Table 2.
Effect of growth regulators and thermal regimes on net photosynthetic rate-Pn (µ mol m−2 sec−1), fiber quality components, number of sympodial branches per plant and boll weight (g) under glass house conditions.
| Thermal regimes | Regulators | Pn | Fiber fineness (micronaire) | Fiber length (mm) | Fiber strength (g/tex) | No. of sympodial branches per plant | Boll weight (g) |
|---|---|---|---|---|---|---|---|
| 32/20 °C | H2O2 (30 ppm) | 28.4 ± 0.53 a | 4.0 a ± 0.20 | 28.7 a ± 1.5 | 30.9 a ± 1.7 | 23.3 a ± 0.56 | 3.7 a ± 0.19 |
| SA (70 ppm) | 25.6 ± 0.50 b | 3.9 a ± 0.19 | 27.8 a ± 1.3 | 30.1 a ± 1.6 | 22.8 a ± 0.44 | 3.8 a ± 0.20 | |
| MLE (30 times diluted) | 24.9 ± 0.50 b | 4.2 a ± 0.23 | 27.8 a ± 1.6 | 29.7 a ± 1.4 | 23.2 a ± 0.41 | 3.8 a ± 0.21 | |
| ASA (70 ppm) | 25.1 ± 0.41 b | 4.1 a ± 0.21 | 28.1 a ± 1.4 | 29.8 a ± 1.5 | 22.9 a ± 0.40 | 3.7 a ± 0.18 | |
| 45/30 °C | Control | 21.5 ± 0.52 c | 3.2 b ± 0.16 | 18.6 b ± 1.0 | 21.8 b ± 1.1 | 14.8 b ± 0.31 | 2.6 b ± 0.17 |
| H2O2 (30 ppm) | 26.1 ± 0.49 a | 3.8 a ± 0.19 | 23.0 a ± 1.1 | 26.9 a ± 1.3 | 17.6 a ± 0.37 | 3.4 a ± 0.14 | |
| SA (70 ppm) | 21.9 ± 0.46 c | 3.2 b ± 0.16 | 18.8 b ± 0.9 | 20.7 b ± 1.0 | 14.5 b ± 0.33 | 2.7 b ± 0.16 | |
| MLE (30 times diluted) | 23.7 ± 0.49 b | 3.7 a ± 0.18 | 21.6 a ± 1.2 | 26.8 a ± 1.2 | 17.4 a ± 0.43 | 3.2 a ± 0.13 | |
| ASA (70 ppm) | 24.0 ± 0.39 b | 3.7 a ± 0.17 | 21.8 a ± 1.3 | 25.7 a ± 1.3 | 17.3 a ± 0.31 | 3.1 a ± 0.15 | |
| 38/24 °C | Control | 15.9 ± 0.31 c | 3.5 b ± 0.18 | 23.9 c ± 1.4 | 25.2 b ± 1.1 | 19.7 b ± 0.50 | 3.2 a ± 0.17 |
| H2O2 (30 ppm) | 21.6 ± 0.36 a | 4.0 a ± 0.21 | 27.1 a ± 1.5 | 29.0 a ± 1.5 | 22.1 a ± 0.45 | 3.6 b ± 0.18 | |
| SA (70 ppm) | 15.0 ± 0.29 c | 3.4 b ± 0.17 | 22.6 c ± 1.1 | 24.1 b ± 1.2 | 19.7 b ± 0.39 | 3.3 a ± 0.19 | |
| MLE (30 times diluted) | 17.8 ± 0.32 b | 3.9 a ± 0.23 | 25.8 b ± 1.2 | 27.7 a ± 1.4 | 22.9 a ± 0.53 | 3.3 b ± 0.16 | |
| ASA (70 ppm) | 17.9 ± 0.37 b | 3.9 a ± 0.20 | 26.0 a ± 1.4 | 28.6 a ± 1.6 | 22.8 a ± 0.52 | 3.7 a ± 0.19 | |
| LSD | 1.42 | 0.21 | 1.43 | 1.51 | 1.02 | 0.20 |
Mean of three replications (n = 3) ± SE and variants having same alphabets are not statistically significant at P˂ 0.05. Main factors and interaction are significant at P˂ 0.01. By using the LSD of the interaction between growth regulators and thermal regimes, lettering is done separately for each thermal regime.