Table 6 Impact of reduced irrigation and potassium level on seed cotton yield and net photosynthetic rate in two cotton growing seasons 2018 and 2019
Cotton cultivars | Seed cotton yield /(kg· ha−1) | Net photosynthetic rate /(μmol (CO2)·m−2·s−1) | ||||||
|---|---|---|---|---|---|---|---|---|
Reduced irrigation | Normal irrigation | Reduced irrigation | Normal irrigation | |||||
K level (0 kg·ha−1) | K level (50 kg·ha−1) | K level (0 kg·ha−1) | K level (50 kg·ha−1) | K level (0 kg·ha−1) | K level (50 kg·ha−1) | K level (0 kg·ha−1) | K level (50 kg·ha−1) | |
Cotton growing season (2018) | ||||||||
 BH-212 | 900 ± 130a | 1090 ± 140a | 1300 ± 135a | 1460 ± 160a | 21.5 ± 2.89a | 23.75 ± 2.75a | 23.4 ± 2.23a | 27 ± 3.92a |
 IUB-2013 | 1400 ± 160b | 1700 ± 135b | 1730 ± 125b | 2030 ± 117b | 28.25 ± 4.79b | 30.75 ± 4.03b | 32.12 ± 3.23b | 36.25 ± 4.79b |
 CIM-554 | 1430 ± 150bc | 1740 ± 130b | 1780 ± 150bc | 2160 ± 170b | 30.50 ± 3.11b | 33.5 ± 3.70b | 36.38 ± 4.89ab | 41.75 ± 4.87b |
 CYTO-124 | 1500 ± 145bc | 1760 ± 150bc | 1800 ± 135bc | 2220 ± 185b | 28.75 ± 4.27b | 34 ± 3.56b | 37.5 ± 4.05c | 38.25 ± 5.12b |
 FH-142 | 1540 ± 140c | 1860 ± 125c | 1850 ± 126c | 2300 ± 189b | 29.38 ± 4.07b | 34.5 ± 4.65b | 36.77 ± 3.11c | 42.5 ± 4.43b |
Cotton growing season (2019) | ||||||||
 BH-212 | 840 ± 120a | 1040 ± 130a | 1260 ± 135a | 1400 ± 165a | 19.23 ± 4.75a | 20.05 ± 3.53a | 19.02 ± 4.71a | 26.38 ± 3.27a |
 IUB-2013 | 1350 ± 160b | 1650 ± 125b | 1680 ± 110b | 1980 ± 136b | 25.02 ± 3.82b | 25.82 ± 5.73bc | 23.62 ± 1.97b | 35.5 ± 2.89b |
 CIM-554 | 1370 ± 150bc | 1690 ± 130bc | 1720 ± 150bc | 2120 ± 168b | 28.75 ± 3.45b | 32.88 ± 3.73c | 30.75 ± 2.63b | 36.92 ± 3.82b |
 CYTO-124 | 1440 ± 130bc | 1720 ± 160bc | 1750 ± 115bc | 2120 ± 146b | 25.2 ± 3.87b | 29.77 ± 2.24bc | 28.4 ± 2.24b | 33.38 ± 3.54b |
 FH-142 | 1480 ± 140c | 1800 ± 128c | 1800 ± 152b | 2250 ± 121b | 26.45 ± 5.7b | 32.42 ± 3.25c | 30.5 ± 3.42b | 38.05 ± 2.66b |