Figure 1
Figure 2
Figure 3
Figure 4
Effects of KNO3 and girdling treatments on fruit yield and various pomological characters of ‘Fremont’ mandarin_
| Treatments | Yield (kg · tree−1) | Fruit diameter (mm) | Fruit weight (g) | Rind thickness (mm) | Juice amount (%) | SSC | Acid amount (%) | SSC/Acid |
|---|---|---|---|---|---|---|---|---|
| DG | 337.50 a | 57.28 a | 94.20 ab | 2.49 c | 50.30 | 10.56 | 1.19 | 8.95 |
| DG + KNO3 | 298.00 ab | 57.79 a | 95.36 a | 3.58 a | 50.80 | 10.60 | 1.16 | 9.18 |
| SG | 335.00 a | 55.77 b | 85.59 c | 2.66 bc | 49.09 | 10.20 | 1.13 | 9.05 |
| SG + KNO3 | 276.00 bc | 56.60 ab | 90.33 b | 2.73 bc | 49.78 | 10.48 | 1.18 | 9.03 |
| KNO3 | 270.00 bc | 57.43 a | 91.79 ab | 2.91 b | 50.24 | 10.76 | 1.17 | 9.26 |
| C | 240.00 c | 55.31 b | 93.75 ab | 2.67 bc | 45.74 | 10.92 | 1.09 | 10.03 |
| Prob > F | 0.0075 | 0.0047 | 0.0009 | 0.0004 | 0.4374 | 0.1574 | 0.4416 | 0.2943 |
| LSD0.05 | 51.584 | 1.352 | 3.921 | 0.394 | NS | NS | NS | NS |
Treatments applied during the trial_
| Treatment | Treatment Code |
|---|---|
| Control | C |
| Single girdling | SG |
| Double girdling | DG |
| Potassium treatment (KNO3) | KNO3 |
| Single girdling + KNO3 | SG + KNO3 |
| Double girdling + KNO3 | DG + KNO3 |
The effects of different treatments on fruit rind colour on ‘Fremont’ mandarin_
| Treatments | Fruit rind colour | |||
|---|---|---|---|---|
| L* | a* | b* | h° | |
| DG | 57.15 | 39.75 | 51.60 cd | 52.63 bcd |
| DG + KNO3 | 56.96 | 39.82 | 51.38 d | 52.19 cd |
| SG | 57.69 | 39.21 | 53.96 ab | 53.48 abc |
| SG + KNO3 | 57.52 | 39.42 | 53.33 bc | 53.93 ab |
| KNO3 | 56.07 | 41.15 | 51.08 d | 51.10 d |
| C | 56.71 | 39.52 | 55.44 a | 54.57 a |
| Prob > F | 0.1259 | 0.0767 | 0.0001 | 0.0025 |
| LSD0.05 | NS | NS | 1.719 | 1.632 |
The effect of different treatments on leaf nitrogen, glucose, fructose, sucrose and total sugar contents of ‘Fremont’ mandarin_
| Treatments | Nitrogen content (%) | Glucose content (%) | Fructose content (%) | Sucrose content (%) | Total sugar content (%) |
|---|---|---|---|---|---|
| DG | 2.47 bc | 0.08 d | 0.08 a | 1.82 b | 1.973 bc |
| DG + KNO3 | 2.48 bc | 0.32 a | 0.05 b | 2.16 a | 2.350 ab |
| SG | 2.47 bc | 0.06 de | 0.04 b | 2.36 a | 2.710 a |
| SG + KNO3 | 2.60 ab | 0.27 b | 0.04 b | 1.57 b | 1.730 c |
| KNO3 | 2.73 a | 0.05 e | 0.04 b | 2.15 a | 2.220 abc |
| C | 2.30 c | 0.20 c | 0.04 b | 2.22 a | 2.240 abc |
| Prob > F | 0.0154 | 0.0001 | 0.0026 | 0.0005 | 0.005 |
| LSD0.05 | 0.218 | 0.023 | 0.015 | 0.283 | 0.548 |
Effects of KNO3 and girdling treatments on bloom drop and fruit retention rate of ‘Fremont’ mandarin (%)_
| Treatments | Bloom drop rate (%) | Fruit retention rate (%) | Rate of fruits remaining after June fruit drop (%) | Rate of mature fruits (%) |
|---|---|---|---|---|
| DG | 61.88 (50.19) bc | 38.12 (39.81) ab | 56.18 (51.07) a | 6.05 (14.00) |
| DG + KNO3 | 63.06 (52.65) abc | 36.94 (37.35) abc | 42.41 (42.19) b | 8.14 (15.04) |
| SG | 55.64 (48.25) c | 44.36 (41.75) a | 26.53 (30.91) c | 4.35 (11.78) |
| SG + KNO3 | 66.93 (56.03) ab | 33.07 (35.07) bc | 25.65 (30.21) c | 4.23 (11.70) |
| KNO3 | 63.46 (53.65) abc | 36.54 (37.16) abc | 27.70 (31.44) c | 4.79 (11.61) |
| C | 67.91 (57.12) a | 32.09 (32.88) c | 36.42 (35.42) bc | 4.04 (10.95) |
| Prob > F | 0.0296 | 0.0410 | 0.0001 | 0.1348 |
| LSD0.05 | 5.569 | 5.265 | 7.341 | NS |