Figures (2)  Tables (7)

    • Figure 1. 

      Plant height of two garlic varieties ('Balady' and 'Northern White') grown under different P fertilizer rates [0 (control) (P1), 43.6 (P2) and 87.2 (P3) kg P ha−1)] in calcareous soil. Data represents ± SE. Different letters indicate significant differences at p ≤ 0.05.

    • Figure 2. 

      Allicin contents in cloves of two garlic varieties ('Balady' and 'Northern White') grown under different P fertilizer rates [0 (control) (P1), 43.6 (P2) and 87.2 (P3) kg P ha−1)] in calcareous soil. Data represents ± SE. Different letters indicate significant differences at p ≤ 0.05.

    • Texture pH Salinity EC
      (dS·m−1)      		 OM CaCO3 Total
      N      		 Available (mg·kg−1)
      P K Ca Mg Na
      Silty clay 8.2 0.8 1.1% 16.7% 0.8% 6.0 156 171 51 0.61
      EC, electrical conductivity; OM, organic matter.

      Table 1. 

      Physical and chemical properties of the experimental soil before planting (0−25 cm).

    • Phosphorus rate Variety Bulb yield
      (ton·ha−1)      		 Mean bulb weight (g) Cloves no. bulb−1
      P1 'Balady' 8.01 ± 0.50 d 25.4 ± 1.4 c 6.33 ± 0.9 c
      'Northern White' 7.40 ± 0.13 d 23.9 ± 1.6 c 6.20 ± 0.5 c
      P2 'Balady' 10.5 ± 0.26 b 31.0 ± 3.0 ab 7.93 ± 0.7 ab
      'Northern White' 9.31 ± 0.62 c 27.7 ± 2.0 bc 7.57 ± 0.6 b
      P3 'Balady' 11.9 ± 0.31 a 34.1 ± 3.0 a 8.53 ± 0.3 a
      'Northern White' 10.6 ± 0.59 b 30.4 ± 2.2 ab 8.00 ± 0.5 ab
      Significance
      Phosphorus (P) *** ** ***
      Cultivar (C) ** * NS
      P × C NS NS NS
      Different letters in the same column indicate significant difference at p ≤ 0.05. * p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.0001. NS, not significant. SE, standard error.

      Table 2. 

      Mean (± SE) of bulb yield, mean bulb weight and number of cloves/bulb of two garlic varieties ('Balady' and 'Northern White') grown under different P fertilizer rates [0 (control) (P1), 43.6 (P2) and 87.2 (P3) kg P ha−1)] in calcareous soil.

    • P
      fertilizer rate      		 Variety Plant growth¶
      Bulb yield (%) Mean bulb
      weight (%)      		 Cloves no.
      per bulb (%)
      P2 'Balady' 31 ± 3.0 22 ± 3.3 25 ± 1.7
      'Northern White' 26 ± 2.1 16 ± 2.1 22 ± 2.6
      P3 'Balady' 49 ± 7.4 34 ± 3.9 35 ± 4.4
      'Northern White' 43 ± 4.9 27 ± 3.5 29 ± 2.7
      ¶ Plant growth (PG) change (%) = ((PGPF – PGnonPF) × 100)/PGnonPF).

      Table 3. 

      Percentage (± SE) change in plant growth (bulb yield, bulb weight and cloves number per bulb) of two garlic varieties ('Balady' and 'Northern White') grown at P fertilizer (PF) or no added P fertilizer (nonPF) in calcareous soil.

    • Phosphorus rate Variety N P K Ca Mg
      mg·g−1 DM
      P1 'Balady' 2.43 ± 0.10 bc 2.26 ± 0.06 e 15.5 ± 0.06 bc 2.47 ± 0.13 d 0.59 ± 0.04 c
      'Northern White' 2.36 ± 0.08 c 2.20 ± 0.02 e 14.6 ± 0.06 c 2.63 ± 0.08 d 0.65 ± 0.09 bc
      P2 'Balady' 2.65 ± 0.11 a 2.76 ± 0.03 c 16.0 ± 0.07 ab 4.15 ± 0.08 b 0.76 ± 0.08 ab
      'Northern White' 2.55 ± 0.05 ab 2.53 ± 0.07 d 15.3 ± 0.08 bc 4.43 ± 0.13 a 0.83 ± 0.09 a
      P3 'Balady' 2.57 ± 0.11ab 3.40 ± 0.14 a 16.7 ± 0.04 a 3.09 ± 0.07 c 0.79 ± 0.12 ab
      'Northern White' 2.44 ± 0.08 bc 3.13 ± 0.13 b 16.1 ± 0.04 ab 3.26 ± 0.13 c 0.87 ± 0.10 a
      Significance
      Phosphorus (P) * *** ** ** **
      Cultivar (C) * ** * ** NS
      P × C NS NS NS NS NS
      Different letters in the same column indicate significant difference at p ≤ 0.05. * p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.0001. NS, not significant. SE, standard error.

      Table 4. 

      Mean (± SE) of macronutrient concentrations in cloves of two garlic varieties ('Balady' and 'Northern White') grown under different P fertilizer rates [0 (control) (P1), 43.6 (P2) and 87.2 (P3) kg P ha–1)] in calcareous soil.

    • P fertilizer rate Variety Nutrient content§
      N (%) P (%) K (%) Ca (%) Mg (%)
      P2 'Balady' 9.1 ± 1.4 22.1 ± 3.0 3.2 ± 0.6 68.0 ± 6.6 28.8 ± 3.3
      'Northern White' 8.1 ± 1.2 15.0 ± 1.8 4.8 ± 0.7 68.4 ± 5.7 27.7 ± 3.1
      P3 'Balady' 5.8 ± 0.8 50.4 ± 5.4 7.7 ± 1.2 25.1 ± 4.4 33.9 ± 5.0
      'Northern White' 3.4 ± 0.6 42.3 ± 5.5 10.3 ± 1.4 23.9 ± 3.8 33.8 ± 4.6
      §Nutrient content (NC) change (%) = ((NCPF – NCnonPF) ×100)/NCnonPF).

      Table 5. 

      Percentage (± SE) change in fodder mineral (N, P, K, Ca, and Mg) contents of two garlic cultivars ('Balady' and 'Northern White') grown at P fertilizer (PF) or no added P fertilizer (nonPF) in calcareous soil.

    • Phosphorus rate Variety Total phenols (mg GAE
      100 g−1)      		 Total flavonoids (mg CE 100 g−1) Antioxidant activity (%)
      P1 'Balady' 582 ± 27 b 56.9 ± 5.2 c 27.6 ± 1.3 bcd
      'Northern White' 535 ± 38 c 53.2 ± 4.9 c 24.2 ± 1.6 d
      P2 'Balady' 684 ± 25 a 71.7 ± 6.2 a 34.8 ± 1.8 a
      'Northern White' 663 ± 18 a 63.5 ± 4.4 b 29.3 ± 2.8 bc
      P3 'Balady' 591 ± 23 b 58.3 ± 4.1 bc 30.7 ± 2.7 b
      'Northern White' 574 ± 19 bc 54.6 ± 3.9 c 26.5 ± 3.2 cd
      Different letters in the same column indicate significant difference at p ≤ 0.05. * p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.0001. NS, not significant. SE, standard error.

      Table 6. 

      Mean (± SE) of total phenols and flavonoids contents and antioxidant activity (dry matter basis) in cloves of two garlic varieties ('Balady' and 'Northern White') grown under different P fertilizer rates [0 (control) (P1), 43.6 (P2) and 87.2 (P3) kg P ha−1)] in calcareous soil.

    • Phosphorus rate Variety Total
      phenols
      content(%)¶      		 Total flavonoid content (%)§ Antioxidant activity (%)*
      P2 'Balady' 17.5 ± 2.0 23.0 ± 2.1 26.0 ± 3.4
      'Northern White' 23.9 ± 2.2 16.3 ± 1.6 21.0 ± 3.0
      P3 'Balady' 1.5 ± 0.2 2.5 ± 0.3 11.2 ± 1.3
      'Northern White' 7.2 ± 0.5 2.6 ± 0.2 9.5 ± 1.2
      ¶Phenol content (PC) change (%) = ((PCPF – PCnonPF) ×100)/PCnonPF). §Flavonoid content (FC) change (%) = ((FCPF – FCnonPF) × 100)/FCnonPF). *Antioxidant activity (AA) change (%) = ((AAPF – AAnonPF) × 100)/AAnonPF).

      Table 7. 

      Percentage (± SE) change in total phenols and flavonoids contents and antioxidant activity of two garlic cultivars ('Balady' and 'Northern White') grown at P fertilizer (PF) or no added P fertilizer (nonPF) in calcareous soil.