| To determine the optimal irrigation amount for greenhouse summer squash in the arid and cold regions of the Hexi Corridor, a randomized complete block design (RCBD) was used to investigate the effects of five irrigation amounts on chlorophyll fluorescence parameters, yield and quality, and water use efficiency during plant growth.The results showed that the maximum quantum yield (Fv/Fm) of summer squash under the A2 treatment (3,990 m3/hm2) followed the pattern mid-stage > late-stage > early-stage during the early, middle, and late fruiting stages, with values of 0.75, 0.73, and 0.68, respectively. The potential activity of photosystem II (Fv/Fo) showed a similar trend, with values of 2.94, 3.28, and 2.86 at the early, middle, and late stages, respectively.Under the A2 treatment, summer squash exhibited the highest agronomic performance, including vine thickness, number of fruits per plant, yield per plant, and yield per 667 m2, with values of 1.75 cm, 10.65, 5.18 kg, and 148,145.70 kg/hm2, respectively. Water use efficiency was also the highest under this treatment, reaching 37.13 kg/m3. In addition, the contents of vitamin C, soluble sugar, and soluble protein in summer squash fruits under the A2 treatment were the highest, at 8.64 mg/100 g, 1.65%, and 7.14 mg/g, respectively, and were significantly higher than those under the other treatments.These results provide a theoretical basis for high-yield, high-quality production and water-saving cultivation of greenhouse summer squash in arid and cold regions. |
