ÃÞ »¨ ѧ ±¨ Cotton Science 2010£¬22£¨2£©£º138-144
Effects of Alternate Partial Root-zone Irrigation on Plant Growth, Photosynthesis and Water Use Efficiency in Cotton Abstract£ºIn this experiment, using partial root-zone drying technique (PRD) with pot-grown cotton plants, we compared the plant growth, photosynthesis and water use efficiency with water stress under alternative partial root-zone irrigation (APRI), fixed partial root-zone irrigation (FPRI), and both partial root-zone irrigation (BPRI). It was found that the pre-dawn and midday leaf water potential in APRI and BPRI were approximately same, but higher than that in FPRI. Furthermore, the stomatal conductance in APRI decreased without obvious change in leaf water status, and transpiration rate declined significantly without much reduction in photosynthetic rate, therefore the photosynthesis water use efficiency improved by 35.86% and 63.51% respectively, as compared to that in FPRI and BPRI treatments. The results also revealed that the leaf growth rate and total leaf area in APRI increased by 67.42% and 27.16%, respectively, compared to that in FPRI at the same irrigation levels according to compensating effects. Further analysis revealed that cotton developed more feeder roots in APRI by using dry-wet alternative irrigation method, the dry mass of feeder roots improved 1.39 times compared to that of FPRI. With 50% reduction of water amount, APRI significantly improved the water use efficiency than FPRI.
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