[Effects of supplemental irrigation based on measuring soil water content on wheat photosynthetic characteristics and dry matter accumulation and allocation].

Taking high-yielding winter wheat cultivar Jimai 22 as test material, a field experiment was conducted to study the effects of supplemental irrigation based on measuring soil water content on the wheat photosynthetic characteristics and dry matter accumulation and allocation. Six treatments were installed, i. e., W1 (soil relative water content was 65% at jointing stage and was 70% at anthesis), DW1 (soil relative water content was 65% 10 d after jointing and was 70% at anthesis), W2 (soil relative water content was 75% at jointing and was 70% at anthesis), DW2 (soil relative water content was 75% 10 d after jointing and was 70% at anthesis), W3 (soil relative water content was 80% at jointing stage and was 70% at anthesis), and DW3 (soil relative water content was 80% 10 d after jointing and was 70% at anthesis). In treatments W2 and DW2, the flag leaf photosynthetic rate (P(n)) and phi(PS II) at late filling stage were higher than those in treatments W3 and DW3, respectively, the dry matter accumulation amount at anthesis and maturity stage and the allocation of accumulated dry matter at pre-anthesis to grain were significantly higher than those in treatments W1 and DW1, and the water use efficiency (WUE) and irrigation production efficiency (IPE) were significantly higher than those in W3 and DW3. Under the same irrigation levels, the flag leaf P(n), and phi(PS II) at late filling stage were higher in treatments DW2 and DW3 than in W2 and W3, respectively, and the dry matter accumulation amount at anthesis and its allocation to grain were lower whereas the dry matter accumulation amount after anthesis, the grain yield, WUE, and IPE were higher in DW2 and DW3 than in W2 and W3. Under our experimental condition, DW2 could be the optimal irrigation pattern of high-yielding with high WUE.