Value
      Cultivar < 0.0001 0.012 < 0.0001 < 0.0001
      Biostimulant 0.51 0.74 0.18 0.89
      Interaction 0.99 0.79 0.085 0.15
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD at p < 0.05.

      Table 6. 

      Marketable yield, number of marketable plants per plot, individual fresh and dry shoot weight varied among five Asian green cultivars and were not affected by biostimulant application when grown in a high tunnel.

    • Cultivar Biostimulant Nitrogenz (mg·g−1) Phosphorousy (mg·g−1) Potassium (mg·g−1) Calcium (mg·g−1) Magnesium (mg·g−1) Sulfur (mg·g−1)
      'Carlton' Control 47.18 b 3.22 d 46.33 efg 13.61 b 1.83 d 4.59 c
      Dune 3.25 d 40.51 fg
      Kelpak Maxx 3.21 d 39.32 g
      Continuum 3.15 d 39.57 g
      'Chun Mei' Control 44.54 cd 5.07 abc 57.53 a−e 11.31 c 2.04 c 4.56 c
      Dune 4.60 bc 52.4 b−e
      Kelpak Maxx 4.79 bc 51.84 b−f
      Continuum 4.84 abc 52.72 b−e
      'Nabai Spring' Control 52.62 a 4.85 abc 50.34 c−g 14.83 a 2.21 b 4.81 c
      Dune 4.77 bc 46.73 d−g
      Kelpak Maxx 4.69 bc 46.64 efg
      Continuum 4.67 bc 46.62 efg
      'QD2-Express' Control 45.79 bc 4.96 abc 58.03 a−d 15.28 a 2.20 b 6.90 a
      Dune 5.12 abc 58.35 abc
      Kelpak Maxx 5.59 a 62.77 ab
      Continuum 4.79 bc 55.49 b−e
      'Win Win Choi' Control 42.86 d 4.42 c 58.4 abc 14.65 a 2.47 a 5.43 b
      Dune 4.49 bc 59.64 abc
      Kelpak Maxx 5.25 ab 67.74 a
      Continuum 4.74 bc 58.48 abc
      p-Value Cultivar < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001 < 0.0001
      Biostimulant 0.052 0.027 0.037 0.016 0.24 0.21
      Interaction 0.70 0.0097 0.0496 0.33 0.51 0.92
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD at p < 0.05. y Where significant, the interaction between cultivar and biostimulant was presented for concentrations of phosphorus and potassium as indicated by the p-values. The main effect of cultivar was presented for nitrogen, calcium, magnesium, and sulfur when there was not a significant interaction.

      Table 7. 

      Macronutrient concentrations varied among five Asian green cultivars or as affected by the interaction between cultivar and biostimulant application.

    • Biostimulant Calciumz (mg·g−1) Boron (µg·g−1) Iron (µg·g−1) Manganese (µg·g−1) Zinc (µg·g−1) Copper (µg·g−1)
      Control 14.59 a 34.97 66.68 ab 54.11 46.85 1.20 ab
      Dune 13.63 b 34.76 60.68 b 54.09 44.36 1.27 ab
      Kelpak Maxx 13.95 ab 35.29 71.88 a 56.01 40.90 1.06 b
      Continuum 13.58 b 35.73 64.33 b 55.33 42.4 1.34 a
      p-Value
      Cultivar < 0.0001 < 0.0001 < 0.0001 < 0.0001 0.0007 0.29
      Biostimulant 0.016 0.72 0.0002 0.49 0.17 0.021
      Interaction 0.33 0.72 0.25 0.89 0.41 0.40
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD at p < 0.05.

      Table 8. 

      Calcium and micronutrient concentrations of five Asian green cultivars as affected by biostimulant treatment when grown in a high tunnel.

    • Cultivar Boronz (µg·g−1) Iron (µg·g−1) Manganese (µg·g−1) Zinc (µg·g−1) Copper (µg·g−1)
      'Carlton' 27.69 e 59.79 b 54.63 b 37.81 b 1.15
      'Chun Mei' 33.89 c 55.72 b 44.92 c 45.54 ab 1.22
      'Nabai Spring' 37.82 b 73.84 a 61.00 a 50.72 a 1.30
      'QD2-Express' 30.51 d 70.87 a 58.16 ab 43.70 ab 1.29
      'Win Win Choi' 46.02 a 69.26 a 55.7 b 40.36 b 1.12
      p-Value
      Cultivar < 0.0001 < 0.0001 < 0.0001 0.0007 0.29
      Biostimulant 0.72 0.0002 0.49 0.17 0.021
      Interaction 0.72 0.25 0.89 0.41 0.40
      z Different lower-case letters suggest significant difference among means within a column as indicated by Tukey's HSD at p < 0.05.

      Table 9. 

      Micronutrient concentrations varied among five Asian green cultivars when grown in a high tunnel production system.